Intraspecific variability of main phytochemical compounds in Picrorhiza kurroa Royle ex Benth. from North Indian higher altitude Himalayas using reversed-phase high-performance liquid chromatography

Abstract

Picrorhiza kurroa Royle ex Benth. is an important medicinal plant belonging to family Scrophulariaceae. It is known to contain iridoid glycosides, picroside I and II as major bioactive compounds. The present study provides an analytical HPLC method with well-resolved and symmetrical peaks for the two reference compounds picroside-I and picroside-II. Separation was achieved on RP-18e, Merck made column. The mobile phase consisted of methanol:water (60:40, v/v) in isocratic elution with flow rate 1 ml/min. Injection volume of standard and samples was 10 μl and run time was 30 min. The detection of analyte was carried out using photodiode array detector with wavelength of 270 nm. Calibration curves were constructed for each analyte. The HPLC method was developed and applied to determine the picroside-I and picroside-II in rhizome of all the seven accessions [Rohtang-3978 m (PKR-1); Marhi-3300 m (PKM-2); Manali-2050 m (PKM-3); Keylong-3350 m (PKK-4); Khoksar-3160 m (PKK-5); Manikaran-1737 m (PKM-6) and Chamba-996 m (PKC-7)] from higher altitude North Indian Himalayas of Himachal Pradesh. Both of these reference compounds have been detected in the rhizome samples of all these seven accessions of P. kurroa. After detailed comparison, it was concluded that the percentage of both analytes were found to be maximum, that is, picroside-I (3.5%) and picroside-II (2.0%) in rhizome parts of P. kurroa collected from Rohtang area (3978 m)