374 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS may add considerable efficacy to the fragrance by blocking the perception of a major component in the mixture of axillary odors (19). Further, lockerroom odors are also thought to be a mixture of axillary and other body odors, such as those from the feet and the genital area, which also contain volatile organic acids as important contributing malodors (20-22). Consequently, the data provided here suggest a general strategy for identifying compounds that can be used to reduce the perception of malodors. This strategy could consist of identifying the principle volatile constituents and synthesizing (or purchasing) a structurally similar, albeit pleasant smelling, compound. For odors whose principle notes consist of organic acids, the ethyl esters we have discussed here, as well as the ethyl esters of the higher and lower homologues of 3M2H described in our previous study (10), provide ideal candidates for use in cross-adaptation paradigms to suppress the perception of volatile C4-C1• organic acids. Acids with these carbon chain lengths are generally found to be associated with both body odors and bacterially mediated odors (23). ACKNOWLEDGMENTS The present research was supported by NRSA grant DC00080 to J.D.P., NIH grant DC00298 to C.J.W. and NIH grant DC-01072 to G.P., and by institutional support to E.V.A. REFERENCES (1) T. Engen, The Perception of Odors (Academic Press, New York, 1982). (2) R. W. Moncrieff, Olfactory adaptation and odour likeness, J. Physiol., 133, 301-316 (1956). (3) J. D. Pierce, Jr., C.J. Wysocki, and E. V. Aronov, Mutual cross-adaptation of the volatile steroid androstenone and a non-steroid perceptual analog, Chem. Senses, 18, 245-256 (1993). (4) J. Todrank, C.J. Wysocki, and G. K. Beauchamp, The effects of adaptation on the perception of similar and dissimilar odors, Chem. Senses, 16, 467-482 (1991). (5) W. S. Cain and E. H. Polak, Olfactory adaptation as an aspect of odor similarity, Chem. Senses, 17, 481-491 (1992). (6) W. S. Cain, Odor intensity after self-adaptation and cross-adaptation, Percept. Psychophys., 7, 271-275 (1970). (7) W. S. Cain and T. Engen, "Olfactory Adaptation and the Scaling of Odor Intensity," in Olfaction and Taste, C. Pfaffman, Ed. (Rockefeller University Press, New York, 1969), pp. 127-141. (8) T. Engen and C. O. Lindstrom, Cross-adaptation to the aliphatic alcohols, Amer. J. Psychol., 76, 96-102 (1963). (9) J. D. Pierce, Jr., C.J. Wysocki, E. V. Aronov, J. B. Webb, and R. M. Boden, The role of perceptual and structural similarity on cross-adaptation, Chem. Senses, 21, 223-237 (1996). (10) J. D. Pierce, Jr., X.-N., Zeng, E. V. Aronov, G. Preti, and C. J. Wysocki, Cross-adaptation of sweaty- smelling 3-methyl-2-hexenoic acid by a structurally-similar, pleasant-smelling odorant, Chem. Senses, 20, 401-411 (1995). (11) X-N. Zeng, J. J. Leyden, H. J. Lawley, K. Sawano, I. Nohara, and G. Preti, Analysis of characteristic odors from human male axillae, J. Chem. Ecol., 17, 1469-1492 (1991). (12) X-N. Zeng, J. J. Leyden, J. G. Brand, A. I. Spielman, K. J. McGinley, and G. Preti, An investigation of human apocrine gland secretion for axillary odor precursors,J. Chem. EcoL, 18, 1039-1055 (1992). (13) W. B. Cutler, G. Preti, A. Krieger, G. R. Huggins, C. R. Garcia, and H. J. Lawley, Human axillary secretions influence women's menstrual cycles: The role of donor extract from men, Horm. Behav., 20, 463-473 (1986). (14) G. Preti, W. B. Cutler, C. R. Garcia, G. R. Huggins, and H.J. Lawley, Human axillary secretions

CROSS-ADAPTATION BY STRUCTURAL ANALOGS 375 influence women's menstrual cycles: The role of donor extract of females, Horm. Behav., 20, 474-482 (1986). (15) A. Ramirez, The success of sweet smell, The New York Times (August 12, 1990). (16) X-N. Zeng, J. J. Leyden, A. I. Spielman, and G. Preti, Analysis of the characteristic human female axillary odors: Qualitative comparison to males, J. Chem. Eco/., 22, 237-257 (1996). (17) A. E. Baydar, M. Petrzilka, and M-P. Schott, Perception of characteristic axillary odors, Perf Flay., 17, 2-9 (1992). (18) C.J. Wysocki, X-N. Zeng, and G. Preti, Specific anosmia and olfactory sensitivity to 3-methyl-2- hexenoic acid: A major component of human axillary odor, Chem. Senses, 18, 652-653 (1993). (19) G. Preti, J. D. Pierce, Jr., X.-N. Zeng, and C. J. Wysocki, U.S. Patent 5,538, 7•9. Method for reducing perception of human underarm odor by a pleasant smelling compound. (20) F. Kanda, E. Yagi, M. Fukuda, K. Nakajima, T. Ohta, and O. Nakata, Elucidation of chemical compounds responsible for foot malodour, Br. J. DermatoL, 122, 771-776 (1990). (21) G. R. Huggins and G. Preti, Vaginal odors and secretions, C/in. Obstet. GynecoL, 24, 355-377 (1981). (22) G. Preti and G. R. Huggins, Cyclic changes in volatile acidic metabolites of human vaginal secretions and their relation to ovulation, J. Chem. EcoL, 1, 361-376 (1975). (23) J.N. Labows and G. Preti, "Human Semiochemicals" in Fragrance: The Psychology and Biology of Perfume, S. van Toiler and G. H. Dodd, Eds. (Elsevier Applied Science Publications, London, 1992), pp. 69-90.