L-(+)-Ergothioneine (L-EGT) | CAS 497-30-3 | Histidine Betaine Thiol (Research Use Only) | Knowlux

Product Summary

Knowlux supplies L-(+)-ergothioneine (L-EGT) as an enantiopure histidine-derived betaine for laboratory research, assay development and formulation pre-studies. The substance is a white to off-white crystalline powder, genuinely water-soluble, and structurally distinct from conventional thiol antioxidants because its sulfur exists predominantly as a thione rather than a free -SH group. Each consignment ships with a batch-tied analytical file (COA, polarimetry printout, NMR trace, SDS, chromatograms and origin documentation) so the material can be traced from container to bench.

Three buyer types purchase this material for unrelated reasons, and the documentation that supports one use does not support the other two:

• Cosmetic formulators need a water-soluble antioxidant with a legal cosmetic-ingredient identity and no colour body.

• Supplement and functional-food brands need a grade whose regulatory status is real in the destination market, with the dosage ceiling stated.

• Laboratories need an enantiopure reference material with a stated optical rotation and a quantified impurity profile.

Most listings merge these three and quote whichever number looks best. This page keeps them separate.

Specification Sheet

Parameter	Detail
Product	L-(+)-Ergothioneine
Synonyms	L-EGT; Ergothioneine; 2-Mercapto-L-histidine betaine; Sympectothion; Thiasine; Thioneine
CAS	497-30-3 (L form)
EC No.	207-843-5
Formula	C9H15N3O2S
Molecular weight	229.30 g/mol
IUPAC name	(2S)-3-(2-thioxo-2,3-dihydro-1H-imidazol-4-yl)-2-(trimethylammonio)propanoate
Nature	Zwitterionic inner salt: permanent quaternary ammonium plus thiol/thione group
Appearance	White to off-white crystalline powder
Melting point	275-277 C (with decomposition)
Water solubility	~200 g/L at 20 C; no co-solvent required
logP / PSA	-3.43 / ~101 A2 (strongly hydrophilic)
Assay	>=99.0% (HPLC, dried basis); >=98.0% available on request
Optical rotation	+122 to +136 degrees (c=1, water)
Identity	HPLC retention match; 1H-NMR; elemental C/H/N within 47.14 / 6.59 / 18.32% +/- 0.4
Grade	Research grade
Water content	<=0.5% (Karl Fischer)
Ash	<=0.2%
Related substances	<=0.8% (hercynine and thioimidazole species reported)
Heavy metals	Pb <=0.5, Cd <=0.3, Hg <=0.1, As <=0.5 mg/kg
Residual protein	<=100 mg/kg (fermentation-derived lots)
Storage	Sealed, light-protected, 2-8 C for long hold; ambient transit acceptable
Hazard classification	H315 (skin irritation); H319 (serious eye irritation); H335 (respiratory irritation)
HS code	2934.99.00
Pack sizes	1 g / 5 g / 10 g / 25 g / 50 g / 100 g
MOQ	1 g
Capacity	Gram to kilogram scale
Origin	China

Three Standards Behind the Specification

Parameter	This listing (99% grade)	China draft (CFSA 2026)	EU novel food (EFSA)
Assay	>=99.0% HPLC	>=99.0 g/100 g, dry basis	>=99.5% HPLC
Optical rotation	+122 to +136 (c=1, H2O)	+122 to +136	>= +122
Appearance	White to off-white powder	White crystal or powder	White powder
Loss on drying	<=0.5%	<=0.7 g/100 g	<=0.5%
Ash	<=0.2%	<=0.2 g/100 g	Not specified
Related substances	<=0.8% (hercynine reported)	Reported per method	<=0.8%
Pb / Cd / Hg / As	<=0.5 / <=0.3 / <=0.1 / <=0.5 mg/kg	Same	<3 / <1 / <0.1 / not specified
Residual protein	<=100 mg/kg (fermentation routes)	<=100 mg/kg	Not specified
Benzaldehyde	<=0.08 g/100 g (synthetic route only)	<=0.08 g/100 g	Not specified
Microbial	TVAC <=10^3, TYMC <=10^2 CFU/g, E. coli absent/g	Per appendix	TVAC <=10^3, TYMC <=10^2

Read the table across, not down: a lot that passes the Chinese draft at 99.0% fails the EU specification at 99.5%, and a rotation of +121 degrees fails all three. The COA header should name which standard each parameter is judged against.

