Identification of Bioactive Compounds in Sclerotia Extracts from <i>Pleurotus tuber-regium</i> (Fr.) Sing. using Gas Chromatograph– Mass Spectrometer (GC-MS)

Abstract

King tuber mushroom (Pleurotus tuber-regium) is a tropical mushroom commonly seen in Australia, Africa and Asia. Trado-medical practitioners use the sclerotia for the treatment of various health disorders. This research aimed at identifying the biologically active compounds present in the sclerotia of this mushroom. In this study, the fungus was first extracted with methanol and re-extracted with ethyl acetate (EA) and dichloromethane (DCM) separately to obtain EA and DCM extracts. Gas chromatography–mass spectrometric (GC-MS) technique was used for the identification of compounds present in EA and DCM extracts. Results revealed the presence of a total of at least twenty-six (26) compounds with 14 and 12 from EA and DCM extracts respectively. The bioactives include n-Hexadecanoic acid, Oleic acid, 10-Octadecenal, Palmitoleic acid, 9, 17-octadecadienal-(z), 11-octadecenoic and methyl ester-(z). In EA extract, n-Hexadecanoic acid had highest concentration (37.67%) followed by 20.65% of 9,12 Octadecadienoic acid and the least was 9,17 Octadecadienal with 0.539%. In DCM extract, 11-Octadecenoic acid methyl ester was most abundant (18.344%) followed by Pentadecanoic acid 14 methyl-methyl ester (14.105%) and the least (4.058%) was 9,12-Octadecadienoic acid. These compounds possess various reported medicinal properties (such as the treatment of high blood pressure, diabetes, asthma, fever and cancer) that could be harnessed for health benefits. Other identified compounds with unknown functions are Trans-2-Dodecen-1-ol trifluoroacetate, cis-11-Hexadecenal, Methyl-18-methylnonadecanoate and Methyl-18-methyl-tetracosanoate. This identification is useful for the establishment of the medicinal properties of the mushroom and isolation of the bioactive compounds, which production can further be enhanced by cost-effective biotechnology techniques.