Analysis of characteristic human female axillary odors: Qualitative comparison to males

Abstract

Odors produced in the human female axillae are of both biological and commercial importance. Several studies have suggested that extracts from female underarm secretions can alter the length and timing of the female menstrual cycle. In addition, more than 1.6 billion dollars are spent annually on products to eliminate or mask the axillary odors. Our recent studies have determined that the characteristic axillary odors in males consist of C6-C11, saturated, unsaturated and branched acids, with (E)-3-methyl-2-hexenoic acid (3M2H) being the major compound in this mixture. The 3M2H appears to be carried to the skin surface bound to two proteins in the axillary secretions. Data reported here show that the same mixture of odorous compounds is found in female axillary secretions, with several minor qualitative differences. Separation of the female apocrine secretions into aqueous and organic soluble fractions demonstrated that 3M2H, and several other members of the acids in the characteristic odor, are released by hydrolysis with base. Electrophoretic separation of the proteins found in the aqueous phase of female apocrine secretions revealed a pattern identical to that seen in males. The qualitative similarity of the acidic constituents making up the characteristic axillary odors of both females and males as well as the proteins present in the aqueous phase suggest a similar origin for axillary odors in both sexes.

A human axillary odorant is carried by apolipoprotein D.

“…To complete the experiments described below, a total of eight separate collections of apocrine secretions were made from 47 different subjects over a period of 2 years. As previously described (13,14), the volume from any given subject ranged from a trace to -50 ,u.…”

“…However, recent studies (12, 13) have presented both organoleptic and analytical evidence that a mixture of C6-C11, straight-chain, branched, and unsaturated acids constitute the characteristic axillary odor. In combined male samples, the E-isomer of 3-methyl-2-hexenoic acid (3M2H) is the dominant analytical component of the mixture, while in combined female samples the straight-chain acids are present in greater relative abundance (14). The Z-isomer is also present in both genders, however in different relative abundance: 10:1 (E/Z) in males (12) and 16:1 (E/Z) in females (14).…”

Facts, fallacies, fears, and frustrations with human pheromones

“…The precursors to axillary odor reside in the apocrine glands (Labows et al, 1982;Zeng et al, 1992Zeng et al, , 1996aZeng et al, , 1996b. The characteristic axillary odor is formed from the interaction of odorless (water-soluble) precursor molecules found in apocrine secretion with the cutaneous axillary microorganisms (Labows et al, 1982;Zeng et al, 1992).…”

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].…”