Syntheses, characterization and biological activity of diorganotin(IV) derivatives of 2-amino-6-hydroxypurine (guanine)

Novel organotin(IV) derivatives of guanine of the general formula, R2Sn(HGu)2 (where, R = Me (1), n-Bu (2) and Ph (3)) have been synthesized by the reaction of R2SnCl2 with sodium salt of guanine (H2Gu or 2-amino-6-hydroxypurine). The IR spectral studies suggest that guanine acts as a monobasic ligand coordinating through N(9) after its deprotonation. The weak bonding through C(6)double bond; length as m-dashO may also be evidenced, whereas 119Sn Mössbauer data suggest that the coordination number of tin is superior than four. The polyhedron around tin in R2Sn(HGu)2 is distorted trigonal–bipyramidal or pseudo-tetrahedral involving very weak interaction from Cdouble bond; length as m-dashO group of neighboring molecule leading to polymerized structure. All the compounds exhibited potent anti-inflammatory activity with no appreciable side effects on blood pressure as evidenced by their very mild cardiovascular activity.