the insoluble residue below about 60 u00b0 c or spray drying to provide a dry solid and f pulverizing the solid under controlled temperature and humidity conditions the aprotic solvent soluble fraction of the extraction process e g chloroform which contains mainly cytotoxic withanolide aglycones and other constituents of the plant which do not contribute to the bioactivity of the ashwagandha composition can be discarded if desired the aqueous alcoholic soluble chloroform insoluble residue contains withanolide glycoside and sitoindoside components which are potent bioactive constituents of ashwagandha the resultant extract powder also contains very high levels of oligosaccharides which act as a carrier for the bioactive withanolide glycosides specifically the water soluble portion of this extract see table 1 column 2 contains at least 25 preferably up to 75 of oligosaccharides which enhance the bioactivity of the withanolide glycosides high molecular weight saccharides which decrease its bioactivity i e polysaccharides are present in only small amounts herein the composition of the extract compositions of this invention are summarized in tables 1 and 2 below withanolide glycosides sitoindosides the major bioactive constituents of withania somnifera are not readily identifiable in hptlc chromatographs however upon carefully controlled hydrolysis where they are converted into withanolide aglycones these components are readily observed in.