Study on the Chemical Composition of Honeycomb Fermentation Liquid and Its Mycelium
Armillaria mellea is a type of facultative parasitic fungus that can attach to decaying trees and trunks, absorb nutrients for growth, and coexist with the traditional Chinese medicine Gastrodia elata to provide the necessary nutrients for growth and development. Two fungi and one type “are essential materials for the cultivation of Gastrodia elata.” Two fungi “refer to the germinating fungi (purple fern mushroom) that promote the germination of Gastrodia elata seeds, as well as the fungi of the genus Armillaria that provide nutrients for the growth of Gastrodia elata tubers. Research on the chemical composition of Armillaria mainly focused on the 1980s and 1990s. So far, more than 100 compounds have been isolated from the fruiting body, mycelium, fermentation broth, fungal hyphae and other parts of Armillaria elata, mainly including phenylpropanoid sesquiterpene aromatic acid esters, alkaloids, sugars, sterols, organic acids, triterpenes, diterpene acids, flavonoids, esters, polyphenols, etc. Among them, phenylpropanoid sesquiterpene aromatic acid esters and other bioactive compounds have been identified. The main components are present in the polar sites of ethyl acetate. Research has shown that honey fungus has protective effects on cardiovascular and cerebrovascular systems, liver protection, blood sugar lowering, immune enhancement, sedative hypnotic, anti-tumor, antibacterial, anti-inflammatory, antioxidant, and other functions. It is a Chinese herbal medicine with potential for development and utilization. At present, the indicators for evaluating the quality of honey fungus are unclear, and no quality standards or production technical regulations related to honey fungus have been released, which affects the standardized cultivation of Tianma and leads to unstable yield and quality of Tianma. Therefore, this study systematically isolated and identified the chemical components of the 95% ethanol extract and ethyl acetate extract of the fermentation broth and mycelium of honey fungus, providing a reference for the quality control and development of honey fungus.

 

 

Discussion and Conclusion
This study isolated 13 fatty acids and their esters, 2 sterols, 1 phenol, and 10 nitrogen-containing compounds from the fermentation broth and mycelium of honey fungus. Among them, 19 compounds, including 5-13, 16, 18-26, were isolated from honey fungus for the first time. The discovery of these components helps to understand the metabolic products produced by honey fungus in different parts. The main components in its fermentation broth are fatty acids and their esters and alkaloids, while the main components in its mycelium are fatty acids and their esters, steroids, and phenols. The fatty acids and their esters isolated from the fermentation broth can be separated from the mycelium; The compounds isolated in this study have similar chemical compositions to the liquid cultures of Lonicera japonica by Zhang Hongqi et al., including sterols, cyclic dipeptides, phenols, and other compounds that may be common components in fungal liquid cultures. In addition, literature has reported that ergosterol and mannose are the main components for evaluating the quality of honey fungus. The compounds (22E, 24S) -5 α, 8 α – cyclodioxo-6,22ergostadiene-3 β ol and ergosterol isolated in this study showed different anti-inflammatory activities against LPS induced RAW 264.7 cell inflammation. Among them, ergosterol is an important component of fungal cell membrane and plays an important role in cellular physiological functions. The anti-inflammatory activity of honey fungus may come from sterols. At the same time, among the 26 compounds reported in this article, in addition to ergosterol, there are multiple other types, which can further provide reference for the construction of the chemical fingerprint of honey fungus and the formulation of production technology regulations or quality standards for liquid strains. Through literature comparison, the components of linoleic acid, ethyl linoleate, para hydroxybenzyl ethyl ether, uracil, proline, etc. isolated in this study have also been isolated in the chemical composition research of their symbiotic plant Tianma, indicating that a close chemical ecological relationship may have been established between honey fungus and Tianma.