Diorganotin(IV) Derivatives of Dipeptides Containing at Least One Essential Amino Acid Residue: Synthesis, Characteristic Spectral Data, Cardiovascular, and Anti‐inflammatory Activities

Abstract

New diphenyltin(IV) derivatives of the formula Ph2SnL, where L is the dianion of glycyltryptophan (Gly‐Trp), glycylphenylalanine (Gly‐Phe), valylvaline (Val‐Val), alanylvaline (Ala‐Val), and leucylalanine (Leu‐Ala), have been synthesized by the reaction of Ph2SnCl2 and the disodium salt of the respective dipeptides. The bonding and coordination behaviour in these derivatives are discussed on the basis of IR, multinuclear 1H, 13C, and 119Sn NMR and 119Sn Mössbauer spectroscopic studies. These investigations suggest that all the dipeptides in Ph2SnL act as dianionic tridentate ligands coordinating through the COO−, NH2, and Npeptide groups. The 119Sn Mössbauer studies, together with the NMR data, suggest a trigonal‐bipyramidal geometry around tin in Ph2SnL with the phenyl groups and Npeptide in the equatorial positions, whereas a carboxylic oxygen and the amino nitrogen atom occupy the axial positions. The anti‐inflammatory and cardiovascular activities, and toxicity of all the synthesized diphenyltin(IV) derivatives of dipeptides and of n‐dibutyltin(IV) derivatives of dipeptides (synthesized and characterized earlier) viz. Gly‐Trp, Val‐Val, Ala‐Val, glycyltyrosine (Gly‐Tyr), leucyltyrosine (Leu‐Tyr), and leucylleucine (Leu‐Leu) are discussed. The n‐dibutyltin(IV) derivatives exhibit better cardiovascular and anti‐inflammatory activities than the diphenyltin(IV) analogues.