新型含2-取代-1,3-噻唑烷和噻唑环的亚胺类化合物的合成及生物活性

通过4-[(2-氰基亚胺基-1,3-噻唑烷-3-基)甲基]-2-氨基噻唑与取代苯甲醛的缩合反应, 合成了14个新型含2-取代- 1,3-噻唑烷和噻唑环的亚胺类化合物5. 所有化合物的结构均经1H NMR和元素分析确证, 并通过X射线单晶衍射分析测定了化合物5a的晶体结构. 初步生物活性试验结果表明, 部分目标化合物具有一定的杀菌活性和植物生长调节活性.     

N-芳基-4-(吡啶-2-基)-5-(1H-1,2,4-三唑-1-基)噻唑-2-胺衍生物的合成及生物活性研究

利用Hantzsch反应合成了13个N-芳基-4-(吡啶-2-基)-5-(1H-1,2,4-三唑-1-基)噻唑-2-胺衍生物,所有化合物的结构均经1H NMR,MS及元素分析确证.研究发现,溶剂对不同取代基的目标化合物的合成影响很大.生物活性测试结果表明,化合物均具有一定的杀菌活性.其中,化合物6c对番茄早疫和苹果轮纹、化合物6g对番茄早疫、化合物6h对黄瓜黑腥及化合物6i对苹果轮纹均显示80%以上的杀菌活性.     

4,5-二氢-1,3,4-噻二唑-5-酮-2-甲氨基取代氰基丙烯酸酯类化合物的 合成及生物活性研究

采用氰基丙烯酸酯与5-甲氧基-1,3,4-噻二唑-2-甲氨在乙醇中加热回流的方法合成了一系列4,5-二氢-1,3,4-噻二唑-5-酮-2-甲氨基取代的氰基丙烯酸酯类化合物. 目标化合物结构均经1H NMR, IR和元素分析确证. 生物活性测试结果表明: 部分化合物对双子叶杂草显示出较好的除草活性及良好的选择性, 化合物6j在1.5 kg/ha的剂量下对油菜的茎叶处理抑制率达到100%; 部分化合物还表现出了一定的杀菌和植物生长调节活性. 构效关系研究发现氰基丙烯酸酯3-位取代基的体积对除草活性影响较大, 3-位为异丙基时活性最高.     

2-{2-[3-(取代苯基)-3-氧代-2-1,2,4-三唑-1-基-丙基]-苯基}-2-甲氧亚氨基乙酸甲酯和乙酰甲胺类衍生物的合成与杀菌活性研究

以2-甲基苯甲酰甲酸甲酯为起始原料, 通过与甲氧基胺的盐酸盐、甲胺、N-溴代丁二酰亚胺(NBS)和1H-1,2,4-三氮唑钠反应合成了两个系列共计22个2-{2-[3-(取代苯基)-3-氧代-2-1,2,4-三唑-1-基-丙基]-苯基}-2-甲氧亚氨基乙酸甲酯和乙酰甲胺类的衍生物. 经IR, 1H NMR和MS对目标化合物进行了结构表征. 用浓度为 10 µg•mL－1的目标化合物进行了初步离体杀菌活性试验, 结果表明: Ha4, Ha5, Ha7对油菜菌核病有杀菌活性; Ha2, Hb8对小麦纹枯病有杀菌活性; Hb4对蔬菜灰霉病有杀菌活性; Hb4, Hb5对小麦赤霉病和小麦纹枯病均有杀菌活性.     

3-(4-β-D-吡喃阿洛糖苷-苯基)-4-芳基-5-芳基-1,2,4-噁二唑啉的合成及其镇静活性的研究

以豆腐果苷为原料,与盐酸羟胺缩合反应生成4-β-D-毗喃阿洛糖苷-苯甲醛肟(2),2与次氯酸叔丁酯发生取代反应生成4-β-D-吡喃阿洛糖苷-α-氯苯甲醛肟(3);再将3与Schiff碱通过1,3-偶极环加成生成一系列3-(4-β-D-吡喃阿洛糖苷-苯基)-4-芳基-5-芳基-1,2,4-噁二唑啉(5a～5h).3和5a～5h共9个化合物均未见文献报道,其结构经1H NMR,IR和MS(HRMS)加以确认,并对5a～5h进行了药理活性筛选.结果表明,部分化合物具有良好的镇静活性.其中,化合物5g(200,100 mg·kg-1)和5h(200,100 mg·kg-1)与豆腐果苷相比较具有更强的活性.     

