Optimized thin layer chromatographic method for screening pharmaceutically valuable alkaloids of Catharanthus roseus (Madagascar Periwinkle)

Abstract

The aerial parts of Catharanthus roseus (C. roseus) plant have been known to contain many important alkaloids such as Vincristine, Vinblastine, Vindoline and Ajmalicine which are of interest to this study. Ajmalicine has also been found in abundance in the roots of this medicinal plant. The main objective of this study was to screen a methanolic extract of C. roseus for the presence of pharmaceutically valuable alkaloids using previously optimized conditions established in our laboratory set up. This methanolic extract was further purified for specific alkaloids present using modified Shams et al. (2009) method I extraction procedure. Extracts of C. roseus have been subjected to optimum conditions before and after Thin layer Chromatography which was performed in a trough chamber of 10 cm x 10 cm area saturated with Ethyl acetate: Benzene: Methanol: 25% Ammonia solution (100:5:5:3) as a developing solvent and sprayed with Cerium Ammonium Sulphate (CAS) reagent specific for the detection of alkaloids. Results have shown that the alkaloids of interest; Vincristine, Vinblastine, Vindoline and Ajmalicine could be chromatographically identified in extracts of C. roseus intact plant after individual alkaloid purification procedure. This has confirmed the anti-neoplastic and anti-hypertensive properties these alkaloids have in making the plant effective in healing cancer and high blood pressure as it was originally used by traditional people.