Guanine complexes with first row transition metal perchlorates

Catalytic reduction of pralidoxime in pharmaceuticals by macrocyclic Ni(II) compounds derived from orthophthalaldehyde

Efficient catalytic method for the reduction of pralidoxime to its amine derivative by macrocyclic Ni(II) compounds has been developed. Ten macrocyclic Schiff base Ni(II) compounds were synthesized via non-template synthesis by treating the corresponding macrocycles with nickel chloride in 1:1 ratio. The resulting compounds were characterized by elemental, IR, (1)H NMR, (13)C NMR, mass, electronic spectra, conductance, magnetic, thermal studies and their structures have been proposed. These compounds were used as catalysts for the reduction of pralidoxime to its amino derivative. The reduced pralidoxime was also characterized by spectral analysis and catalytic cycle has been established. The reduced product was determined spectrophotometrically by treating with ninhydrin reagent and the percent yields were found to be in the range of 75.12-82.36%.

Synthesis, spectral studies and antibacterial activity of novel macrocyclic Co(II) compounds

Ten novel macrocyclic Co(II) compounds have been synthesized by treating four N(4) and six N(2)O(2) donor macrocycles with cobalt chloride in methanol. These compounds were characterized by elemental, IR, (1)H, (13)C NMR, mass, electronic spectral analysis, molar conductance and magnetic susceptibility measurements. Thermal behavior of these compounds has been studied by the thermogravimetric analysis. An octahedral geometry has been proposed for all of these complexes. All the macrocycles and macrocyclic Co(II) compounds along with existing antibacterial drugs were screened for antibacterial activity against Gram +ve and Gram -ve bacteria. All these compounds were found to be more active when compared to streptomycin and ampicillin.

Pyrazolylborate-zinc-nucleobase-complexes, 2:(1) preparations and structures of Tp(Cum,Me)Zn and Tp(Ph,Me)Zn complexes

The interactions of the nine most significant nucleobases (thymine, uracil, dihydrouracil, cytosine, adenine, guanine, diaminopurine, xanthine, hypoxanthine, in their deprotonated forms) with zinc and with themselves in pyrazolylborate zinc complexes Tp(Cum,Me)Zn-base and Tp(Ph,Me)Zn-base are described. Except for guanine, the complexes Tp*Zn-base could be isolated in all cases. Structure determinations could be performed for seven of the eight product types. Except for dihydrouracil and xanthine, the zinc ion is attached to that nitrogen of the base which in nucleosides bears the sugar moiety. In the solid state, all zinc-bound nucleobases are involved in hydrogen bonding interactions. Except for xanthine, this includes homo base pairing across a crystallographic inversion center.