Original Articles
Venkata Sai Prakash Chaturvedu
Abstract
Systematic phytochemical studies of the dichloromethane (CH2Cl2) fraction of the aqueous extract of Astragalus propinquus on a C-18 column using a Biotage Flash Chromatography system yielded three flavonoids namely 5- hydroxy-4´, 6, 7 trimethoxyflavone (salvigenin), 4´, 5, 7-trihydroxyflavone (apigenin), and 3´,4´, 5, 7- tetrhydroxyflavone (luteolin). The structures of the isolated compounds salvigenin, apigenin, and luteolin were characterized on the basis of extensive spectral studies and literature search. Further, the complete 1H and 13C NMR spectral assignments of the three isolated compounds are reported on the basis of 1D (1H and 13C) and 2D (COSY, HSQC, and HMBC) NMR spectral data.