Production dynamics of Withaferin A in Withania somnifera (L.) Dunal complex.

Withaferin A (WA) is an important withanolide holding promise in cancer treatment and as a relatively safe radiosensitive/chemotherapeutic agent, which is present in traces in all parts of Withania somnifera except the leaves, where as it is reported to be present in only two non-Indian chemotypes (South African chemotype/Israel chemotype 1). The present studies have marked its presence in all Indian populations (wild/cultivated), as well as two identified Indian chemotypes (AGB002 and AGB025). The quantitative dynamics of WA production in Indian populations and interchemotypic hybrids developed at our institute have been studied, and the results were compared with five previously reported chemotypes from Israel, South Africa and India. An analysis on inheritance characteristics based on presence/absence of WA in hybrid plants and their respective parents is given for future studies on the chemogenetics of this complex species in greater detail. Further, the production potential of WA in vitro propagated plants of elite varieties developed at our institute is discussed, in view of maintaining chemotypic fidelity and stability from a production point of view. Also, evidence-based clues suggesting the leaves as the site of the synthesis of WA is provided.