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Abstract

In the current paper, secondary metabolites separated from Tupistra plants have been reviewed. Approximately 200 phytochemicals, classified in various chemical classes of bioactive compounds, have been compiled, along with their sources and references. The most striking feature is that the most frequently isolated compounds have been spirostanol sapogenins, and spirostanol and furostanol saponins, most of which are new in nature. The application of both Tupistra plant extracts and isolated compounds in biological assays is also one of the crucial aims in pharmacological discoveries. Tupistra constituents have demonstrated valuable properties in the field of pharmacology, such as antioxidative, antimicrobial, antidiabetic, and antihepatic activities, but their cytotoxic and anti-inflammatory actions can be considered as the more remarkable. In vivo cancer-related activities of the tested Tupistra samples were mostly based on apoptosis. Further phytochemical investigations, together with extensive assessments of the biological profiles and mechanism of action studies of the components of Tupistra species are to be expected.

Keywords

phytochemistry steroids cytotoxicity anti-inflammation

Introduction

Natural products have been shown to possess pharmacological and biological properties that might be beneficial in the treatment of diseases. They can also serve as a source of inspiration for the development of possible new medications. Natural products have been extensively researched in recent decades for their potential applications in medicinal chemistry and molecular science, and as pharmaceuticals.¹

Tupistra (family Asparagaceae) is a genus of flowering plants that can be found in Asia. It contains about 26 species.² Plants of this genus are of great value in folk medicine, for example, the rhizome of Tupistra chinensis Baker is always recognized as one of the ingredients for pain attenuation, blood stasis dissipation, detoxification, traumatic injury, and rheumatoid arthralgia.³ Tupistra nutans Wall. ex Lindl., locally named “Nakima,” is native to India, Nepal, Bhutan, China, and Laos. Its root decoction is used to treat body pain and weakness.⁴ Studies on Tupistra plants have shown therapeutically critical evidence, such as cytotoxic, anti-inflammatory, antimicrobial, and antidiabetic activities.^4–10 Regarding phytochemical reports, steroids, flavonoids, phenols, and aromatic derivatives can be considered as major secondary metabolites.^4–10

Although experimental reports are now abundant, none of the overviews has been discussed so far. The current review aims to provide useful information on the phytochemistry and pharmacology of the genus Tupistra. The data have been retrieved from various resources, but primarily from Google Scholar, Sci-finder, ISI Web of Science, Scopus, Reaxys, and systematic publishers. The terms “Tupistra,” “phytochemistry,” and “pharmacology” were the most meaningful keywords used to search for references.

Phytochemistry

Phytochemical and pharmacological studies of medicinal plants have made substantial progress in recent years, with an emphasis on novel molecules with therapeutic qualities.^11–17 The focus of this section is on publications over the last 40 years that deal with phytochemical investigations of Tupistra species. Up to now, approximately 200 compounds with diverse chemical structures have been isolated from the Tupistra genus, but steroid derivatives have predominated. Among the 20 Tupistra species, T. aurantiaca (Baker) Wall. ex Hook. f., T. nutans Wall. ex Lindl., T. wattii (C. B. Clarke) Hook. f., T. yunnanensis F. T. Wang & S.Yun Liang and T. chinensis Baker have been the most studied, especially the last. Table 1 outlines the compound name and the species from which it has been isolated, and Figures 1 to 5 show the chemical structures of these secondary metabolites.

Figure 1.

Spirostanol sapogenins from genus Tupistra.

Figure 2.

Spirostanol saponins from genus Tupistra.

Figure 3.

Furostanol saponins, and other types of steroids from genus Tupistra.

Figure 4.

Flavonoids, phenols, and aromatic derivatives from genus Tupistra.

Figure 5.

Alkaloids, lignans, amides, and triterpenoid from genus Tupistra.

Table 1.

Chemical Constituents From Tupistra Species.