N-取代芳酰氨基-5-氟代苯基-2-呋喃甲酰硫脲的合成与生物活性测定

从5-氟代苯基-2-呋喃甲酸出发, 经酰化、异硫氰酸酯化, 再与取代芳酰肼反应合成了20个未见文献报道的N-取代芳酰氨基-5-氟代苯基-2-呋喃甲酰硫脲. 目标产物的结构经IR, ¹H NMR和元素分析测定确证. 初步生物活性测试表明, 部分化合物对棉花枯萎病、黄瓜灰霉病、苹果轮纹病和棉花炭疽病有较好的选择性杀菌活性; 部分目标化合物有较好的除草活性.     

含1,2,4,5-四取代苯基的吡唑-4-甲酰胺类化合物的设计、 合成及生物活性

通过活性亚结构拼接的方法, 设计合成了一系列含四取代苯基的吡唑-4-甲酰胺类化合物, 所有化合物的结构均通过高分辨质谱（HRMS）和核磁共振氢谱（¹H NMR）确证. 生物活性测试结果表明, 部分化合物对苹果纹轮病菌、 水稻纹枯病菌、 油菜菌核病菌和黄瓜灰霉病菌表现出较好的杀菌活性. 化合物5c表现出较广的杀菌谱, 在浓度为50 μg/mL时对苹果纹轮病菌的抑制活性高达95.5%. 初步构效关系分析发现, 吡唑环N取代基为甲基或叔丁基时, 化合物表现出较好的活性; 含并环结构的化合物5′杀菌活性低于含单个苯环的化合 物5; 苯环取代基R²为低于4个碳的脂肪链时, 化合物杀菌活性更高.     

1,3-双(2-取代硫醚-1,3,4-噁二唑-5-基)苯的合成及其杀菌活性

以间苯二甲酸二甲酯为起始原料,经酰肼化、关环和硫醚化反应合成了8个新型的1,3-双(2-取代硫醚-1,3,4-噁二唑-5-基)苯,其结构经1H NMR,MS和元素分析表征。初步的生物活性测试结果表明,部分化合物具有较好的杀菌活性。     

新型(3-取代苯基-2-丙烯-1-亚基)-苯甲酰腙类化合物的设计、合成及生物活性研究

为了发现有高杀菌活性的先导化合物,通过活性亚结构拼接方法,将具有生物活性的肉桂醛与苯甲酰肼进行拼接,设计合成了一系列新型(3-取代苯基-2-丙烯-1-亚基)-酰腙类化合物.该类化合物以取代的苯甲酸为原料,经3步反应制得,结构经1H NMR,IR及元素分析确证.离体生测结果表明部分化合物对蘑菇酪氨酸酶及小麦赤霉病、黄瓜灰霉病和黄瓜炭疽病表现出一定的抑制活性,并对化合物进行了初步构效关系分析,其中化合物5r表现出与多氧霉素B相当的杀菌活性.     

3-羰基-4-氮杂-△5-雄甾烯-17-肟衍生物的合成及其抑制5α-还原酶活性研究

以雄甾-4-烯-3,17-二酮(AD)为起始原料,合成了14个甾体17位肟醚和肟酯类新化合物.所合成的化合物结构均经过MS,1H NMR谱确证,并对所合成的化合物进行了老鼠5α-还原酶抑制生物活性初步评价.结果表明：受试化合物均有一定的5α-还原酶抑制活性,其中化合物5a,5c,5d有较高的5α-还原酶抑制活性,与参比药物Espristeride相当.     

Synthesis,docking and ADMET prediction of novel 5-（（5-substituted- 1 -H- 1,2,4-triazol-3-yl ） methyl ）-4, 5,6,7-tetrahydrothieno [ 3,2-c ] pyri- dine as antifungal agents

A novel series of 5-((5-substituted-1H-1,2,4-triazol-3-yl)methyl)-4,5,6,7-tetrahydrothieno[3,2-c]pyridines 5(a–i) has been synthesized from thienopyridine hydrazide, substituted aromatic nitriles using 4-dimethylaminopyridine(DMAP) as a catalyst under microwave irradiation and evaluated for their in vitro antifungal activity. Compound 5g is found to be more potent against Candida albicans when compared with miconazole. Docking study of the newly synthesized compounds was performed, and results showed good binding mode in the active site of fungal enzyme P450 cytochrome lanosterol 14 ademethylase. ADMET properties of synthesized compounds were also analyzed and showed good drug like properties. The results of in vitro antifungal activity, docking study and ADMET prediction revealed that the synthesized compounds have potential antifungal activity and can be further optimized and developed as a lead compound.     

