Phytochemical and pharmacological investigation of Kickxia ramosissima

Abstract

Kickxia ramosissima (Wall.) Janch. (Scrophulariaceae) is a small herb that is highly appreciated as a traditional medicine in the Indian subcontinent [1 – 2]. The scientific data reporting its constituents are poor and therefore the present investigation was undertaken to discover the main constituents. A double maceration was performed at room temperature with methanol 90%, followed by liquid-liquid partition with various solvents. Each fraction was then tested for claimed biological activities including antibacterial, antifungal, cytotoxic and antiglycation assays. The microorganisms used were Staphylococcus aureus, Escherichia coli, Candida albicans, Microsporum canis and MRC-5 cells as a cytotoxicity control. The n-hexane fraction showed notable antibacterial (IC50 8 µg/mL) and antifungal (IC50 24.40 µg/mL) activity. All other fractions were considered as inactive (IC50> 64 µg/mL). The ethyl acetate fraction showed the highest anti-glycation (Advanced Glycation Endproducts, AGEs) activity (IC50 87.14 µg/mL), followed by the n-butanol (IC50 144.62 µg/mL), methanol 90% (IC50 167.16 µg/mL) and chloroform (IC50 175 µg/mL) fractions. In order to provide adequate phytochemical information all extracts were further fractionated using repetitive flash chromatography and analysed by TLC and HPLC-DAD. For the isolation of major compounds, a semi preparative HPLC(RP)-DAD-MS system was used. Subsequently NMR and mass spectra were recorded to elucidate the structure of the isolated compounds, which could be identified as iridoids (1 – 4) flavonoids (5 – 6),p-hydroxy-coumaric acid methyl ester (7) and p-hydroxy-benzoic acid methyl ester (8). Compound 4 was a new iridoid. Biological evaluation of isolated compounds is in progress.