Regulatory Status by Market

The regulatory point most listings get wrong: in China, ergothioneine is today a legal cosmetic ingredient and a food ingredient still in the approval pipeline, not an approved novel food. Pages that quote a 2024 announcement number alongside a 30 mg/day Chinese limit are mixing an EU figure into a Chinese document; the Chinese draft proposes <=20 mg/day.

Structural and Stability Notes

At physiological pH the thiol is almost entirely in the thione form, which is why ergothioneine does not autoxidise the way cysteine or glutathione do. This is a rare property for a low-molecular-weight thiol and the reason a plain aqueous stock holds up better than intuition suggests.

The permanent quaternary ammonium makes the molecule an inner salt with no net charge dependence on pH, and pushes logP to -3.43. It dissolves in water to roughly 200 g/L, needs no DMSO, and partitions poorly into lipids. Formulators who treat it as a lipophilic antioxidant and attempt oil-phase dissolution will observe crystallisation.

Biologically, uptake is carrier-mediated via the OCTN1 transporter, also called the ergothioneine transporter, which carries the molecule into cells and mitochondria. That is a mechanism statement, not a benefit claim; it explains why published work focuses on tissues expressing the transporter.

Analytical Release

Check	Method
Assay	HPLC-UV, 254 nm, external standard, dried basis
Optical rotation	Polarimetry, c=1 in water, 20 C
Identity	Retention match plus 1H-NMR; elemental C/H/N within specified tolerance
Related substances	HPLC gradient; hercynine and thioimidazole peaks integrated and reported
Residual protein	Coomassie Bradford (fermentation-derived lots)
Water / ash	Karl Fischer; gravimetric
Metals	ICP-MS for Pb, Cd, Hg, As
Microbiology	TVAC, TYMC, E. coli

Chromatograms, the polarimeter printout and the NMR trace travel with the lot. A purity figure without a rotation reading is an incomplete release for this molecule.

Handling and Storage

Water is the solvent: prepare the stock at the concentration required, filter if clarity matters, and skip the co-solvent step. Keep solutions neutral to mildly acidic; alkali plus trace metals accelerates oxidation to the disulfide, and strong oxidants destroy the imidazole ring. Solid material is heat-stable enough for normal processing but should be kept sealed, dry and out of direct light; 2-8 C is the long-hold condition, and a 24-month retest period is typical for sealed drums. Expect slight off-white variation between lots; report it against the colour standard rather than against a photograph.

Research Applications

• Water-phase antioxidant in emulsions, serums and sun-care formulations, typically 0.01-0.1% as an exploratory range

• Supplement premix and capsule fill, dosed in single-digit to tens of milligrams per serving

• Functional beverage and solid-drink mixes, where full water solubility removes the turbidity problem

• Cell-culture and fermentation media additive, protecting sulphur-containing enzymes from oxidative stress

• Analytical standard for EGT quantification in mushroom, plasma and formulation matrices

• Stress-testing model thiol in oxidation and metal-chelation studies

No statement above is a health claim, a therapeutic indication or a dosing instruction.

Documentation and Traceability

Each lot is released against its own file: certificate of analysis with raw chromatograms and rotation printout, SDS in the destination language, certificate of origin, allergen and residual-protein statements, and a specification cross-reference sheet naming which standard each parameter is judged against. Custom pack sizes and client-template documentation are quoted per project.

Packing and Dispatch

1 kg foil bag inside a light-blocking carton; 5 kg tin; 25 kg fibre drum with double food-grade liner and nitrogen flush. Shipments leave Hubei within the quoted lead time, ambient by default, with cold packs where route or season requires. Export documents (invoice, packing list, COA, SDS, origin certificate) are prepared before dispatch.

About Knowlux

Knowlux Biotechnology, Hubei, China, is a GMP-oriented supplier of peptides, active substances and fine-chemical research compounds to laboratories, CDMOs, formulators and distributors in more than 40 countries. Beyond catalogue supply we handle custom synthesis, bespoke pack sizes and documentation packages built to a client's audit template.

Compliance and Use Restriction

This material is released strictly for laboratory research use. It must not be administered to humans or animals, must not be used in diagnosis or therapy, and is not offered for retail, personal or household use.

Ergothioneine is authorised in some jurisdictions as a cosmetic ingredient and, in the EU and US, as a food or supplement ingredient within defined limits. Those regulatory positions attach to compliant cosmetic-, food- and supplement-grade supply chains and do not apply to, and are not represented by, this research-grade lot.

Statements describing published research are scientific background only. They are not medical advice, not a health claim, and not dosing or therapeutic guidance.