Antioxidative vs cytotoxic activities of organotin complexes bearing 2,6-di-tert-butylphenol moieties

Copyright © 2018 John Wiley & Sons, Ltd. Two series of organotin(IV) complexes with Sn–S bonds on the base of 2,6-di-tert-butyl-4-mercaptophenol (L1SH) of formulae Me2Sn(L1S)2 (1); Et2Sn(L1S)2 (2); Bu2Sn(L1S)2 (3); Ph2Sn(L1S)2 (4); (L1)2Sn(L1S)2 (5); Me3Sn(L1S) (6); Ph3Sn(L1S) (7) (L1 = 3,5-di-tert-butyl-4-hydroxyphenyl), together with the new ones [Me3SnCl(L2)] (8), [Me2SnCl2(L2)2] (9) (L2 = 2-(N-3′,5′-di-tert-butyl-4′-hydroxyphenyl)-iminomethylphenol) were used to study their antioxidant and cytotoxic activity. Novel complexes 8, 9 of MenSnCl4 − n (n = 3, 2) with Schiff base were synthesized and characterized by 1H, 13C NMR, IR and elemental analysis. The crystal structures of compounds 8 and 9 were determined by X-ray diffraction analysis. The distorted tetrahedral geometry around the Sn center in the monocrystals of 8 was revealed, the Schiff base is coordinated to the tin(IV) atom by electrostatic interaction and formation of short contact Sn–O 2.805 Å. In the case of complex 9 the distorted octahedron coordination of Sn atom is formed. The antioxidant activity of compounds as radical scavengers and reducing agents was proved spectrophotometrically in tests with stable radical DPPH, reduction of Cu2+ (CUPRAC method) and interaction with superoxide radical-anion. Moreover, compounds have been screened for in vitro cytotoxicity on eight human cancer cell lines. A high activity against all cell lines with IC50 values 60–160 nM was determined for the triphenyltin complex 7, while the introduction of Schiff base decreased the cytotoxicity of the complexes. The influence on mitochondrial potential and mitochondrial permeability for the compounds 8 and 9 has been studied. It is shown that studied complexes depolarize the mitochondria but don't influence the calcium-induced mitochondrial permeability transition

Влияние ионизирующего излучения на параметры p-канальных МОП-транзисторов

The results of experimental studies of the influence of gamma radiation Co60 on the basic parameters of silicon epitaxial-planar p-channel MOSFET transistors under different electrical modes are presented. Transistors were manufactured according to radiation-resistant DMOS technology with design standards of 1.4 μm. As a result of transistor studies, it was established that the values of all basic parameters after the radiation dose D = 106 rads (SiO2) in active electrical irradiation modes remained within the limits of the performance criteria; the parameter, most sensitive to influence of a dose of irradiation by gamma-quanta is the threshold voltage; in the passive electrical irradiation mode the transistor’s radiations resistance in all parameters corresponds to a dose of 2,8·106 rads (SiO2). A sufficiently high radiation resistance of the studied p-channel MOSFETs makes it possible to recommend them for use in aviation and space equipment. The different degrees of radiation degradation of the studied parameters during irradiation are due to their dependence either on the effects of ionization in the layers of sub-gate and insulating dielectrics, or structural damage in the bulk silicon of the transistor active regions. The high radiation resistance of the studied p-channel MOSFETs allows recommending them for use in aviation and space equipment.Представлены результаты экспериментальных исследований влияния гамма-излучения Со60 на основные параметры кремниевых эпитаксиально-планарных p-канальных МОП-транзисторов при различных электрических режимах. Транзисторы изготовлены по радиационно-стойкой ДМОП-технологии с проектными нормами 1,4 мкм. В результате исследований транзисторов установлено: значения всех основных параметров после дозы облучения D = 106 рад (SiO2) в активных электрических режимах облучения остались в пределах критериев работоспособности; наиболее чувствительным к воздействию дозы облучения гамма-квантами является пороговое напряжение; в пассивном электрическом режиме облучения стойкость транзисторов по всем параметрам соответствует дозе 2,8·106 рад (SiO2). Показано, что разная степень радиационной деградации исследуемых параметров при облучении обусловлена их зависимостью либо от эффектов ионизации в слоях подзатворных и изолирующих диэлектриков, либо от структурных нарушений в объемном кремнии активных областей транзисторов. Высокая радиационная стойкость исследованных р-канальных МОП-транзисторов позволяет рекомендовать их для использования в аппаратуре авиационной и космической техники

Antioxidative vs cytotoxic activities of organotin complexes bearing 2,6-di-tert-butylphenol moieties

Copyright © 2018 John Wiley & Sons, Ltd. Two series of organotin(IV) complexes with Sn–S bonds on the base of 2,6-di-tert-butyl-4-mercaptophenol (L1SH) of formulae Me2Sn(L1S)2 (1); Et2Sn(L1S)2 (2); Bu2Sn(L1S)2 (3); Ph2Sn(L1S)2 (4); (L1)2Sn(L1S)2 (5); Me3Sn(L1S) (6); Ph3Sn(L1S) (7) (L1 = 3,5-di-tert-butyl-4-hydroxyphenyl), together with the new ones [Me3SnCl(L2)] (8), [Me2SnCl2(L2)2] (9) (L2 = 2-(N-3′,5′-di-tert-butyl-4′-hydroxyphenyl)-iminomethylphenol) were used to study their antioxidant and cytotoxic activity. Novel complexes 8, 9 of MenSnCl4 − n (n = 3, 2) with Schiff base were synthesized and characterized by 1H, 13C NMR, IR and elemental analysis. The crystal structures of compounds 8 and 9 were determined by X-ray diffraction analysis. The distorted tetrahedral geometry around the Sn center in the monocrystals of 8 was revealed, the Schiff base is coordinated to the tin(IV) atom by electrostatic interaction and formation of short contact Sn–O 2.805 Å. In the case of complex 9 the distorted octahedron coordination of Sn atom is formed. The antioxidant activity of compounds as radical scavengers and reducing agents was proved spectrophotometrically in tests with stable radical DPPH, reduction of Cu2+ (CUPRAC method) and interaction with superoxide radical-anion. Moreover, compounds have been screened for in vitro cytotoxicity on eight human cancer cell lines. A high activity against all cell lines with IC50 values 60–160 nM was determined for the triphenyltin complex 7, while the introduction of Schiff base decreased the cytotoxicity of the complexes. The influence on mitochondrial potential and mitochondrial permeability for the compounds 8 and 9 has been studied. It is shown that studied complexes depolarize the mitochondria but don't influence the calcium-induced mitochondrial permeability transition