Chemical fingerprinting and quantification of bioactive metabolites in Pueraria tuberosa (Willd.) DC. and its marketed samples: Implications for quality control in herbal medicine

Quality control of Vidarikand in Indian market

Abstract

The present study aims to distinguish Pueraria tuberosa (Willd.) DC. from its common adulterants, sold in Indian market as the Ayurvedic drug “Vidarikand”. Authentic samples of Vidarikand were collected from three natural locations, and marketed samples were procured from twelve major herbal markets in India. Pharmacognostic parameters of collected samples were standardized as per API guidelines, and known bioactive metabolites viz., gallic acid (1), p-coumaric acid (2), puerarin (3), biochanin A (4), daidzein (5), and genistein (6) were quantified using RP-HPLC. The separation was achieved using a mobile phase containing 0.1% orthophosphoric acid in water (A) and acetonitrile (B). Elution was carried out in an isocratic manner (65:35% v/v; A: B), with a flow rate of 0.7 mL min^-1. HPLC data revealed significant variation in the quantification of bioactive metabolites between natural populations and marketed samples. Analysis of HPLC fingerprints showed that authentic samples contained a higher number of peaks (both known and unknown), whereas marketed samples exhibited fewer peaks, except for PT-8. The sample procured from the Trivandrum market (PT-8) displayed a chemical profile somewhat similar to authentic P. tuberosa, suggesting that it could be genuine. However, based on its morphology and the absence of puerarin, daidzein, and genistein, it was identified as Ipomoea sp. This study will aid in the quality control of Vidarikand by distinguishing it from visually similar adulterants in various herbal markets in India, helping to ensure the safety and efficacy.