含哌啶的新型1,2,4-噁二唑类衍生物的设计合成及抗真菌活性研究

为了寻找新型高效的抗菌先导化合物,采用活性亚结构拼接法,设计合成了17个含哌啶的新型1,2,4-噁二唑类衍生物4a～4b和6a～6o,其结构经¹H NMR、¹³C NMR和高分辨质谱(HRMS)表征. N-(1-苯甲酰基哌啶-4-基)-4-(5-(三氟甲基)-1,2,4-噁二唑-3-基)苯甲酰胺(6e)结构由X射线单晶衍射法加以确证.抗菌活性测试结果表明:在浓度为3.13mg/L时, N-(1-乙酰基哌啶-4-基)-4-(5-(三氟甲基)-1,2,4-噁二唑-3-基)苯甲酰胺(6a)、N-(1-(环丙甲酰基)哌啶-4-基)-4-(5-(三氟甲基)-1,2,4-噁二唑-3-基)苯甲酰胺(6c)、6e、4-((4-(5-(三氟甲基)-1,2,4-噁二唑-3-基)苯甲酰胺基)甲基)哌啶-1-甲酸叔丁酯(4b)和N-((1-(苯甲酰基)哌啶-4-基)甲基-4-(5-(三氟甲基)-1,2,4-噁二唑-3-基)苯甲酰胺(6o)对大豆锈病(Phakopsora pachyrhiz)的抑制率分别为70%、82%、95%、78%和98%,优于Flufenoxa...     

含双酰胺结构的1,2,4-噁二唑类衍生物的设计、合成及抗菌活性

为了寻找新型抗菌先导化合物,采用活性亚结构拼接的方法引入新的活性片段及取代基,设计合成了27个新型含双酰胺结构的1,2,4-噁二唑类衍生物4a～4c和6a～6x,经核磁共振氢谱（1H NMR）和高分辨质谱（HRMS）确证其化学结构.抗菌活性测试结果表明,当浓度为3.13 mg/L时,化合物6f, 6i, 6m, 6n和6q对大豆锈病(Phakopsorapachyrhiz)的防效分别为80%, 90%, 80%, 90%和70%,优于杀菌剂Flufenoxadiazam(30%)和对照药剂苯醚甲环唑(50%);化合物6i和6n的抗菌活性优异,当浓度为1.56 mg/L时,对大豆锈病仍有50%和70%的抗菌活性.化合物6n在浓度为1.56mg/L时,对玉米锈病(Pucciniasorghi)具有100%防效的优异抗菌活性.分子对接模拟结果表明,化合物6n与组蛋白去乙酰化酶4(HDAC 4)具有多种相互作用,与PRO-298, LEU-299及HIS-158号残基形成的氢键作用可能是其抗菌活性优异的重要原因.     

含氟1,3,4-噁唑啉和1,3,4-噁二唑类化合物的合成及其抗癌活性

对氟苯甲酰腙与乙酸酐或丙酸酐反应后再脱水环化制得2-苯基-3-乙酰基-5-对氟苯基-1,3,4-噁唑啉(3)或2-苯基-3-丙酰基-5-对氟苯基-1,3,4-噁唑啉(4).N-对氟苯甲酰基-N′-苯甲酰肼在POCl3存在下脱水环化制得2-苯基-5-对氟苯基-1,3,4-噁二唑(6).新化合物3,4和6的结构经1H NMR,IR,MS和元素分析表征.用MTT方法评价了其对HepG-2,A549-1和231-2癌细胞株的体外生长抑制活性.结果表明,3,4和6均具有潜在的体外抑制癌细胞生长活性,其中3的活性最强.     

含1,2,4-三唑和1,3,4-噁二唑硫醚类化合物的合成及结构表征

在KOH溶液中,芳甲酰肼(2)与CS2生成钾盐3;然后3在水合肼作用下经过环化、取代、肼解得3-巯基-4-氨基-5-苯基-4H-1,2,4-三唑-乙酸酰肼(6),6再与CS2回流成环生成化合物5-(4-氨基-5-苯基-4H-1,2,4-三唑-3-硫烷基)-1,3,4-噁二唑-2-硫醇(7),最后7与取代苄基氯反应得目标化合物A1～A6,与芳基甲醛反应得终产物B1～B15.目标化合物的结构均经1H NMR,13C NMR,IR,MS或HRMS确证结构.     