No	Compounds	Species	References
Steroids
Spirostanol sapogenins
1	Aurantigenin [(25S)-spirost-5-en-1β, 3α, 25-triol]	T. aurantiaca root	¹⁸
2	(25S)-3α-Acetoxy-1α,2β,4α,5α,7α-pentahydroxyspirostan-6-one	T. chinensis rhizome	¹⁹
3	3β-Acetoxy-1α,2α,4β,5α,7α-pentahydroxy-spirost-25(27)-en-6-one	T. chinensis rhizome	¹⁹
4	1β,2β,3β,4β,5β,7α-Hexahydroxyspirost-25(27)-en-6-one	T. aurantiaca root, T. chinensis rhizome and underground part, T. yunnanensis rhizome	^7,19–24
5	Convallagenin B	T. chinensis rhizome, T. wattii rhizome, T. yunnanensis rhizome	^7,21,24,25
6	Isorhodeasapogenin	T. chinensis rhizome	⁹
7	Kitigenin	T. wattii rhizome	²⁵
8	Neopentrogenin	T. chinensis rhizome	²²
9	3-epi-Neoruscogenin	T. aurantiaca root, T. chinensis rhizome and underground part	^{7,18,21,23,26}
10	Δ²⁵⁽²⁷⁾-Pentrogenin	T. aurantiaca root, T. chinensis root, rhizome and underground part, T. yunnanensis rhizome	^{22,24,27–29}
11	Ranmogenin A [spirost-25(27)-ene-1β,3β,4β,5β-tetraol]	T. chinensis root, rhizome and underground part	^18,21,27
12	Ranmogenin B	T. aurantiaca root	²³
13	Ranmogenin C	T. aurantiaca root	²³
14	Ranmogenin D	T. aurantiaca root, T. wattii rhizome	^29,30
15	3-Epi-ruscogenin [(25R)-spirost-5-en-1β,3α –diol]	T. aurantiaca root, T. chinensis root, rhizome and underground part, T. yunnanensis rhizome	^{8,18,23,24,26}
16	(25R,S)-Spirostan-1β,3α,5β-triol	T. chinensis rhizome	⁹
17	Spirost-25(27)-en-1β,2β,3β,4β,5β,6β,7α-heptol	T. chinensis rhizome	²²
18	Spirost-25(27)-en-1β,3α,4β,5β,6β-pentol	T. chinensis rhizome	²²
19	Spirost-25(27)-en-1β,3α,5β-triol	T. chinensis rhizome	²²
20	Tupichigenin A [(20S,22R)-spirost-25(27)-ene-1β,2β,3β,5β-tetraol]	T. chinensis underground part	²⁰
21	Tupichigenin B	T. chinensis underground part	²⁷
22	Tupichigenin C	T. chinensis underground part	²⁷
23	Tupichigenin D	T. chinensis rhizome and underground part	^22,26
24	Tupichigenin E	T. chinensis rhizome and underground part	^7,21,26
25	Tupichigenin F	T. chinensis underground part	²⁶
26	Tupisteroide C	T. chinensis root	³¹
27	Wattigenin A	T. chinensis rhizome, T. wattii rhizome	^22,30
28	Wattigenin B	T. wattii rhizome	²⁵
29	Wattigenin C	T. wattii rhizome	²⁵
Spirostanol saponins
30	Convallagenin A 3-O-β-D-glucopyranoside	T. chinensis rhizome	⁹
31	Convallagenin B 5-O-β-D-glucopyranoside	T. wattii rhizome	³²
32	3-Epi-diosgenin-3-β-D-glucopyranoside	T. chinensis root and rhizome	⁸
33	Convallamarogenin 3-O-β-D-glucopyranoside	T. chinensis rhizome	⁹
34	(24S,25R)-1β-Hydroxy-3β-[(β-D-glucopyranoside)oxy]-spirost-5-en-24-yl-β-D-glucopyranoside	T. chinensis root and rhizome	⁸
35	25(R)-1β-Hydroxy-spirost-5-en-3α-yl-O-β-D-glucopyranoside [3-epi-ruscogenin-3-β-D-glucopyranoside]	T. chinensis root and rhizome, T. yunnanensis rhizome	^8,21,24,33
36	Isorhodeasapogenin 3-O-β-D-glucopyranoside	T. chinensis rhizome	^9,33
37	Isorhodeasapogenin 3-O-glucopyranosyl-(1 3--β-D-glucopyranoside	T. chinensis rhizome	⁹
38	Neopentrogenin-5-O-β-D- glucopyranoside	T. chinensis rhizome	²²
39	3-Epi-neoruscogenin-3-β-D-glucopyranoside	T. chinensis rhizome	²¹
40	1β,2β,3β,4β,5β-Pentahydroxy-spirost-25(27)-en-5-O-β-D-glucopyranoside	T. chinensis root and rhizome	^22,28,31
41	Reinocarnoside B	T. chinensis rhizome	⁹
42	Rhodeasapogenin 3-O-β-D-glucopyranoside	T. chinensis rhizome	^9,33
43	Rhodeasapogenin 3-O-glucopyranosyl-(1 st-β-D-glucopyranoside	T. chinensis rhizome	⁹
44	Rhodeasapogenin 1-(β-D-xylopyranoside)	T. chinensis rhizome	⁷
45	Ruscogenin-3-O-β-D-glucopyranoside	T. chinensis rhizome	³³
46	(25R)-5β-Spirostan-1β,3β-diol-3-O-β-D-fructofuranosyl-(2-25(β-D-glucopyranoside	T. chinensis rhizome	²²
47	(25R)-5β-Spirostan-1β,3α-diol-3-O-β-D-glucopyranoside	T. chinensis rhizome	⁹
48	(25R)-5β-Spirostan- 1β,3β-diol-3-O-β-D-glucopyranosyl-(1(2-2β-D-glucopyranoside	T. chinensis rhizome	²²
49	(25R)-5β-Spirostan-1β,3β-diol-1-O-α-L-rhamnopyranosyl-(1-25(β-D-xylopyranosido-3-O-β-D-glucopyranoside	T. chinensis rhizome	¹⁰
50	(25S)-5β-Spirostan-1β,3β-diol-1-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosido-3-O-α-L-rhamnopyranoside	T. chinensis rhizome	¹⁰
51	(25S)-5β-Spirostan-3β-ol-3-O-β-D-glucopyranosyl-(1O-2)β-D- glucopyranoside	T. chinensis rhizome	²²
52	(25R)-5β-Spirostan-3β-ol-3-O-β-D-glucopyranosyl-(1O-2)β-D-glucopyranoside	T. chinensis rhizome	²²
53	(25R,S)-Spirostan-1β,3α,5β-triol-3-O-β-D-glucopyranoside	T. chinensis rhizome	^9,33
54	(25R,S)-Spirostan-1β,3β,5β-triol-3-O-β-D-glucopyranosyl-(1O-2)β-D-glucopyranoside	T. chinensis rhizome	⁹
55	5β-Spirost-25(27)-en-1β,3β-diol-3-O-β-D-glucopyranosyl-(1O-2)β-D-glucopyranoside	T. chinensis rhizome	²²
56	Spirost-25(27)-en-3β,5β-diol-5-O-β-D-glucopyranoside	T. chinensis rhizome	⁹
57	5β-Spirost-25(27)-en-1β,3β-diol-1-O-α-L-rhamnopyranosyl-(1-2)-β-D-xylopyranosido-3-O-β-D-glucopyranoside	T. chinensis rhizome	¹⁰
58	5β-Spirost-25(27)-en-1β,3β-diol-1-O-α-L- rhamnopyranosyl-(1→2)-β-D-xylopyranosyl-3-O-α-L-rhamnopyranoside	T. chinensis rhizome	³⁴
59	(24S)-Spirost-25(27)-en-1β,3β,4β,5β,6β,24β-hexahydroxy-24-O-β-D-glucopyranoside	T. chinensis root and rhizome	⁸
60	Spirost-25(27)-en-1β,2β,3β,4β,5β,7α-hexaol-6-one-4-O-β-D-xylopyranoside	T. chinensis rhizome	²²
61	5β-Spirost-25(27)-en-1β,3β-diol-1-O-α-L-rhamnopyranosyl-(11→2)β-D-xylopyranosido-3-O-α-L-rhamnopyranoside	T. chinensis rhizome	¹⁰
62	5β-Spirost-25(27)-en-3β-ol-3-O-β-D-glucopyranosyl-(111→2β-D-glucopyranoside	T. chinensis rhizome	²²
63	Spirost-25(27)-en-1β,2β,3β,4β,5β-pentol-2-O-α-L-arabinopyranoside	T. chinensis rhizome	²²
64	Spirost-25(27)-en-1β,2β,3β,4β,5β-pentol-2-O-β-D-xylopyranoside	T. chinensis rhizome	²²
65	Spirost-25(27)-en- 1β,2β,3β,5β-tetraol-5-O-β-D-glucopyranoside	T. chinensis rhizome	²²
66	(20S,22R)-Spirost-25(27)-ene-1β,3β,4β,5β-tetraol-5-O-β-D-glucopyranoside	T. chinensis root and rhizome	^22,28
67	(20S,22R)-Spirost-25(27)-en-1β,3β,5β-trihydroxy-1-O-β-D-xyloside	T. chinensis root and rhizome	³⁵
68	(20S, 22R)-Spirost-25(27)-en-1β,3β,5β-triol-3-O-β-D-glucopyranoside	T. chinensis rhizome	⁹
69	Spirost-25(27)-en-1β,3β,5β-triol-5-O-β-D-glucopyranoside	T. chinensis root and rhizome	^22,28
70	Spirost-25(27)-en-1β,3β,5β-triol-3-O-β-D-glucopyranosyl-(111→2β-D-glucopyranoside	T. chinensis rhizome	⁹
71	T-17 [(25R)-5β-Spirostan-1β,3β-diol-1-O-α-L-rhamnopyranosyl-(11→2)β-D-xylopyranosido-3-O-α-L-rhamnopyranoside]	T. chinensis rhizome	^10,36
72	Tupichinin A	T. chinensis root and rhizome	^7,8
73	Tupichinin B	T. chinensis rhizome	²
74	Tupichinin C	T. chinensis rhizome	²
75	Tupichinin D	T. chinensis rhizome	²
76	Tupisteroide A	T. chinensis root	³¹
77	Tupistroside A	T. yunnanensis rhizome	²⁴
78	Tupistroside B	T. yunnanensis rhizome	²⁴
79	Tupistroside G	T. chinensis rhizome	³³
80	Tupistroside H	T. chinensis rhizome	³³
81	Tupistroside I	T. chinensis rhizome	³³
82	Wattoside G [(25R)-1β,2β,3β,5β-tetrahydroxy-spirostan-4β-yl-O-β-D-xylopyranoside]	T. wattii rhizome	³²
83	Wattoside H [(24S,25S)-24-[(β-D-glucopyranosyl)oxy]-1β,2β,3β,4β,5β,7β-hexahydroxyspirostan-6-one]	T. wattii rhizome	³²
84	Wattoside I [(24S,25S)-1β,3β-dihydroxy-5β-spirostan-24-yl-O-β-D-glucopyranosyl-(1n-6-β-D-glucopyranoside]	T. chinensis rhizome, T. wattii rhizome	^22,32
Furostanol saponins
85	5β-Furost-Δ²⁵⁽²⁷⁾-en-1β,2β,3β,4β,5β,7α,22ξ,26-octaol-6-one-26-O-β-D-glucopyranoside	T. chinensis root and rhizome	^35,37
86	5β-furost-25(27)-en-1β,2β, 3β,4β,5β,6β,7α,22α,26-nonaol-26-O-β-D-glucopyranoside	T. chinensis root and rhizome	³⁸
87	5β-Furost-Δ²⁵⁽²⁷⁾-en-1β,2β,3β,4β,5β,6β,7α,22ξ,26-nonaol-26-O-β-D-glucopyranoside	T. chinensis rhizome	³⁷
88	(25S)-5β-Furost-1β,2β,3β,4β,5β,22α,26-heptaol-26-O-β-D-glucopyranoside	T. chinensis rhizome	⁵
89	(25S)-Furost-1β,3α,5β,22α,26-pentol-26-O-β-D-glucopyranoside	T. chinensis rhizome	³⁹
90	(25S)-Furost-1β,3β,5β,22α,26-pentol-26-O-β-D-glucopyranoside	T. chinensis rhizome	³⁹
91	26-O-β-D-Glucopyranosyl-(22S,25S)-furostan-22,25-epoxy-1β,3α,5β,26-tetrol-3-O-β-D-glucopyranoside	T. chinensis rhizome	¹⁰
92	26-O-β-D-Glucopyranosyl-(22S,25S)-furostan-22,25-epoxy-1β,3β,5β,26-tetrol-3-O-β-D-glucopyranoside	T. chinensis rhizome	¹⁰
93	26-O-β-D-Glucopyranosyl-(22S,25S)-furostan-22,25-epoxy-3β,5β,26,27-tetrol-5-O-β-D-glucopyranoside	T. chinensis rhizome	¹⁰
94	26-O-β-D-Glucopyranosyl-(22S,25S)-5β-furostan-22,25-epoxy-1β,3α,26-triol-3-O-β-D-glucopyranoside	T. chinensis rhizome	¹⁰
95	26-O-β-D-Glucopyranosyl-(22S,25S)-5β-furostan-22,25-epoxy-1β,3β,26-triol-3-O-β-D-glucopyranoside	T. chinensis rhizome	¹⁰
96	26-O-β-D-glucopyranosyl-furost-25(27)-en-1β,3β,5β,22α,26-pentaol-3-O-β-D-glucopyranoside	T. chinensis rhizome	³⁹
97	26-O-β-D-Glucopyranosyl-furost-25(27)-ene-3β,4β,5β,22α,26-pentol-5-O-β-D-glucopyranoside	T. chinensis rhizome	³⁹
