Identification of new odoriferous compounds in human axillary sweat.

3-Hydroxy-3-methylhexanoic acid (1) and the 3-sulfanylalkan-1-ols 2-5 were identified to contribute to the odor of human axillary sweat. Quantitative analyses of axillary sweat extracts from 50 healthy men showed an unambiguous correlation between the detected levels of 1 and the intensity of the axillary odor. Chiral-GC analyses revealed 1 to be a 72:28 mixture of the (S)/(R)-isomers. Optically pure (S)-1 (>97% ee) emanated a strong spicy note, which recalled typical axillary odors. 3-Methyl-3-sulfanylhexan-1-ol (2), the enantiomeric ratio of which equaled that of 1, was present in greater quantity than any of the other 3-sulfanylalkanols. Optically pure (S)-2 (>97% ee) had a strong meaty, fruity note, also reminiscent of axillary odor. The compounds identified, in particular (S)-1 and (S)-2, contribute significantly to the olfactory impression of human axillary odor.