取代二噁二唑硫醚及砜衍生物合成及抗菌活性

取代二噁二唑硫醚及砜衍生物合成及抗菌活性     

含磺酰胺结构的1,3,4-噁二唑砜类化合物的设计、合成及抗菌活性研究

为了寻找新型抗菌剂,采用活性亚结构拼接,设计合成了23个含磺酰胺结构的1,3,4-噁二唑砜类化合物,并对其抗菌活性进行了测试.在100μg/m L浓度下,大多数化合物对水稻细菌性条斑病菌(Xanthomonas oryzae pv.oryzicola)和水稻白叶枯病菌(Xanthomonas oryzae pv.oryzae)表现出优异的离体抗菌活性.除N-((5-(丙基磺酰基)-1,3,4-噁二唑-2-基)甲基)-4-(三氟甲基)苯磺酰胺(18)外,所有化合物对水稻细菌性条斑病菌的半数有效浓度(EC₅₀)值为1.3～22.5μg/mL所有化合物对水稻白叶枯病菌的EC₅₀为1.1～32.7μg/m L,均优于对照药剂叶枯唑(84.1和71.4μg/mL)和噻菌酮(122.1和84.0μg/m L).此外,4-氟-N-((5-(甲基磺酰基)-1,3,4-噁二唑-2-基)甲基)苯磺酰胺(4)可以通过抑制胞外多糖(EPS)的产生、生物膜的形成以及改变细胞膜的通透性和细胞表面形态,从而抑制水稻细菌性条斑病菌和水稻白叶枯病菌的正常生长.     

3-(吗啉吡啶基)-5-取代异噁唑类化合物的合成及抗菌活性研究

以6-氯-3-吡啶甲醛为原料, 通过多步反应合成了一系列3-(吗啉吡啶基)-5-取代异噁唑类化合物, 并用IR, 1H NMR, 13C NMR和MS进行了结构确证. 这些化合物均以异噁唑为母核, 具有近似的平面结构, 在异噁唑环的3-位引入吗啉吡啶基, 而在5-位引入酯基、取代氨基、三唑环和噁唑烷酮环. 研究了这些化合物对金黄色葡萄球菌、耐甲氧西林金黄色葡萄球菌、表皮葡萄球菌、粪肠球菌和大肠杆菌的抑制活性, 发现与噁唑烷酮类上市药物利奈唑胺相比, 目标化合物均显示出更低的抗菌活性, 最低抑制浓度(MIC)大于32 mg/L, 这些试验结果表明异噁唑母核的5-位缺乏sp3杂化结构, 可能会导致抗菌活性的显著降低.     

5-嘧啶基-1,2,4-噁二唑衍生物的合成及生物活性研究

通过嘧啶甲酰氯与取代的苄胺肟反应得到一系列结构新颖的5-嘧啶基-1,2,4-噁二唑类化合物,并对其结构进行了表征,培养并测定了化合物5a的晶体结构;将目标化合物晶体结构对接到靶酶酵母乙酰辅酶A羧化酶(ACCase)的活性位点,发现目标化合物与复合物晶体中的禾草灵分子的构象及结合模式相似;初步生物活性测试表明部分化合物具有较好的除草活性.     

噁唑、苯并噁唑及1,3,4-噁二唑硫醚的合成及抗肿瘤活性研究

设计并以噁唑、苯并噁唑及1,3,4-噁二唑硫醇与卤代烃反应合成了14个硫醚类杂环化合物, 其中13个化合物未见文献报道. 目标化合物的结构均通过¹H NMR谱、MS和元素分析进行了表征. 采用MTT [3-(4,5-dimethylthiagol-2-yl)- 2,5-diphenyltetrogolium bromide]法对14个目标化合物进行了体外抗肿瘤活性测定, 结果表明: 在10^－5 mol/L 浓度下, 10个化合物对肿瘤细胞具有抑制活性.     

新型含1,3,4-噁二唑的吡唑类化合物的合成及其抗肿瘤活性

以4-甲氧基苯乙酮为原料,设计并合成了7个新型的含1,3,4-噁二唑的吡唑类化合物(7a~7g),其结构经1H NMR,IR和ESI-MS表征。并用MTT法测定了7a~7g抑制人肝癌细胞Hep G2增殖的体外活性。结果表明,5-[3-(4-甲氧基苯基)-1-苯甲基吡唑-5-基]-2-[N-(4-溴苯基)乙酰胺-2-硫基]-1,3,4-噁二唑7g具有较好的抑制活性,其IC50为60.06μM。     

Focused microwave irradiation-assisted synthesis of N-cyclohexyl-1,2,4-oxadiazole derivatives with antitumor activity

A facile synthesis of 3,5-disubstituted 1,2,4-oxadiazole derivatives under focused microwave irradiation (FMWI) is reported. Arylamidoximes 1a–i and dicyclohexylcarbodiimide (DCC) were carried out in DMF under FMWI to obtain 1,2,4-oxadiazoles 2a–i in 61–81% yields. All compounds exhibited antiproliferative activities in vitro against three human cancer cell lines HCT-116, PC-3, and SNB-19.     

