3-Methyl-3-sulfanylhexan-1-ol
3-Methyl-3-sulfanylhexan-1-ol is a primary alcohol that is hexan-1-ol which is substituted by a methyl group and a thiol group at position 3. It is the odor component of human axilla sweat and the major species at pH 7.3.
The molecule was identified in 2004. The odor may be described as "rotten onions or meat" while its / enantiomers are described as "sweat and onion-like" for and "fruity and grapefruit-like" for. Some variation between enantiomer ratios may exist due to gender differences in skin micribiota composition and in precursor molecule production.
Synthesis
Apocrine sweat glands produce an S-glutathione conjugate secreted via ABCC11 transporters into vesicles. The conjugate is converted into a S-Cys-Gly-3M3SH thiol before excretion through the gland to the skin.Bacteria found to create 3M3SH from human sweat include primarily Staphylococcus haemolyticus, other Staphylococcus clade members such as Staphylococcus hominis, and Corynebacterium xerosis, though at a lesser extent compared to S. haemolyticus. In S. hominis, the bacterial cell imports the thiol precursor via a proton-coupled oligopeptide transporter. After intake of the thiol precursor, the strains metabolize it to produce 3-methyl-3-sulfanylhexan-1-ol.