A triterpene ketone from an anti-mycobacterial tuberculosis chromatography eluate from the n-hexane fraction of the fruits of Harungana madagascariensis Lam. Ex Poiret (Hypericaceae)

Abstract

Clinical cases of drug resistant tuberculosis (TB) are a global threat because of the cost and extended duration of treatment regimen. This underscores the continuous drive to discover new therapeutic agents that are faster, simpler and affordable often by recourse to natural products. This report highlights the potentials of the Nigerian medicinal plant Harungana madagascariensis Lam. Ex Poiret (Hypericaceae) as a source of lead agents for the discovery and development of anti-tuberculosis drugs. The fruit of H. madagascariensis was extracted with 70% aqueous ethanol by cold maceration. The crude 70 % aqueous ethanol extract was partitioned with n-hexane to give n-hexane (NHF) soluble portions. The NHF was fractionated further on a column packed with normal phase silica gel (200-400 Mesh size) to afford the chromatography fractions used in this study. The structure of isolated compound was elucidated using spectroscopic (NMR, IR, and MS) techniques. Anti-Mycobacteria tuberculosis susceptibility screening of the chromatography fractions was done using Lowenstein Jensen method with rifampicin, ethambutol, isoniazid and dihydrostreptomycin as reference anti-TB drugs for comparison. Four fractions NHF1-4 were obtained from the NHF. The chromatography fractions: NHF2 and NHF3 inhibited the growth of the Mycobacteria tuberculosis. From the NHF2 was isolated the known bioactive triterpene ketone friedelan-3-one. This preliminary screening underscores the potentials of this ethno medicinal plant as a source of lead compounds for the development of anti-TB drugs.