98	(25R)-26-O-β-D-glucopyranosyl-furost-20(22)-en-1β,3β,5β,26-tetraol-3-O-β-D-glucopyranoside	T. chinensis rhizome	^39,40
99	(25S)-26-O-β-D-glucopyranosyl-furost-20(22)-en-1β,3β,5β,26-tetraol-3-O-β-D-glucopyranoside	T. chinensis rhizome	^39,40
100	26-O-β-D-Glucopyranosyl-furost-25(27)-ene-3β,5β,22α,26-tetraol-5-O-β-D-glucopyranoside	T. chinensis rhizome	³⁹
101	(25S)-26-O-β-D-Glucopyranosyl-furost-5(6)-ene-3β,22α,26-triol-3-O-α-L-rhamnopyranosyl-(1ost-β-D-glucopyranosyl-(11ostβ-D-galactopyranoside	T. chinensis rhizome	³⁹
102	26-O-β-D-Glucopyranosyl-5β-furost-25(27)-en-3β,22α,26-triol-3-O-β-D-glucopyranosyl-(11ostβ-D-glucopyranoside	T. chinensis rhizome	³⁹
103	(25R)-26-O-β-D-glucopyranosyl-furost-5(6)-en-3β,22α,26-triol-3-O-β-D-glucopyranosyl-(1rostβ-D-glucopyranosyl-(1rostβ-D-glucopyranoside	T. chinensis rhizome	^39,41
104	(25S)-26-O-β-D-glucopyranosyl-furost-5(6)-en-3β,22α,26-triol-3-O-β-D-glucopyranosyl-(1rostβ-D-glucopyranosyl-(1rostβ-D-glucopyranoside	T. chinensis rhizome	⁴¹
105	(25R)-26-O-β-D-Glucopyranosyl-furost-1β,3β,5β,22α,26-pentaol-3-O-β-D-glucoside	T. chinensis root and rhizome	^39,42
106	(25S)-26-O-β-D-Glucopyranosyl-furost-1β,3β,5β,22α,26-pentaol-3-O-β-D-glucoside	T. chinensis root and rhizome	^39,42
107	(25S)-26-O-β-D-Glucopyranosyl-5β-furost-1β, 3β,22α,26-tetraol-3-O-β-D-glucopyranoside	T. chinensis root and rhizome	³⁸
108	(25S)-26-O-β-D-Glucopyranosyl-furost-3β,5β,22α,26-tetraol-5-O-β-D-glucopyranoside	T. chinensis rhizome	³⁹
109	(25R)-26-O-β-D-Glucopyranosyl-5β-furost-1β,3α,22α,26-tetraol-3-O-β-D-glucopyranoside	T. chinensis rhizome	³⁹
110	(25R)-26-O-β-D-glucopyranosyl-5β-furost-1β,3β,22α,26-tetraol-3-O-β-D-glucopyranoside	T. chinensis rhizome	³⁹
111	(25S)-26-O-β-D-Glucopyranosyl-5b-furost-1β,3β,22α,26-tetraol-1-O-α-L-rhamnopyranosyl-(1furoβ-D-xylopyranoside	T. chinensis rhizome	³⁹
112	(25R)-26-O-β-D-Glucopyranosyl-furost-1β, 3β, 26-trihydroxy- 5(6), 20(22)-dien-3-O-β-D-glucopyranoside	T. chinensis root and rhizome	^38,43
113	(25S)-26-O-β-D-Glucopyranosyl-furost-1β,3β,26-trihydroxy-20(22)-en-3-O-β-D-glucopyranoside	T. chinensis rhizome	⁴³
114	26-O-β-D-Glucopyranosyl-furost-1β,3β,5β,22α,26- pentaol-25(27)-ene-3-O-β-D-glucoside	T. chinensis root	⁴²
115	(25R)-26-O-β-D-glucopyranosyl-5β-furost-1β,3β,22α,26-tetraol-3-O-β-D-glucopyranoside	T. chinensis rhizome	^39,40
116	(25S)-26-O-β-D-glucopyranosyl-5β-furost-1β,3β,22α,26-tetraol-3-O-β-D-glucopyranoside	T. chinensis rhizome	^39,40
117	(25R)-26-O-β-D-Glucopyranosyl-5β-furost-1β,3β,22α,26-tetraol-3-O-β-D- glucopyranosyl-(1→4)-β-D-glucopyranoside	T. chinensis rhizome	³⁹
118	(25S)-26-O-β-D-glucopyranosyl-5-furost-1β,3β,22α,26-tetraol-3β- O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside	T. chinensis rhizome	³⁹
119	(25R)-26-O-(β-D-glucopyranosyl)-5β-furost-1β,3β,22α,26-tetrol 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside	T. chinensis rhizome	⁴⁴
120	(25S)-26-O-(β-D-glucopyranosyl)-5b-furost-1β,3β,22α, 26-tetrol 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside	T. chinensis rhizome	⁴⁴
121	(25S)-6-O-β-D-Glucopyranosyl-5β-furost-3β,6β,22α,26-tetraol-26-O-β-D-glucopyranoside	T. chinensis rhizome	⁵
122	(25R)-26-O-β-D-glucopyranosyl-5β-furost-3β,22α,26-triol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside	T. chinensis rhizome	³⁹
123	(25S)-26-O-β-D-glucopyranosyl-5β-furost-3β,22α,26-triol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside	T. chinensis rhizome	³⁹
124	3-O-β-D-Glucopyranosyl-(1→2)-β-D-glucopyranosyl-5β-furost-25(27)-en-1β,3β,22α,26-tetraol-26-O-β-D-glucopyranoside	T. chinensis rhizome	⁵
125	3-O-β-D-glucopyranosyl-(1→ 4)-β-D-glucopyranosyl (25R)-5β-furost-1β,3β,22α,26-tetrol 26-O-β-D-glucopyranoside	T. chinensis rhizome	⁴⁵
126	3-O-β-D-glucopyranosyl-(15 4)β-D-glucopyranosyl (25S)-5β-furost-1β,3β,22α,26-tetrol 26-O-β-D-glucopyranoside	T. chinensis rhizome	⁴⁵
127	(25S)-3-O-β-D-Glucopyranosyl-(15 4)β-D-glucopyranosyl-furost-1β,3β, 26-trihydroxy-20(22)-en-26-O-β-D-glucopyranoside	T. chinensis rhizome	⁴³
128	(25R)-3-O-β-D-Glucopyranosyl-(122)-β-D-glucopyranosyl-furost-1β,3β, 26-trihydroxy-20(22)-en-26-O-β-D-glucopyranoside	T. chinensis rhizome	⁴³
129	3-O-β-D-glucopyranosyl-(25S)-22-O-methyl-5β-furost-1β, 3β, 5β, 22α, 26-pentaol-26-O-β-D-glucopyranoside	T. chinensis rhizome	^39,46
130	(25R)-26-O-β-D-glucopyranosyl-22α-methoxy-furost-5(6)-en-3β,26-diol-3-O-β-D-glucopyranosyl-(1-en-β-D-glucopyranosyl-(1-en-β-D-glucopyranoside	T. chinensis rhizome	³⁹
131	(25S)-26-O-β-D-glucopyranosyl-22α-methoxy-furost-5(6)-en-3β,26-diol-3-O-β-D-glucopyranosyl-(1-en-β-D-glucopyranosyl-(1-en-β-D-glucopyranoside	T. chinensis rhizome	³⁹
132	(22α,25R)-26-O-β-D-Glucopyranosyl-22-methoxyl-furost-5(6)-en-3β,26-diol-3-O-α-L-rhamnopyranosyl-(1methβ-D-glucopyranosyl-(11metβ-D-galactopyranoside	T. chinensis rhizome	³⁹
133	1β,2β,3β,4β,5β,26-Hexahydroxyfurost-20(22), 25(27)-dien-5,26-O-β-D-glucopyranoside	T. chinensis root and rhizome	³⁵
134	(22S,25S)-1β,3β,4β,5β,26,27-Hexanol-furospirost-5, 26-O-β-D-glucopyranoside	T. chinensis root and rhizome	⁸
135	25(S)-22-methoxy-1β,3β,4β,5β,26-pentahydroxy- furost-26-yl O-β-D-glucopyranoside	T. yunnanensis rhizome	²⁴
136	1β,2β,3β,4β,5β,6β,7α,23ξ,26-Nona-hydroxyfurost- 20(22),25(27)-dien-26-O-β-D-glucopyranoside	T. chinensis root and rhizome	³⁵
137	Tupisgenin	T. aurantiaca root, T. yunnanensis rhizome	^18,25
138	Tupisteroide B	T. chinensis root and rhizome	^31,35
139	Tupistroside C	T. yunnanensis rhizome	²⁴
140	Tupistroside D	T. yunnanensis rhizome	²⁴
141	Tupistroside E	T. chinensis root and rhizome, T. yunnanensis rhizome	^24,38
142	Tupistroside F	T. yunnanensis rhizome	²⁴
143	Tupistroside J	T. chinensis root and rhizome	³⁸
144	Tupistroside K	T. chinensis root and rhizome	³⁸
145	Tupistroside L	T. chinensis root and rhizome	³⁸
146	Tupistroside M	T. chinensis root and rhizome	³⁸
147	Tupistroside N	T. chinensis root and rhizome	³⁸
148	Wattoside B	T. wattii rhizome	⁴⁷
149	Wattoside C	T. wattii rhizome	⁴⁷
150	Wattoside D	T. wattii rhizome	⁴⁷
Other types
151	Daucosterol	T. chinensis rhizome and underground part	^21,26
152	β-Sitosterol	T. chinensis rhizome and underground part	^21,26
153	Stigmasterol	T. chinensis underground part	²⁶
154	Oleandrigenin-3-O-[O-β-D-glucopyranosyl (1→2)]-α-L-rhamnopyranoside	T. wattii rhizome	⁴⁷
155	Tupichinin A	T. chinensis rhizome	⁶
156	Tupichinolide [oleandrigenin 3-(α-L-rhamnopyranoside)]	T. chinensis rhizome	⁷
157	Tupipregnenolone	T. chinensis underground part	²⁶
Flavonoids
Flavans
158	(2R)-7,4′-dihydroxy-8-methylflavan	T. chinensis rhizome	³³
159	(2R,3R)-3,4′-Dihydroxy-7-methoxyflavan	T. chinensis rhizome	³³
160	Tupichiol A	T. chinensis rhizome and underground part	^26,33
161	Tupichinol B	T. chinensis rhizome and underground part	^26,33
162	Tupichinol C	T. chinensis rhizome and underground part	^26,33
163	Tupichinol D	T. chinensis rhizome	⁶
164	Tupichiside A	T. chinensis rhizome	³³
Flav-2-ene
165	2-(4-hydroxyphenyl)-4H-chromen-7-ol	T. chinensis rhizome	⁶
Flavones
166	3,7-Dihydroxy-2-(4-hydroxyphenyl)-chromen-4-one	T. chinensis rhizome	⁶
167	3-hydroxy-2-(4-hydroxyphenyl)-7-methoxychromen-4-one	T. chinensis rhizome	⁶
168	Rhamnocitrin	T. chinensis rhizome	⁶
169	3,5,7,8-Tetramethoxy-2-(4-methoxyphenyl)-chromen-4-one	T. chinensis rhizome	⁶
170	Tupichinol E	T. chinensis rhizome	⁶
171	Tupichinol F	T. chinensis rhizome	⁶
Phenols and aromatic derivatives
172	4-Allylpyrocatechol	T. chinensis underground part	²⁶
173	Benzoic acid	T. chinensis underground part	²⁶
174	Caffeic acid	T. nutans root	⁴
175	Chlorogenic acid	T. nutans root	⁴
176	p-Coumaric acid	T. chinensis underground part, T. nutans root	^4,26
177	Ferulic acid	T. nutans root	⁴
178	p-Hydroxybenzaldehyde	T. chinensis underground part	²⁶
179	p-Hydroxybenzoic acid	T. nutans root	⁴
180	Cis-p-hydroxycoumaric acid	T. chinensis underground part	²⁶
181	Isovanillic acid	T. chinensis underground part	²⁶
182	Methylparaben	T. chinensis underground part	²⁶
183	1-Phenylhexan-1-ol	T. chinensis underground part	²⁶
184	Protocatechuic acid	T. nutans root	⁴
185	Salicylic acid	T. nutans root	⁴
186	Syringic acid	T. chinensis underground part	²⁶
187	Vanillic acid	T. chinensis underground part	²⁶
188	Vanillin	T. chinensis underground part	²⁶
Alkaloids
189	Oxoglaucine	T. chinensis rhizome	⁶
190	Oxopurpureine	T. chinensis rhizome	⁶
Lignan and neolignan
191	(+)-Syringaresinol	T. chinensis underground part	²⁶
192	Tupichilignan A	T. chinensis rhizome	⁶
Amides
193	2-[([1,1′-Biphenyl]-4-ylsulfonyl)amino]-benzoic acid	T. chinensis root and rhizome	⁴⁸
194	2-[2-([1,1′-Biphenyl]-4-ylsulfonylamino)- benzoylamino]- benzoic acid methyl ester	T. chinensis root and rhizome	⁴⁸
Amino acid
195	Phenylalanine	T. nutans root	⁴
Triterpenoid
196	Betulin	T. chinensis rhizome	⁴⁹

