Study on triterpenes from polypore fungi

Abstract

Polysaccharides and triterpenes have been reported as the major bioactive compounds of polypore fungi and their bioactivities can be varied from one species to another depeding on the substrate and location where the mushroom grows. The main aims of this project were to determine the contents of triterpene crude extracts from different Ganoderma (polypore) species collected from Vietnam and initially study their biological activities. In this project, the triterpenes from fruiting bodies of Ganoderma were extracted by using kinetic maceration method using ethanol as a solvent. Among the three studied species, crude triterpenes yield obtained from G. submubraculum (1.80%) was slightly higher than the yield of G. capense (0.44%) and significantly lower than that of G. applanatum (7.29%). For antimicrobial activity, clinically important bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus and Salmonella typhimurium were selected and anti-bacterial screening was conducted using the agar well diffusion technique. Crude triterpenes from all three Ganoderma species displayed antibacterial activities towards the studied pathogens. The result indicated that the most susceptible pathogen to the triterpenes was Pseudomonas aeruginosa (14.45± 1.88mm) and the extract from G. capense displayed higher inhibition zones toward the pathogens than others. In term of the cytotoxicity, at the concentration of 100μg/mL, the extracts had very low cytotoxity against liver cancer cell line (Hep G2) and cervical cancer cell line (HeLa). However, they showed remarkably antioxidant activities. Especially, crude triterpene from G. capense had EC50 of 20.427μg/ml, which is comparable with that of the positive control as 13.128μg/ml. The above results would be useful in the decision-making process of preserving precious fungi and for further studies on the use of wild mushrooms for medicinal purposes. Keywords: crude extract, polypore fungi, Ganoderma, triterpenes, bioactivity