Electron factors in the properties of cytochrome P-450 and mechanism of activation of molecular oxygen

A quantum-chemical calculation was carried out for the electronic structures of coordination compounds of general formula: FeP(L1)(L2) (P--porphin; L1 = SHCH3, [SCH3]-, [SC6F4H]-; L2 = CO, NO, O2), modeling the active site of cytochrome P450. It was shown that Coulomb repulsion between the electrons of the sulfur lone pair leads to the transfer of the electronic density from the ligands L1 = [SCH3]- or [SC6F4H]- to the porphyrin of/and to the L2 ligand. This explains the origin of the band at 450 nm in the absorption spectra of the complexes of cytochrome P450 with CO, the absence of such a band in those with O2, and the strong activation of dioxygen by cytochrome P450.     

Polymerization of 4-nitrophenylacrylate under microwave heating conditions]

The 2,2'-azodiisobutyronitrile-induced radical polymerization in solution of 4-nitrophenyl acrylate was performed under microwave heating at a frequency of 2.45 GHz. This approach allows the control of the molecular mass of poly(4-nitrophenyl acrylate) used in the synthesis of multivalent glycoconjugates. It was found that the polymerization of 4-nitrophenyl acrylate under microwave irradiation results in products with a narrower molecular mass distribution than at conventional heating.     

Polymerization of 4-Nitrophenyl Acrylate under Microwave Heating Conditions

The 2,2"-azodiisobutyronitrile-induced radical polymerization in solution of 4-nitrophenyl acrylate was performed under microwave heating at a frequency of 2.45 GHz. This approach allows the control of the molecular weight of poly(4-nitrophenyl acrylate) used in the synthesis of multivalent glycoconjugates. It was found that the polymerization of 4-nitrophenyl acrylate under microwave irradiation results in products with a narrower molecular mass distribution than at conventional heating.     

Synthesis and study of the fungicidal activity of amine salts of glycyrrhizic acid

Amine and triphenyl phosphine salts of glycyrrhizic acid have been synthesized by the reaction of glycyrrhizic acid with amines and triphenyl phosphine in absolute methanol, and their antimicrobial and fungicidal activities have been investigated.     

Electron factors in peroxidase properties and the mechanism of activation of oxygen with heme-containing proteins

A quantum-chemical calculation was carried out for the electronic structure of coordination compounds of general formula FeP (L1) (L2) (P-porphine; L1-imidazole or imidazolate; L2-CO, O2 or is absent), modelling the active sites of number of hemoproteins. The elucidation of electronic structures of the complexes under consideration explains the similar shapes and band positions of optical absorption and magnetic circular dichroism spectra of oxy- and carboxycomplexes of myoglobin, hemoglobin, and peroxidase. It is shown that the Coulomb repulsion between electrons of the lone pair of the imidazolate distal nitrogen leads to the transfer of the electronic density from this ligand to the dioxygen. This results in the strong dioxygen activation leading, in particular, to the high catalytical activity of peroxidase.