硫脲及其席夫碱衍生物合成与应用研究进展

硫脲类化合物因其独特的分子结构、良好的理化性能以及广泛的生物活性,在材料、医药、农药和配位催化等领域有重要的应用。因而其合成方法受到广泛关注。近年来,微波合成、超声波合成、无溶剂合成、离子液合成、相转移催化合成等一系列高效、绿色的合成方法在硫脲类化合物的合成中得到广泛的应用。结合本课题组的研究成果,本文着重综述了硫脲和席夫碱类化合物的合成方法及其应用,并对今后的研究方向进行了展望。     

酰基硫脲的合成、性质及生物活性

综述了近年来酰基硫脲类化合物的的合成,性质及生物活性的研究进展,参考文献22篇。     

含1，3，4-噁二唑取代的酰基硫脲的合成及杀菌活性

大量文献报道了1，3，4-噁二唑的合成及广泛的生物活性，酰基硫脲类化合物也因其广谱的生物活性引起了人们浓厚的研究兴趣。根据活性因子叠加的原理，本文将一系列1，3，4-噁二唑引入到酰基硫脲中，从对氯苯氧乙酸出发，得到的酰基异硫氰酸酯再与一系列2-氨基-5-芳基-1，3，4-噁二唑反应，合成了10个酰基硫脲类化合物。所有化合物均经元素分析、红外光谱、核磁共振谱和质谱确认。同时对所有化合物进行了生物活性测试。合成路线如下。     

含1,3,4-(口恶)二唑取代的酰基硫脲的合成及杀菌活性

大量文献报道了1,3,4-(口恶)二唑的合成及广泛的生物活性[1-3],酰基硫脲类化合物也因其广谱的生物活性引起了人们浓厚的研究兴趣[4-5].根据活性因子叠加的原理,本文将一系列1,3,4-(口恶)二唑引入到酰基硫脲中,从对氯苯氧乙酸出发,得到的酰基异硫氰酸酯再与一系列2-氨基-5-芳基-1,3,4-(口恶)二唑反应,合成了10个酰基硫脲类化合物.所有化合物均经元素分析、红外光谱、核磁共振谱和质谱确认.同时对所有化合物进行了生物活性测试.合成路线如下.     

酰胺基硫脲和1,2,4-三唑的合成和生物活性

设计并合成了１６个酰胺基硫脲类化合物的１４个１、２、４－三唑－５－硫醇类化合物。生物活性初筛试验表明,两类化合物对水稻和黄瓜幼苗有一定的生长调节活性。     

1-苯并噻唑硫乙酰基-4-芳酰氨基硫脲类化合物的合成

Dorothy曾对烷基和芳基取代的硫脲类化合物的合成及应用作过评论^[1].     

N-(2-甲氧羰基-1-甲基)-乙基-(N′-D-乙酰基吡喃型糖)硫脲类化合物的合成及生物活性

N-(2-甲氧羰基-1-甲基)-乙基-(N′-D-乙酰基吡喃型糖)硫脲类化合物的合成及生物活性;糖基硫脲;β-氨基丁酸;合成;生物活性     

N-(2-甲氧羰基-1-甲基)-乙基-(N′-D-乙酰基吡喃型糖)硫脲类化合物的合成及生物活性

N-(2-甲氧羰基-1-甲基)-乙基-(N′-D-乙酰基吡喃型糖)硫脲类化合物的合成及生物活性;糖基硫脲;β-氨基丁酸;合成;生物活性     

N—芳酰基—N′—（4—安替比林基）硫脲类化合物的合成

N,N′-二取代芳酰基硫脲类化合物具有多种重要的生物活性,如抗真菌、抗病毒及抑制中枢神经系统等,因而对此类化合物的研究已引起人们的广泛兴趣,许多学者进行了这一方面的合成工作。为了进一步研究不同的取代基团对此类化合物生物活性的影响,作     

N-(安替比林-4-基)-N'-取代芳甲酰基硫脲的合成及其生物活性

合成了12个含安替比林基的取代芳甲酰基硫脲类化合物,用1H NMR,IR和元素分析确证了它们的结构,并进行了室内生物活性测试.生测实验证明部分酰基硫脲类化合物,比如N-(安替比林-4-基)-N'-m(或o)-甲苯甲酰基硫脲,N-(安替比林-4-基)-N-o-硝基苯甲酰基硫脲,N-(安替比林-4-基)-N'-m(或p)-氯苯甲酰基硫脲,具有一定的细胞分裂素活性.     

