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121.
122.
一些砷、锑的配合物具有抗癌、杀菌等生物功能[1,2],可用于药物研究.近年来,用砷剂(主要是三氧化二砷)治疗急性早幼粒细胞白血病(APL),具有缓解率高而复发率低的优点,引起世人的关注.因砒霜中仅含氧和砷,起药物作用的实际是砷(Ⅲ).因此,选择有生物功能的配体合成新型砷配合物对治疗白血病可能有一定药物作用.由于砷的无机盐易水解,故合成砷的生物配合物很困难,对砷配合物的研究也很少报道 [3-7].本文用异烟肼、L-苯丙氨酸和三碘化砷通过室温固相反应合成了两种未见报道的砷配合物,经元素分析,紫外光谱,X-射线粉末衍射,中、远红外光谱和热重差热分析确定了配合物的化学组成,并对配合物的抑菌活性进行了研究. 相似文献
123.
聚乙烯醇高含水胶固定化脲酶的研究 总被引:2,自引:0,他引:2
冷冻-部分脱水法制成的聚乙烯醇高含水胶固定化脲酶活力收率及对脲素的分解能力明显高于聚丙烯酰胺囱定化脲酶,稳定性相近;用低浓度的戊二醛后处理,提高了固定化酶的稳定性。 相似文献
124.
利用弯曲键理论,详细讨论了旋光性的脂肪族链状化合物分子内存在的螺旋结构,同样是右螺是右旋的,左螺旋是左旋的。从螺旋方向可以推断旋光方向,知道旋光方向也可以推断构型。 相似文献
125.
硫脲化合物的合成及其生物活性 总被引:13,自引:0,他引:13
硫脲化合物的合成及其生物活性董燕红,司宗兴(北京农业大学应用化学系北京100094)关键词噻二陛-甲酰基,硫脲,胺类,合成,生物活性酰基硫脲在抗真菌、抗结核、抗病毒、除草以及调节植物生长方面具有广泛应用[1,2]。1,2,3-噻二唑杂环作为有效前体正... 相似文献
126.
Xi‐Zhao Wang Jiong Jia Yan Zhang Wei‐Ren Xu Wei Liu Fang‐Niu Shi Jian‐Wu Wang 《中国化学会会志》2007,54(3):643-652
The synthesis of a series of new 5‐isoxazolpenicillins is described, which were obtained by coupling substituted isoxazoles with 6‐APA. Concise large‐scale synthesis of 3,5‐disubstituted isoxazoles by 1,3‐dipolar cycloaddition using copper(I) as catalyst was also investigated. Representative compounds were assayed for antimicrobial activities, showing satisfactory antimicrobial activities against Gram‐negative bacteria. 相似文献
127.
Òscar Rubio-Pons Boris Minaev Oleksandr Loboda Hans Ågren 《Theoretical chemistry accounts》2005,113(1):15-27
The phosphorescence spectrum of p-dichlorobenzene has been calculated using multiconfiguration self-consistent-field wave functions and the quadratic response technique. Attention has been paid to the intensity distribution of the singlet–triplet (3B1u1Ag) transition through a number of vibronic subbands. The second order spin–orbit coupling (SOC) contribution to the spin splitting of the 3B1u (3*) state is found to be almost negligible, and the calculations therefore provide a good estimate for the zero-field splitting (ZFS) parameters based only on the electron spin–spin coupling expectation values. Nuclear quadrupole resonance constants for the different Cl isotopes are also calculated to accomplish the ZFS assignment. The electric dipole activity of the spin sublevels in the triplet–singlet transitions to the ground-state vibrational levels is estimated by calculations of derivatives using distorted geometries which are shifted from the equilibrium position along different vibrational modes. A vibrational analysis of the phosphorescence spectrum, based on the SOC-induced mixing of the singlet and triplet states calculated along different vibrational modes, provides reasonable agreement with experimental data.Acknowledgment O. R.-P. would like to thank the European MOLPROP network for support. The authors thank Alexander Baev for fruitful discussions. This work was supported by the Swedish Royal Academy of Science (KVA). 相似文献
128.
Nanocrystalline TiO2 samples with mesoporous structure were prepared via a solvothermal treatment of surfactant-stabilized TiO2 sols. The samples were obtained from media of different acidities including nitric acid, deionized water, and ammonia (denoted as HT-1, HT-2 and HT-3, respectively). These samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2-sorption (BET surface area), micro-Raman spectroscopy, infrared absorption spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activities of the samples were tested by the self-photosensitized degradation of an azo dye, Mordant Yellow 10 (MY), in aqueous solution under visible light irradiation. The results reveal that all three samples have high surface area and are pure anatase phase. The sample prepared in nitric acid medium possesses the most ideal mesoporous structure and also exhibits a blue shift in the Raman spectrum. All three samples show much higher photocatalytic activity than the commercial P-25. The activity order of the three samples is HT-1>HT-2>HT-3. 相似文献
129.
Nanostructure Pt Electrode Obtained via Self-assembly of Nanoparticles on Conductive Oxide-coated Glass Substrate 总被引:1,自引:0,他引:1
Self-assembly of platinum nanoparticles were applied to fabrication of counter electrode for dye-sensitized solar cells on conductive oxide-coated glass substrate. The present Pt electrode exhibits high exchange current density of 220 mA/cm^2, which is comparable to those prepared by electrodeposition, magnetron sputtering or thermal decomposition of platinum chloride. After analysis by transmission electron microscopy (TEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), it was found that the catalyst was structurally characterized as nanosized platinum metal clusters and was continuously arranged on electrode surface. The present nanostructure electrode had high electrocatalytic activity for the reduction of iodine in organic solution. 相似文献
130.
D. Tirzite A. Krauze A. Zubareva G. Tirzitis G. Duburs 《Chemistry of Heterocyclic Compounds》2002,38(7):795-800
The alkylation of 3-cyano-1,4-dihydropyridine-2(3H)-thiones or the condensation of an aromatic aldehyde, cyanothioacetamide, acetylacetone, and methyl iodide in the presence of piperidine has given a series of novel 5-acetyl-2-alkylthio-4-aryl-6-methyl-1,4-dihydropyridine-3-carboxylic acid nitriles. A compound was obtained from 3,5-di(tert-butyl)-4-hydroxybenzaldehyde in the molecule of which were combined the active part of the antioxidant ionol and a 1,4-dihydropyridine ring. It was found that, among the compounds synthesized, the highest antiradical activity occurred in a compound having two hydroxyl groups in the 4-phenyl substituent. 相似文献