Synthesis,in vitro antibacterial and antifungal evaluation of novel 1,3,4-oxadiazole thioether derivatives bearing the 6-fluoroquinazolinylpiperidinyl moiety

A series of structurally novel 1,3,4-oxadiazole thioether derivatives(6a-6z) containing a 6-fluoroquinazolinylpiperidinyl moiety were designed and synthesized using pharmacophore hybrid approach,and their structures were fully characterized by ^1H NMR,¹³C NMR and HRMS spectra.Among them,the structure of compound 6 d was further corroborated via single-crystal X-ray diffraction analysis.In vitro antibacterial bioassays showed that compounds 6 a,6 g,6 u and 6 v possessed EC₅₀ values of 30.4,30.6,27.5 and 26.0 μg/mL against phytopathogenic bacterium Xanthomonas oryzae pv.oryzae,respectively,which were significantly superior to that of commercially-available bactericide Bismerthiazol(85.1 μg/mL).Moreover,in vitro antifungal bioassays indicated that seven compounds demonstrated broad-spectrum fungicidal acitivties against six types of phytopathogenic fungi at 50 μg/mL.The present work showed the potential of 1,3,4-oxadiazole thioether derivatives carrying a 6-fluoroquinazolinylpiperidinyl moiety as effective antimicrobial agents for crop protection,deserving further investigations in the future.     

Novel 1,3,4-oxadiazole thioether and sulfone derivatives bearing a flexible N-heterocyclic moiety: Synthesis,characterization, and anti-microorganism activity

In the search for more efficient and versatile anti-phytopathogen agents, a series of new 1,3,4-oxadiazole thioether/sulfone analogues bearing a flexible N-containing heterocyclic pattern were elaborately prepared, and their bioactivities against plant pathogenic microorganisms were systematically evaluated. Bioassay screening results demonstrated that compounds 32 and 33 significantly inhibited the growth of Xanthomonas oryzae pv. oryzae (Xoo) in vitro (32, EC₅₀ = 5.17 mg L^?1; 33, EC₅₀ = 1.19 mg L^?1), which were significantly surpass commercial bismerthiazol (BT) and thiodiazole copper (TC). Meanwhile, pot experiments confirmed the prospective applications of compound 33 in managing rice bacterial leaf blight and its good safety toward rice plants. Further studies showed that compound 33 interfered with the formation of bacterial biofilms and inhibited bacterial virulence factors. Furthermore, an in vitro antifungal bioassay showed that compound 32 possessed remarkable growth inhibitory activity against Sclerotinia sclerotiorum (S.s., EC₅₀ = 22.16 mg L^?1) and Verticillium dahlia (V.d. EC₅₀ = 32.78 mg L^?1). These results all confirmed that the designed 1,3,4-oxadiazole compounds displayed potential for managing plant microbial diseases through targeting dihydrolipoamide S-succinyltransferase (DLST).     

2－芳酰氨基－5－（5－苯基－2H－四唑2－甲基）－1，3，4－噻二唑类化合物的合成

在浓硫酸作用下，由５－（５－苯基－２Ｈ四唑－２－乙酰基）－４－芳酰氨基硫脲１ａ～ｎ制得了一系列新的２－芳酰氨基－５－（５－苯基－２Ｈ－四唑－２－甲基）－１，３，４－噻二唑化合物（２ａ～ｎ）。所有化合物的结构均经元素分析、ＭＳ分析，部分代表化合物经ＩＲ、￣ＨＮＭＲ分析确证；初步观察了２ａ～ｎ在１％浓度下对大肠杆菌（Ｇ￣－）的抑制作用，发现２ｄ，２ｅ，２ｆ，２ｎ显示出较强的活性。     

新型1-(1,3,5-三嗪-6-基)-3-甲基-4-(5-苯基-1,3,4-噁二唑-2-基)吡唑的合成及活性评价

设计合成了18个以吡唑桥连1,3,4-噁二唑和1,3,5-三嗪的新型多杂环分子[7A(a~f),7B(a~f)和7C(a~f)];通过红外光谱(IR)、核磁共振波谱(NMR)和高分辨质谱(HRMS)等对目标分子进行了结构表征;评价了目标分子对蛋白酪氨酸磷酸酯酶1B(PTP1B)和细胞分裂周期25磷酸酯酶B(Cdc25B)的抑制活性.结果表明,所有目标分子对PTP1B和Cdc25B均有较好的抑制活性,其中,9个目标分子表现出优异的PTP1B和Cdc25B抑制效果,IC50值低于齐墩果酸(PTP1B抑制活性测试参照物)和正钒酸钠(Cdc25B抑制活性测试阳性参照物),有望成为潜在的PTP1B和Cdc25B抑制剂.     