Spirostanol Sapogenins

Steroids structurally formulated with a sterane nucleus are present in both animals and plants. The compounds in this chemical class possess various skeletons such as brassinosteroids, cucurbitacins, bufadienolides, withanolides, sapogenins, and bile acids.⁵⁰ Sapogenins are recognized as aglycones, or non-saccharides, some of which can serve as a starting point for semisynthetic steroidal hormones.⁵¹ Sapogenin-type spirostanols are likely to be the main class of secondary metabolites found in Tupistra species. Spirostanol sapogenin derivatives are highly concentrated in the rhizome or underground parts of T. aurantiaca, T. chinensis, T. wattii, and T. yunnanensis; 29 metabolites (1-29) are listed in Table 1 and Figure 1.^{7–9,18–31} (25S)-Spirost-5-en-1β, 3α, 25-triol (1), named aurantigenin, was first reported from T. aurantiaca root, whereas 2 new analogs, (25S)-3α-acetoxy-1α,2β,4α,5α,7α-pentahydroxyspirostan-6-one (2) and 3β-acetoxy-1α,2α,4β,5α,7α-pentahydroxy-spirost-25(27)-en-6-one (3), were first isolated from T. chinensis rhizome.^18,19 1β,2β,3β,4β,5β,7α-Hexahydroxyspirost-25 (27)-en-6-one (4) was one of the new constituents isolated from T. aurantiaca root, and then from T. chinensis rhizome and underground part, and T. yunnanensis rhizome.^7,19–24 Convallagenin B (5), a well-known spirostanol sapogenin, has been reported from the rhizome of T. chinensis, T. wattii, and T. yunnanensis,^7,21,24,25 but isorhodeasapogenin (6) has been established as a new derivative from T. chinensis rhizome.⁹ Kitigenin (7) and neopentrogenin (8) were isolated from the rhizome extracts of T. chinensis and T. wattii, respectively^22,25; neither had been detected in the genus Tupistra before.

Compound 4, 3-epi-neoruscogenin (9), Δ²⁵⁽²⁷⁾-pentrogenin (10), and 3-epi-ruscogenin (15) can be considered as major Tupistra spirostanol sapogenins. Both compounds 10 and 15 were found in T. aurantiaca, T. chinensis, and T. yunnanensis.^{8,22,24,26–29} Phytochemical research on the 60% EtOH extract of T. chinensis rhizome has led to the isolation of 3 new spirostanol sapogenins, (25R,S)-spirostan-1β,3α,5β-triol (16), spirost-25(27)-en-1β,3α,4β,5β,6β-pentol (18), and spirost-25(27)-en-1β,3α,5β-triol (19), together with one known analog, spirost-25(27)-en-1β,2β,3β,4β,5β,6β,7α-heptol (17).^9,22

In 2000 and 2003, Pan et al successfully isolated 5 new sapogenins, trivially named as tupichigenins A-E (20-24), from the MEOH extract of the underground parts of Taiwanese T. chinensis.^20,26,27 The search for cytotoxic agents from the medicinal plant T. chinensis resulted in the isolation from the MeOH extract of the root of the novel polyhydroxylated sapogenin, tupisteroide C (26), as white needles.³¹ On the basis of NMR spectroscopic evidence, a steroid, named wattigenin A (27), was isolated from the fresh rhizome of T. wattii and elucidated as a new spirostanol sapogenin.³⁰ It was then found in T. chinensis rhizome.²² Similarly, wattigenins B-C (28-29) were identified as novel polyhydroxylated sapogenins in the 95% EtOH extract of fresh rhizome of T. chinensis.²⁵

Spirostanol and Furostanol Saponins

Saponins derived from Tupistra plants have 2 parts in their structure. The aglycone has a spirostanol or furostanol nucleus, whereas the glycosyl part is formed of either monosaccharides such as glucopyranose, galactopyranose, xylopyranose, rhamnopyranose, and arabinopyranose or disaccharides such as β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside or α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside (Figures 2 and 3). T. chinensis, T. wattii, and T. yunnanensis are main sources of spirostanol and furostanol saponins. Sixty-five compounds (30-84) were assigned as spirostanol saponins (Table 1 and Figure 2),^{2,7–10,21,22,24,28,31–33,35,36,39} while compounds 85 to 150 are furostanol saponins (Table 1 and Figure 3).^{5,8,10,18,22,24,31,35,37,39–47}

Taking spirostanol saponins into consideration, glycosylation generally happens at C-1, C-3, C-5, and C-24. Similar to the above spirostanol sapogenins, the saponins have either an R- or S-configuration at carbon C-25. In the genus Tupistra, convallagenin A 3-O-β-D-glucopyranoside (30) and convallagenin B 5-O-β-D-glucopyranoside (31) have only been isolated from the rhizomes of T. chinensis and T. wattii, respectively.^9,32 The underground part of T. chinensis seems to be a good reservoir of spirostanol saponins. Based on physicochemical results and NMR spectral analysis, Song et al reported that the 65% EtOH extract of T. chinensis underground parts contained 2 new spirostanol saponins, (24S,25R)-1β-hydroxy-3β-[(β-D-glucopyranoside)oxy]-spirost-5-en-24-yl-β-D-glucopyranoside (34), and (24S)-spirost-25(27)-en-1β,3β,4β,5β,6β,24β-hexahydroxy-24-O-β-D-glucopyranoside (59), in addition to 2 known ones, 3-epi-diosgenin-3-β-D-glucopyranoside (32), and 25(R)-1β-hydroxy-spirost-5-en-3α-yl-O-β-D-glucopyranoside [3-epi-ruscogenin-3-β-D-glucopyranoside] (35).⁸ In 2016, Xiang et al reported that the 60% EtOH extract of T. chinensis rhizome was characterized by the presence of 18 new compounds, (25R)-5β-spirostan-1β,3β-diol-3-O-β-D-fructofuranosyl-(2→6)-β-D-glucopyranoside (46), (25R)-5β-spirostan-1β,3α-diol-3-O-β-D-glucopyranoside (47), (25R)-5β-spirostan-1β,3β-diol-3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (48), (25R)-5β-spirostan-1β,3β-diol-1-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosido-3-O-β-D-glucopyranoside (49), (25S)-5β-spirostan-1β,3β-diol-1-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosido-3-O-α-L-rhamnopyranoside (50), (25R,S)-spirostan-1β,3β,5β-triol-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside (54), 5β-spirost-25(27)-en-1β,3β-diol-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside (55), spirost-25(27)-en-3β,5β-diol-5-O-β-D-glucopyranoside (56), 5β-spirost-25(27)-en-1β,3β-diol-1-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosido-3-O-β-D-glucopyranoside (57), 5β-spirost-25(27)-en-3β-ol-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside (62), spirost-25(27)-en-1β,2β,3β,4β,5β-pentol-2-O-α-L-arabinopyranoside (63), spirost-25(27)-en-1β,2β,3β,4β,5β-pentol-2-O-β-D-xylopyranoside (64), spirost-25(27)-en-1β,2β,3β,5β-tetraol-5-O-β-D-glucopyranoside (65), (20S,22R)-spirost-25(27)-ene-1β,3β,4β,5β-tetraol-5-O-β-D-glucopyranoside (66), (20S, 22R)-spirost-25(27)-en-1β,3β,5β-triol-3-O-β-D-glucopyranoside (68), spirost-25(27)-en-1β,3β,5β-triol-5-O-β-D-glucopyranoside (69), spirost-25(27)-en-1β,3β,5β-triol-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside (70), and [(25R)-5β-spirostan-1β,3β-diol-1-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosido-3-O-α-L-rhamnopyranoside (71), together with 13 known analogs (33, 36-38, 40-43, 51-53, 60, and 61).^9,10,22,39

