Interaction of organotin(IV) moieties with nucleic acid constituent: Synthesis, structural characterization and anti-inflammatory activity of tri-i-propyltin(IV) and diorganotin(IV) derivatives of guanosine

Tri-i-propyltin(IV) and diorganotin(IV) derivatives of guanosine of the general formulae, i-Pr3Sn(HGuO).H2O and [R2Sn(O)(HGuO).H2O]n, where R = Me, n-Oct and Ph; H2GuO = Guanosine, have been synthesized by either sodium salt or azeotropic removal of water method. The bonding and coordination behavior in these derivatives are discussed on the basis of FT-IR, multinuclear 1H, 13C and 119Sn NMR and 119Sn Mössbauer spectroscopic studies. These investigations suggest that guanosine acts as monoanionic monodentate coordinating through O-2′ of the ribofuranose group. Diorganotin(IV) derivatives of guanosine have a polymeric structure with Snsingle bondOsingle bondSn bridges and cis-disposition of the organic groups in a distorted trigonal-bipyramidal geometry around the tin atom. 119Sn Mössbauer and 119Sn NMR spectral data of tri-i-propyltin(IV) derivative support a penta-coordinate distorted trigonal-bipyramidal structure having equatorial organic groups, and involving a water molecule and O-2′ of the ribofuranose group in the axial positions. Some extent of intermolecular hydrogen-bonding involving water or (OH) groups leading to some degree of polymerization could not be ignored. Tri-i-propyltin(IV) and diorganotin(IV) derivatives of guanosine exhibited very low anti-inflammatory activity (~ 7.51–9.21% inhibition) at 40 mg kg− 1 dose and LD50 values > 200 mg kg− 1 in albino rats.