Abstract

The aim of present study is comparative evaluation of iridoid glucosides and flavonoids phytochemicals in different species of Swertia collected from different geographical region in India using HPLC-PDA-MS analytical method and their antioxidant potential. Total seven species of Swertia viz. S. nervosa (SW-1), S. bimaculata (SW- 2) and S. chirata (SW-3), S. ciliata (SW-4), S. paniculata (SW-5), S. cordata (SW-6), and S. alata (SW-7) and six phytochemicals/biological active compounds viz. Swertiamarin, Sweroside, Swertisin, Amarogentin, Luteolin and Genistein have been selected for study. All compounds were separated on C-18 column using mobile phase A (0.5% acetic acid in water) and phase B (100% acetonitrile) in a gradient mode. Total six peaks from six compounds of seven species were unequivocally detected by comparing their UV spectra, retention time, TIC data, and in MS spectra under positive electrospray ionization mode (ESI-MS), fragmentation pattern of all targeted compounds with those of standard compounds. All targeted species were differentiated by variation in relative concentrations of the six compounds. Antioxidant potentials of all selected compounds were also evaluated. Higher total polyphenolic contents is reported in S. chirata and simultaneously validated through antioxidant activity assay such as β-carotene oxidation inhibition, DPPH radicals scavenging activity, and reducing potential in comparison to other species. Our developed and validated analytical methods HPLC-PDA-MS not only facilitate qualitative and quantitative study of targeted compounds in all species of Swertia but have important application in systematic evaluation of distribution of studied iridoids and flavonoid compounds. The developed method can be well employed in the detection and quantitative evaluation of targeted compounds in the bulk samples and different species of Swertia at industrial level.

Keywords: HPLC-PDA-MS; Iridoid compounds; Flavonoid compounds; Swertia species; Antioxidant potential