Analysis of characteristic odors from human male axillae

Abstract

A number of studies concerning the analysis of axillary odors have assumed that the characteristic odor produced in the axillae is due to volatile steroids and isovaleric acid. Organoleptic evaluation of Chromatographic eluants from axillary extracts was employed to isolate the region in the chromatogram where the characteristic odor eluted. The odor of the dissolved eluant was eliminated when it was treated with base, suggesting that acids make up the characteristic axillary odor. Subsequent extraction of the pH-adjusted axillary extract in conjunction with organoleptic evaluation of the Chromatographic eluant, preparative gas chromatography, and analysis by GC-MS as well as GC-FTIR showed the presence of a number of C6 to C11 straight-chain, branched, and unsaturated acids as important contributors to the axillary odor. The major odor component is (E)-3-methyl-2-hexenoic acid. Three homologous series of minor components are also important odor contributors; these consist of the terminally unsaturated acids, the 2-methyl-C6 to -C10 acids and the 4-ethyl-C5 to -C11 acids. These types of acids have not been reported previously as components of the human axillary secretions and have not been proposed previously as part of the principal odor components in this area.

Body odour of monozygotic human twins: a common pattern of odorant carboxylic acids released by a bacterial aminoacylase from axilla secretions contributing to an inherited body odour type

“…Here, we used a much more focused approach, which is specifically directed towards known odorant volatiles and a known biochemical mechanism of odour release (Zeng et al 1991;Natsch et al 2003Natsch et al , 2006. Most of the background contaminants in the odourless fresh sweat were first eliminated by a solvent extraction step.…”

“…In total, the list of these analytes comprised 35 compounds. Many of them had been found before (Zeng et al 1991;Natsch et al 2006) and their odour had been characterized (Zeng et al 1991;Natsch et al 2003Natsch et al , 2006Hasegawa et al 2004). They primarily comprised methyl esters of series of methylbranched, unsaturated or hydroxylated acids.…”

Facts, fallacies, fears, and frustrations with human pheromones

“…The details of the chemical identification, exact structures, and synthesis (of noncommercially available compounds) have been described (Zeng et al, 1991(Zeng et al, , 1992. In terms of relative abundance, these acids, in particular (E)-3-methyl-2-hexenoic (E-3M2H), are present in far greater quantity than volatile steroids, e.g., androstenone, which were previously thought to be important axillary odors (Gower and Ruparelia, 1993).…”

High throughput volatile fatty acid skin metabolite profiling by thermal desorption secondary electrospray ionisation mass spectrometry

“…Individual skin profiles have been developed as 'barcodes' of scent for forensic [21] and diagnostic application [22], and gender and age specific signatures have been proposed as contributing factors to an individual's profile [23][24][25][26]. Olfactory analysis, either in-vivo or by organoleptic analysis of chromatographic eluents [27], combined with analytical measurement have established levels of odour to correlate with VSCs and VFAs, with 3-methyl-2-hexenoic acid cited as a critical molecular factor [26][27][28]. Finally, the quantity of anecdotal evidence of canine olfaction of disease, increasingly supported by scientific studies [29][30][31][32], reinforces the proposition of non-invasive skin VOC profiling for diagnosis and condition monitoring.…”