Synthesis,characterisation and mesomorphic behaviours of non-symmetrically substituted 1,2,4- and 1,3,4-oxadiazole derivatives

Two series of non-symmetrically substituted bent-core mesogens derived from the central 3,5 and 2,5 cores of the 1,2,4- and 1,3,4-oxadiazole derivatives, respectively, containing ether and ester linkage have been synthesised by several straightforward synthetic procedures, and their mesomorphic behaviour was studied by optical polarising microscopy (OPM) and differential scanning calorimetry (DSC). The last five homologues of the 1,2,4-oxadiazole series exhibit a monotropic nematic phase on cooling, while the 1,3,4-oxadiazole derivatives do not show any liquid crystalline properties but rather a crystal to isotropic transition is observed by OPM. We show that the bent angles of the 1,2,4- and 1,3,4-oxadiazole rings are crucial in observing the liquid crystal (LC) phases formed, and also that the length of the alkyl substituent is observed to have a significant effect on the nature of the LC phases.     

Polycyclic systems containing 1,2,4-oxadiazole ring 2. 4-(1,2,4-Oxadiazol-5-yl)pyrrolidin-2-ones: Synthesis and prediction of biological activity

A one-pot condensation of 5-oxopyrrolidine-3-carboxylic acids, carbonyldiimidazole, and benzamidoximes leads to the formation of the novel 4-(1,2,4-oxadiazol-5-yl)pyrrolidin-2-one bicyclic systems, the structures of which have been confirmed by IR and ¹H NMR methods and by liquid chromato-mass spectrometry. The results of a PASS prediction of the biological activity of the synthesized compounds are presented. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 758–764, May, 2008.     

Ultrasound-assisted,one-pot,three-component synthesis and antibacterial activities of novel indole derivatives containing 1,3,4-oxadiazole and 1,2,4-triazole moieties

Thirteen novel indole derivatives were efficiently synthesized through ultrasound irradiation by using 4-amino-5-(1H-indol-3-yl)-4H-[1,2,4]triazole-3-thiol (8) and 2-mercapto-5-substituted-1,3,4-oxadiazoles (5a–m). Compared with conventional and microwave methods, yields increased to 82–93%, and reaction times decreased to 15–35 min. The structures of these novel compounds were characterized by spectral data and elemental analysis. Two out of the synthesized compounds (10f and 10l) exhibited excellent activity against Staphylococcus aureus and Escherichia coli, and thus warrant further research.     

Synthesis and in vitro antibacterial activity of new oxoethylthio-1,3,4-oxadiazole derivatives

In the present investigation, a series of 2(4-pyridyl)-5[(aryl/heteroarylamino)-1-oxoethyl]thio-1,3,4-oxadiazole were synthesized using isonicotinohydrazide and substituted aryl/heteroaryl amines using pyridine as solvent. Newly synthesized compounds were tested for their in vitro anti-tubercular activity against Mycobacterium tuberculosis H37Rv using the BACTEC 460 radiometric system. Among the synthesized compounds, compounds 2(4-pyridyl)-5((2-nitrophenylamino)-1-oxoethyl)thio-1,3,4-oxadiazole (5e), 2(4-pyridyl)-5((4-nitrophenylamino)-1-oxoethyl)thio-1,3,4-oxadiazole (5g) and 2(4-pyridyl)-5((2-pyrrolylamino)-1-oxoethyl)thio-1,3,4-oxadiazole (5k) produced highest efficacy and exhibited >90% inhibition at a concentration of 0.0077, 0.0052 and 0.0089 μM, respectively. All the new compounds were pharmacologically evaluated for their in vitro Antimicrobial activity.     

2,5-双取代-1,3,4-噁二唑类化合物的合成与表征

以3-( 4-氟苯基) -1H-吡唑-5-甲酸乙酯为原料,与H2NNH2?H2O发生肼解生成3-( 4-氟苯基) -1H-吡唑-5-甲酰肼,再与CS2环化生成2-巯基噁二唑中间体,最后在巯基上进行烷基化反应合成了一系列新型的2-硫醚-5-吡唑基-1,3,4-噁二唑类化合物,并利用IR、1H NMR、HRMS等波谱技术对目标化合物结构进行了表征。该合成方法具有原料易得,后处理简便,收率较高的优点。     

三芥子酸甘油酯类似物的合成及抑菌活性

以N-(2-溴乙基)邻苯二甲酰亚胺或N-(4-溴丁基)邻苯二甲酰亚胺和硫氢化钠为起始原料,通过取代、肼解、亲核加成等反应合成了10个三芥子酸甘油酯(erucin)类似物,通过核磁共振氢谱、碳谱及质谱对其结构进行了确认。采用比浊法初步测试了其对大肠杆菌、金黄色葡萄球菌、白色葡萄球菌、藤黄八叠球菌、枯草芽孢杆菌、蜡状芽孢杆菌和四联球菌等7种菌的生长抑制活性,测试结果显示,化合物对测试菌种都表现出较好的生长抑制活性,其中苄硫乙基-1-硫代异硫氰酸酯(5e)和苄硫基丁基-1-硫代异硫氰酸酯(5j)活性最高,对大肠杆菌的最低生长抑制浓度仅为7.8μg/m L,对金黄色葡萄球菌的最低生长抑制浓度也仅为15.6μg/m L和31.2μg/m L。