Silver derivatives of multi-donor heterocyclic thioamides as antimicrobial/anticancer agents: unusual bio-activity against methicillin resistant , , and and human bone cancer cell line.

The basic aim of this study pertains to the synthesis of silver nitrate complexes and the study of their antimicrobial and anticancer bio-activity. A series of new silver(i) derivatives of -substituted-imidazolidine-2-thiones (L-NR, R = Et, Pr , Bu , Ph), purine-6-thione (purSH), 2-thiouracil (tucH), pyrimidine-2-thione (pymSH) and pyridine-2-thione (pySH) of composition [Ag(S-L-NR)(PPh)(ONO)] {R = Et (1), Pr (2), Bu (3), Ph (4)}, Ag(N,S-purSH)(μ-dppm)·2HO (5) (dppm = PhP-CH-PPh), Ag(L)(PPh) {L = N,S-purSH (6); S-tucH (7)}, Ag(N,S-pymS)(PPh) (8), and [Ag(N,S-pyS)(PPh)] (9) have been synthesized and structurally characterized. These new and some previously reported complexes {Ag(L-NH)(PPh) (10), Ag(L-NMe)(PPh) (11), and Ag(S-bzimSH)(PPh) (12), L-NH = 1,3-imidazolidine-2-thione; L-NMe = 1-methyl-3-imidazolidine-2-thione and bzimSH = benzimidazoline-2-thione)} have shown moderate to high anti-microbial activity against Gram positive bacteria, namely methicillin resistant (MRSA) and (MTCC 740), and Gram negative bacteria, namely (MTCC 435), (MTCC 439), (MTCC 1457) and a yeast (MTCC 22). These complexes have also been found to be bio-safe as studied using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. The anti-tumor study of silver complexes against human osteosarcoma cell line (MG63) has shown IC values in the range of 6-33 μM.