Mallet A I, Holland K T, Rennie P J, Watkins W J, Gower D B
Institute of Dermatology, U.M.D.S. Guy's Hospital, University of London, U.K.
J Chromatogr. 1991 Jan 2;562(1-2):647-58. doi: 10.1016/0378-4347(91)80615-j.
The known involvement of axillary microflora with under-arm odour (UAO) production led us to determine whether the odorous 16-androstene steroids are formed in the axilla by bacterial metabolism of an odourless precursor such as testosterone. Axillary bacteria from 34 men were selectively cultured for aerobic coryneform bacteria (ACB), Micrococcaceae and propionibacteria. Overnight suspensions of bacteria were incubated separately at 37 degrees C for two weeks with radiolabelled testosterone plus unlabelled testosterone (0.5 mg) and 0.5-mg quantities of 4,16-androstadien-3-one (androstadienone) and 5,16-androstadien-3 beta-ol (androstadienol). After extraction and purification by Sep-Pak cartridges and thin-layer chromatography, the eluted steroids were derivatised as the pentafluorobenzyl oximes (PFBO) and tert.-butyl dimethylsilyl (TBDMS) ethers. Saturated analogues were used as internal standards. Selected-ion monitoring electron-impact mass spectrometry was performed at the m/z corresponding to the M+.ion for the PFBO derivatives and the [M - 57]+ ion for the TBDMS ethers. Only ACB produced classical musk-like UAO (UAO + ve) in an in vitro odour-producing system with 29% being UAO -ve. ACB (UAO +ve) metabolised far more (p = 0.001) testosterone than ACB (UAO -ve), the principal metabolites being 5 alpha(beta)-dihydrotestosterone, 5 alpha(beta)-androstane-3,17-dione and 4-androstene-3,17-dione (4-androstenedione). No non-polar 16-androstenes were formed. Micrococcus luteus (ten strains) metabolised testosterone to 4-androstenedione only; propionibacterium spp. did not metabolise testosterone at all. However, incubation of 16-androstenes with ACB gave evidence for 4-ene-5 alpha(beta)-reduction, 3 alpha(beta)-oxido-reduction and epimerisation. In general the direction of transformations favoured formation of the more odorous 5 alpha-androst-16-en-3-one (5 alpha-androstenone) and 5 alpha-androst-16-en-3 alpha-ol (3 alpha-androstenol) from less odorous steroids. Such transformations, in vivo, would not require de novo synthesis of 5 alpha-androstenone or 3 alpha-androstenol and would be consistent with utilisation by ACB of 16-androstenes already present in small quantities in fresh apocrine secretions, which are odourless, to produce a more powerfully smelling mixture on the axillary skin surface.
已知腋窝微生物群与腋下异味（UAO）的产生有关，这促使我们去确定有气味的16-雄烯类固醇是否是由腋窝中细菌对诸如睾酮等无气味前体的代谢形成的。从34名男性身上采集腋窝细菌，选择性培养需氧棒状杆菌（ACB）、微球菌科和丙酸杆菌。将细菌的过夜悬浮液分别在37℃下与放射性标记的睾酮加未标记的睾酮（0.5毫克）以及0.5毫克的4,16-雄二烯-3-酮（雄二烯酮）和5,16-雄二烯-3β-醇（雄二烯醇）一起孵育两周。通过Sep-Pak柱和薄层色谱法进行提取和纯化后，洗脱的类固醇被衍生化为五氟苄基肟（PFBO）和叔丁基二甲基甲硅烷基（TBDMS）醚。饱和类似物用作内标。在对应于PFBO衍生物的M +离子的m/z以及TBDMS醚的[M - 57]+离子处进行选择离子监测电子轰击质谱分析。在体外气味产生系统中，只有ACB产生典型的麝香样UAO（UAO阳性），其中29%为UAO阴性。ACB（UAO阳性）代谢的睾酮比ACB（UAO阴性）多得多（p = 0.001），主要代谢产物为5α（β）-二氢睾酮、5α（β）-雄烷-3,17-二酮和4-雄烯-3,17-二酮（4-雄烯二酮）。未形成非极性的16-雄烯类化合物。藤黄微球菌（十株）仅将睾酮代谢为4-雄烯二酮；丙酸杆菌属根本不代谢睾酮。然而，16-雄烯类化合物与ACB一起孵育提供了4-烯-5α（β）-还原、3α（β）-氧化还原和差向异构化的证据。一般来说，转化方向有利于从不太有气味的类固醇形成气味更浓的5α-雄甾-16-烯-3-酮（5α-雄烯酮）和5α-雄甾-16-烯-3α-醇（3α-雄烯醇）。在体内，这种转化不需要5α-雄烯酮或3α-雄烯醇的从头合成，并且与ACB利用新鲜顶泌汗腺分泌物中已少量存在的16-雄烯类化合物一致，这些分泌物是无气味的，从而在腋窝皮肤表面产生气味更浓烈的混合物。
