Isolation of antifungal compound from Paeonia suffruticosa and its antifungal mechanism.

OBJECTIVE: To isolate antifungal compound from Paeonia suffruticosa, and to find the antifungal mechanisms by observing the ultrastructural modifications of yeasts in growth phase produced by 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG). METHODS: Peony (Paeonia suffruticosa) root bark (PRB) was separated by solvent extraction and purified by high performance liquid chromatography (HPLC) method using analytical and preparative reversed phase C18 column on the basis of bio-assay method. In order to investigate the antifungal mechanism of PGG, Yeasts were submitted to different concentrations [3 × minimum inhibition concentration (MIC), 0.3 × MIC] for 1 h under constant stirring at 30 °C, and transmission electron microscopy was performed. RESULTS: Based on the antifungal activity of PRB on Candida glabrata CBS138, the antifungal compound were isolated in ethyl acetate layer of PRB and identified as PGG by mass spectrometry, 1H nuclear magnetic resonance (NMR) analyses, with molecular weight of 940 and molecular formular as C41H32O26. Transmission electron microscopy showed that PGG degraded the cell wall envelope. CONCLUSION: The results suggest that PGG may be responsible for the antifungal activity of PRB by disrupting the structure of cell wall directly.

Chemical constituents from the roots of Homonoia riparia.

A new compound and twelve known compounds were isolated from the ethyl acetate extract of the roots of Homonoia riparia Lour, which are used in folk medicine for treatment of hepatitis, bellyache and scald, by the method of silica gel column chromatography repeatedly with a gradient of PE-EtOAc, PE-Me2CO, CHCl3-Me2CO, CHCl3-MeOH. Their structures were identified as a new compound 1-oxo-aleuritolic acid (1), and twelve known compounds aleuritolic acid (2), 3-acetoxy-aleuritolic acid (3), taraxerone (4), taraxerol (5), methyl 3-acetoxy-12-oleanen-28-oate (6), 3-acetoxy-12-oleanen-28-ol (7), ursolic acid (8), lupenol (9), 3beta-acetoxy-lupenol (10), cleomiscosin A (11), chrysophanol (12), and gallic acid (13), which were obtained from this plant for the first time, by the spectroscopic techniques of NMR, HMBC, IR and MS, separately. Among the cytotoxicities evaluation of compounds 1 -3 towards AGZY 83-a (human lung cancer cells) and SMMC-7721 (human liver cancer cells) tumor cells was assayed by MTT methods with cis-dichlorodiamminoplatinum (DDP) used as positive control. Compound 2 exerted weak activity against AGZY 83-a with the IC50 value of 33.055 microg x mL(-1), while 1 and 3 showed no activity to these two cell lines.

Anticancer activity of tirucallane triterpenoids from Amoora dasyclada.

A new tetranortriterpene 3alpha-acetoxy-24,25,26,27-tetranortirucalla-7-ene-23(21)-lactone (3), and eleven other compounds were isolated from the twigs of Amoora dasyclada. The structure of compound 3 was identified on the basis of spectroscopic data, and the bioactive experiments of 1 and 3-5 against AGZY 83-a (human lung cancer cells) and SMMC-7721 (human liver cancer cells) are documented. Among them, compound 5 exhibited a strong activity against SMMC-7721.