A New Approach to the Design of Novel Inhibitors of Na+,K+-ATPase: 17α-Substituted Seco-D 5β-Androstane as Cassaine Analogues
摘要:
A new three-dimensional model for the relative binding mode of cassaine 1 and digitoxigenin 2 at the digitalis receptor site is proposed on the basis of the structural and conformational similarities among 1, 2 and its 14,15-seco analogues 3 and 4. Accordingly, the speculation that also 17 alpha-substituted derivatives of the digitalis 5 beta,14 beta-androstane skeleton could efficiently bind to the Na+,K+-ATPase receptor is put forward and verified through the synthesis of some related compounds. The binding affinity shown by 2-(N,N-dimethylamino)ethyl 3 beta,14-dihydroxy-5 beta,14 beta-androstane-17 alpha-acrylate 6 (IC50 = 5.89 mu M) and, much more significantly, by the corresponding 14,15-seco-14-oxo derivative 9 (IC50 = 0.12 mu M) substantiates the new hypothesis and opens new prospects to the design of novel inhibitors of Na+,K+-ATPase as potential positive inotropic compounds.
A New Approach to the Design of Novel Inhibitors of Na+,K+-ATPase: 17α-Substituted Seco-D 5β-Androstane as Cassaine Analogues
摘要:
A new three-dimensional model for the relative binding mode of cassaine 1 and digitoxigenin 2 at the digitalis receptor site is proposed on the basis of the structural and conformational similarities among 1, 2 and its 14,15-seco analogues 3 and 4. Accordingly, the speculation that also 17 alpha-substituted derivatives of the digitalis 5 beta,14 beta-androstane skeleton could efficiently bind to the Na+,K+-ATPase receptor is put forward and verified through the synthesis of some related compounds. The binding affinity shown by 2-(N,N-dimethylamino)ethyl 3 beta,14-dihydroxy-5 beta,14 beta-androstane-17 alpha-acrylate 6 (IC50 = 5.89 mu M) and, much more significantly, by the corresponding 14,15-seco-14-oxo derivative 9 (IC50 = 0.12 mu M) substantiates the new hypothesis and opens new prospects to the design of novel inhibitors of Na+,K+-ATPase as potential positive inotropic compounds.
New seco-D steroid derivatives, processes for their preparation and pharmaceutical compositions are provided, which are active on the cardiovascular system. The seco-D steroid derivatives have the following general formula (I): ##STR1##