Chemical compositions and antimicrobial property of three edible and medicinal Cordyceps species

Abstract

To evaluate the nutritional and health-promoting value of three edible and medicinal mushrooms Cordyceps gunnii, C. taii and C. jiangxiensis, and get a considerable data for establishing the quality control standard of Cordyceps preparations, in this study, we investigated their proximate compositions, nutraceutical ingredients and antimicrobial properties. The polysaccharide, cordycepic acid, and nucleosides contents were quantitated. The relative nucleoside contents, in descending order, were C. jiangxiensis > C. taii > C. gunnii, while cordycepin was not detected in any of the species. C. gunnii, C. taii and C. jiangxiensis all contained high levels of unsaturated fatty acids (UFA) and essential amino acids. The percent of UFA relative to total fatty acids was 78.7% for C. gunnii, 66.9% for C. taii and 79.0% for C. jiangxiensis. All Cordyceps species displayed similar amino acid profiles, with a high level of total amino acids ranging from 146.0 to 168.3 mg/g. Glutamic acid and aspartic acid were the two principal amino acids, which comprised over 10% of the total amino acid contents. Essential amino acids made up 37.05%, 39.39% and 39.37% of the total amino acids of C. gunnii, C. taii and C. jiangxiensis, respectively. Abundant amounts of iron, zinc and selenium were found in this species, while toxic microelements were presented at very low amounts. Among these species tested, only C. taii showed a potent antimicrobial effect, and its active ingredients mainly were from three extraction fractions including chloroform, acetidin and acetone. These results suggested that this species may be a promising source of nutraceuticals and drugs.