کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1327467 | 977484 | 2005 | 5 صفحه PDF | دانلود رایگان |
The synthesis of 2-(2-mercaptoethylamino)ethylidene–1,1-bisphosphonic acid (2) is reported (overall yield >90%), via nucleophilic addition of cystamine to vinylidene–bisphosphonic acid (1) followed by reduction of disulfide bonds with Me3P. Reaction of 1 with cysteamine forms the isomeric 2-(2-aminoethylthio)ethylidene–1,1-bisphosphonate (3) in an almost quantitative yield. Thiol groups of 2 in water at pH 7 react with epoxy rings more than 30 times faster compared to the known 2-mercaptoethylidene–1,1-bisphosphonate. Elimination of the thiol group is observed as a side-reaction in the reduction of disulfides with phosphines. Stabilization of bioprosthetic tissues with triglycidylamine in the presence of 2 results in covalent immobilization of 2 via an epoxy-SH reaction; this inhibits the long-term calcification of bioprosthetic heart valve tissues to almost undetectable levels.
Nucleophilic addition of cystamine to vinylidene-bisphosphonic acid followed by reduction of disulfide bonds with Me3P gives HSCH2CH2NHCH2(PO3H2)2 (2) in a high yield. Bioprosthetic tissues stabilized with triglycidylamine in the presence of 2 demonstrate an almost complete inhibition of long-term in vivo calcification.Figure optionsDownload as PowerPoint slide
Journal: Journal of Organometallic Chemistry - Volume 690, Issue 10, 16 May 2005, Pages 2543–2547