Thus, the root and rhizome of T. chinensis may be thought of as a rich resource of new spirostanol saponins. In another phytochemical report, apart from the known compound rhodeasapogenin 1-(β-D-xylopyranoside) (44), the 95% EtOH extract of Chinese T. chinensis rhizome also contained one new steroidal saponin, tupichinin A (72).⁷ Three new saponins, tupichinins B-D (73-75), were also isolated from the EtOAc fraction of T. chinensis rhizome.² A new polyhydroxylated saponin, tupisteroide A (76), was obtained as a white amorphous powder from the n-BuOH fraction of T. chinensis air-dried powdered rhizome.³¹ Two new saponins, tupistrosides A-B (77-78), were obtained, glycosylated at C-3.²⁴ From the 60% EtOH extract of T. chinensis fresh rhizome, 3 new steroidal saponins, tupistrosides G-I (79-81), were recorded.³³ A combination of NMR spectroscopy and acid hydrolysis led to the identification of the chemical structures of wattosides G-I (82-84), 3 new compounds originating from the EtOH extract of T. wattii fresh rhizome.³²

Regarding furostanol saponins, the chemical structures of the isolated compounds (85-150) have been generally established with hydroxyl groups at C-1, C-2, C-3, C-4, and C-5, as well as glycosylation normally occurring at C-1, C-3, C-5, and C-26 (Figure 3). The compounds resemble spirostanol sapogenins and spirostanol saponins, with either R- or S-configuration at carbon C-25. Significantly, among 66 isolated compounds, 55 were new in the literature. The rhizome and root of T. chinensis were the main sources of these typical compounds. Silica gel CC aided by HPLC aided the isolation of 2 new isomers, 5β-furost-Δ²⁵⁽²⁷⁾-en-1β,2β,3β,4β,5β,7α,22ξ,26-octaol-6-one-26-O-β-D-glucopyranoside (85) and 5β-furost-Δ²⁵⁽²⁷⁾-en-1β,2β,3β,4β,5β,6β,7α,22ξ,26-nonaol-26-O-β-D-glucopyranoside (87) from the MeOH extract of T. chinensis rhizome, collected from Shennogjia, China.³⁷ Together with 2 known compounds, 5β-furost-25(27)-en-1β,2β, 3β,4β,5β,6β,7α,22α,26-nonaol-26-O-β-D-glucopyranoside (86), and (25S)-26-O-β-D-glucopyranosyl-5β-furost-1β,3β,22α,26-tetraol-3-O-β-D-glucopyranoside (107), 8 new furostanol saponin derivatives 1β,2β,3β,4β,5β,26-hexahydroxyfurost-20(22),25(27)-dien-5,26-O-β-D-glucopyranoside (133), (22S,25S)-1β,3β,4β,5β,26,27-hexanol-furospirost-5,26-O-β-D-glucopyranoside (134), 1β,2β,3β,4β,5β,6β,7α,23ξ,26-nona-hydroxyfurost-20(22),25(27)-dien-26-O-β-D-glucopyranoside (136), and tupistrosides J-N (143-147) were the main constituents of the 65% EtOH extract of T. chinensis root and rhizome.^8,35,38 Meanwhile, new saponins, tupistrosides C-F (139-142), were obtained from the MeOH extract of T. yunnanensis fresh rhizome.²⁴ Bioassay and chromatographic fractionation of the n-BuOH fraction led to the isolation and NMR spectroscopic determination of 5 new pairs of diastereoisomeric furostanol saponins, including (25R)-26-O-β-D-glucopyranosyl-furost-20(22)-en-1β,3β,5β,26-tetraol-3-O-β-D-glucopyranoside (98) and (25S)-26-O-β-D-glucopyranosyl-furost-20(22)-en-1β,3β,5β,26-tetraol-3-O-β-D-glucopyranoside (99); (25R)-26-O-β-D-glucopyranosyl-furost-5(6)-en-3β,22α,26-triol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside (103) and (25S)26-O-β-D-glucopyranosyl-furost-5(6)-en-3β,22α,26-triol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside (104); (25R)-26-O-β-D-glucopyranosyl-5β-furost-1β,3β,22α,26-tetraol-3-O-β-D-glucopyranoside (115) and (25S)-26-O-β-D-glucopyranosyl-5β-furost-1β,3β,22α,26-tetraol-3-O-β-D-glucopyranoside (116); (25R)-26-O-(β-D-glucopyranosyl)-5β-furost-1β,3β,22α, 26-tetrol 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside (119) and (25S)-26-O-(β-D-glucopyranosyl)-5b-furost-1β,3β,22α,26-tetrol 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside (120); and 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl (25R)-5β-furost-1β,3β,22α,26-tetrol 26-O-β-D-glucopyranoside (125) and 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl (25S)-5β-furost-1β,3β,22α,26-tetrol 26-O-β-D-glucopyranoside (126).^40,41,44,45 In the same manner, a pair of diastereoisomers, (25R)-26-O-β-D-glucopyranosyl-furost-1β,3β,5β,22α,26-pentaol-3-O-β-D-glucoside (105) and (25S)-26-O-β-D-glucopyranosyl-furost-1β,3β,5β,22α,26-pentaol-3-O-β-D-glucoside (106), and another new saponin, 26-O-β-D-glucopyranosyl-furost-1β,3β,5β,22α,26-pentaol-25(27)-ene-3-O-β-D-glucoside (114) were isolated from the MeOH extract of T. chinensis root.⁴²

In 2012 and 2013, Liu et al used silica gel CC and HPLC to isolate and identify the structures of many new saponins from the ethanolic extract of T. chinensis rhizome, such as (25S)-5β-furost-1β,2β,3β,4β,5β,22α,26-heptaol-26-O-β-D-glucopyranoside (88), (25R)-26-O-β-D-glucopyranosyl-furost-1β,3β,26-trihydroxy-5(6),20(22)-dien-3-O-β-D-glucopyranoside (112), (25S)-26-O-β-D-glucopyranosyl-furost-1β,3β,26-trihydroxy-20(22)-en-3-O-β-D-glucopyranoside (113), (25S)-6-O-β-D-glucopyranosyl-5β-furost-3β,6β,22α,26-tetraol-26-O-β-D-glucopyranoside (121), 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-5β-furost-25(27)-en-1β,3β,22α,26-tetraol-26-O-β-D-glucopyranoside (124), (25S)-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-furost-1β,3β,26-trihydroxy-20(22)-en-26-O-β-D-glucopyranoside (127), (25R)-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-furost-1β,3β,26-trihydroxy-20(22)-en-26-O-β-D-glucopyranoside (128), and tupisteroide B (138).^5,31,43 Two articles published by Xiang et al in 2016 reported the detailed structural elucidation of fifteen new furostanol saponins, comprising (25S)-furost-1β,3α,5β,22α,26-pentol-26-O-β-D-glucopyranoside (89), (25S)-furost-1β,3β,5β,22α,26-pentol-26-O-β-D-glucopyranoside (90), 26-O-β-D-glucopyranosyl-(22S,25S)-furostan-22,25-epoxy-1β,3α,5β,26-tetrol-3-O-β-D-glucopyranoside (91), 26-O-β-D-glucopyranosyl-(22S,25S)-furostan-22,25-epoxy-1β,3β,5β,26-tetrol-3-O-β-D-glucopyranoside (92), 26-O-β-D-glucopyranosyl-(22S,25S)-furostan-22,25-epoxy-3β,5β,26,27-tetrol-5-O-β-D-glucopyranoside (93), 26-O-β-D-glucopyranosyl-(22S,25S)-5β-furostan-22,25-epoxy-1β,3α,26-triol-3-O-β-D-glucopyranoside (94), 26-O-β-D-glucopyranosyl-(22S,25S)-5β-furostan-22,25-epoxy-1β,3β,26-triol-3-O-β-D-glucopyranoside (95), 26-O-β-D-glucopyranosyl-furost-25(27)-ene-3β,4β,5β,22α,26-pentol-5-O-β-D-glucopyranoside (97), 26-O-β-D-glucopyranosyl-furost-25(27)-ene-3β,5β,22α,26-tetraol-5-O-β-D-glucopyranoside (100), (25S)-26-O-β-D-glucopyranosyl-furost-5(6)-ene-3β,22α,26-triol-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside (101), 26-O-β-D-glucopyranosyl-5β-furost-25(27)-en-3β,22α,26-triol-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside (102), (25S)-26-O-β-D-glucopyranosyl-furost-3β,5β,22α,26-tetraol-5-O-β-D-glucopyranoside (108), (25R)-26-O-β-D-glucopyranosyl-5β-furost-1β,3α,22α,26-tetraol-3-O-β-D-glucopyranoside (109), (25S)-26-O-β-D-glucopyranosyl-5b-furost-1β,3β,22α,26-tetraol-1-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside (111), and (22α,25R)-26-O-β-D-glucopyranosyl-22-methoxyl-furost-5(6)-en-3β,26-diol-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside (132), along with several known analogs (Table 1).^10,39 Among them, 3 groups of compounds 89 and 90, 91 and 92, and 94 and 95 were diastereoisomeric pairs.

