To investigate the non-alkaloidal chemical constituents of the stems and leaves of Melodinus suaveolens and their antibacterial activities. Compounds were isolated and purified by repeated silica gel, Sephadex LH-20, RP18, and preparative HPLC. Their structures were elucidated by comparison with published spectroscopic data, as well as on the basis of extensive spectroscopic analysis. The antibacterial screening assays were performed by the dilution method. Fourteen compounds were isolated, and identified as lycopersene (1), betulinic aldehyde (2), 3β-acetoxy-22,23,24,25,26,27-hexanordammaran-20-one (3), 3a-acetyl-2, 3, 5-trimethyl-7a-hydroxy-5-(4,8,12-trimethyl-tridecanyl)-1,3a,5,6,7,7a-hexahydro-4-oxainden-1-one (4), 3β-hydroxy-28-norlup-20(29)-ene-17β-hydroperoxide (5), 3β-hydroxy-28-norlup-20(29)-ene-17α-hydroperoxide (6), β-sitosterol (7), 28-nor-urs-12-ene-3β, 17β-diol (8), α-amyrin (9), ergosta-4,6,8(14),22-tetraen-3-one (10), 3β-hydroxy-urs-11-en-28,13β-olide (11), betulin (12), obtusalin (13), and ursolic acid (14). Among the isolates, compounds 1, 2, 6, 8, 10, and 14 showed potent antibacterial activities against the four bacteria. This is the first report of the antibacterial activity of the constituents of Melodinus suaveolens.

Objective To study the chemical constituents from the stems and leaves of Cryptolepis buchananii. Methods Compounds were isolated and purified by chromatography on silica gel, Sephadex LH-20, ODS columns, and preparative HPLC. Their structures were identified by NMR and MS, as well as comparison on spectral data with literature values. Results Thirteen compounds were obtained from the EtOAc fraction of methanol extract in the stems and leaves of C. buchananii and their structures were elucidated as isoscopoletin(1),(+)-3-hydroxy-β-ionone(2),(3R, 6R, 7E)-3-hydroxy-4, 7-megastigmadien-9-one(3), ficusic acid(4),(+)-pinoresinol(5),(+)-8-hydroxypinoresinol(6),(+)-syringaresinol(7), diaaurantiamide acetate(8), loliolide(9),(–)-balanophonin(10), chrysoeriol(11), 9-hydroxy-10E, 12Z-octadecadienoic acid methyl ester(12), and ficusesquilignan A(13). Conclusion All the compounds are isolated from the plants of Cryptolepis R. Br. for the first time.

A phytochemical investigation on the stems of Anodendron formicinum led to the isolation of eight prenylbenzoic acid derivatives. Three of these were new compounds, designated as formicinuosides A (1), B (2), and C (3). Their structures were elucidated on the basis of extensive spectroscopic analysis, as well as by comparison with the reported spectroscopic data. This is the first report of chemical constituents from A. formicinum and their antimicrobial activities. Among the isolated compounds, compounds 4, 6 and 8 showed significant antibacterial activities against Providensia smartii with MIC values of 0.781 μg/mL. Moreover, compound 8 showed remarkable antibacterial activity against Escherichia coli with MIC value of 0.781 μg/mL.