466 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS the non-availability of a reference sample. There was no spot corresponding to the reference sample of androst-4-ene-$:17-dione, possibly because the conversion to testosterone occurs rapidly. Desoxycorticosterone The presence of androst-4-ene-$:17-dione, testosterone and testosterone acetate was demonstrated. Once again it was not possible to demonstrate the presence of testololactone. Hydrocortisone The presence of androst-4-ene-ll[t-ol-3:17-dione was demonstrated and from2the size and intensity of the spot, its concentration increased steadily with time. No other steroid metabolites were detected. DISCUSSION It was clearly demonstrated that Cladosporium herbarum metabolises steroids in a similar manner to C. resinae. The degradation of desoxy- corticosterone followed an identical pathway to that of progesterone and therefore the nature of the C •7 side chain would appear to be unimportant. The degradation of hydrocortisone did not proceed beyond the point of formation of androst-4-ene-ll[i-ol-$:17-dione. The only difference between the systems, apart from the C•7 side chains, is the presence of an lilt- hydroxyl group in hydrocortisone and androst-4-ene-ll[t-ol-$:17-dione. Hence it is possible that the presence of the 1111-hydroxyl group blocks the formation of 111t-hydroxy-testosterone which would be found in theory. Using the experimental technique described it is possible to detect degradation products in micro-quantities. It is possible that the technique can be directly applied to pharmaceutical and cosmetic emulsions. Explora- tory work in this direction has been encouraging. The type of degradation observed in investigations reported could well occur in cosmetic prepara- tions, and this technique can be used to assist in rapidly determining the nature of the substrate and the chemical pathway of the degradation. From this information it may then be possible to introduce a suitable blocking agent into the formula or to eliminate the substrate. The main drawback in establishing the details of the chemical pathway is that the method relies on the availability of reference samples.

THE METABOLISM OF STEROIDS BY CLADOSPORIUM HERB.4RUM 467 It is possible to evaluate the efficiency of preservatives by using nutrient medium seeded with the susceptible material and the preservative, or as our present studies tend to indicate, by direct examination of the cream seeded with vegetative organism. In a parallel study to the steroids, for instance, we were able to confirm the ineffectiveness of the hydroxy- benzoates used and demonstrate that these too were utilised as a substrate. (Received: 8th September 1967) REFERENCES (1) Private communication from Commonwealth Mycological Institute. (2) Fonken, G. S., Murray, H. C. and Reineke, L. M. J. Am. Chem. Soc. 82 5507 (1960). (3) Peterson, D. H., Eppstein, S. H., Meister, P. D., Murray, H. C., Leigh, H. M., Weintraub, A., and Reineke, L. M. J. Am. Chem. Soc. 75 5768 (1953). (4) U.S. Pat. 2,967,803. (5) U.S. Pat. 2,768,928. (6) U.S. Pat. 2,602,769.