Characteristic spectral studies, and antimicrobial and anti-inflammatory activities of diorganotin(IV) derivatives of dipeptides

New diorganotin(IV) complexes of general formula R2SnL (R = n-Bu and Ph, an d L = dianion of alanylphenylalanine (H2L-1), phenylalanylleucine (H2L-2), phenylalanylphenylalanine (H2L-3), glycylleucine (H2L-4) and glycylisoleuci ne (H2L-5) have been prepared and characterised by elemental analyses, mola r conductance, and the bonding in these complexes is discussed in terms of their IR, far-IR, H-1-, C-13- and Sn-117-NMR, and Sn-119 Mossbauer spectral studies. The monomeric 1:1 complexes have distorted trigonal bipyramidal s tructure with cia-equatorial organic groups. The complexes, soluble in DMSO , have been screened against a wide spectrum of bacteria (Escherichia coli, Rhizobium meliloti, Pseudomonas putida and Aeromonas formicans) and fungi (Aspergillus niger, Pencillium chrysogenum, Aureobasidium pullulans and Ver ticillium dahliae) and are found to be active. The LD50 values (> 500 mg kg (-1)) have also been determined in the albino rats. Some of the complexes a lso exhibit very high anti-inflammatory activity. (C) 1999 Elsevier Science S.A. All rights reserved.