去氢枞醇杂环类化合物的合成及细胞毒性研究

以去氢枞酸(1)为原料,经氢化铝锂还原得到去氢枞醇(2),2与氯乙酰氯在氮气保护和DMAP催化条件下反应合成中间产物去氢枞醇氯乙酸酯(3),3与杂环化合物经亲核取代反应合成了12个新型去氢枞醇杂环类化合物(4a ～41).利用IR、1H NMR、13C NMR和HR-MS等对目标化合物的结构进行表征,采用MTT法测试目...     

去氢枞酸异丙醇胺衍生物的合成及其细胞毒性评价

为了寻找高效的抗肿瘤活性化合物,设计合成了一系列去氢枞酸异丙醇胺类化合物,利用IR、NMR和MS对其结构进行表征。采用噻唑蓝(MTT)法评价了目标化合物对四种不同肿瘤细胞T24(人膀胱移行癌细胞)、HepG2(人肝癌细胞)、SK-OV-3(人卵巢癌细胞)、A549(人肺癌细胞)和LO2(人正常肝细胞)的抗增殖活性。结果表明,部分化合物对肿瘤细胞的抑制作用优于阳性对照顺铂。其中,化合物3d对四种细胞株表现出最好的抗增殖效果,IC₅₀值分为8.10±0.28,8.65±0.10,13.21±0.35和8.24±0.42 μmol.L_-1^{。初步机理研究表明},化合物3d使A549细胞周期阻滞在G1/G0期,并诱导A549细胞凋亡,且呈浓度依赖性。     

去氢枞酸蔗糖酯的溶剂法合成

松香主要成分是二萜树脂酸(C29H29COOH,含量约为90％),可用作表面活性剂的合成原料。将松香树脂酸与蔗糖进行酯化反应,即可合成松香-蔗糖基非离子表面活性剂。目前关于高级脂肪酸蔗糖酯和松香基表面活性剂的研究有许多报道,但有关松香蔗糖酯的研究报道极少,工艺极不成熟,且都使用未经改性的松香,结构中仍保留两个易氧化的双键,不利于长时间储存和使用。从歧化松香中分离提纯去氢枞酸,     

苯乙酮类去氢枞酰腙的合成

以去氢枞酸为原料,经三氯化磷酰氯化得到去氢枞酰氯(2);2与85%水合肼反应合成了去氢枞酰肼(3);3再分别与苯乙酮及其衍生物发生缩合反应得到4个新型的苯乙酮类去氢枞酰腙化合物,其结构经UV,1H NMR和IR表征.     

ATRP法合成聚去氢枞酸丙烯酸乙二醇酯的研究

本研究从歧化松香中提取的去氢枞酸(DHA)出发,经酰氯化后与丙烯酸(2-羟基)乙酯反应,合成了去氢枞酸丙烯酸乙二醇酯(DHAAGE);并以此为单体,2-溴-异丁酸乙酯(EBr-iB)为引发剂,CuBr/2,2'-联吡啶(2,2'-bipyridine)为催化体系,在90 oC下,利用原子转移聚合(ATRP)法制备了聚去氢枞酸丙烯酸乙二醇酯(PDHAAGE).利用FT-IR、1H-NMR和GPC对所制备的单体和聚合物进行了表征,同时考察了单体转化率随聚合反应时间的变化.结果表明,聚合反应动力学曲线呈良好线性关系,表观聚合速率常数kp′为3.6 ×10-7 s-1;所得聚合物的分子量分布很窄.     

