system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Androgenic activity of the 19 noestosterone nucleus is decreased by ?
assistant
The correct answer is  Ans. is 'b' i.e., Removal of methyl group at C 19Substitution of a 7a-methyl group in 17b-hydroxyestr-4-en-3-one (19-noestosterone) or its 17a-methyl derivative enhanced the androgenic activities of the parent compounds as well as their ability to bind to b protein and to prostate cell nuclei. Thus, 7a, 17a-dimethyl-19-noestosterone had an apparent affinity for bprotein several times higher than that of 5a-dihydrotestosterone.