Two new acylated flavonol glycosides from Mimosa pigra L. leaves sub-family Mimosoideae

Autor: Chinedu J.O. Okonkwo, OE Afieroho, Obioma U. Njoku, Tochukwu J.N. Okonkwo, Peter Proksch
Rok vydání: 2016
Předmět:
Zdroj: Future Journal of Pharmaceutical Sciences, Vol 2, Iss 2, Pp 71-75 (2016)
ISSN: 2314-7245
DOI: 10.1016/j.fjps.2016.08.003
Popis: Background Mimosa pigra L. (Fabaceae-Mimosoideae) is a large shrub native to tropical America and economically important as a medicinal plant; it is also an invasive plant and a noxious weed. Methods M . pigra leaves were air dried, pulverised and extracted with 96% ethanol. The ethanol extract (MPEE) was partitioned with diethyl ether (DEE) and ethyl acetate (EA) in succession to yield DEE fraction (DEEF), EA fraction (EAF) and EA insoluble fraction (EAIF). Results Sephadex LH-20 gel filtration chromatography (GFC) of the EAF and semi-preparative HPLC purification of the GFC sub-fractions afforded two new acylated flavonol glycosides [myricetin (2″- O -galloyl)-3- O - α - l -rhamnopyranoside, I ; and quercetin (2″- O -galloyl)-3- O - α - l -rhamnopyranoside, II ] in M. pigra . Alongside three other flavonol glycosides (myricetin 3- O - α - l -rhamnopyranoside, III ; quercetin 3- O - α - l -rhamnopyranoside, IV ; and quercetin 3- O - α - l -arabinopyranoside, V ). The structures of compounds I – V were assigned by ultraviolet/visible (UV) spectroscopy, 1D and 2D 1 H and 13 C NMR spectroscopy and liquid chromatography-electrospray-mass spectrometry (LC-ESI-MS). Conclusion Myricetin, quercetin and their glycoside derivatives are strong antioxidants; and elicit cytotoxic effect on human cancer cell lines among other pharmacological activities. The isolation of acylated flavonoids in M. pigra provided an important insight on the evolutionary trend of the medicinal plant. While the dominance of flavonols, may account for the various ethnomedicinal uses of the herb and the mechanism and mode of its confirmed pharmacological actions.
Databáze: OpenAIRE