Stage- and Rearing-Dependent Metabolomics Profiling of Ophiocordyceps sinensis and Its Pipeline Products

SIMPLE SUMMARY: The caterpillar fungus O. sinensis is a historical ethnopharmacological commodity in China. The recent die-off of its wild population has raised the urgent task of ensuring the natural conservation of both the fungus and its host species Thitarodes. During the last decade, artificial cultivation of the caterpillar fungus has been established to supplement its declining natural colony. However, it is crucial to determine the nutritional background of the artificially reared cordyceps complex and its related products, i.e., mycelia and fruiting bodies reared on media. The current study aims to determine the comprehensive metabolic profiles of 17 treatments from 3 groups, including O. sinensis fungus, Thitarodes insect and cordyceps complex. We found that the metabolomics of O. sinensis-related products were mainly determined by the fruiting bodies rather than the culture methods. Our results suggest that artificially cultured fruiting bodies and cordyceps may have indistinguishable metabolite compositions as the natural ones. These results are highly intriguing in many aspects, from understanding the infection mechanism of caterpillar fungus, to commercial applications of caterpillar fungi quality authentication. It provides insights into the development of better alternatives for wild cordyceps and serves the future biological conservation of the fungal/insect species. ABSTRACT: Cordyceps, a parasitic complex of the fungus Ophiocordyceps sinensis (Berk.) (Hypocreales: Ophiocordycipitaceae) and the ghost moth Thitarodes (Lepidoptera: Hepialidae), is a historical ethnopharmacological commodity in China. Recently, artificial cultivation of Chinese cordyceps has been established to supplement the dwindling natural resources. However, much is unknown between the natural and cultivated products in terms of nutritional aspect, which may provide essential information for quality evaluation. The current study aims to determine the metabolic profiles of 17 treatments from 3 sample groups including O. sinensis fungus, Thitarodes insect and cordyceps complex, using Gas Chromatography - Quadrupole Time-of-Flight Mass Spectrometry. A total of 98 metabolites were detected, with 90 of them varying in concentrations among groups. The tested groups could be separated, except that fungal fruiting body was clustered into the same group as Chinese cordyceps. The main distinguishing factors for the groups studied were the 24 metabolites involved in numerous different metabolic pathways. In conclusion, metabolomics of O. sinensis and its related products were determined mainly by the fruiting bodies other than culture methods. Our results suggest that artificially cultured fruiting bodies and cordyceps may share indistinguishable metabolic functions as the natural ones.