Isolation, identification of some chemical constituents and antimicrobial activity of different extracts from withania somnifera growing at Albaha Region, KSA

Abstract

The purpose of this study is to investigate some chemical constituents and biological activities of different extracts of Withania somnifera (WS) growing in Albaha region KSA. The volatile oils of both leaves and stems were extracted by hydrodistillation method and analyzed using Gas Chromatography/ Mass spectrometry (GC/MS) technique. The pet ether extracts of different parts (leaves, stems and seeds) of the plant were fractionated into acetone insoluble fraction, unsaponifiable matter and fatty acids which were identified using (GC/MS) analysis. All defatted plant powder of each organ were extracted with methanol (80 %) which subsequently fractionated using (chloroform, ethyl acetate and n-butanol) respectively. Flavonoidal content of all extracts was determined using the standard Aluminum chloride spectrophotometric method while phenolic content was determined by using Folin-Ciocalteau spectrophotometric method. The results of the antimicrobial activity of different showed that, the extracts of leaves and stems only showed activity against gram positive bacteria while, all gram negative bacteria are resistant to all extracts except ethyl acetate extract of leaves.