Iridoid Glycosides and Phenylpropanoids from Asystasia Gangetica (L) T. Anderson Var. Micrantha (Acanthaceae)

Asystasia gangetica (L) T. Anderson var. micrantha (Acanthaceae) or commonly known as Chinese Violet or rumput Israel in Malaysia is a rapidly growing herb usually found among short grasses and along pathways. This plant is used traditionally to treat diabetes mellitus, ear disease and gonorrhea. Its anthelmintic activity helps to treat swelling and rheumatism. The present study was designed to isolate and elucidate chemical constituents from A. gangetica. The methanolic extract of the A. gangetica leaves was fractionated by using vacuum liquid chromatography (VLC) and preparative high-performance liquid chromatography (HPLC). Selected fractions were purified by recycling HPLC and monitored by using ultra high-performance liquid chromatography (UHPLC). The structures of isolated compounds were characterized by using various spectroscopic methods, mainly nuclear magnetic resonance (NMR) and comparisons with previously reported data. Five phytochemical constituents namely, salidroside (1), verbascoside (2), forsythiaside (3), 3''-O-caffeoyl-6-O-rhamnopyranosyl catalpol (4), and 4''-O-caffeoyl-6-O-rhamnopyranosyl catalpol (5) were purified using recycling HPLC. Compounds 2, 3 and 5 were identified for the first time from A. gangetica. (author)