Phytochemical Profile of Prunus africana Stem Bark from Kenya

Abstract

Prunus africana (Hook.f.) is an evergreen tree that grows in African mountains. P. africana species’ bark and bark extracts are used for the treatment of benign prostate hyperplasia. The pharmacological efficacy of the extracts is believed to be due to synergistic effect of several compounds such as phytosterols, pentacyclic triterpenoids and ferulic acid esters. High demand for the bark and bark extracts of P. africana has led to over-exploitation of the natural population resulting to it being listed as an endangered species; Appendix II of CITES. Conservation of the species can be done through domestication. However, growth factors need to be established first to ensure success of on-farm production. With this in mind, the World Agroforestry Centre established a P. africana stand at Muguga, Kenya to evaluate the species phytochemical profile and yields. Phytochemistry profiling was carried out using liquid Chromatography coupled to Mass Spectrometry (LC-MS) and Gas Chromatography-Mass Spectrometry (GC-MS). Myristic acid, linoleic acid, lauric acid, methyl myristate, methyl laurate and methyl linoleate were the major compounds present after analysis of essential oils in the bark samples while campesterol, β-sitosterol, lup-20(29)-en-3-one, palmitic acid, β-sitostenone, (3.β.,5.α)- stigmast-7-en-3-ol, stigmastan-3,5-diene and α-tocopherol were detected in dichloromethane and hexane extracts of the three populations. In methanolic extract we detected cyanidin-O-galactoside, cyanidin-3-O-rutinoside, procyanidin B5, robinetinidol- (4-α-8) catechin-(6,4-α)robinetinol and ursolic acid.. All these compounds have been reported to have salutary benefits in humans. The phytochemical data has important implications in coming up with strategies for sustainable harvesting and conservation of this species as well as its management on-farm.