RAPID ISOLATION OF THE BIOACTIVE METABOLITE OF CYMBOPOGON PROXIMUS AND DEVELOPMENT OF LC METHOD

Abstract

Objective: Development of a rapid isolation method to afford the bioactive metabolite (proximadiol: prox) from its herb (Cymbopogan proximus Stapf.) in the purest form and validate an LC method for its determination was our goal in this work. Methods: Prox was isolated by chromatographic techniques from the dichloromethane extract of the herb on alumina column, using petroleum ether-ethyl acetate solvent mixtures with increasing polarity.The determination of prox was achieved by LC method. The chromatographic separation was carried out on Thermo Hypersil ODS (4.5 x 250 mm, 10 µm) column, in the presence of 8-chlorotheophylline as an internal standard. The mobile phase was composed of 0.1 M phosphate buffer (pH: 3.5): methanol (60:40 v/v) and was pumped at a flow rate of 1 ml/min. The detection and quantification were done at 210 nm.Results: The structure elucidation of the isolated compound was identified on the basis of its spectral data.A simple and reproducible LC method was developed for the determination of the isolated purified Prox. Adequate separation and good resolution were obtained between prox and 8-chlorotheophylline. Quantification was achieved at 210 nm over concentration range 12.00-33.60 µg/ml with mean percentage recovery of 99.29±0.340. The method was validated in accordance with USP specifications. All analytical criterions were within acceptable range. The validity of the results was assessed by applying standard addition technique. The results obtained were compared with the reported method.Conclusion: The proposed method could be applied for routine quality control analysis of pharmaceutical formulations containing prox.