煤烘玉米和饮水为介质地氟病区骨畸形病人全血尿多元素含量的分析

采集了贵族个煤烘玉米为主要介质和河北２个饮水为介质氟病区内骨畸形病人的全血、尿、检测了其中８种元素含量,结果表明,贵州各氟病区少儿骨软化与成年骨硬化畸形病人的全血铝、钙、磷、铁和尿氟、铝均显著高于同龄对照组,尿磷均低于同龄对照组。少儿骨软化病人全血锌均下降,尿锌多下降。某水型氟病区骨软化经产妇尿氟、全血铜升高;骨软化少年全血铝显著升高,锌、铁下降,尿氟升高,尿锌,磷下降。海边的典型氟骨症病人全血、     

Analytical strategies to determine antibiotic residues in fish

The accelerated growth of aquaculture has resulted in a series of harmful effects to human health. The widespread and unrestricted use of antibiotics in this industry, to prevent bacterial infections, leads to remaining amounts in the aquatic environment. This has resulted in the emergence of antibiotic-resistant bacteria in aquaculture environments, in the increase in antibiotic resistance in fish pathogens as well as in the transfer of these resistance determinants to human pathogens. Moreover, the use of large amounts of antibiotics may lead to the presence of residual antibiotics in fish tissue and fish products. Fluoroquinolones, tetracyclines, penicillins, sulphonamides and other antibiotics, exhibiting activity against both Gram-positive and Gram-negative bacteria, are widely used for the treatment and prevention of diseases in fish. An extended and comprehensive review on the recent analytical methodologies concerning antibiotic residues in fish reported in the literature is provided in the present article. Emphasis is given on sample preparation regarding isolation and purification, chromatographic conditions and method validation according to legislation. Results of published assays are comparatively presented and criticised.     

Species differences in the metabolism of arsenic compounds

Humans are exposed via air, water and food to a number of different arsenic compounds, the physical, chemical, and toxicological properties of which may vary considerably. In people eating much fish and shellfish the intake of organic arsenic compounds, mainly arsenobetaine, may exceed 1000 μg As per day, while the average daily intake of inorganic arsenic is in the order of 10–20 μg in most countries. Arsenobetaine, and most other arsenic compounds in food of marine origin, e.g. arsenocholine, trimethylarsine oxide and methylarsenic acids, are rapidly excreted in the urine and there seem to be only minor differences in metabolism between animal species. Trivalent inorganic arsenic (AsIII) is the main form of arsenic interacting with tissue constituents, due to its strong affinity for sulfhydryl groups. However, a substantial part of the absorbed AsIII is methylated in the body to less reactive metabolities, methylarsonic acid (MMA) and dimethylarsinic acid (DMA), which are rapidly excreted in the urine. All the different steps in the arsenic biotransformation in mammals have not yet been elucidated, but it seems likely that the methylation takes place mainly in the liver by transfer of methyl groups from S-adenosylmethionine to arsenic in its trivalent oxidation state. A substantial part of absorbed arsenate (AsV) is reduced to AsIII before being methylated in the liver. There are marked species differences in the methylation of inorganic arsenic. In most animal species DMA is the main metabolite. Compared with human subjects, very little MMA is produced. The marmoset monkey is the only species which has been shown unable to methylate inorganic arsenic. In contrast to other species, the rat shows a marked binding of DMA to the hemoglobin, which results in a low rate of urinary excretion of arsenic.     

UNDERSTANDING THE HYDROPHOBIC EFFECT

The hydrophobic effect is the common expression for processes where nonpolar groups in molecules are spontaneously removed from water. Thermodynamic analysis of hydrocarbon solubility in water, micellization and adsorption of surfactants show that the hydrophobic effect can be understood in terms of two contributions. The first contribution is attributed to the structuring, or rearrangement, of water molecules in the vicinity of a hydrophobe. This contribution is favorable, and hence increases the solubility of hydrocarbons in water, increases the cmc, and decreases the adsorption of surfactants. The second contribution is attributed to the formation of a cavity in the water in order to accomodate the hydrophobe. This contribution dominates over the first one and is unfavorable, i.e. it decreases the solubility of hydrocarbons in water, decreases the cmc, and increases the adsorption of surfactants. Thus, the cause of the hydrophobic effect is to be found in the large energy required to form a cavity in the water. On the other hand the temperature dependence of the hydrophobic effect is entirely determined by the water structuring, or rearrangement, in the vicinity of a hydrophobe.     

Determination of Occurrence Characteristics of Heavy Metals in Soil and Water Environments in Tianshan Mountains,Central Asia

China has one of the fastest-growing economies in the world, but this economic development has important implications for environmental changes in this country. Our research was to quantify the presence of heavy metals in soil and water environments in the Tianshan Mountains region of China, associated with the economic development of this region. We used anomaly analysis, correlation analysis, and principal component analysis to assess the occurrence characteristics of heavy metals in this area. Results showed that Co, Cr, As, and Ni are more prevalent in water environments than in soil environments; in contrast, Cd, Zn, Pb, Hg, and Mn are more prevalent in soil samples than in water samples. This analysis grouped 10 heavy metals in soil and water environments into three principal components. In soil environments, the prevalence order was Co, Ni, Cr, As > Mn, Zn, Pb > Hg, Cd, Cu. In water environments, the order was Cu, Co, Ni, Cr, As > Hg, Mn, Zn > Cd, Pb. It is possible to distinguish between the natural and the anthropogenic sources of heavy metals in the Tianshan Mountains. With the current rapid economic development in the Tianshan Mountains, anthropogenic sources are playing principal roles in serious heavy metal accumulations in this region. This problem warrants immediate and widespread attention to prevent further deterioration of the soil and water environments.     