聚去氢枞酸丙烯酸乙二醇酯的合成与表征

从歧化松香中提取的去氢枞酸(DHA)出发,经酰氯化后与丙烯酸(2-羟基)乙酯反应,合成了去氢枞酸丙烯酸乙二醇酯(DHAAGE);并以此为单体,偶氮二异丁腈(AIBN)为引发剂,四氢呋喃为溶剂,在60℃下,利用常规自由基聚合(CPR)法制备了聚去氢枞酸丙烯酸乙二醇酯(PDHAAGE)。考察了单体转化率随聚合时间的变化,并利用FT-IR1、H-NMR、GPC、TG和DSC等对PDHAAGE进行了分析和表征。同时考察了PDHAAGE在不同溶剂中的溶解性。结果表明,得到的PDHAAGE的数均分子量(Mn)约为5400,分子量分布小于1.40;Tg为95.8℃,Tm为375.8℃,热分解温度Td为396.4℃,说明PDHAAGE具有很好的热稳定性;PDHAAGE易溶于中等极性的有机溶剂中。     

新型杀菌农药去氢枞酸铜乳油有效成分分析

本文选用高效液相色谱法测定去氢枞酸的含量，从而可以推算去氢枞酸铜的含量。此分析方法的回收率为98％～101％，变异系数为2．96％。     

新型去氢枞酸基磺酰胺类化合物的合成及其生物活性

去氢枞酸与SOCl2反应制得去氢枞酸酰氯(2);芳磺酰氯与乙二胺经N-酰化反应制得N-芳磺酰基乙二胺(4a~4k);在DMAP催化下,2分别与4a~4k经N-酰化反应合成了11个新型的去氢枞酸基磺酰胺类化合物(5a~5k),其结构经1H NMR,13C NMR,IR和ESI-MS表征。生物活性测试结果表明,在用药量为50μg·mL-1时,5a~5k对黄瓜枯萎病菌、苹果轮纹病菌、番茄早疫病菌、花生褐斑病菌和小麦赤霉病菌有一定的抑菌活性,其中去氢枞酸基间甲基苯磺酰胺(5c)对番茄早疫病菌的杀菌活性最佳,抑制率为73.6%;在用药量为100μg·mL-1时,大部分化合物对油菜的胚根生长有一定抑制作用,其中去氢枞酸基对甲氧基苯磺酰胺(5d)的抑菌活性最佳,抑菌率为57.1%。     

脂肪族二酸二烷基双去氢枞基双噁二唑的合成及除草活性

以去氢枞酸为原料,制备去氢枞酸酰氯.以脂肪族二酸为原料,经过脂肪族二酸二乙酯得到脂肪族二酸二酰肼.脂肪族二酸二酰肼与去氧枞酸酰氯在相转移催化下反应得到N,N＇-二去氢枞酰基取代脂肪族二酸二酰肼,再脱水环合,得到5个标题化合物脂肪族二酸二烷基双去氢枞基双噁二唑.通过元素分析,IR,MS,1H NMR和13C NMR对所合成的新化合物进行了结构表征.初步的除草活性测试表明,化合物6b～6e在100 μg/mL浓度下对油菜的胚根生长具有良好的抑制作用,抑制率均超过80％.     

2-取代酰氨基-5-去氢枞基-1,3,4-噻二唑衍生物的合成及杀菌活性

为了寻找具有更高生物活性的新颖先导化合物,本文以去氢枞酸为原料,设计并合成了11个具有1,3,4-噻二唑骨架的新型去氢枞酸衍生物,通过1H NMR、13C NMR、IR、EI-MS和元素分析确认了目标产物的结构。初步的生物活性测试结果表明,大部分化合物具有一定的杀菌活性,其中,化合物2在浓度为50mg/L时对番茄早疫病菌的抑制率达88.9%。     

Dipole moment derivatives of H2O and H2S

The dipole and quadrupole derivatives of H₂O and H₂S are calculated analytically, using the coupled Hartree—Fock method first proposed by Gerratt and Mills. The greater efficiency, of this method allows SCF wave functions very, close to the Hartree—Fock limit to be used. Agreement, with experimental data is good.     

A quantum-mechanical study of the lone-pairs in H2O and H2S

It is shown from SCF-MO studies using localised orbitals that the angles between the lone-pairs in H₂O and H₂S are 115° and 127°, in agreement with the qualitative predictions of the Sidgwick-Powell theory.     

