Estimation of withanolide-A in diverse genotypes of Ashwagandha Withania somnifera (L.) Dunal

Withania somnifera (L.) Dunal (Fain. Solanaceae) commonly known as Ashwagandha has been used in traditional Indian medicine system from ancient times. Roots of the plant are being used in the preparation of many Ayurvedic medicines for treatment of many diseases. Many compounds have been reported -and isolated from the roots, which mainly consists of withanolides, (steroidal lactones). In present study, the roots of 25 diverse W. somnifera genotypes were collected and evaluated for morphological parameters, such as root length, root diameter and dry root yield. Total alkaloids, crude fibers and starch content were also estimated from the dried roots of these accessions. TLC and HPLC revealed the presence of withanolide A in the methanolic extract of roots from diverse genotypes. Quantification through reverse-phase HPLC revealed varied concentrations of withanolide A in different genotypes grown under field conditions. Accumulation of withanolide A was reported highest in the genotype UWS-59 makes this genotype superior for medicinal use.