共查询到20条相似文献,搜索用时 187 毫秒
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已见含氟类有机物具有杀菌能力的报道,将氟元素引入到噻吩并嘧啶酮的衍生物之中,考查其杀菌活性。通过Gewald反应生成噻吩,产物同PPh3、C2Cl6、Et3N作用得到膦亚胺,再用对氟苯基异氰酸酯与之作用得到碳二亚胺,之后与伯胺反应得到10种新的标题化合物,其结构经1HNMR、MS和元素分析表征。生物活性测试表明,此类衍生物对常见农作物部分菌体均表现出较大的抑制作用,其中以2-正庚氨基-3-对氟苯基-5-甲基-6-(1H-1,2,4-三唑-1-基)-噻吩并[2,3-d]嘧啶-4(3H)-酮活性最好,它对棉花枯萎菌的抑制率达90%。该系列物质相对不含氟元素的同种取代基的噻吩并嘧啶酮衍生物的杀菌活性有一定程度的提高。 相似文献
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《化学与生物工程》2016,(3)
通过Gewald反应合成噻吩衍生物,再由噻吩衍生物、对氟苯基异氰酸酯分别与甲醇、乙醇、正丙醇经串联aza-Wittig反应合成了3个新型的2-烷氧基-3-对氟苯基-5-甲基-6-(1 H-1,2,4-三唑-1-基)噻吩并[2,3-d]嘧啶-4(3 H)-酮,经1 HNMR、MS和元素分析表征了其结构,并初步测定了合成化合物的抑菌活性。结果表明,在用药浓度为5×10-5g·L-1时,3种化合物对常见农作物菌种均表现出一定的抑菌活性,其中以2-甲氧基-3-对氟苯基-5-甲基-6-(1 H-1,2,4-三唑-1-基)噻吩并[2,3-d]嘧啶-4(3 H)-酮的活性最高,对水稻纹枯菌的抑制率达90%。 相似文献
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5-(4-烷基苯基)-2-(4-氰基苯基)-嘧啶的合成 总被引:1,自引:0,他引:1
对 5 (4 烷基苯基 ) 2 (4 氰基苯基 ) 嘧啶的合成进行了研究 ,以 5 (4 正己基苯基 ) 2 (4 氰基苯基 ) 嘧啶 (Ⅳ )的合成为例 ,论述了以 4 己基苯乙酸为原料 ,先依次制得 4 己基苯乙酰氯 ,1 二甲氨基 3 二甲亚胺基 2 (4 正己基苯基 ) 丙烯 高氯酸盐 (Ⅰ ) ,得率 84%。进而在甲醇钠存在下与 4 溴苯基脒盐酸盐 (Ⅱ )相对接 ,合成 5 (4 正己基苯基 ) 2 (4 溴苯基 ) 嘧啶 (Ⅲ ) ,得率 87%。最后Ⅲ和CuCN反应合成了液晶化合物Ⅳ ,得率 78%。其结构由1HNMR和IR光谱所证实 ,同时还测定了其DSC。另外在合成Ⅱ时 ,必须在无水条件下进行 ,而且在通入氯化氢气体时 ,反应温度保持 - 5~ 0℃ ,其反应得率 97%。 相似文献
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Alkema WB Hensgens CM Snijder HJ Keizer E Dijkstra BW Janssen DB 《Protein engineering, design & selection : PEDS》2004,17(5):473-480
Penicillin acylase catalyses the condensation of Calpha-substituted phenylacetic acids with beta-lactam nucleophiles, producing semi-synthetic beta-lactam antibiotics. For efficient synthesis a low affinity for phenylacetic acid and a high affinity for Calpha-substituted phenylacetic acid derivatives is desirable. We made three active site mutants, alphaF146Y, betaF24A and alphaF146Y/betaF24A, which all had a 2- to 10-fold higher affinity for Calpha-substituted compounds than wild-type enzyme. In addition, betaF24A had a 20-fold reduced affinity for phenylacetic acid. The molecular basis of the improved properties was investigated by X-ray crystallography. These studies showed that the higher affinity of alphaF146Y for (R)-alpha-methylphenylacetic acid can be explained by van der Waals interactions between alphaY146:OH and the Calpha-substituent. The betaF24A mutation causes an opening of the phenylacetic acid binding site. Only (R)-alpha-methylphenylacetic acid, but not phenylacetic acid, induces a conformation with the ligand tightly bound, explaining the weak binding of phenylacetic acid. A comparison of the betaF24A structure with other open conformations of penicillin acylase showed that betaF24 has a fixed position, whereas alphaF146 acts as a flexible lid on the binding site and reorients its position to achieve optimal substrate binding. 相似文献
