👤 Sachin Dhanani

We report the synthesis and biochemical evaluation of a number of 4-hydroxyphenyl ketones as potential inhibitors of the enzyme 17beta-hydroxysteroid dehydrogenase (17beta-HSD). In particular, we evaluated compounds against the catalysis of the conversion of androstenedione (AD) to testosterone (T) [17beta-HSD type 3 (17beta-HSD3)], furthermore, in an effort to determine the specificity of our compounds, we evaluated the ability of the compounds to inhibit the catalysis of the conversion of estrone (E1) to estradiol (E2) [17beta-HSD type 1 (17beta-HSD1)] as well as the conversion of dehydroepiandrosterone (DHEA) to AD [by 3beta-hydroxysteroid dehydrogenase (3beta-HSD)]. The results of our study suggest that the synthesised compounds are, in general, able to inhibit 17beta-HSD3 whilst being weak inhibitors of 17beta-HSD1. Against 3beta-HSD, we discovered that all of the synthesised compounds were weak inhibitors (all were found to possess less than 50% inhibition at [I]=500 microM). More specifically, we discovered that 1-(4-hydroxy-phenyl)-nonan-1-one (15) was the most potent against 17beta-HSD3 (IC(50)=2.9 microM) whilst possessing poor inhibitory activity against 17beta-HSD1 ( approximately 36% inhibitory activity against this reaction at [I]=100 microM) and less than 10% inhibition for the conversion of DHEA to AD. We have therefore provided good lead compounds in the design and synthesis of novel non-steroidal inhibitors of 17beta-HSD3. Show less

The cytochrome P450 enzyme, 17alpha-hydroxylase/17,20-lyase (P450(17alpha)), is a potential target in hormone-dependent cancers. We report the synthesis, biochemical evaluation and rationalisation of the inhibitory activity of a number of azole-based compounds as inhibitors of the two components of P450(17alpha), i.e., 17alpha-hydroxylase (17alpha-OHase) and 17,20-lyase (lyase). The results suggest that the imidazole-based compounds are highly potent inhibitors of both components, with N-7-phenyl heptyl imidazole (21) (IC(50)=0.32 microM against 17alpha-OHase and IC(50)=0.10 microM against lyase) and N-8-phenyl octyl imidazole (23) (IC(50)=0.25 microM against 17alpha-OHase and IC(50)=0.21 microM against lyase) being the two most potent compounds within the current study, in comparison to ketoconazole (KTZ) (IC(50)=3.76 microM against 17alpha-OHase and IC(50)=1.66 microM against lyase). Furthermore, consideration of the inhibitory activity against the two components show that the compounds tested are less potent towards the 17alpha-OHase component, a desirable property in the development of novel inhibitors of P450(17alpha). Structure-activity relationship determination of the range of compounds synthesised suggests that logP (log of the partition coefficient) is a key physicochemical factor in determining the overall inhibitory activity. In an effort to determine the viability of these compounds becoming potential drug candidates as well as to show specificity of these compounds, we undertook the biochemical evaluation of the synthesised compounds against two isozymes of 17beta-hydroxysteroid dehydrogenase [namely type 1 (17beta-HSD1) and type 3 (17beta-HSD3)] and 3beta-hydroxysteroid dehydrogenase (3beta-HSD). Consideration of the inhibitory activity possessed by the compounds considered within the current study against 3beta-HSD, 17beta-HSD1 and 17beta-HSD3 shows that there is no clear structure-activity relationship and that the compounds appear to possess similar inhibitory activity against both 3beta-HSD and 17beta-HSD3 whilst against 17beta-HSD1, the compounds appear to possess poor inhibitory activity at [I]=100 microM. Indeed, two of the most potent inhibitors of P450(17alpha), (compounds 21 and 23), were found to possess relatively good levels of inhibition against the three enzymes-compound 21 was found to possess approximately 32%, approximately 21% and approximately 37% inhibition whilst compound 23 was found to possess approximately 38%, approximately 30% and approximately 28% inhibition against 3beta-HSD, 17beta-HSD1 and 17beta-HSD3 respectively. We therefore concluded that the azole-based compounds synthesised within the current study are not suitable for further consideration as potential drug candidates due to their lack of specificity. Show less

We report the preliminary results of the synthesis and biochemical evaluation of a number of 4-hydroxyphenyl ketones as inhibitors of the isozyme of the enzyme 17beta-hydroxysteroid dehydrogenase (17beta-HSD) responsible for the conversion of androstenedione (AD) to testosterone (T), more specifically type 3 (17beta-HSD3). The results of our study suggest that we have synthesised compounds which are, in general, potent inhibitors of 17beta-HSD3, in particular, we discovered that 1-(4-hydroxy-phenyl)-nonan-1-one (8) was the most potent (IC(50) = 2.86 +/- 0.03 microM). We have therefore provided good lead compounds in the synthesis of novel non-steroidal inhibitors of 17beta-HSD3. Show less