A fundamental possibility of using the ability of low-molecular-weight DNA molecules to form optically active cholesteric liquid-crystalline dispersions (CLCDs) to estimate the efficacy of DNA-binding radioprotectors is studied. On the example of the well-known dye Hoechst 33 258, which interacts with DNA by the minor-groove-binding and has pronounced radioprotective properties, it is shown that the change in the amplitude of anomalous signal of circular dichroism of the CLCDs formed from DNA molecules preliminarily irradiated with X-rays in the absence and in the presence of the test compound makes it possible to estimate the value of its protective effect.

Complexes of various metals have a broad scope of applicability as luminescent materials. These compounds are used both as components of displays, batteries, and semiconductors and in the fields of biology and medicine. This review describes complexes containing group 13, 14, and 15 elements in the molecules, which can be considered as promising luminophores. Their photophysical properties and some aspects of physiological activity are presented.

Исследована принципиальная возможность использования способности молекул ДНК низкой молекулярной массы образовывать оптически активные холестерические жидкокристаллические дисперсии (ХЖКД) для оценки эффективности ДНК-специфичных радиопротекторов. На примере широко известного красителя Hoechst 33258, взаимодействующего с ДНК по модели связывания в малой бороздке и обладающего выраженными радиозащитными свойствами, показано, что изменение амплитуды аномального сигнала кругового дихроизма ХЖКД, формируемых из молекул ДНК, предварительно облученных рентгеновским излучением в отсутствии и в присутствии исследуемого соединения, позволяет оценить величину его защитного действия.

Novel complexes of lanthanum and cerium possessing antioxidant 2,6-di-tert-butylphenol moiety have been synthesized and characterized using NMR, IR spectroscopy, thermogravimetry and elemental analysis. Their redox properties have been investigated using cyclic voltammetry. Antioxidant activity has been evaluated in a series of model reactions in vitro. The affinity of the compounds for single electron transfer has been estimated in the CUPRAC test, while their radical scavenging capacity has been monitored in the DPPH test and their interaction with the superoxide radical anion has been investigated in the NBT test. It has been demonstrated that both complexes exhibit extraordinary antioxidant activity far surpassing that of known standards. The cerium complex appears to be 20 times more effective at scavenging superoxide radical anions than its lanthanum counterpart, which may be due to the unique +4 oxidation state of cerium. Biological activity has also been estimated in numerous in vitro assays. The ability of the complexes to inhibit lipoxygenase LOX-1B has been observed in a corresponding assay, showing mild inhibitory activity for both compounds. Cytotoxicity was evaluated using the common MTT assay, and the cytoprotective properties of the compounds were investigated using clonogenic analysis. Both compounds were found to be non-toxic at operating concentrations, and the cerium complex showed cytoprotective activity at radiation doses of about 2 Gy. These findings suggest that the synthesized complexes have the potential to be effective antioxidants and low-toxic cytoprotectors.

New complexes I – IV of di- tert -butyltin with ligands based on heterocyclic thioamides (2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole) and 2,6-di- tert -butyl-4-mercaptophenol are synthesized and studied by X-ray diffraction (XRD). The XRD results for single crystals of I , II , and IV are presented (CIF files CCDC nos. 2251495, 2251493, and 2251494, respectively). Specific features of the synthesized crystal structures are discussed. Complexes I and II contain the expected Sn–C and Sn–S bonds and an additional coordination with the nitrogen atom in the heterocycles, which indicates the octahedral environment of the Sn(IV) atom (coordination number 6). The coordination polyhedron in complex IV can be described as a distorted tetrahedron (coordination number 4). The proposed compounds are studied as antiproliferative agents. Their antiproliferative activity is determined using the human cancer cell lines (PC3, MCF-7, НСT116, A549, and normal cells WI38). A dependence of the activity on the ligand structure is found. A comparative evaluation of the activity shows that the introduction of the antioxidant 2,6-di- tert -butyl-4-mercaptophenol fragment into complex IV substantially decreases the cytotoxicity.

