Synthesis and structure-activity relationships of 14 beta-hydroxy-5 alpha-pregnanes: pregnanes that bind to the cardiac glycoside receptor

Identification and characterization of novel sodium/potassium-ATPase inhibitors by virtual screening of a compound database

The medicinal value of cardiac glycoside inhibitors for the treatment of congestive heart failure symptoms stems from their ability to specifically inhibit the ion transport activity of the transmembrane enzyme sodium/potassium-ATPase (Na/K-ATPase) in myocardial cells. In this study, we used the inhibitory potencies of 39 cardiac glycoside analogues for the development of a quantitative structure-activity relationship (QSAR) model for Na/K-ATPase inhibition. In conjunction with a substructure and similarity search, the QSAR model was used to select ten potential inhibitors from a commercial compound database. The inhibitory potencies of these compounds were measured and four were found to be more active than the commonly used inhibitor ouabain. The results of the bioassays were incorporated into a second QSAR model, whose physical interpretation suggested that the nature of substituents in positions 10, 12, and 17 at the cyclopentanoperhydrophenanthrene core of the inhibitors was critical for enzyme inhibition. All descriptors of the QSAR models were conformation-independent, making the search protocol a suitable tool for the rapid virtual screening of large compound databases for novel inhibitors.

Expeditious and convenient synthesis of pregnanes and its glycosides as potential anti-dyslipidemic and anti-oxidant agents

A series of new pregnane derivatives and its glycosides were synthesized in order to find new 'leads' against some important targets. The 3beta-hydroxy-16alpha-(2-hydroxy ethoxy) pregn-5-en-20-one (5) was synthesized from 3beta-hydroxy-5,16-pregnadiene-20-one (2) by adopting general modified procedure using BF(3):Et(2)O as a catalyst. Reduction of 5, with sodium borohydride yielded 3beta,20beta-dihydroxy-16alpha-(2-hydroxy ethoxy) pregn-5-en (7) as the major isolable product. O-alkylation of the C-20-oxime-pregnadiene (9) with 1,5-dibromopentane yielded 20-(O-5-bromopentyl)-oximino-3beta-hydroxy-pregn-5,16-diene (11). Synthesis of C-16 substituted pregnane glycosides (20) and (21) were accomplished with the imidate method using BF(3):Et(2)O. The synthesis of 4-chlorobenzoate (3) and 2-chlorobenzoate (4), derivatives of 2 were also accomplished. These compounds were evaluated for their anti-dyslipidemic and anti-oxidant activity and amongst them compounds 3 and 7 showed more lipid lowering and anti-oxidant activity.

The reaction of digitoxin and digoxin with cyanoacetic acid hydrazide: synthesis of coumarin, thiazole, thiophene and pyridine derivatives with potential biological activities

The reaction of either Digitoxin or Digoxin with cyanoacetic acid hydrazide gave the hydrazone derivatives 3a and 3b respectively. The reactivity of the latter products towards chemical reagents was studied to give heterocyclic derivatives with potential biological activities.