Research progress on biosynthesis and application of L-ergothionein
Natural ergothioneine, also known as L-ergothioneine (L-EGT), has a molecular weight of 229.3, is a white crystal that is easily soluble in water (0.9 mol per liter at 24 ℃). It is a natural antioxidant such as thioimidazole amino acids that participate in maintaining the redox state within the body’s cells. In 1909, Tanret et al. first isolated LEGT from the parasitic ergot fungus on the grass plant rye, and subsequently discovered L-EGT in human blood, which attracted people’s attention. Under physiological conditions, L-EGT mainly exists in the form of thiones, maintaining stability and making it less prone to self oxidation (see Figure 1). Due to its unique structure, L-EGT has higher stability and antioxidant activity than glutathione. Research has shown that L-EGT has the potential to prevent and treat diseases such as cancer, cardiovascular disease, cognitive impairment caused by oxidative stress, as well as to preserve and preserve fresh food. In 2016, the European Food Safety Authority issued a safety assessment statement for L-EGT as a new type of food, paving the way for the development of L-EGT related pharmaceuticals and foods. Based on the strong antioxidant, safety, and stability advantages of L-EGT, it has shown promising application prospects in cosmetics, functional foods, medical, therapeutic, and biomedical fields.

L-EGT is a highly efficient, safe, and stable natural antioxidant with excellent free radical scavenging ability, chelation of divalent cations, and food preservation and anti-corrosion effects. The human body absorbs L-EGT through the organic cation transporter OCTN1 on the cell membrane surface, protecting cells from oxidative stress, inhibiting the body’s inflammatory response, and protecting the skin from UV stress. However, the human body’s ability to obtain L-EGT from food is limited, and the high price of L-EGT on the market restricts people from supplementing with additional L-EGT. At present, it is difficult to synthesize L-EGT by chemical methods, and there are disadvantages such as difficulty in ensuring product safety, high synthesis raw materials and costs. Extracting from edible mushrooms rich in LEGT has problems such as low extraction efficiency, long time consumption, and difficulty in large-scale preparation, which still cannot fundamentally solve the problem of insufficient L-EGT production. The biosynthesis pathways of LEGT in bacteria and fungi have been analyzed, and in the future, stable and high-yield L-EGT engineering bacteria should be constructed using genetic engineering methods, combined with modern green and low-carbon fermentation technology to achieve large-scale production of L-EGT, fundamentally reducing the production cost of LEGT.
Given that L-EGT has the potential to prevent and treat diseases such as cancer, cardiovascular disease, and cognitive impairment, but lacks strong clinical trial data, further research on L-EGT trials should be strengthened.