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j. Soc. Cosmet. Chem., 44, 211-220 (July/August 1993) Growth inhibition of coryneform bacteria by a mixture of three natural products Farnesol, glyceryl monolaurate, and phenoxyethanol' HGQ U.-F. HAUSTEIN, J. HERRMANN, U. HOPPE, W. ENGEL, and G. SAUERMANN, Department of Skin Diseases, University of Leipzig (U.-F. H., J. H. ), and the Paul Gerson Unna Research Center, Beiersdorf AG, Hamburg (U. H., W. E,, G. S.), Germany. Received January 11, 1993. Synopsis Axillary realodor is produced by secretions of the apocrine sweat glands that are contaminated by coryne- form bacteria. One of the mechanisms of deodorant action is to inhibit bacterial growth. This investigation was designed to study the bactericidal effect of the mixture of three natural products, HGQ,* on wild strains of axillary coryneform bacteria. Thirty corynebacteria species could be isolated and identified biochemically from 530 underarm swabs. Their sensitivity to the HGQ mixture was determined by means of the minimum bactericidal concentration. It ranged from 0.025% to 1% HGQ. 47% of the strains were inhibited by less than 0.1% HGQ, 30% by less than 0.3%, and 23% by less than 1.0% HGQ. The sensitivity to HGQ did not correlate with specific corynebacteria strains but with the survival time of the strains, i.e., the most sensitive strains had the shortest survival times at 4øC, both on blood agar and in the stab culture. Our studies show that HGQ, a mixture composed of three products occurring in plant or animal species, farnesot, gtyceryl monolaurate, and phenoxyethanol, kills corynebacteria and that it can be recommended for use as an effective deodorant, as has already been confirmed by its successful use in practice. HGQ and its components are biologically degradable to more than 60% within 28 days. Only CO 2 and H20 are formed, since there is no nitrogen contained in HGQ. Furthermore, this finding indicates that although the synergistically acting HGQ mixture has a selective bactericidal effect, it is degraded naturally after use, which is not true of the first generation of deodorants. INTRODUCTION The underarms play an important role in the generation of body odor. Odor is generated here from secretions of the apocrine sweat glands, which are primarily contaminated by coryneform bacteria (20). C3-fatty acids, (iso)butyric acid, isovaleric acid, and androgen steroids such as I6, 5-0-androsten-3•-ol and 16,5-0-androsten-3-1 have been identified as the odorous substances. The latter are excreted in odorless axillary sweat as water- * Farnesot Plus ©, Dragoco Gerberding & Co. GmbH, D-3450 Holzminden, Germany. 211