Antioxidant and cytotoxic properties of water‐soluble crude polysaccharides from two edible mushroom species of Ramaria

Abstract

Water‐soluble crude polysaccharides (WSCPs) were isolated from the fruiting bodies of Ramaria flava (Schaeff.) Quél. (RFCP) and Ramaria cf. aurea (Schaeff.) Quél. (RACP). Species of Ramaria were collected in Boyacá‐Colombia. WSCPs were obtained by hot‐water extraction, ethanol precipitation, and dialysis and characterized using UV‐Vis spectroscopy, gel permeation chromatography, high‐performance liquid chromatography‐diode array detector, fourier transform infrared and nuclear magnetic resonance spectroscopy. Different assays evaluated the antioxidant capacity, and the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT)‐assay was used to determine cytotoxic effects. Chemical compositional analysis revealed that RFCP and RACP are heteropolysaccharides with molecular weights of 407 and 818 kDa, respectively compose mainly of glucose, mannose, galactose, fucose, and glucuronic acid with small amounts of protein and polyphenols. The backbone of RFCP and RACP is composed of β‐D‐Glcp‐(4→,→3)‐β‐D‐Glcp‐(1→,→2,6)‐α‐D‐Galp‐(1→,→3,6)‐α‐D‐Manp‐(1→. Antioxidant capacity demonstrated that both crude polysaccharides exhibit reducing power, radical scavenging ability, and a protective effect on lipid‐peroxidation. MTT assay showed that RFCP and RACP inhibited the growth of cancer cells HCT 116‐(colorectal) and MG‐63‐(bone) in a concentration‐dependent manner. Compared with RFCP, RACP showed better antioxidant capacity and cytotoxic effects due to differences in composition, molecular weight, and triple‐helical conformation. Overall, WSCPs exhibited a promising biological effect, highlighting the cultural, nutritional, and medicinal value of wild mushrooms.