Synthesis and bioactivity of pyrazole acyl thiourea derivatives

Sixteen novel pyrazole acyl thiourea derivatives 6 were synthesized from monomethylhydrazine (phenylhydrazine) and ethyl acetoacetate. The key 5-chloro-3-methyl-1-substituted-1H-pyrazole-4-carbonyl chloride intermediates 4 were first generated in four steps through cyclization, formylation, oxidation and acylation. Thess were then reacted with ammonium thiocyanate in the presence of PEG-400 to afford 5-chloro-3-methyl-1-substituted-1H-pyrazole-4-carbonyl isothiocyanates 5. Subsequent reaction with fluorinated aromatic amines resulted in the formation of the title compounds. The synthesized compound were unequivocally characterized by IR, 1H-NMR, 13C-NMR and elemental analysis and some of the synthesized compounds displayed good antifungal activities against Gibberella zeae, Fusarium oxysporum, Cytospora mandshurica and anti-TMV activity in preliminary antifungal activity tests.     

Synthesis, characterization and antifungal evaluation of 5-substituted-4-amino-1,2,4-triazole-3-thioesters

A series of 5-substituted-4-amino-1,2,4-triazole-3-thioesters was synthesized by converting variously substituted organic acids successively into the corresponding esters, hydrazides, 5-substituted-1,3,4-oxadiazole-2-thiols, 5-substituted-1,2,4-triazole-2-thiols and 5-substituted-1,3,4-oxadiazole-2-thioesters. Finally the target compounds were obtained by refluxing 5-substituted-1,3,4-oxadiazole-2-thioesters in the presence of hydrazine hydrate and absolute alcohol. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The synthesized compounds were evaluated for their in vitro antifungal activity. Some of the evaluated compounds possessed significant antifungal activity as compared to a terbinafine standard.     

Design,Ultrasonic-assisted Synthesis and Evaluation In vitro Antimicrobial Activity of Bis-isoxazole Derivatives Bearing Chloro-pyridinyl Group

An ultrasonic-assisted synthesis of bis-isoxazole derivatives was developed. Eight 3-(6-chloropyridin-3-yl)-5-{[(3-aryli-soxazol-5-yl)methoxy]methyl}isoxazoles were synthesized by 1,3-dipolar cycloaddition reaction between substituted isoxazolyl alkyne compounds and 6-chloro-N-hydroxynicotinimidoyl chloride. The structures of the synthesized compounds were confirmed by HRMS, FTIR, ¹H and ¹³C NMR spectroscopy. Wherein, the antifungal and antibacterial activities of target compounds were tested. The synthesized compounds 6a and 6h exhibited better antifungal activity in comparison with the standard drug itraconazole. The minimum inhibitory concentrations(MICs) of both compound 6a and compound 6h were both 4 μg/mL against Candida albicans ATCC 10231.     

Synthesis and antimicrobial activity of 2,4-diaryl-2,3-dihydrobenzo[b][1,4]thiazepines

A new series of structurally diverse 2,3-dihydrobenzo[b][1,4]thiazepines (2,3-dihydro-1,5-benzothiazepines) with substituted phenyl groups at C(2) and C(4) have been synthesized by reaction of 3-(5-bromo-2-methoxyphenyl)-1-arylpropen-1-ones with 2-aminobenzenethiols. The structures of all the synthesized compounds were confirmed by their analytical and spectral data (IR, ¹H NMR, ¹³C NMR). All the synthesized compounds were evaluated for antibacterial and antifungal activity against a variety of bacterial and fungal strains and interesting results were obtained. Some of the compounds had antibacterial and antifungal activity comparable to that of ciprofloxacin and fluconazole.     

Synthesis,Characterization and Biological Activities ofN-Acyl-3-(3-pyridyl)-5-aryl-pyrazoles

Ten novel N-acyl-3-(3-pyridyl)-5-aryl-pyrazoles were synthesized by Claisen condensation of the aryl methyl ketones with ethyl nicotinate, the cyclization with hydrazine hydrate and the N-acylation with acyl chloride in turn. The structures of all the compounds synthesized were confirmed by means of Fourier transform infrared(FTIR), ¹H NMR, mass spectroscopy and elemental analysis. The biological activities of the title compounds were examined by disc diffusion method against Escherichia coli, Staphylococcus aureus, Pyricularia oryzae and Rhizoctnia solani. All the N-acyl-3-(3-pyridyl)-5-aryl-pyrazoles exhibited a certain degree of antibacterial and antifungal activities. Comparatively, compounds 3c and 3d exhibited much significant antibacterial and antifungal activities than the other pyrazole derivatives.     

