Isolation, characterisation and in silico toxicity evaluations of thiocarbamates, isothiocyanates, nitrile, glucosinolate and lipids from moringa oleifera lam. Seed

Abstract

The phytochemical composition of medicinal plants is responsible for the ethnopharmacological applications. These phytochemicals vary in plants of same species planted in various geographical locations. The seed of Moringa oleifera Lam., a widely consumed multi-medicinal plant was examined for the bioactive phytochemicals. With the aid of Nuclear Magnetic Resonance (1H-NMR/13C-NMR) spectrometer, Electrospray Ionisation Mass Spectrometry (ESI-MS) and Fourier Transform Infrared (FT-IR) spectroscopy, the phytochemical investigation of the seed of M. oleifera afforded nine compounds which included niazimicin 1, niazidin 2, glucomoringin isothiocyanate 3, niazinin acetate 4, niazinin triacetate 5, niazirinin 6, glucotropaeolin 7, triolein 8, trivaccenin 9. The Gas Chromatography-Mass Spectrometry (GC-MS) analysis of a major oily fraction revealed the presence of additional ten compounds which include oleic acid (major), 13-docosenoic acid, stearic acid, p-hydroxybenzyl cyanide, α-l-rhamnopyranose and other fatty acids/esters. This is the first account of a fully acetylated niazinin (a 4-(2’,3',4’-O-triacetyl-α-L-rhamnosyloxy)benzyl isothiocyanate) 5 from Moringa oleifera seed. The in silico toxicity evaluation indicated that most of the isolated compounds are either immunotoxic, carcinogenic or mutagenic. The result thus obtained could serve a basis for the pharmacological and toxicological evaluation and profiling of the seed. The result further implied the need for dosage regulation of the consumption of the seed.