Another report recorded a new furostanol saponin, tupisgenin (137), from T. aurantiaca root; this compound has since also been detected in T. yunnanensis rhizome.^18,24 Lastly, 3 of 4 saponins, wattosides B-D (148-150), with a new furostanol backbone bearing multi hydroxyl groups, have been isolated from T. wattii rhizome.⁴⁷

Other Steroids

Other types of steroids have also been proved during the search for bioactive compounds from Tupistra species (Figure 3). Together with major components spirostanol sapogenins, T. chinensis underground part, collected from Taiwan, contained 3 well-known sterols, daucosterol (151), β-sitosterol (152), and stigmasterol (153), along with a new pregnane steroid, tupipregnenolone (157).²⁶ Tupichinin A (155) was also identified as a new C21 steroid type pregnane glycoside from the CHCl₃ fraction of T. chinensis rhizome.⁶ Unfortunately, compounds 72 and 155 have the same name. It was similar to oleandrigenin-3-O-[O-β-D-glucopyranosyl (1→2)]-α-L-rhamnopyranoside (154),⁴⁷ tupichinolide (156), a new secondary metabolite from the 95% EtOAc fraction of T. chinensis rhizome, can be also classified as a steroid type cardenolide.⁷

Flavonoids, Phenols, and Aromatic Derivatives

Flavonoids play a great role in food chemistry and pharmacology, and terrestrial plants are the main resource of this chemical class.^10,17,52,53 Flavonoid derivatives from Tupistra species are present in 3 skeletons, flavans (158-164), flav-2-ene (165), and flavones (166-171) (Table 1 and Figure 4). These compounds have only been reported for T. chinensis. In an effort to find cytotoxic agents, chromatographic separation on the 60% MeOH extract of T. chinensis fresh rhizome led to the isolation of a new flavan-3-ol glucoside, tupichiside A (164), along with 2 known derivatives, (2R)-7,4′-dihydroxy-8-methylflavan (158) and (2R,3R)-3,4′-dihydroxy-7-methoxyflavan (159).³³ From the underground part of T. chinensis, 3 previously undescribed derivatives were isolated, comprising 2 flavan-3-ols, tupichiols A-B (160-161), and 1 flavan, tupichinol C (162).²⁶ T. chinensis rhizome further yielded another new flavan-3-ol, tupichinol D (163).⁶ Metabolites 160 to 161 and 163 to 164 share the same absolute 2R,3R-configuration at carbons C-2 and C-3. 2-(4-Hydroxyphenyl)-4H-chromen-7-ol (165), a unique flav-2-ene, has been isolated from Tupistra plants. A phytochemical survey conducted by Pan et al (2006) also determined the existence of 2 new flavones, tupichinols E-F (170-171), in addition to 4 known analogs, 3,7-dihydroxy-2-(4-hydroxyphenyl)-chromen-4-one (165), 3-hydroxy-2-(4-hydroxyphenyl)-7-methoxychromen-4-one (167), rhamnocitrin (168), and 3,5,7,8-tetramethoxy-2-(4-methoxyphenyl)-chromen-4-one (169).⁶ Compounds 170 to 171 are characterized by being methylated at C-8.

Phenols and aromatic derivatives have also been recorded for Tupistra species. Herein, a list of 17 isolated compounds (172-188) has been summarized (Table 1 and Figure 4). Phenols and aromatic derivatives have been primarily found in T. chinensis and T. nutans. 4-Allylpyrocatechol (172), benzoic acid (173), p-hydroxybenzaldehyde (178), cis-p-hydroxycoumaric acid (180), isovanillic acid (181), methylparaben (182), 1-phenylhexan-1-ol (183), syringic acid (186), vanillic acid (187), and vanillin (188) were isolated and structurally identified from T. chinensis underground part.²⁶ The strong antioxidative potential of T. nutans may be due to its rich content of phenolics; the root was shown to contain caffeic acid (174), chlorogenic acid (175), ferulic acid (177), p-hydroxybenzoic acid (189), protocatechuic acid (184), and salicylic acid (185).⁴ p-Coumaric acid (176) is present in both T. chinensis underground parts and T. nutans root.^4,26

Miscellaneous

Other phytochemicals from Tupistra species include 2 alkaloids, oxoglaucine (189) and oxopurpureine (190), 1 lignin, (+)-syringaresinol (191), 1 neolignan, tupichilignan A (192), 2 amides 2-[([1,1′-biphenyl]-4-ylsulfonyl)amino]-benzoic acid (193) and 2-[2-([1,1′-biphenyl]-4-ylsulfonylamino)-benzoylamino]-benzoic acid methyl ester (194), 1 amino acid, phenylalanine (195), and 1 triterpenoid, betulin (196) (Table 1 and Figure 5).^4,6,26,48 All were detected from the genus Tupistra for the first time. Especially, neolignan 192 and amide 194 were new to the literature.

Pharmacological Activities

There have been numerous studies using both Tupistra secondary metabolites and extracts for pharmacological examinations, which may be classified into: cytotoxic,^{3,7,8,10,22,23,26,28,32–36,38,39,41,48,54,55} anti-inflammation,^{9,10,22,37,39,44,56–58} antimicrobial,^4,19 antioxidant,⁴ antidiabetic,⁴ and other beneficial effects.⁵⁶ An overview of previous pharmacological evaluations of Tupistra plants are discussed in detail and outlined in Table 2.

Table 2.

Pharmacological Activities of Isolated Compounds and Plant Extracts From Genus Tupistra.

No	Models	Effect	References
Cancer-related activities
5, 7, and 29	In vitro	IC₅₀ = 37.31-54.48 μmol/L/K562 cell	²⁵
10	In vitro	100% Inhibition/NUGC and HONE-1 cells	²⁶
11	In vitro	96% inhibition/NUGC and HONE-1 cells	²⁶
28	In vitro	IC₅₀ = 75.15 μmol/L/A2780a cell	²⁵
31 and 82-84	In vitro	IC₅₀ = 35.67-76.96 μmol/L/K562 cell	³²
35, 45, and 80	In vitro	IC₅₀ = 0.2-0.9 μM/LoVo and BGC-823 cells	³³
39	In vitro	IC₅₀ = 5.02-11.40 μM/A-549 and MCF-7 cells	⁷
46	In vitro	IC₅₀ = 21.5-61.4 μM/FaDu, Detroit 562, CNE-1, CNE-2, HepG2, K562, and SPC-A-1	²²
49, 50, 57, 61, and 71	In vitro	IC₅₀ = 3.4-18.1 μM/HepG2, CNE-1, CNE-2, and SPC-A-1 cells	¹⁰
51	In vitro	IC₅₀ = 12.7-22.7 μM/FaDu, Detroit 562, CNE-1, CNE-2, HepG2, K562, and SPC-A-1	²²
55	In vitro	IC₅₀ = 20.2-33.6 μM/FaDu, Detroit 562, CNE-1, CNE-2, HepG2, K562, and SPC-A-1	²²
58	In vitro	IC₅₀ = 2.0 ± 0.2 µM/HL-60 cell	³⁴
67	In vitro	IC₅₀ = 86.63 μmol/L/A549 cell IC₅₀ = 88.21 μmol/L/H1299 cell	³⁵
69	In vitro	IC₅₀ = 52.66 μmol/ L/A549 cell IC₅₀ = 57.29 μmol/L/H1299 cell	²⁸
71	In vitro	Induced cell death in SGC-7901 and AGS cells	³⁶
72	In vitro	IC₅₀ = 5.02-11.40 μM/MCF-7 and SW480 cells	⁷
72	In vitro	IC₅₀ = 25.3 μM/A549 cell IC₅₀ = 26.1 μM/HepG2 cell	⁸
90	In vitro	IC₅₀ = 1.1-1.2 μM/FaDu and Detroit 562 cells	³⁹
91-95	In vitro	IC₅₀ > 50 μM/HepG2, CNE-1, CNE-2, and SPC-A-1 cells	¹⁰
97	In vitro	IC₅₀ = 18.1 μM/FaDu cell	³⁹
109	In vitro	IC₅₀ = 36.0 μM/Detroit 562 cell	³⁹
130	In vitro	IC₅₀ = 39.5 μM/Detroit 562 cell	³⁹
133, 136, and 138	In vitro	IC₅₀ > 100 μmol/L/A549 and H1299 cells	³⁵
145	In vitro	IC₅₀ = 72.5 ± 2.4 μmol/L/SW620 cell	³⁸
146	In vitro	IC₅₀ = 88.6 μmol/L/HepG2 cell	³⁸
147	In vitro	IC₅₀ = 77.3 ± 2.5 μmol/L/SW620 cell	³⁸
156	In vitro	IC₅₀ = 0.06-0.12 μM/HL-60, SMMC-7721, A-549, MCF-7, and SW480 cells	⁷
160	In vitro	IC₅₀ = 2.5-2.7 μM/Human LoVo and BGC-823 cells	³³
164	In vitro	IC₅₀ > 4.7 μM/Human LoVo and BGC-823 cells	³³
172	In vitro	96% inhibition, NUGC cell	²⁶
193 and 194	In vitro	IC₅₀ > 79.8 μM/HCT116, HT29, A549, and H1299 cells	⁴⁸
Anti-inflammatory activities
4, 8, 10, 17-19, 23, 27, 38, 40, 46, 48, 51-52, 55, 50, 62-66, 75, and 84	In vitro	IC₅₀ > 50 µM/NO inhibition	²²
6 and 16	In vitro	IC₅₀ > 50 µM/NO inhibition	⁹
33, 42, 43, 54, 56, and 70	In vitro	IC₅₀ = 16.1-40.0 μM/NO inhibition
49, 50, 57, 61, and 71	In vitro	IC₅₀ = 3.1-4.4 μM/NO inhibition	¹⁰
51	In vitro	IC₅₀ = 11.5 µM/NO inhibition	²²
85	In vitro	NO content = 87.34 µmol/L	³⁷
87	In vitro	NO content = 108.34 µmol/L	³⁷
93	In vitro	IC₅₀ = 23.3 μM/NO inhibition	¹⁰
97, 102, 104, 105, 110, and 131	In vitro	IC₅₀ = 22.3-46.2 μM/NO inhibition	³⁹
98	In vitro	IC₅₀ = 15.7 μM/NO inhibition	³⁹
119 and 120	In vitro	Inhibited COX-2 production	⁴⁴
Antimicrobial activities
2	In vitro	IC₅₀ = 1675 µM/P. digitatum IC₅₀ = 831 µM/R. stolonifera	¹⁹
3	In vitro	IC₅₀ = 2623 µM/P. digitatum IC₅₀ = 1910 µM/R. stolonifera	¹⁹
4	In vitro	IC₅₀ = 2132 µM/P. digitatum IC₅₀ = 1593 µM/R. stolonifera	¹⁹
29	In vitro	IC₅₀ = 682 µM/P. digitatum IC₅₀ = 1146 µM/R. stolonifera	¹⁹
Pharmacological activities of extracts
Cancer-related activities
Saponin extract of T. chinensis	In vitro	81% Inhibition/HeLa cell 92% Inhibition/HL-60 cell	⁴¹
Saponin extract of T. chinensis	In vitro	Inhibited the proliferation of SKOV3 cell	³
Saponin extract of T. chinensis	In vitro	IC₅₀ = 4.11 μg/mL/A549 cell IC₅₀ = 6.47 μg/mL/MCF-7 cell IC₅₀ = 7.78 μg/mL/HeLa cell	⁵⁴
Saponin extract of T. chinensis	In vitro	Significantly inhibited S-180 cell by NF-kB signaling suppression	⁵⁶
Anti-inflammatory activities
Saponin extract of T. chinensis	In vivo	Prevented mice from LPS-induced death	⁵⁸
70% EtOH extract of T. chinensis	In vivo and in vitro	Decreased the levels of inflammatory cytokines TNF-α and IFN-γ	⁵⁷
Water extract of T. chinensis	In vivo	Inhibited acetic acid-induced capillary permeability and xylene-induced ear edema in mice	⁵⁸
n-Butanol, ethyl acetate, water and petroleum ether extracts of T. chinensis	In vivo	Prevented isoproterenol-induced myocardial injury	⁵⁶
Antioxidative activities
Ethyl acetate extract of T. nutans	In vitro	IC₅₀ = 21.31 µg/mL/DPPH radical scavenging capacity	⁴
Butanol extract of T. nutans	In vitro	IC₅₀ = 65.15 µg/mL/DPPH radical scavenging capacity	⁴
n-Hexane extract of T. nutans	In vitro	IC₅₀ = 168.88 µg/mL/DPPH radical scavenging capacity	⁴
Methanol extract of T. nutans	In vitro	IC₅₀ = 184.05 µg/mL/DPPH radical scavenging capacity	⁴
Water extract of T. nutans	in vitro	IC₅₀ = 309.41 µg/mL/DPPH radical scavenging capacity	⁴
Antimicrobial activity
70% Methanol extract of T. nutans	In vitro	Inhibitory zone = 10.17-19.16 mm/S. aureus, S. enterica, E. coli, C. albicans, A. niger, A. favus, and A. fumigatus	⁴
Antidiabetic activities
Ethyl acetate extract of T. nutans	In vitro	81.68% inhibition/α-glucosidase inhibition	⁴
n-Hexane, extract of T. nutans	In vitro	73.49% inhibition/α-glucosidase inhibition	⁴
Butanol extracts of T. nutans	In vitro	70.93% inhibition/α-glucosidase inhibition	⁴
Water extract of T. nutans	In vitro	64.89% inhibition/α-glucosidase inhibition	⁴
Methanol extract of T. nutans	In vitro	60.01% inhibition/α-glucosidase inhibition	⁴

