A New strategy for Quantitative Analysis of Ergothioneine in Fermentation Broth by RP-HPLC

Hypsizygus marmoreus as a Source of Indole Compounds and Other Bioactive Substances with Health-Promoting Activities

Hypsizygus marmoreus is an edible medicinal mushroom species with a high dietary value. In this study, the fruiting bodies of commercial and self-cultivated crops and mycelium from in vitro H. marmoreus cultures (both white and brown varieties) were evaluated. This study aimed to analyze the presence of indole compounds and other biologically active substances and determine the effect that the addition of zinc and magnesium ions to the culture medium has on the content of the tested compounds in mycelial cultures. The content of indole compounds and other organic compounds was determined using high-performance liquid chromatography, the content of bioelements was determined using flame atomic absorption spectrometry, the glucan content was determined spectrophotometrically, and the antioxidant activity of extracts was estimated using DPPH, FRAP, and ABTS methods. The results showed that H. marmoreus mycelium from in vitro cultures is a good source of indole compounds, bioelements, glucans, and lovastatin. Mycelia from in vitro cultures showed the most diverse composition of indole compounds (L-tryptophan, 5-hydroxy-L-tryptophan, tryptamine, 5-methyltryptamine, and melatonin). Additionally, in vitro cultures of H. marmoreus enriched with Zn and Mg salts increased the contents of Na, Ca, Zn, 5-methyltryptamine, melatonin, protocatechuic acid, sterols, and total glucans. Only in the case of the white variety of mycelial enriched cultures, ergothioneine and Mg levels also increased. To summarize, the content of the active compounds differed depending on the H. marmoreus variety and the tested material.

Recent Strategies for the Biosynthesis of Ergothioneine

Ergothioneine (EGT) is a unique naturally occurring amino acid that is usually biosynthesized by bacteria and fungi. As a food-derived antioxidant and cytoprotectant, it has several physiological benefits and has a wide range of applications in food, medicine, and cosmetics. Traditional production of EGT is mainly through biological extraction or chemical synthesis; however, these methods are inefficient, making large-scale production to meet the growing market demand difficult. Nowadays, the rapid development of synthetic biology has greatly accelerated the research on the EGT production by microbial fermentation. In this paper, the biological characteristics, applications, biosynthesis, separation, and detection methods of EGT were fully reviewed. Furthermore, the approaches and challenges for engineering microbial cells to efficiently synthesize EGT were also discussed. This work provides new ideas and future research potentials in EGT production.

The current status of biotechnological production and the application of a novel antioxidant ergothioneine

Ergothioneine is a sulfur-containing histidine derivative, that possessesexcellent antioxidant activity and has been used in the food and cosmetics industries. It plays a significant role in anti-aging and the prevention of various diseases. This review will briefly introduce the functions and applications of ergothioneine, elaborate the biosynthetic pathways of ergothioneine and describe several strategies to increase the production of ergothioneine. Then the efficient extraction and detection methods of ergothioneine will be presented. Finally, several proposals are put forward to increase the yield of ergothioneine, and the development prospects of ergothioneine will be discussed.

The biology of ergothioneine, an antioxidant nutraceutical

Ergothioneine (ERG) is an unusual thio-histidine betaine amino acid that has potent antioxidant activities. It is synthesised by a variety of microbes, especially fungi (including in mushroom fruiting bodies) and actinobacteria, but is not synthesised by plants and animals who acquire it via the soil and their diet, respectively. Animals have evolved a highly selective transporter for it, known as solute carrier family 22, member 4 (SLC22A4) in humans, signifying its importance, and ERG may even have the status of a vitamin. ERG accumulates differentially in various tissues, according to their expression of SLC22A4, favouring those such as erythrocytes that may be subject to oxidative stress. Mushroom or ERG consumption seems to provide significant prevention against oxidative stress in a large variety of systems. ERG seems to have strong cytoprotective status, and its concentration is lowered in a number of chronic inflammatory diseases. It has been passed as safe by regulatory agencies, and may have value as a nutraceutical and antioxidant more generally.