Proximate and Fourier transform infrared (FTIR) spectroscopic analysis of phytochemicals from hexane extracts of root and leaf of Rauvolfia vomitoria (Afzel)

Abstract

This research, aimed to determine phytochemical constituents and identify functional groups of the secondary metabolites of Rauvolfia vomitoria (Afzel) root and leaf. Soxhlet extraction was carried out using n-hexane. Proximate analyses using standard procedures revealed that 100 g of root contained 64.5 g of carbohydrates, 14.48 g of fibre, some crude fat and proteins. Phytochemical screening confirmed the presence of various phytochemicals such as alkaloids, saponins, cardiac glycosides, terpenoids, steroids, phenolics, tannins and flavonoids. Quantitatively analyses revealed that 100 g of dry root/leaf contained 161.3 mg/147.65 mg alkaloids, 10.70 mg/17.68 mg saponins, 30.01 mg/44.16 mg reducing sugar and 17.92 mg/10.79 mg cardiac glycosides. Others detected are 9.45 mg/13.92 mg steroids, 18.63 mg/14.10 mg tannins and 77.01 mg/107.16 mg phenolics, respectively. FTIR spectroscopy showed peaks with diverse functional groups, including N-H (alkaloids), C-O (triterpenoid), O-H (flavonoids), C=C (phenolics) and C=O (steroids).  The present study demonstrated the plant parts could serve as good sources of macronutrients.