Abbreviation: LPS, lipopolysaccharide.

Cancer-Related Activities

A great deal of research has shown a strong correlation between saponins and cytotoxic activities, with several specific structural motifs targeting different cancer cells.⁵⁹ Herein, both isolated compounds and plant extracts of Tupistra species have been evaluated as cytotoxic candidates due to the high amount of spirostanol saponins. Saponins convallagenin B 5-O-β-D-glucopyranoside (31), and wattosides G-I (82-84), which were isolated from rhizomes of T. wattii, exhibited significant in vitro cytotoxic activity against K562 cancer cells, with IC₅₀ values ranged from 35.67 to 76.96 μmol/L, as compared to the positive control cis-DDP (IC₅₀ = 69.33 μmol/L).³² Spirostanol saponins 35, 45, and 80 were reported to possess remarkable cytotoxic effects on LoVo and BGC-823 cancer cells, with IC₅₀ values of 0.2 to 0.9 μM, which were much lower than that of cisplatin (IC₅₀ = 4.6-5.9 μM).³³

Spirostanol saponins 39 and 72, obtained from T. chinensis, selectively inhibited A-549, MCF-7, and SW480 cancer cells, in which the cytotoxic effect against A-549 and MCF-7 cancer cells of 39 (IC₅₀ = 5.02-11.40 μM) and MCF-7 and SW480 cells of 72 (IC₅₀ = 5.02-11.40 μM) were better than those of the positive control cisplatin (IC₅₀ = 122.56-19.70 μM).⁷ In the same way, spirostanol glycoside 69 significantly exhibited an inhibitory effect against A549 and H1299 cells, with IC₅₀ values of 52.66 and 57.29 μmol/L, respectively.²⁸ In another cytotoxic assessment against 7 human cancer cells, FaDu, Detroit 562, CNE-1, CNE-2, HepG2, K562, and SPC-A-1, the IC₅₀ values of compounds 46, 51, and 55 were established as 51 (IC₅₀ = 12.7-22.7 μM) > 55 (IC₅₀ = 20.2-33.6 μM) > 46 (IC₅₀ = 21.5-61.4 μM).²² Spirostanol saponin 72 showed moderate cytotoxicity against A549 and HepG2 cells, with IC₅₀ values of 25.3 μM and 26.1 μM, respectively.⁸

Spirostanol saponins seem to be better than furostanol saponins in cytotoxicity assays. Only spirostanol saponin 67 showed an inhibitory effect on A549 and H1299 cancer cells, with respective IC₅₀ values of 86.63 and 88.21 μmol/L, but furostanol saponins 133, 136, and 138 were inactive.³⁵ Five spirostanol saponins (49, 50, 57, 61, and 71) showed potential cytotoxic activity against HepG2, CNE-1, CNE-2, and SPC-A-1 cells (IC₅₀ 3.4-18.1 μM), in contrast to furostanol saponins 91 to 95 (IC₅₀ > 50 μM), which were inactive.¹⁰ However, in the case of the antiproliferative effect against FaDu and Detroit 562 cells, furostanol saponin 90 successfully suppressed the growth of these 2 cancer cell lines with IC₅₀ values of 1.1 to 1.2 µM; furostanol saponin 97 was also active against FaDu cancer cells (IC₅₀ = 18.1 μM). Furostanol saponins 109 and 130 inhibited Detroit 562 cancer cells, with IC₅₀ values of 36.0 and 39.5 μM, respectively.³⁹ Similarly, furostanol saponins 145 and 147 had respective IC₅₀ values of 72.5 ± 2.4 and 77.3 ± 2.5 μmol/L against SW620 cancer cells, while furostanol saponin 146 repressed HepG2 cancer cell growth with an IC₅₀ value of 88.6 μmol/L.³⁸

Besides saponins, steroid derivatives also showed good inhibitory effects on cancer cell lines. Spirostanol sapogenins 5, 7, and 29 resisted K562 cancer cell growth, with IC₅₀ values ranging from 37.31 to 54.48 μmol/L, while analog 28 showed strong cytotoxic activity against A2780a cancer cells (IC₅₀ = 75.15 μmol/L).²⁵ Δ²⁵⁽²⁷⁾-Pentrogenin (10) inhibited NUGC and HONE-1 cancer cells at a concentration of 50 μM, while ranmogenin A (11) only showed toxicity to NUGC cells, with 96% inhibition.²⁶ The cardenolide, tupichinolide (156), exhibited potent cytotoxicity against 5 human cancer cell lines, HL-60, SMMC-7721, A-549, MCF-7, and SW480, with IC₅₀ values between 0.06 and 0.12 μM, better than those of the positive control, cisplatin (2.03-19.70 μM).⁷

Some small molecules derived from Tupistra plants also showed cytotoxic properties. The flavan aglycone exhibited more cytotoxic activity than its glucoside when compared with the inhibitory effect against Human LoVo and BGC-823 cancer cells {160 (IC₅₀ = 2.5-2.7 μM) and 164 (IC₅₀ > 4.7 μM)}.³³ Compound 172, a di-phenol, showed 96% inhibition against NUGC cells.²⁶ In cytotoxicity assays against HCT116, HT29, A549, and H1299 cells, 2 amides (193 and 194) with IC₅₀ values > 79.8 μM indicated moderate activity but were much less potent than the positive standard 5-Fu (IC₅₀ = 2.4-4.3 μM).⁴⁸

Unrevealing the cytotoxic mechanisms of Tupistra constituents is also crucial in pharmacological studies. Yi et al (2018) proved that 5β-spirost-25(27)-en-1β,3β-diol-1-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyl-3-O-α-L-rhamnopyranoside (58) suppressed the growth of HL-60 cancer cells with an IC₅₀ value of 2.0 ± 0.2 µM after 48 h treatment, due to the regulation of caspase-3, Bax, Bcl-2, and PARP (apoptotic mechanism), and the Akt/mTOR/p70S6K signaling pathway and by AMPK signaling activation (autophagy).³⁴ Likewise, spirostanol saponin T-17 (71) may be a promising chemotherapeutic substance for human gastric cancer treatment since it induced cell death in SGC-7901 and AGS cancer cells in dose-dependent concentrations, following apoptosis and autophagy through caspase-mediated and JNK pathways.³⁶

