Amino Acids Analysis of the Four Mushroom Species, Antioxidant Activity and Immunostimulant Evaluations of their Polysaccharides Extracts

Abstract

Mushrooms have been valued as edible and medical resources. This project aimed to evaluate of four mushrooms such as Pleurotus ostreatus (Fr.) Kummer, Pleurotus opuntiae (Dur.& Lev.) Sacc., Pleurotus sajor-caju (Fr.) Sing, and Ganoderma lucidum (Curtis) for amino acids, two extraction methods, antioxidant activity, total phenolic content, 1H NMR analysis and in vitro immunostimulant activity, compared the cultivation between TISTR and Nakhon Prathom area. The results showed that glutamic acid and aspartic acid were abundant amino acids, while alanine, leucine, lysine, arginine, serine, phenyl alanine and threonine were found varied in those mushrooms. The most common amino acids found in P. sajor-caju were found in lower amounts in G. lucidum. There amino acids content was contrast with the antioxidant activity and total phenolic content. Meanwhile the 1H NMR chemical shifts illustrated signals of a mixture of polysaccharides resonated at  \(\delta\) 3.0-4.0 ppm, and fatty acids at  \(\delta\)  0.70-2.30 ppm of the A extract as well as the two signals of anomeric protons  \(\alpha\) -glucan and  \(\beta\) -glucan of the B extract appeared at δ 5.36 ppm and 4.47 ppm, respectively.  The bioassay in vitro immunostimulant activity of all mushroom extracts showed good immunostimulant booster at concentration of  0.5 mg/mL. It was found that the A and B extracts of G. lucidum were the most potent immunostimulant activity followed by the A extract of P. sajor-caju, and they had higher activity than  \(\beta\) -glucan standard with % phagocytic activity of 187.12±2.17, 166.23±0.56, 155.00±2.93, respectively. Future works will focus on their in vivo immunostimulant activity, healthy drinks and nutraceutical product development.