Neobavaisoflavone May Modulate the Activity of Topoisomerase Inhibitors towards U-87 MG Cells: An In Vitro Study

Despite many advances in therapy, glioblastoma (GB) is still characterized by its poor prognosis. The main reason for this is unsuccessful treatment, which slightly extends the duration of remission; thus, new regimens are needed. One of many types of chemotherapeutics that are being investigated in this field is topoisomerase inhibitors, mainly in combination therapy with other drugs. On the other hand, the search for new anti-cancer substances continues. Neobavaisoflavone (NBIF) is a natural compound isolated from Psoralea corylifolia L., which possesses anti-oxidant, anti-inflammatory, and anti-cancer properties. The aim of this study was to evaluate the effect of NBIF in human U-87 MG glioblastoma cells in comparison to normal human NHA astrocytes, and to examine if it influences the activity of irinotecan, etoposide, and doxorubicin in this in vitro model. We demonstrated that NBIF decreases U-87 MG cells viability in a dose-dependent manner. Furthermore, we found that it inhibits cell growth and causes glutathione (GSH) depletion more intensely in U-87 MG cells than in astrocytes. This study also provides, for the first time, evidence of the potentialization of the doxorubicin effect by NBIF, which was shown by the reduction in the viability in U-87 MG cells.     

Phosphaalkynes—Syntheses,Reactions, Coordination Behavior [New Synthetic Methods (73)]

Organophosphorus compounds have been applied in two ways in chemical synthesis. They can either be used as a reagent in a step of the synthesis (for example, in the Wittig reaction) or they can be incorporated directly into the target molecule. This second application, in particular, has expanded greatly in the last few years with the preparation of low-coordination phosphorus compounds. These include the phosphaalkynes, which are of great interest to organic and inorganic chemists. Phosphaalkynes have been employed in the synthesis of heterocyclic compounds, phosphaarenes and their valence isomers, and polycyclic compounds. Further applications have been the use of phosphaalkynes as new ligand systems in complex chemistry and their cyclooligomerization with organometallic reagents. While the chemical properties of phosphaalkynes have little in common with those of nitriles, they are in many ways very similar to those of the isoelectronic acetylenes.     

中性溶质在反相毛细管电色谱中的保留行为

分别在以甲醇、乙腈、异丙醇和四氢呋喃为有机改性剂的４种二元流动相体系中对中性溶质在反相毛细管电色谱中的保留行为进行了研究。不仅考察了有机改性剂的种类和浓度对电渗淌度的影响,而且建立了溶质容量因子与有机改性剂在流动相中体积分数间的定量关系,此外还对样品在反相毛细管电色谱和反相毛细管高效液相色谱中的保留行为进行了比较,发现中性溶质在这两种分离模式中的容量因子基本相同。     

Staudinger reaction at in-bridgehead positions of phosphorus macrobicyclic compounds

Reaction of in,in-phosphite 1 with thiophosphoryl azide 2 affords in,in-dithiophosphate 3, in,in-thiophosphate-imidophosphate 4, and in,in-phosphite-imidophosphate 5. Compounds 4 and 5 are the first examples of the modification of in-bridgehead positions in macrobicyclic compounds with groups larger than methyl. The benzaldehyde arms of the in-substituent in 4 and 5 jut out of the cage bars. In 4 they are trapped between the macrocyclic arms to give the NMR spectra of a Cs-symmetric solution-state structure. In contrast, in 5 the benzaldehyde arms can move between the gaps of the cage. This results in 1H and 13C NMR spectra which are consistent for a compound with C3v symmetry. In,out-diimidophosphate 7 is obtained in moderate yield by reaction of in,out-phosphite 6 with thiophosphoryl azide 2. Its in-benzaldehyde moieties are not fixed between the cage arms, but can freely move from one gap to the next as is indicated by NMR measurements.     

An Overview of NO Signaling Pathways in Aging

Nitric Oxide (NO) is a potent signaling molecule involved in the regulation of various cellular mechanisms and pathways under normal and pathological conditions. NO production, its effects, and its efficacy, are extremely sensitive to aging-related changes in the cells. Herein, we review the mechanisms of NO signaling in the cardiovascular system, central nervous system (CNS), reproduction system, as well as its effects on skin, kidneys, thyroid, muscles, and on the immune system during aging. The aging-related decline in NO levels and bioavailability is also discussed in this review. The decreased NO production by endothelial nitric oxide synthase (eNOS) was revealed in the aged cardiovascular system. In the CNS, the decline of the neuronal (n)NOS production of NO was related to the impairment of memory, sleep, and cognition. NO played an important role in the aging of oocytes and aged-induced erectile dysfunction. Aging downregulated NO signaling pathways in endothelial cells resulting in skin, kidney, thyroid, and muscle disorders. Putative therapeutic agents (natural/synthetic) affecting NO signaling mechanisms in the aging process are discussed in the present study. In summary, all of the studies reviewed demonstrate that NO plays a crucial role in the cellular aging processes.