ABSTRACT
The bio guided fractionation of the dichloromethane/methanol (1:1) crude extract of the air-dried whole plant of C. aegyptiaca led to the isolation of one new flavone derivative designated conyflavone (1) and one new clerodane diterpene type designated conyclerodane (2) along with five known compounds including two flavonoids Gardenin C (3), chrysosplenetin (4) and two steroids glucoside of ß-sitosterol (5), the mixture of stigmasterol (6) and ß-sitosterol (6') and ent-2b,18,19trihydroxycleroda-3,13-dien-16,15-olide (7). The structures were established by spectroscopic methods including IR, 1D and 2D NMR in conjunction with mass spectroscopy and by comparison to data of related compounds described in literature. The stereocentres in compound 2 were determined by SC-XRD analysis. Crude extract as well as fractions and pure compounds were evaluated in vitro for their antibacterial activities against four pathogenic and two clinical isolate strains using microdilution methods. Extracts and compounds displayed a moderate antibacterial activity with MIC values ranging from 125 to 500 µg/mL.
Subject(s)
Asteraceae , Conyza , Plant Extracts/chemistry , Anti-Bacterial Agents/chemistry , Glucosides , Microbial Sensitivity TestsABSTRACT
As part of our search for new secondary metabolites from Macaranga hurifolia Beille, a phytochemical investigation was carried out on the fruits that led to the isolation and characterization of two new prenylated flavonol derivatives named macafolias A (1) and B (2), along with five known compounds. Their chemical structures were established on the basis of extensive analysis of their 1-D and 2-D NMR (1H, 13C, APT, COSY, HSQC and HMBC) in conjunction with mass spectroscopy and by comparison with data from the literature. The in vitro assay of the antibacterial potency of the crude extract, fractions and some pure compounds were evaluated against a wide range of bacteria strains.
