Abstract: L-ergothioneine (EGT) is a naturally occurring chiral amino acid antioxidant which biosynthesized by some mushrooms,streptomycete,mycobacteria,etc.EGT can be absorbed and assimilated by plants and animals,and distributed in most animal cells and tissues.Because of its particularly biological functions and pharmacological activities,EGT is widely used in pharmaceuticals,food,health products and cosmetics industries as a physiological cytoprotector.This paper reviewed the biosynthesis and degradation of EGT,so as to improve the production levels of EGT by metabolic modulation,and dig further physiological functions and applications of EGT.

Key words: L-ergothioneine, precursor, biosynthetic pathway, degradation