Review of odorants in human axillary odour and laundry malodour: The importance of branched C7 chain analogues in malodours perceived by humans†

In our daily lives we are confronted with various kinds of malodour problems. Detailed analysis at the molecular level of the malodorous constituents with gas chromatography–mass spectrometry and gas chromatography–olfactometry can be used to identify the key chemicals responsible for the malodours, and such information can provide novel starting points for the development of new deodorants. This paper describes two characteristic sources of malodour in daily life: axillary and laundry malodour. Detailed analytical studies identified specific major contributors to these malodours: 3-hydroxy-3-methylhexanoic acid, 3-mercapto-3-methylhexan-1-ol and 4-methyl-3-hexenoic acid. Biochemical and microbiological studies then elucidated the mechanisms generating these odours and proved the involvement of microbes in odour formation. In this review, we discuss the importance of the branched C7 chain, which is common to all the major volatile substances identified in these studies and perceived by the human nose with an extraordinary sensitivity. Copyright © 2012 John Wiley & Sons, Ltd.