The central element of the "metastatic organotropism" is a shift of the pro/antioxidant balance in cells and activation of oxidative stress and protective antioxidant systems. We studied the effects of bis(3,5-di-tert-butyl-4-hydroxyphenylthiolate)dimethylol (Me-3) in the maximum effective and toxic total doses on the level of markers of oxidative stress and antioxidant protection in the liver of mice with melanoma B16 before the appearance of macroscopic metastases. In 48 h after tumor inoculation, Me-3 was administered intraperitoneally once a day for 5 days in total doses of 375 and 500 mg/kg according to the classical method. Administration of the hybrid organotin compound Me-3 produced different effects on the pro/antioxidant state of the microenvironment of liver tissue as the target of melanoma B16 metastasis. The results suggest that inversion of the anti/prooxidant profile of Me-3 is determined by its dose.

Three novel water-soluble tertiary amines with 2,6-di-tert-butylphenol and pyridine fragments were synthesized and characterized. The electrochemical behavior of compounds was studied by cyclic voltammetry, radical scavenging and antioxidant activities were studied. The activity of the compounds towards superoxide radical-anion was estimated. Based on the DPPH and CUPRAC, tests compound with 2-substituted pyridine fragment can act as radical scavenging agent. Antioxidant activity was found to depend on the structure of compounds. Moreover, a prolonged antioxidant activity of compounds was discovered in lipid peroxidation of Russian sturgeon liver homogenate in vitro. High antioxidant activity of amine hydrochloride with 2-substituted pyridine fragment allows one to suggest it for future practical usage as potential pharmacological agent with cytoprotective and antioxidant properties.

We performed a comparative analysis of the pharmacological activity of the hybrid organotin compound bis(3,5-di-tert-butyl-4-hydroxyphenylthiolate)dimethylol (Me-3) administered in different modes to mice with transplanted melanoma B16 to identify the most effective dosage regimen. Three modes of administration were used: preventive (before transplantation of tumor cells), classical according to Z. P. Sof'ina (48 h after transplantation of tumor cells), and delayed (7 days after transplantation of tumor cells, after formation of nodules of the primary tumor node). Compound Me-3 was administered at a total dose of 375 mg/kg intraperitoneally once a day for 5 days. The classical mode of administration was identified as the most effective, which indicates the preventive antimetastatic activity of Me-3 on the model of the transplanted mouse tumor melanoma B16.

A series of novel imidazole-containing ligands and their organotin complexes were synthesized and characterized by NMR, IR, MALDI and elemental analysis. Redox behavior was studied by cyclic voltammetry (CV). Antioxidant properties were estimated in model reactions of single-electron reduction (CUPRAC-test), scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and O2−. radical anion, enzymatic oxidation of linoleic acid by lipoxygenase and Fe3+-induced lipid peroxidation of rat liver homogenates. It was found that ligands and complexes both possess radical scavenging activity of prolonged action type. Compounds exhibited notable antioxidant activity in lipid peroxidation. Cytotoxicity was estimated in standard MTT-test on multiple cell lines. Compounds demonstrated high toxicity on colon carcinoma and breast cancer cells and based on obtained data, lead compound was proposed. Additional assays were carried out for the lead compound, including regular MTT-test on cancer cells possessing various resistant mechanisms and modified MTT-test on tumor tissue samples, obtained from patients as well as apoptosis and cell cycle studies. All organotin complexes were also studied for their influence on tubulin polymerization. It was demonstrated that obtained compounds demonstrate unorthodox activity, promoting microtubules assembly rate instead of inhibiting it. Significant influence of compound 5 on G2/M phase of cell cycle is in accordance with influence on tubulin polymerization and lets us to mark synthesized compounds as mitotic poisons. The results open up the scopes for the search of novel antitumor agents for treatment of advanced forms of cancer.