Activity of catalysts in 1-butanol reaction with H2S

Reaction of 1-butanol with H₂S has been studied at 300 °C and 0.1 MPa on catalysts of various composition. The catalysts that contain mainly strong proton sites on their surface accelerate dehydration of alcohol alone. In the presence of catalysts possessing acidic and basic Lewis sites 1-butanethiol is formed. Reaction rate increases as the concentration and strength of Lewis acid sites increase.     

Collisional ionization of fast K atoms by H2S and D2S

The process K + H₂S/D₂S → HS^?/DS^? + K⁺+ H/D has been investigated for K impact energies from near threshold to ≈100 eV. Positive and negative ion energy spectra have been obtained in the forward direction. The threshold for HS^? or DS^?production corresponds to the HS^?/DS^?+ H/D limit of the ²A₁ H₂S^?/D₂S^? state at 1.55 eV.     

Catalytic reaction of tetrahydrofuran with H2S

The reaction of tetrahydrofuran with H₂S catalyzed by acid-base catalysts has been studied. Catalysts containing an acid-base pair, i.e. a Lewis acid center and a base center, are the most active and selective towards thiolane. Proton donor catalysts and those containing only basic centers are of low activity and selectivity.

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H₂S - . , - : - , . , , .

     

Synthesis and Cytotoxic Activity of 5-Benzoylhexahydropyrimidine Derivatives

Russian Journal of Organic Chemistry - The reaction of ethyl benzoylacetate with formaldehyde and natural amino acid ester hydrochlorides in acetate buffer (AcONa/AcOH, pH 4.0) at room temperature...     

The solubility of H2S in liquid sulfur

The need for fundamental data describing the dissolution of hydrogen sulfide, H₂S, in Claus recovered liquid sulfur prompted an examination of equilibrium H₂S solubility at typical industrial condensation temperatures and partial pressures. An FT/IR absorption technique has been described and new H₂S solubility measurements have been reported for partial H₂S pressures from 0.4 to 56 kPa and temperatures from 120 to 155 °C. The measurements were combined with previously reported values for atmospheric pressures of H₂S and used to calibrate a semi-empirical equation for the Henry's law solubility in liquid sulfur as a function of temperature. Estimations were compared to Claus plant field data and appear to underestimate the H₂S solubility for the first and second catalyst condenser stages. This underestimation was attributed to rapid condensation resulting in super-saturation of the recovered sulfur liquid, or an inaccurate measurement of the condensation temperatures.     

Photofragmentation of H2S in the first continuum

The dynamics of the photofragmentation of H₂S in the first continuum has been investigated at laser wavelengths 193, 222 and 248 nm. The HS fragments are produced mainly in υ = 0, as expected, but a non-negligible part of the HS radicals produced are vibrationally excited. The distribution of the vibrationally excited radicals peaks at υ = 3 or 4 at 193 nm and at υ = 2 at 222 nm. From the angular distribution of the H fragments it can be concluded that the anisotropy parameter β decreases with increasing wavelength. These results can be explained by a predissociation mechanism. Excitation in the first continuum takes place from the ¹A₁ ground state to the bound ¹B₁ state. This state is predissociated by a repulsive ¹A₂ state producing electronically ground-state H and HS fragments, of which the HS fragments can be vibrationally excited, resulting in a bimodal vibrational distribution. The increase of β with increasing wavelength is caused by a non-negligible lifetime in the ¹B₁ state.     

The photodissociation of H2S: A study of indirect photodissociation

We have performed calculations for the photodissociation of H₂S using surfaces constructed to test a model proposed by van Veen et al., in which the dissociation occurs via predissociated levels of the bound ¹B₁ excited state. Total Franck-Condon factors for the photodissociation and partial Franck-Condon factors for the product vibrational distributions are presented.     

Synthesis of thiolane from tetrahydrofuran and H2S in the presence of proton-donor catalysts

In the presence of proton-donor catalysts, at 300–400°C tetrahydrofuran interaction with H₂S yields up to 25% thiolane. These catalysts are low-selective and have low stability due to the occurrence of decomposition and polymerization processes.

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300–400°C H₂S 25%. .