Abstract
Three new glycosides, derriacuminosides A-C (
Introduction
Derris elliptica is a climbing shrub belonging to the Leguminosae family. It is widely grown or cultivated in subtropical and tropical regions. The roots of D elliptica have long been used for poisoning fish and plant pests.1-3 In traditional medicines, D elliptica is used to treat sickness of breasts, toothache, bleeding, and stomachache. 4 Up to date, several phytochemical studies have been reported on the roots and aerial parts of D elliptica. Flavonoids in several subgroups, such as flavone, isoflavone, pterocarpan, cumaronochromone, and especially rotenoid, were identified as major components of this plant.5-8 These types of compounds have been shown to have potential cytotoxic and anti-inflammatory activities.9,10 The roots of D elliptica contain rotenoids, such as rotenone, deguelin, and tephrosin, which are toxic ingredients responsibility for the plant's insecticidal property.5,7 Other phenolic compounds, including flavone, isoflavone, pterocarpan, and cumaronochromone, have been revealed from the aerial parts of this plant. 8 However, there have been no continuous phytochemical studies on this plant for the past decade. In our program to find natural anti-inflammatory agents, the water extract of D elliptica stems showed potential NO inhibitory activity, which was selected for chemical investigation. Herein, we report the identification of 3 new glycosides and their inhibitory activity on NO production in LPS activated RAW264.7 cells.
Results and Discussion
The stems of D elliptica were extracted with methanol. The methanol extract was suspended in water and successively partitioned with dichloromethane and ethyl acetate. The water-soluble extract was fractionated by column chromatography, and purified by semi-preparative HPLC to obtain compounds
Structures of compounds
Compound
Key HMBC (H→C) and COSY (H⁃H) correlations of
Compounds
1H NMR and 13C NMR Spectroscopic Data for Compounds
Measured at a125 MHz and b500 MHz.
The water-soluble extract of D elliptica (100 µg/mL) was screened for NO inhibitory activity and showed an inhibitory percentage of 70.8 ± 3.5%. Thus, compounds
Material and Methods
General Experimental Procedures
Optical rotation was recorded on a JASCO P-2000. HRESIMS were obtained on an AGILENT 6530 Accurate Mass Q-TOF, and NMR spectra on a BRUKER Avance III spectrometer. Semi-preparative HPLC was performed on an AGILENT 1260 Infinity II system using a YMC J′sphere ODS-H80 column (20 mm × 250 mm, 4 µm) and isocratic mobile phase at a flow rate of 3.0 mL. Thin layer chromatography (TLC) was carried out on pre-coated plates (silica gel 60 F254 or RP-18 F254S), and column chromatography (CC) using either silica gel, reversed phase (RP-18), or diaion HP-20 resins.
Plant Material
Fresh samples of Derris elliptica (Wall.) Benth. were collected in October 2020 at the Me Linh station for biodiversity, Vinh Phuc, Vietnam, and identified by Dr Nguyen The Cuong at the Institute of Ecology and Biological Resources, VAST. A voucher specimen (code: NCCT-P105) is kept at the Institute of Marine Biochemistry, VAST.
Extraction and Isolation
The stems of D elliptica were dried at 60 °C and pulverized to fine powder. The powdered material (15 kg) was ultrasonically extracted with methanol at room temperature, 3 times (10 L of methanol and 30 min each time), to give the methanol extract. The methanol extract (450 g) was then mixed with 3 L of water and successively extracted with dichloromethane and ethyl acetate to give dichloromethane, ethyl acetate, and water-soluble fractions. The water soluble fraction was separated by diaion HP-20 CC eluting with methanol/water (1/3, 1/1, 1/0, v/v) to yield 3 fractions, W1-W3. Fraction W1 was chromatographed on a silica gel column, eluting with dichloromethane/acetone (2/1, v/v) to give 5 fractions, W1A-W1E. Fraction W1A was repeatedly chromatographed on a silica gel column, eluting with dichloromethane/ethyl acetate (1/1, v/v) to give 2 fractions, W1A1 and W1A2. Fraction W1A1 was purified by semi-preparative HPLC using acetonitrile/water (3/7, v/v) to give compound
Derriacuminoside A (1 )
White amorphous powder,
Derriacuminoside B (2 )
White amorphous powder,
Derriacuminoside C (3 )
White amorphous powder,
Acid Hydrolysis and Confirmation of Sugar Residue
Compounds
Nitric Oxide Assay
RAW 264.7 cells were cultured in DMEM containing L-glutamine (2 mM), HEPES (10 mM), sodium pyruvate (1 mM), and fetal bovine serum (10%). The cells (2 × 105 cells/well) were incubated in humidified atmosphere (95% air and 5% CO2) at 37 °C. After 24 h incubation, to each well was added either compounds (0.8-100 µM/mL) or vehicle, followed by LPS (1 μg/mL) in the next 2 h. The cells were then incubated for an additional 24 h. After that, cell viability was measured by MTT assay and the amount of NO production in the cell medium was determined by Griess reaction. Culture medium (100 μL) was mixed with an equal volume of Griess reagent and incubated at room temperature for 10 min. Absorbance was measured at 540 nm on a microplate reader. Nitrite concentration as an indicator of NO production was determined using a standard curve, which was built by NaNO2 serial diluted solutions. Experiments were performed in triplicate. IC50 values were generated by TableCurve 2Dv4 software.
Conclusions
From the stems of D elliptica 3 new glycosides were isolated, characterized, and named derriacuminosides A-C (
Supplemental Material
sj-docx-1-npx-10.1177_1934578X221126299 - Supplemental material for Three New Glycosides From the Stems of Derris elliptica
Supplemental material, sj-docx-1-npx-10.1177_1934578X221126299 for Three New Glycosides From the Stems of Derris elliptica by Bui Thi Thu Trang, Nguyen Xuan Nhiem, Nguyen Thi Huong, Nguyen Thi Thanh Mai, Nguyen Tuan Anh and Phan Van Kiem in Natural Product Communications
Footnotes
List of Abbreviations
Authors’ contributions
Research idea: NX Nhiem, PV Kiem. Isolation and bioassay: BTT Trang, NT Huong, NT Anh. Structure elucidation and writing: BTT Trang, NTT Mai, NX Nhiem, PV Kiem.
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.
Ethical Approval
Our institution does not require ethical approval for reporting individual cases or case series.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research is funded by Graduate University of Science and Technology under grant number GUST.STS.ĐT2020-HH12.
Statement of Human and Animal Rights
This article does not contain any studies with human or animal subjects.
Statement of Informed Consent
There are no human subjects in this article and informed consent is not applicable.
Supplemental Material
Supplemental material for this article is available online.
References
Supplementary Material
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