Hercynine: Uses and Biosynthesis
Hercynine is an intermediate related to sulfur-containing amino acids and is chemically classified as a betaine compound. It is water-soluble. It serves as the primary biosynthetic precursor and oxidative metabolite of ergothioneine. Structurally, hercynine is the product of histidine methylation. As its molecule lacks a sulfur atom, it is referred to as a "sulfur-free precursor" [1-2].
Biosynthesis
In nature, hercynine is primarily synthesized by fungi and actinobacteria. Microorganisms capable of synthesizing hercynine and ergothioneine include fungi from the phyla Ascomycota, Basidiomycota, Zygomycota, and Deuteromycota, as well as slime molds (e.g., Physarum polycephalum) and aerobic actinobacteria (e.g., Streptomyces, Nocardia, Actinoplanes) [1]. These microorganisms synthesize hercynine via the histidine methylation pathway. The specific steps are as follows:
In fungi and actinobacteria, the enzyme EgtD converts the amino acid histidine into hercynine; subsequently, in the presence of a sulfur donor, the enzyme EanB catalyzes the direct synthesis of ergothioneine from hercynine [2].
Extraction Method
The method for extracting hercynine from microbial cultures involves extracting dried microbial biomass with hot water, concentrating the extract, suspending the residue in 75% ethanol, separating the mixture via alumina column chromatography, and finally eluting with 80% ethanol to isolate the compound.
Uses
The primary use of hercynine is as a direct precursor for the biosynthesis of ergothioneine. Additionally, it serves as an indicator of antioxidant activity in food and beverage testing and holds potential application value in wound-healing membrane materials.
References
[1] Genghof, D. S. (1970). Biosynthesis of ergothioneine and hercynine by fungi and Actinomycetales. Journal of Bacteriology, 103 2, 475–478. https://doi.org/10.1128/jb.103.2.475-478.1970
[2] Valachova, K., Svik, K., Biro, C., Collins, M. N., Jurcik, R., Ondruska, L., Soltes, L. (2020). Impact of Ergothioneine, Hercynine, and Histidine on Oxidative Degradation of Hyaluronan and Wound Healing. Polymers, 13 1. https://doi.org/10.3390/polym13010095
