Compounds · Other compounds · Sulphur compounds
Lenthionine
Also known as 1,2,3,5,6-Pentathiepane — an analysis may use any of these names
Dried shiitake, rich, meaty, with deep umami.
- CAS
- 292-46-6
- Formula
- C2H4S5
- Molar mass
- 188.37
- Odour threshold
- —
- Boiling point
- ≈ 240 °C estimated
Where it comes from
Biosynthetic pathway: Sulphur compounds — enzymes cut sulphur precursors the moment tissue is damaged.
Fresh shiitake has no lenthionine. The compound forms only when the mushrooms are dried: enzymes in the mushroom tissue cut a sulphur-containing precursor, and that process needs time, not high heat. Drying here does not preserve the smell but creates it.
Why it sits where it does
A seven-membered ring containing as many as five sulphur atoms. Very heavy for its small number of carbons, so it sits towards the end of the band.
Where else you meet it
Found only in dried shiitake. Fresh mushrooms have none at all — it forms during drying.
Dictionary entries that mention this compound
About the boiling-point figure
Not yet cross-checked against a primary source. The value is provisional, used to place the compound on the volatility axis. Why this detail matters