Synthesis, IR, UV/vis-, (1)H NMR and DFT study of chelatophore functionalized 1,3-benzoxazinone spiropyrans.

Six novel functionalized spiropyran's derivatives of 2H-1,3-benzoxazinone series were synthesized by introducing the substituents with chelating ability into 2H-chromene part of the 8'-formyl-7'-hydroxy-3-methyl-4-oxo-3,4-dihydro-2H-1,3-benzoxazine-2-spiro-2'-[2H]-chromene (I) by condensation with 2-aminophenol, 2-amino-4-methylphenol, 2-amino-4-nitrophenol, 2-amino-1-methylbenzimidazole, 4-amino-4H-1,2,4-triazole, N-(4-aminophenyl)acetamide. (1)H NMR, UV/vis, IR spectroscopy combined with quantum-chemical calculations employing density functional theory (DFT) were used to study their structure. All substances, except 2-amino-4-nitrophenol derivative exist in solid state and in solution solely in closed spiroform, while the mentioned one undergoes partial spiropyran ring opening. In DMSO solution NMR spectra show ratio of 2:1 of closed and opened form, correspondingly.

[Interaction between bee venom melittin and human blood albumin]. / Vzaimodeistvie melittina pchelinogo iada s al'buminom krovi cheloveka.

It is shown that bee venom melittin interacts with human blood albumin at pH 8.0-8.5 in the presence of NaCl (concentration over 0.1%) and forms a precipitating complex (MA), the albumin/melittin ratio being 1:12 for the monomer melittin. With a decrease of pH down to 5.3 and salt concentration below the limit mentioned, the precipitate is destroyed. The complex is soluble in the distilled water. Conditions for carrying the precipitation reaction between albumin and melittin in agarose gel are chosen. The titration method has been used to determine that melittin is bound up with albumin in the molar ratio (10-12):1 for monomeric melittin or 3:1 for tetrameric melittin.

[Features of transport function and structure of serum albumin in cancer]. / Kharakteristika transportnoi funktsii i struktury syvorotochnogo al'bumina u onkologicheskikh bol'nykh.

Levels of lipid ligands in serum albumin from cancer patients were assayed versus tumor localization. Abnormal non-specific increase in albumin-bound lipids as well as in peroxidation products was found. Gas-liquid chromatography of different polynonsaturated fatty acids pointed to the enhancement of their metabolism via the omega 3 pathway. The despiralization-type changes in secondary structure of albumin identified by procedures of spectral analysis and the decline in reserve functional activity of protein in tumor patients were matched by a rise in levels of serum albumin-transported ligands. It is suggested that such increase in the ligand-binding ability of albumin provides a major adaptive factor involved in oncopatology.

[Level of hemoglobin A1c and modified blood serum albumin in patients with diabetes mellitus]. / Soderzhanie gemoglobina A1c i modifitsirovannogo al'bumina syvorotki krovi u bol'nykh sakharnym diabetom.

Hemoglobin A1c was studied by means of isoelectric focusing in borate-polyol system and modified albumin--using electrophoresis of blood serum on acetate-cellulose films with subsequent TCA-ethanol sedimentation in healthy volunteers and patients with diabetes mellitus. These parameters were increased in the patients, whereas content of the albumin was decreased and the content of hemoglobin A1c was altered only slightly during treatment of diabetes. Content of hemoglobin A1c and modified albumin was shown to depend on the compensation state of diabetes mellitus.

[Fucosylation of serum proteins in stomach cancer]. / Fukozilirovanie belkov syvorotki krovi pri rake zheludka.

Content of fucose and of fucosylated protein fractions was studied in blood serum of healthy donors as well as in blood serum of patients with chronic gastritis and with stomach cancer. Concentration of fucose was increased in blood serum under conditions of the tumor generalization. At the same time, content of fucosylated albumin was elevated within early steps of stomach cancer, while the content of fucosylated globulins was decreased. Estimation of albumin-bound fucose might be used in diagnosis of stomach cancer.

[The degree of modification of serum albumin as a toxicological test]. / Stepen' modifikatsii syvorotochnogo al'bumina kak toksikologicheskii test.

A procedure is developed, involving electrophoresis and TCA-ethanol treatment of electrophoregramms, which enabled to estimate quantitatively the modified derivatives of albumin just in blood serum without the protein isolation. The method is based on ability of native albumin to maintain its solubility after TCA-ethanol treatment. At the same time, modified albumin with conformational alterations was fixed on a carrier and might be estimated using colorimetry or densitometry. The procedure developed might be used in chemical industry for evaluation of toxic effects of some substances.

[Microcalorimetric study of the domain organization of serum albumin]. / Mikrokalorimetricheskoe issledovanie domennoi organizatsii syvorotochnogo al'bumina.

Scanning microcalorimetry was used for studying the melting of the structure of human and bovine serum albumins and their fragments. It was shown that the melting of the native structure of serum albumin observed by the excessive heat absorption is a complex process which is described by three simple transitions overlapping in temperature. This means that the serum albumin molecule consists of three more or less independent cooperative structures, domains.

[Modification of the amino acid residues in the serum albumin of oncological patients]. / Modifikatsiia aminokislotnykh ostatkov al'bumina krovi onkologicheskikh bol'nykh.

A modified form of albumin isolated from the blood of oncological patients was studied. A modification of N-terminal amino acid, 50% tyrosine groups, free SH-group of cysteine and lysine group in the fourth position in the N-terminal sequence of amino acids was discovered. The possibility of a post-translation modification of serum albumin in disease in individual amino acid groups is discussed.

[Properties of human serum albumin in ischemic heart disease]. / Svoistva al'bumina syvorotki krovi cheloveka pri ishemicheskoi bolezni serdtsa.

Conformational changes in blood serum albumin under heart ischemia are found from the dispersion parameters of optical rotation and circular dichroism. It is also found that patients with myocardium infarction have a considerable amount of carbohydrate components in the modified albumin form.