Linked Life Data

3455050

Source:http://linkedlifedata.com/resource/pubmed/id/3455050

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4-5
pubmed:dateCreated
1988-9-30
pubmed:abstractText
A number of progesterone derivatives, having a 17 alpha-acetoxy group and various functions at C-3 and C-6, interact at the cardiac glycoside (CG) binding site, using [3H]ouabain in a radioligand binding assay (RBA) with membranes from dog myocardium. We now report on results of structure-activity studies concerned with modification of the A and B rings as they influence potency in the RBA. Some progesterone derivatives with 5 alpha- or 5 beta-stereochemistry show weak receptor competing activity. Among the congeners highest potency is associated with the presence of C-4 or C-4,6 unsaturation and a C-6 substituent (CH3, Cl, Br) whose importance appears to reside in its steric rather than electronic character. The C-3 function may be carbonyl, 3 beta-hydroxy or 3 beta-acetoxy when associated with C-4 or C-4,6 unsaturation. In compounds with other substituents that promote activity, C-6 alpha substitution with -CH3, -Cl, or -Br strongly enhances activity; -F, -OCH3, carbonyl, or the unsubstituted compound promotes weak binding; and -OC2H5, -OAc, -OCOOCH3, or -OH eliminates binding activity. Receptor interaction with the double bond at C-4, but not C-5, appears to be particularly important for binding. The most potent analog identified thus far is chlormadinone acetate (17 alpha-acetoxy-6-chloropregna-4,6-diene-3,20-dione), which has 1/20 the potency of ouabain in the RBA. Studies to determine optimal structural requirements for CG-receptor binding by these hormonal steroid congeners, in conjunction with appropriate biological assays, may provide insight into the nature of a putative endogenous counterpart, lead to a better understanding of the mode of action of the CG and yield CG-like compounds with superior therapeutic properties.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0039-128X
pubmed:author
pubmed:issnType
Print
pubmed:volume
49
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
383-96
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:articleTitle
Structure-activity relationships of progesterone derivatives that bind to the digitalis receptor: modifications in A and B rings.
pubmed:affiliation
Faculty of Pharmacy, University of Manitoba, Winnipeg, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't