Synthesis and antitumor activity of N^1-acetylamino-（5-alkyl/aryl-1,3,4-thiadiazole-2-yl）-5-fluorouracil derivatives

A new series of N^1-acetylamino-（5-alkyl/aryl- 1,3,4-thiadiazole-2-yl）-5-fluorouracil derivatives were designed and synthesized. These compounds have not been reported in literature, and their structure chemical were confirmed by IR, ^1H NMR and MS （HRMS）. The results of antitumor inhibitory activity test showed that some compounds possess more potent antitumor inhibitory activity than 5-fluorouracil.     

2-取代苯基-5-(3,4,5-三甲氧基苯基)-1,3,4-噁二唑衍生物的合成及生物活性研究

合成了10个2-取代苯基-5-(3,4,5-三甲氧基苯基)-1,3,4-噁二唑衍生物. 并经过元素分析, IR, ¹H NMR, ¹³C NMR对其结构进行了确认. 初步生物活性测试表明, 部分化合物具有一定抗癌活性.     

Synthesis and antimicrobial screening of 1,3,4-oxadiazole and clubbed thiophene derivatives

In the present study, a novel series of 2-{5-[4-(1-aza-2-(2-thienyl)vinyl)phenyl](1,3,4-oxadiazol-2-ylthio)}-N-arylacetamides (IV)_1–12 were synthesized and tested for their antimicrobial activity. Newly synthesized compounds were screened for their antibacterial and antifungal activities on Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus pyogenes, Candida albicans, Aspergillus niger and Aspergillus clavatus. The chemical structures of newly synthesized compounds were elicited by IR, ¹H NMR, ¹³C NMR and mass spectral data. The synthesized bio-active compounds exhibited excellent to moderate antimicrobial activity. Compounds (IV)₅, (IV)₆ and (IV)₇ possess excellent antibacterial activity whereas compounds (IV)₆, (IV)₉ and (IV)₁₁ possess excellent antifungal activity.     

微波促进下2,5-二取代-1,3,4-(口恶)二唑衍生物的合成

报道了微波促进无溶剂条件下二酰基肼可以良好产率脱水闭环得到2，5-二取代-1，3，4-E二唑衍生物。反应产率受取代基影响较大，苯基取代时产率较高，烷基取代时产率较低；反应产率与所用的无机支持有关，其中以酸性三氧化二铝的效果最佳。此法不仅环境友好且操作安全，避免使用化学脱水剂。     

3-(3-吲哚基)-5-吡唑甲酰胺的合成及抑菌活性

本文以3-乙酰吲哚、草酸二乙酯、水合肼等为原料,经缩合、环化、水解反应制备3-(3-吲哚基)吡唑-5-甲酸,后者再与苄胺或2-苯乙胺在EDC-BTOH催化下合成了一系列N-取代苄基-3-(3-吲哚基)吡唑-5-甲酰胺和N-(2-取代苯基乙基)-3-(3-吲哚基)吡唑-5-甲酰胺。采用平板计数法测试了化合物对大肠杆菌和金黄色葡萄球菌的抑制活性,结果表明,在浓度为80 μg/mL时部分化合物有较高的抑菌活性。     

Synthesis of organo soluble aromatic poly(amide-imide)s based on 2-(5-(3,5-dinitrophenyl)-1,3,4-oxadiazole-2-yl)pyridine in an ionic liquid

In this work,the syntheses of new thermally stable poly(amide-imide)s with pendant 2-pyridyl-1,3,4-oxadiazole units in n-butyl methyl imidazolium bromide as reaction media have been reported.A new dicarboxylic acid has been derived from the reaction of diamine,2-(5-(3,5-diaminophenyl)-1,3,4-oxadiazole-2-yl)pyridine(POBD),and trimellitic acid anhydride.Polymers were prepared from the reaction of the diimide-diacid(DIDA) and different aromatic diamines in butyl methyl imidazolium bromide,[bmim][Br],in the ...     

多亚甲基桥连双（5—甲基—2—巯基—1,3,4—噻二唑）的合成与鉴定

通过多亚甲基二溴化物桥连双合成了４个新配体合物，并通过元素分析，ＩＲ，ＵＶ和＾１ＨＮＭＲ确定了它们的结构。     

Synthesis and Crystal Structure of 2-（ 4-Decarboxydehydroabietyl）- 5-p-tolyl-[ 1,3,4 ]-oxadiazole

2-（4-Decarboxydehydroabietyl）-5-p-toyl-[1,3,4]-oxadiazole, C28H34N2O, has been synthesized and characterized by IR, NMR, elemental analysis and single-crystal X-ray diffraction method. The crystal belongs to the orthorhombic system, space group P212121 with a = 6.1351（5）, b = 14.8495（19）, c = 25.9050（2） A, V = 2360.0（4） A3, Z = 4, Mr = 414.57, Dc = 1.167 Mg/m^3, 2 = 0.71073 A,μ（MoKa） = 0.070 mm^-1, F（000） = 896, the final R = 0.0452 and wR = 0.1076 for 1647 observed reflections with I 〉 2σ（I）. There are five rings in the crystal structure of the title compound, but the oxadiazole ring is non-coplanar with the benzene ring D.     

