Ergothioneine, a natural amino acid derivative, is found in various natural sources, one of which is the golden oyster mushroom (*Pleurotus citrinopileatus*), due to its high ergothioneine content. This article will explore the scientific value and industrial applications of this natural active ingredient, focusing on keywords such as golden oyster mushroom, golden oyster mushroom extract, plant extracts, and raw materials.

How much ergothioneine is in golden oyster mushrooms?

The golden oyster mushroom, also known as the golden oyster or lemon yellow oyster mushroom, is an edible mushroom with high nutritional value. It is rich in various bioactive substances and is used in the research of functional foods and cosmetic raw materials. According to several studies, the average ergothioneine content in the fruiting bodies of golden oyster mushrooms can reach 1.2–2.5 mg/g dry weight (i.e., 1200–2500 micrograms per gram of dry mushroom), which is a high level among common edible mushrooms.

This data is significantly higher than that of common button mushrooms (*Agaricus bisporus*, approximately 0.5–1.0 mg/g) and shiitake mushrooms (*Lentinula edodes*, approximately 0.8–1.2 mg/g), and is close to or even exceeds some varieties of *Boletus* species, which are known as the "king of ergothioneine."

Therefore, golden oyster mushroom extract, as a stable source of ergothioneine, is increasingly being used in anti-aging skincare products, immune-regulating supplements, and sports nutrition products, becoming a new favorite in the plant extract raw material market.

Which fungi have the highest ergothioneine content?

Although the golden oyster mushroom performs excellently, there are still several "champion" contenders in the fungal kingdom that surpass it in ergothioneine content:

1. Boletus species: Some wild Boletus mushrooms can have ergothioneine content as high as 2.8–3.5 mg/g, making them one of the highest known natural sources.

2. Chanterelle (Cantharellus cibarius): The content is approximately 2.0–3.0 mg/g, combining both flavor and nutrition.

3. Maitake Mushroom (Grifola frondosa): In addition to polysaccharides, it also contains 1.8–2.2 mg/g of ergothioneine, exhibiting a synergistic effect.

Although these wild mushrooms have higher content, due to resource scarcity, high prices, and difficulty in large-scale cultivation, the Golden Oyster Mushroom (Pleurotus citrinopileatus) has become an ideal raw material source for industrial extraction of ergothioneine due to its artificial cultivation, stable yield, and controllable cost.

Five Core Advantages of Ergothioneine

1. Superb Antioxidant Capacity: Ergothioneine is a natural thione-type amino acid that efficiently scavenges free radicals, especially hydroxyl radicals and singlet oxygen, protecting cell membranes and DNA from oxidative damage.

2. Unique Cell Targeting: The human body has a specific transporter protein, OCTN-1, which actively concentrates ergothioneine in tissues with high oxidative stress, such as the skin, liver, and kidneys, achieving precise protection.

3. Photoprotective Effect: Under ultraviolet irradiation, ergothioneine can reduce apoptosis of skin fibroblasts and inhibit melanin production, and is widely used in anti-photoaging skincare products.

4. Anti-inflammatory and Immunomodulatory Effects: Studies have shown that ergothioneine can inhibit the NF-κB pathway, reduce the release of inflammatory factors, and has potential intervention value for chronic inflammation.

5. High Stability and Good Safety: Compared with easily oxidized components such as vitamin C, ergothioneine remains stable at high temperatures, light, and a wide pH range. Animal experiments show that its acute toxicity is extremely low, with an LD50 > 5g/kg, classifying it as a non-toxic substance.

Industrial Application Prospects of Golden Oyster Mushroom Extract

• Beauty and Skincare: Added to serums and creams, focusing on "anti-aging" and "brightening skin tone" concepts;

• Functional Foods: As a core ingredient in dietary supplements, supporting cell health and immunity;

• Sports Nutrition: Helps alleviate exercise-induced oxidative stress and muscle fatigue;

• Pet Health: Some high-end pet food brands have begun adding ergothioneine to extend the lifespan of pets.

In terms of extraction technology, mainstream companies utilize a combination of water extraction, alcohol precipitation, and macroporous resin purification technology, which can increase the ergothioneine concentration in *Pleurotus citrinopileatus* extract to 5% (i.e., 50mg/g), meeting the demand for high-purity raw materials.

High-Quality Ergothioneine Raw Material Supplier

Among numerous plant extract suppliers, Xi'an Sost Biotech Co., Ltd. is a high-tech enterprise specializing in the research and development and production of natural products. The company owns a standardized GMP workshop and advanced testing platforms such as high-performance liquid chromatography (HPLC) and mass spectrometry (MS), ensuring that the active ingredient content of each batch of *Pleurotus citrinopileatus* extract is stable and meets the standards for heavy metals and microorganisms.

Currently, the company has established an overseas warehouse in the United States, providing localized warehousing and fast delivery services for Pleurotus citrinopileatus extract (5% ergothioneine) to North American customers, supporting B2B bulk purchasing and customized extraction services. The product is widely used in cosmetics, health products, and food and beverage industries, and is highly praised by customers.
Contact Information:
Email: ericyang@xasost.com
Website: www.sostapi.com
COA, MSDS, test reports, and sample requests are available.

Conclusion
Pleurotus citrinopileatus is not only a delicious edible mushroom but also an important source of natural ergothioneine. Its extract, with its high content, high stability, and broad application prospects, is becoming a "golden raw material" in the plant extract market. With the deepening of scientific research and the growth of consumer demand, natural fungal extracts represented by *Pleurotus citrinopileatus* will play an increasingly important role in the health industry chain.
For raw material purchasers, brand owners, and R&D institutions, choosing a supplier like Xi’an Sost Biotech with a complete quality system and global service capabilities is a crucial step in ensuring product competitiveness.

References
1.Ey, J. M., et al. (2007). "Dietary sources and bioavailability of ergothioneine." *Preventive Medicine*, 45(5), 533–538.
2.Cheah, I. C., & Halliwell, B. (2012). "Ergothioneine: recycling and protective roles in the body." *Free Radical Biology and Medicine*, 52(9), 1507–1519.
3.Kalaras, M. D., et al. (2017). "Ergothioneine content of edible mushrooms as affected by cultivation conditions." *Journal of Agricultural and Food Chemistry*, 65(34), 7542–7548.
4.National Institutes of Health (NIH). "Ergothioneine: A Unique Antioxidant." *Office of Dietary Supplements*.
5. Zhang, Y., et al. (2020). "Optimization of extraction and purification of ergothioneine from *Pleurotus citrinopileatus* using response surface methodology." *Molecules*, 25(12), 2899.