A new antimetabolite, 5-morpholinomethyl-2-thiouracil - spectral properties, thermal profiles, antibacterial, antifungal and antitumour studies of some of its metal chelates

A new antimetabolite of thymine, 5-morpholinomethyl-2-thiouracil (MMTU) has been synthesized via the Mannich reaction of 2-thiouracil, formaldehyde and morpholine. The product was chemically and structurally characterized using various techniques ranging from microelemental analysis to XRD studies. About thirteen metal ion complexes of MMTU have been isolated and were found to exhibit five different types of bonding pattern such as unidentate dimeric, bidentate, bidentate binuclear, tridentate binuclear and tetradentate binuclear. To gain theoretical support for the experimental findings regarding the donor atoms proposed based on spectral studies of the complexes semiempirical quantum mechanical calculations were carried out using MOPAC. The anomalous behaviour exhibited by a few complexes was explained based on steric constraint and stabilization energy gain upon six membered chelate formation. Thermodynamic and kinetic parameters were evaluated. Antimicrobial, antifungal and antitumour studies have also been carried out. Structure, thermal stability and biological activity of the complexes have been correlated.