Bioassay-guided fractionation of the crude extract of the whole plant of Macleaya cordata R. Br. led to the isolation of four alkaloids, which were identified as sanguinarine (1), chelerythrine (2), protopine (3) and α-allocryptopine (4) on the basis of their physicochemical and spectrometric data. Compounds 1 and 2 demonstrated a significant antifungal activity against the six test fungi with median inhibitory concentrations (IC50) ranging from 0.47 to 6.13 μg/mL. Compound 1 was the most effective with an IC50 of 0.47 μg/mL on Rhizoctonia solani. Furthermore, compounds 1 and 2 also demonstrated strong antibacterial activity, with IC50 values ranging from 5.01 to 11.3 μg/mL, and minimum inhibitory concentrations (MIC) ranging from 8.0 to 32.0 μg/mL. This is the first report on the activity of the alkaloids from M. cordata against economically important phytopathogenic fungi and bacteria.
MarngiM, RossierD, CrettazP, JollietO. (2002) Life cycle impact assessment of pesticides on human health and ecosystems. Agriculture, Ecosystems and Environment, 93379–392;
DixonRA. (2001) Natural products and plant disease resistance. Nature, 411843–847.
4.
ZhouL, WedgeDE. (2008) Agricultural application of higher plants for their antimicrobial potentials in China. In Crop Protection Research AdvancesBurtonEN, WilliamsPV. (Eds), Nova Science Publishers, New York, 213–233.
5.
WuC. (1999) Papaveraceae. In Flora Republicae Popularis SinicaeWuC. (Ed), Science Press, Beijing, China, Vol. 32, 78–79.
6.
Jiangsu Institute of Botany. (1988) Xinhua Compendium of Material Medica. Shanghai Science & Technology Publishing House, Shanghai, China;
7.
UlrichovaJ, WalterovaD, VavreckovaC, KamaradV, SimanekV. (1996) Cytotoxicity of benzo[c]phenanthridinium alkaloids in isolated rat hepatocytes. Phytotherapy Research, 10220–223;
8.
SedoA, VlasicovaK, BartakP, VespalecR, VicarJ, SimanekV, UlrichovaJ. (2002) Quaternary benzo[c]phenanthridine alkaloids as inhibitors of aminopeptidase N and dipeptidyl peptidase IV. Phytotherapy Research, 1684–87;
9.
MatsuhashiR, SatouT, KoikeK, YokosukaA, MimakiY, SashidaY, NikaidoT. (2002) Nematicidal activity of isoquinoline alkaloids against a species of Diplogastridae. Planta Medica, 68169–171;
10.
NewmanSE, RollMJ, HarkraderRJ. (1999) A naturally occurring compound for controlling powdery mildew of greenhouse roses. HorScience, 34686–689;
11.
LiuH, ZhouL. (2008) Inhibitory activity of the extracts of Macleaya cordata, Reynoutria japonica and Scutellaria baicalensis on plant pathogens. Phytopathology, 98S92.
12.
WangGX, WangJF, YuanJL, ShenYH, ZhengW, LiL. (2007) Activity of sanguinarine from Macleaya cordata to Dactylogyrus and six pathogenic bacteria in aquaculture. Acta Botanica Boreali-Occidentalia Sinica, 271650–1655;
13.
MarekR, TousekJ, DostalJ, SlavikJ, DommisseR, SklenarV. (1999) 1H and 13C NMR study of quaternary benzo[c]phenathridine alkaloids. Magnetic Resonance in Chemistry, 37781–787;
14.
KimSR, HwangSY, JangYP, ParkMJ, MarkelonisGJ, OhTH, KimYC. (1999) Protopine from Corydalis ternata has anticholinesterase and antiamnesic activities. Planta Medica, 65218–221;
15.
UnsalC, SaryarG, MatA, OktayogluE, OzhatayN. (2006) Distribution of alkaloids in the samples of Papaver dubium subsp. lecoqii var. lecoqii from Turkey: a potential source for thebaine. Biochemical Systematics and Ecology, 34170–173.
16.
HamidR, RotshteynY, RabadiL, ParikhR, BullockP. (2004) Comparison of Alamar blue and MTT assays for high throughput screening. Toxicology in vitro, 18703–710;
17.
XuL, ZhouL, ZhaoJ, LiJ, LiX, WangJ. (2008) Fungal endophytes from Dioscorea zingiberensis rhizomes and their antibacterial activity. Letters in Applied Microbiology, 4668–72.
18.
FinneyS. (1978) Probit Analysis. Cambridge University Press, Cambridge, UK;
19.
PengYL, ShishiyamaJ. (1988) Temporal sequence of cytological events in rice leaves infected with Pyricularia oryzae. Canadian Journal of Botany, 66730–735;
20.
FioriACG, Schwan-EstradaKRF, StangarlinJR, VidaJB, ScapimCA, CruzMES, PascholatiSF. (2000) Antifungal activity of leaf extracts and essential oils of some medicinal plants against Didymella bryoniae. Journal of Phytopathology, 148483–487.
21.
WeidenbornerM, HindorfH, JhaHC, TsotsonosP, EggeH. (1989) Antifungal activity of isoflavonoids against fungi of the genus Aspergillus. Phytochemistry, 283317–3319.