Synthesis and antifungal activity of novel sulfone derivatives containing 1,3,4-oxadiazole moieties

A series of new sulfone compounds containing 1,3,4-oxadiazole moieties were synthesized. The structures of these compounds were confirmed by spectroscopic data (IR, 1H- and 13C-NMR) and elemental analyses. Antifungal tests indicated that all the title compounds exhibited good antifungal activities against eight kinds of plant pathogenic fungi, and some showed superiority over the commercial fungicide hymexazol. Among them, compounds 5d, 5e, 5f, and 5i showed prominent activity against B. cinerea, with determined EC?? values of 5.21 μg/mL, 8.25 μg/mL, 8.03 μg/mL, and 21.00 μg/mL, respectively. The present work demonstrates that sulfone derivatives such as 5d containing a 1,3,4-oxadiazole moiety can be used as possible lead compounds for the development of potential agrochemicals.     

Synthesis and antiviral activity of novel thioether derivatives containing 1,3,4-oxadiazole/thiadiazole and emodin moieties

A series of novel thioether derivatives containing 1,3,4-oxadiazole/thiadiazole and emodin moieties were designed and synthesized. The structures of the target compounds were confirmed by ¹H NMR, ¹³C NMR, Infrared, and elemental analysis. The results of bioactivity analysis showed that most of the target compounds exhibited moderate to good antiviral activity against tobacco mosaic virus at a concentration of 500 mg/L. Especially, among the title compounds, Y2, Y8, and Y10 possessed appreciable curative activity in vivo, with inhibition rates of 50.51, 52.08, and 54.62%, respectively, which were similar to that of Ningnanmycin (53.40%).     

2-芳基-3-N-丙酰基-5-(4-溴苯基)-1,3,4-噁唑啉类化合物的合成

噁唑啉类化合物是重要的杂环族化合物,在农药化学和医药化学中应用及其广泛。在现有的文献中已报道的大多是3-N乙-酰基-1,3,4噁-唑啉类化合物的合成[1-6],而3-N乙-酰基-1,3,4噁-唑啉类化合物的合成却很少见。为了深入研究同一分子中聚集不同骨架杂环化合物的合成以及开发新型高     

Synthesis and pharmacological evaluation of 9(10H)-acridone bearing 1,3,4-oxadiazole derivatives as antimicrobial agents

In the present study a new acridone derivatives were synthesized. The newly synthesized compounds were characterized by IR, NMR and C, H, N, S analyses. All newly synthesized compounds were screened for their antibacterial (Staphylococcus aureus, Streptococcus viridans and Escherichia coil) and antifungal (Gibberela, Cercospora arachidicola, Physolospora piricola and Fusarium oxysporum) studies. The results revealed that all synthesized compounds have a significant biological activity against the tested microorganisms.     

Synthesis,characterization and antimicrobial evaluation of novel halopyrazole derivatives

Two novel halopyrazole derivatives (3, 5) were synthesized from 5-chloro-3-methyl-1-phenylpyrazole-4-carboxaldehyde (1) using appropriate synthetic routes. Newly synthesized compounds were characterized using elemental analysis, spectral data (IR, ¹H NMR, ¹³C NMR and mass spectrometry) and were evaluated for their in vitro antimicrobial activity. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) were determined for the test compounds as well as for reference standards. The investigation of antimicrobial screening revealed that compounds (3, 5) showed good antibacterial and antifungal activities, respectively.     

Synthesis and Fungicidal Activities of 2-Alkylthio-5-(3,4,5-tribenzyloxyphenyl)-l, 3,4-oxadiazoles

Ten novel 2-alkylthio-5-(3, 4, 5-tribenzyloxyphenyl)-1, 3, 4-oxadiazole derivatives (5a-j) were synthesized from methyl 3, 4, 5-trihydroxybenzoate by etherification, hydrazidation, cyclization and thioetherification reactions. The structures of 5a-j were confirmed by 1HNMR, MS spectra and elemental analysis. The results indicated that most of the compounds 5 exhibited good fungicidal activities. The activity of 5h is higher than 90% against Fusarium oxysporum and Botrytis cinereapers in 50 mg/L.