含1,2,4-三唑并[3,4-b]-1,3,4-噻二唑杨梅素衍生物的设计、合成及生物活性研究

Design,Synthesis and Biological Activity of Myricetin Derivatives Containing 1,2,4-Triazolo[3,4-b]-1,3,4-thiadiazole

利用活性拼接的原理,以杨梅苷为原料,将1,2,4-三唑并[3,4-b]-1,3,4-噻二唑引入到杨梅素结构中,合成了一系列含三唑并噻二唑的杨梅素衍生物,通过1H NMR、13C NMR和高分辨质谱(HRMS)进行了结构表征,并通过X单晶衍射实验确认了3-(3-((3-乙基-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫代)丙氧基)-5,7-二甲氧基-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A5)的结构.生物活性测试结果表明:浓度为100μg/mL时,3-(3-((3-(4-(叔丁基)苯基)-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫基)丙氧基)-5,7-二甲氧基-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A15)对柑桔溃疡病菌(Xac)的抑制率为63.3%,优于对照药噻菌铜(57.3%);部分化合物对烟草花叶病毒(TMV)表现出较好的抑制活性.其中,治疗活性方面,化合物A5,5,7-二甲氧基-3-(4-((3-(甲氧基甲基)-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫代)丁氧基)-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A8),5,7-二甲氧基-3-(3-((3-苯基-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫代)丙氧基)-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A9),5,7-二甲氧基-3-(4-((3-(对甲苯基)-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫代)丁氧基)-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A12)的EC50值分别为88.3,139.1,109.9,160.1μg/mL,优于对照药宁南霉素(227.2μg/mL).保护活性方面,5,7-二甲氧基-3-(4-((3-苯基-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫代)丁氧基)-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A10),5,7-二甲氧基-3-(4-((3-(4-甲氧基苯基)-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫基)丁氧基)-2-(3,4,5-三甲氧基苯)-4H-色酮-4-酮(A14),3-(3-((3-(4-(叔丁基)苯基)-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫基)丙氧基)-5,7-二甲氧基-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A15),3-(4-((3-(4-叔丁基)苯基)-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫基)丁氧基)-5,7-二甲氧基-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A16),3-(4-((3-(4-氯苯基)-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫基)丁氧基)-5,7-二甲氧基-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A18)的EC50值分别为103.1,107.4,86.3,79.2,111.5μg/mL,优于对照药宁南霉素(179.2μg/mL).微量热涌动实验表明,化合物A12和A16与烟草花叶病毒外壳蛋白(TMV-CP)具有较强的亲和力,分子对接实验表明,化合物A16与TMV-CP具有较强的相互作用.

A series of myricetin derivatives containing 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole moiety were designed and synthesized using myricetin as the starting material through active splicing strategy.All target compounds were characterized by 1H NMR,13C NMR and high-resolution mass spectra(HRMS).Single crystal X-ray diffraction experiments were carried out with 3-(3-((3-ethyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-6-yl)thio)propoxy)-5,7-dimethoxy-2-(3,4,5-trimethoxyphenyl)-4Hchromen-4-one(A5).When the concentration was 100μg/mL,the inhibition rate of 3-(3-((3-(4-(tert-butyl)phenyl)-[1,2,4]-triazolo[3,4-b][1,3,4]thiadiazol-6-yl)thio)propoxy)-5,7-dimethoxy-2-(3,4,5-trimethoxyphenyl)-4H-chromen-4-one(A15)against Xanthomonas axonopodis pv.citri(Xac)was 63.3%,which was better than that of the control drug thiophanate-copper(57.3%).Biological activity test results that these compounds showed good inhibitory activity against tobacco mosaic virus(TMV).Among them,in terms of therapeutic activity,the EC50 values of compounds A5,5,7-dimethoxy-3-(4-((3-(methoxymethyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-6-yl)thio)butoxy)-2-(3,4,5-trimethoxyphenyl)-4H-chromen-4-one(A8),5,7-dimethoxy-3-(3-((3-phenyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-6-yl)thio)propoxy)-2-(3,4,5-trimethoxyphenyl)-4H-chromen4-one(A9),and 5,7-dimethoxy-3-(4-((3-(p-tolyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-6-yl)thio)butoxy)-2-(3,4,5-trimethoxyphenyl)-4H-chromen-4-one(A12)were 88.3,139.1,109.9,160.1μg/mL,respectively,which were better than the control drug ningnanmycin(227.2μg/mL).In terms of protective activity,the EC50 values of compounds 5,7-dimethoxy-3-(4-((3-phenyl-[1,2,4]-triazolo[3,4-b][1,3,4]thiadiazol-6-yl)thio)butoxy)-2-(3,4,5-trimethoxyphenyl)-4H-chromen-4-one(A10),5,7-dimethoxy-3-(4-((3-(4-methoxyphenyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-6-yl)thio)butoxy)-2-(3,4,5-trimethoxyphenyl)-4H-chromen-4-one(A14),A15,3-(4-((3-(4-(tert-butyl)phenyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-6-yl)thio)butoxy)-5,7-dimethoxy-2-(3,4,5-trimethoxyphenyl)-4H-chromen-4-one(A16),and 3-(4-((3-(4-chlorophenyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-6-yl)thio)butoxy)-5,7-dimethoxy-2-(3,4,5-trimethoxyphenyl)-4H-chromen-4-one(A18)were 103.1,107.4,86.3,79.2,111.5μg/mL,respectively,which were better than the control drug ningnanmycin(179.2μg/mL).Microscale thermophoresis(MST)indicated that compounds A12 and A16 have strong binding force to tobacco mosaic virus coat protein(TMV-CP).Molecular docking experiments showed that compound A16 has a strong interaction with TMV-CP.