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以水杨酸甲酯和取代苯乙酸为原料.经缩合、环化得到中间体4-羟基-3-取代苯基-2H-苯并吡喃-2-酮,与酰氯反应,合成了16个未见文献报道的4-羟基-3-取代苯基-2H-苯并吡喃-2-酮衍生物(3),所有目标化合物结构均通过1H NMR、IR和LC/MS确证.初步生物活性测试表明:在质量浓度25 mg/L下,化合物3k和30对黄瓜灰霉病菌抑制率分别为67.3%和73.9%;在质量浓度500 mg/L下,化合物3d、3k和3e对稻纹枯病菌的活性分别为75.0%、73.6%和100%. 相似文献
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Summary The reversible attachment of C-terminal amino acids to poly(ethylene glycol) supports succeeds in high yields by reaction of amino acid derivatives with 4-(2-bromopropionyl)phenylacetic acid N-hydroxysuccinimidester and subsequent coupling to the polymer.For communicatin 3 of this series see: Anzinger, H., Mutter, M.; Pol. Bull. 6, 595 (1982) 相似文献
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Serena Vittorio Dr. Laura Ielo Salvatore Mirabile Prof. Rosaria Gitto Dr. Antonella Fais Sonia Floris Prof. Antonio Rapisarda Prof. Maria Paola Germanò Prof. Laura De Luca 《ChemMedChem》2020,15(18):1757-1764
Tyrosinase is a type-3 copper protein involved in the biosynthesis of melanin pigments; therefore, the inhibition of its enzymatic activity represents a promising strategy for the treatment of hyperpigmentation-related disorders. To address this point, we previously designed a class of 4-(4-fluorobenzyl)piperazin-1-yl-based compounds, which proved to be more active inhibitors against tyrosinase from mushroom Agaricus bisporus than the positive control kojic acid. Herein, we report the synthesis of further series of 4-(4-fluorobenzyl)piperazin-1-yl analogues bearing a (hetero)aromatic fragment as key feature to improve protein affinity. The newly synthesized compounds were assayed in vitro and proved to be potent inhibitors in the low-micromolar range. The active 2-thienyl and 2-furyl derivatives were selected for further modification to allow their binding mode to be analyzed by docking studies and to give satisfactory safety profiles. 相似文献
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季鏻盐相转移催化卡宾法合成医药中间体(±)-α-氨基苯乙酸 总被引:1,自引:0,他引:1
在自制的四种季盐相转移催化剂和氯化锂的催化作用下 ,由苯甲醛 ,氯仿和氨合成了医药中间体 (± ) - α-氨基苯乙酸 ,研究了催化剂的催化性能 ,选择了较佳的催化剂和合成反应的较佳条件。结果表明 ,在苯甲醛和催化剂的摩比为 1∶ 1 ;氯化锂与苯甲醛的摩尔比为 2∶ 1 ;反应温度控制在 0~ - 1 5°C之间 ;反应时间 4h的条件下 ,(± ) - α-氨基苯乙酸其化学产率达 72 %。该合成法具有收率较高且避免了 Strecker合成法使用高毒性原料的特点 ,反应条件较易达到。其存在的不足是催化剂不易分离 ,不能反复利用。提出了解决该问题的途径之一是采用“三相转移催化剂”。 相似文献
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以苯乙酸为原料,4-氟苯基苯乙酮在HBr/H2O2作用下发生α-溴代,合成2-溴-1-(4-氟苯基)-苯乙酮,再与异丁酰乙酰苯胺在碱性条件下发生α-碳上的取代反应,得到阿托伐他汀钙的关键中间体4-氟-α-(2-甲基-1-氧丙基)-γ-氧-N,β-二苯基-苯丁酰胺,总收率57.3%。化合物结构经核磁、质谱得到确认。 相似文献