Synthesis and antimicrobial activity of some novel substituted 1,2,4‐triazoles bearing 1,3,4‐oxadiazoles or pyrazoles

Several derivatives of substituted 1,2,4‐triazole bearing the pyrazole (or oxadiazole) ring were synthesized via the reaction of 2,4‐dihydro‐4‐benzyl‐5‐(isomeric pyridyl)‐3H‐1,2,4‐triazole‐3‐thione 1a , 1b , 1c with ethyl chloroacetate, hydrazine hydrate, and acetyl acetone (or CS₂/KOH) in absolute ethanol. The intermediate then undergoes an intramolecular cyclization in acidic medium. The newly synthesized compounds 4a , 4b , 4c to 7a , 7b , 7c were characterized using IR, NMR, and MS Spectroscopy. Some of the synthesized compounds 4 , 5 , 7a , 7b , 7c were evaluated for their antibacterial and antifungal activities. Most of these compounds indicated activity comparable to Gentamycine. Also some of them are more active than Tolnaftate, a known antifungal drug. J. Heterocyclic Chem., (2011)     

Mild and Ecofriendly Tandem Synthesis,and Spectral and Antimicrobial Studies of N1-Acetyl-5-aryl-3-(substituted styryl)pyrazolines

N¹-acetyl-5-aryl-3-(substituted styryl)pyrazolines were synthesized by the cyclocondensation of 1,5-substituted diphenyl-1,4-pentadien-3-ones with hydrazine hydrate and a cyclizing agent such as acetic acid in ethanol. The title compounds were synthesized using conventional and solvent-free approaches, which involves mechano-chemical mixing, microwave-irradiation, and ultrasound-irradiation methods in the presence of a solid support. The synthesized compounds have been characterized by elemental analyses and spectral data (IR, PMR, and FAB-mass). All the synthesized compounds have been evaluated for their antibacterial and antifungal activities. Some compounds have shown promising biological activity.     

CAN catalyzed one-pot synthesis and docking study of some novel substituted imidazole coupled 1,2,4-triazole-5-carboxylic acids as antifungal agents

The present work describes a facile,one-pot three component synthesis of a series of 3-[(4,5-diphenyl-2-substituted aryl/heteryl)-1H-imidazol-1-yl]-1H-1,2,4-triazole-5-carboxylic acid derivatives M(1-15).Benzil,aromatic aldehydes and 3-amino-l,2,4-triazole-5-carboxylic acid was refluxed in ethanol using cerric ammonium nitrate(CAN) as a catalyst to give the title compounds in good yields.The compounds were evaluated for their in vitro antifungal and antibacterial activity.Compounds M1,M9,and M15 were found to be equipotent against Candida albicans when compared with fluconazole.Compounds M2.M5,and M14 showed higher activity against Streptococcus pneumoniae.Escherichia coli and Streptococcus pyogenes,respectively,compared with ampicillin.Docking study of the newly synthesized compounds was performed,and the results showed good binding mode in the active sites of C albicans enzyme cytochrome P450 lanosterol 14α-demethylase.The results of in vitro antifungal activity and docking study showed that synthesized compounds had potential antifungal activity and can be further optimized and developed as a lead compound.     

Synthesis and Pharmacological Evaluation of a Novel Series of 2‐((2‐Aryl thiazol‐4‐yl)methyl)‐5‐(alkyl/alkylnitrile thio)‐1,3,4‐oxadiazole Derivatives as Possible Antifungal Agents

In the present investigation, a novel series of 2‐[(2‐arylthiazol‐4‐yl)methyl]‐5‐(alkyl/alkylnitrile thio)‐1,3,4‐oxadiazole derivatives were synthesized by cyclo‐condensation of 2‐(2‐substituted thiazol‐4‐yl)aceto hydrazide with carbon disulfide followed by S‐alkylation with alkyl halide in dry acetone. All the newly synthesized compounds were characterized by spectral (IR, ¹H NMR, ¹³C NMR, mass, and elemental analysis) methods. The title compounds were screened for in vitro antifungal activity and most of the synthesized compounds show moderate to good antifungal activity.