New Miner aloe orticoids: 5α -Dihydroaldosterone and 5α-Dihydro-11-Deoxycorticosterone*

Abstract

Mineralocorticoid activity of several .DELTA.4-3-ketosteroids and their 5.alpha.-dihydro analogs were evaluated by bioassay using urinary Na:K ratio of adrenalectomized rats as an index of mineralocorticoid activity. Among .DELTA.4-3-ketosteroids, aldosterone, 11-deoxycorticosterone, corticosterone, cortisol, 11-dehydrocorticosterone and cortisone showed mineralocorticoid activity with aldosterone, the most potent of the series, showing virtually maximum activity at a dose of 0.25 .mu.g/rat. 5.alpha.-Dihydroaldosterone and 5.alpha.-dihydro-11-deoxycorticosterone possessed distinct mineralocorticoid activity, although less than aldosterone and 11-deoxycorticosterone. 5.alpha.-Dihydrocorticosterone, 5.alpha.-dihydrocortisol, 5.alpha.-dihydro-11-dehydrocorticosterone and 5.alpha.-dihydrocortisone did not show mineralocorticoid activity in doses up to 100 .mu.g/rat. Reduction of the 4,5 double bond diminishes mineralocorticoid activity of .DELTA.4-3-ketosteroids. 5.alpha.-Dihydroaldosterone has distinct mineralocorticoid activity with potency of 1.8% of that of aldosterone and approximately the same as that of 11-deoxycorticosterone.