Anti-Inflammatory Activities

Anti-inflammatory activity provides basic evidence to confirm the traditionally medicinal application of Tupistra species for the treatment of pharyngolaryngitis and rheumatic diseases. Using the lipopolysaccharide (LPS) stimulated inflammatory syndrome in the abdominal cavity of C57BL/6 mice, furostanol saponins 85 and 87, at a dose of 40 µg/mL, showed inhibitory action against NO production with released NO contents of 87.34 and 108.34 µmol/L, respectively³⁷; the positive control, aspirin, showed a released NO content of 106.86 µmol/L.³⁷ In another model, 2 other furostanol saponins, 119 and 120, at a dose of 20 µg/mL, displayed anti-inflammatory activity by inhibition of COX-2 production.⁴⁴

In the continuing search for potential anti-inflammatory agents from Tupistra species, furostanol saponins, once again, were demonstrated to serve as important components responsible for such activity. Compound 98 inhibited NO production, with a best IC₅₀ value of 15.7 μM, better than that of furostanol saponins 97, 102, 104, 105, 110, and 131 (IC₅₀ 22.3-46.2 μM), and the reference compound, indomethacin (IC₅₀ = 47.4 μM).³⁹

Similar to the cytotoxic activity, the anti-inflammatory results for spirostanol saponins were found to be better than those for furostanol saponins. For example, significant IC₅₀ values ranging from 3.1 to 4.4 μM were assigned to 5 spirostanol saponin derivatives (49, 50, 57, 61, and 71) in the anti-inflammatory assay against NO production, while furostanol saponin 93 had an IC₅₀ value of 23.3 μM.¹⁰

Both spirostanols and their saponins derived from T. chinensis species could be considered as promising anti-inflammatory agents. As shown in Table 2, among 23 tested compounds, the spirostanol saponin with the most potential (51) significantly inhibited NO production, with an IC₅₀ value of 11.5 µM, approximately more than 4 times as effective as that of the positive control indomethacin (IC₅₀ = 47.4 µM). Interestingly, the axial shape of the methyl group at C-25 in 51, when transferred into an equatorial shape, as in 52, caused a rapid attenuation in the anti-inflammatory effect, which compound 52 lacked (IC₅₀ > 50 µM).²² The glycosyl parts of the spirostanol saponins are more likely to be responsible for the anti-inflammatory effects, by which spirostanol saponins 33, 42, 43, 54, 56, and 70 successfully inhibited NO production, with IC₅₀ values of 16.1 to 40.0 μM, but spirostanol sapogenins 6 and 16 failed to do so.⁹

Antimicrobial Activities

Recently, bioassay and fractionation of the 95% EtOH extract of T. chinensis rhizome led to the isolation of 4 spirostanol sapogenins 2 to 4, and 29.¹⁹ These were subjected to antimicrobial activity against 2 saprolegnoid fungi Penicillium digitatum ACCC 30389 and Rhizopus stolonifera ACCC 30389. The results against P. digitatum were 29 (IC₅₀ 682 µM) > the positive control sodium benzoate (819 µM) > 2 (1675 µM) > 4 (2132 µM) > 3 (2623 µM). Against R. stolonifera, 2 (831 µM) > 29 (IC₅₀ 1146 µM) > 4 (1593 µM) > 3 (1910 µM) > the positive control sodium benzoate (3449 µM).¹⁹

Pharmacological Activities of Extracts

The saponin extract of T. chinensis at a concentration of 10 μg/mL controlled the growth of HeLa (81% inhibition) and HL-60 (92% inhibition) cancer cells.⁴¹ In another study, saponin extract obtained from T. chinensis was investigated for its ability to inhibit the proliferation of ovarian cancer cells by using the MTT assay. The results indicated that this extract, in a dose-dependent manner, significantly inhibited the proliferation of SKOV3 cancer cells through the apoptotic mechanism by suppression of the Wnt/β-catenin signaling pathway.³ With a high total saponin percentage of 80%, the saponin extract of T. chinensis has also shown cytotoxic activity toward A549, MCF-7, and HeLa cancer cells, with IC₅₀ values of 4.11, 6.47, and 7.78 μg/mL, respectively. The underlying mechanism in human A549 cells was explained by the mitochondria-dependent apoptotic pathway.⁵⁴ For sarcoma S-180 cells, T. chinensis saponin extract was examined for in vitro and in vivo inhibitory effects. The in vitro results showed that this extract significantly inhibited S-180 cell growth at doses of 160 and 320 µg/mL after 48 h treatment, while its in vivo mechanism is due to NF-kB signaling suppression in a dose-dependent manner.⁵⁵

T. chinensis is renowned for treatment of various diseases such as pharyngolaryngitis, rheumatism, hepatitis, bruises, and stomach pain.⁶⁰ This may be due to its anti-inflammatory effects. Saponin extract from T. chinensis at doses of 200 and 400 mg/kg in 5 days treatment prevented mice from LPS-induced death by downregulation of IL-1β and TNF-α expressions.⁵⁸ In both in vivo and in vitro models, the 70% EtOH extract of T. chinensis, in a concentration-dependent manner (75, 150, 300 mg/kg), caused a decrease in levels of inflammatory cytokines TNF-α and IFN-γ, and also controlled serum transaminases and lactic dehydrogenase levels in Con A-induced hepatitis in mice.⁵⁷

T. chinensis water extract at a dose of 10 g/kg was reported to significantly inhibit acetic acid-induced capillary permeability and xylene-induced ear edema in mice.⁶⁰ In another pharmacological experiment, against isoproterenol-induced myocardial injury in mice, the n-butanol and ethyl acetate extracts of T. chinensis plant showed a higher effect in comparison to those obtained from water and light petroleum extracts.⁵⁶ Therefore, it can be concluded that medium polar extracts of T. chinensis containing phenols and aromatic derivatives seem better than strong or weak polar extracts.

Among Tupistra species, T. nutans has strong antioxidative activity due to its high phenolic content. The DPPH radical scavenging capacity of T. nutans extracts was in the order ethyl acetate (IC₅₀ 21.31 µg/mL) > n-butanol (65.15 µg/mL) > n-hexane (168.88 µg/mL) > methanol (184.05 µg/mL) > water (309.41 µg/mL).⁴

T. nutans is also a potential antimicrobial agent. Its 70% MeOH root extract at concentrations of 0.12 to 0.25 mg/mL induced inhibitory zones between 10.17 and 19.16 mm against 7 microorganisms, Staphylococcus aureus, Salmonella enterica, Escherichia coli, Candida albicans, Aspergillus niger, A. flavus, and A. fumigatus; mycostatin (1 mg/mL), the positive control, produced inhibitory zones of 8.00 to 18.00 mm.⁴

To date, T. nutans is the only Tupistra species that has been tested for antidiabetic activity. Among 5 extracts (n-hexane, ethyl acetate, n-butanol, methanol, and water), its ethyl acetate extract established the best α-glucosidase inhibitory percentage of 81.68%; the rest showed 60.01% to 73.49% inhibition, as compared to that of the positive control acarbose (98.10%).⁴ The ethyl acetate extract has the highest phenolic (51.20 mg/g GAE) and flavonoid (15.20 mg/g QE) contents.⁴

Conclusion

For the first time, the current review has provided a general overview of the phytochemistry and pharmacology of the genus Tupistra. Phytochemical studies of Tupistra species have resulted in the isolation and structural elucidation of about 200 secondary metabolites. These compounds are of various chemical classes, but steroids, flavonoids, and simple phenols have been considered as major components. The characteristic steroids are spirostanol sapogenins, and spirostanol and furostanol saponins. The different parts of T. chinensis have been used the most frequently in both phytochemical and pharmacological studies. Tupistra saponins are promising agents for cancer related and anti-inflammatory activities, and spirostanol saponins are generally found to be better than furostanol saponins for these properties. Some spirostanol saponins were better than the positive controls in assays, for example, saponins 25(R)-1β-hydroxy-spirost-5-en-3α-yl-O-β-D-glucopyranoside (35), 3-ruscogenin-3-O-β-D-glucopyranoside (45), and tupistroside H (80) inhibited the growth of LoVo and BGC-823 cancer cells with IC₅₀ values of 0.2 to 0.9 μM, as compared to that of the positive control, cisplatin (IC₅₀ = 4.6-5.9 μM). (25S)-5β-Spirostan-3β-ol-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside (51) significantly inhibited NO production, with an IC₅₀ value of 11.5 µM, which was more effective than indomethacin (IC₅₀ = 47.4 µM). It is also viewed that the cancer-related activities of Tupistra constituents mostly are based on an apoptotic mechanism. Tupistra plant extracts containing rich percentages of phenolic and aromatic compounds show antimicrobial, antioxidative, and antidiabetic activities. Further research on the pharmacological kinetics and mechanisms is necessary

Footnotes

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship and/or publication of this article.

ORCID iD

Ninh The Son

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Genus Tupistra : A Comprehensive Review of Phytochemistry and Pharmacological Activity

Abstract

Keywords

Introduction

Phytochemistry

Spirostanol Sapogenins

Spirostanol and Furostanol Saponins

Other Steroids

Flavonoids, Phenols, and Aromatic Derivatives

Miscellaneous

Pharmacological Activities

Cancer-Related Activities

Anti-Inflammatory Activities

Antimicrobial Activities

Pharmacological Activities of Extracts

Conclusion

Footnotes

Declaration of Conflicting Interests

Funding

ORCID iD

References