丹皮酚肟醚类化合物的合成及抗血小板聚集活性

以丹皮酚为原料,与溴乙烷在碱性条件下反应,得到乙基丹皮酚醚,其酮羰基与盐酸羟胺反应生成相应的肟,肟羟基与相应的二溴丁烷反应得到乙基丹皮酚肟溴代烷基醚,再将其与不同的胺反应得到5个乙基丹皮酚肟胺基丁基醚衍生物。4a~4e的结构经过红外光谱、核磁共振氢谱和质谱确证。考察了反应温度及投料比对乙基丹皮酚肟收率的影响,得到最佳反应条件为:反应温度50℃,n(乙基丹皮酚)∶n(盐酸羟胺)=1∶3,此条件下收率可达94.0%。体外抗血小板聚集活性结果表明,4a~4e的活性均强于对照药阿司匹林,其中化合物4b的活性最强。特别是中间体乙基丹皮酚肟(2)表现出很好的抗血小板聚集活性。     

新型丹皮酚偶氮类衍生物的合成及其抑菌活性

[目的]寻找具有较高抑菌活性的丹皮酚偶氮类化合物。[方法]根据活性拼接原理将具有抑菌活性的偶氮基团引入丹皮酚结构中,合成一系列丹皮酚偶氮类衍生物,并采用菌丝生长速率法对其抑菌活性进行初步筛选。[结果]目标化合物结构经~1H NMR和ESI-MS确证,除化合物4a外,其他化合物均为首次被报道。化合物4b~4h在50 mg/L时对番茄灰霉病菌、玉米大斑病菌、马铃薯早疫病菌表现出比母体丹皮酚及阳性对照百菌清更高的抑制活性,其抑制率均可达到70%以上。[结论]丹皮酚偶氮类化合物表现出较好的抑菌活性,可以将其作为先导化合物,设计合成更多的类似物以获得高效、低毒和对非靶标生物安全的新型杀菌剂。     

百里酚偶氮类衍生物的合成及其抑菌活性

[目的]寻找具有较高抑菌活性的百里酚偶氮类化合物。[方法]以百里酚为母体,采用组合优化原理合成系列百里酚偶氮类衍生物,并采用菌丝生长速率法对其抑菌活性进行了初步筛选,对抑菌活性较好的化合物测定EC50值。[结果]目标化合物结构经~1H NMR和HR-MS确证,化合物3a、3b、3c、3h、3i和3j为已知化合物,其余化合物3d、3e、3f、3g、3k为首次报道。目标产物3a和3d在100 mg/L对除番茄灰霉病菌外的所有供试病菌均表现出比阳性对照霉灵更高的抑菌活性。化合物3a对玉米大斑病菌和苹果腐烂病菌的EC50值远低于霉灵对2种病菌的EC50值,表现出较好的抑菌活性。[结论]百里酚偶氮类化合物表现出较好的抑菌活性,可在其结构基础上,进行多位点和基团的修饰,有望发现抑菌活性更高的广谱型抑菌化合物,为开发高效、低毒和对非靶标生物安全的新型杀菌剂提供理论参考。     

丹皮酚及其席夫碱衍生物的抑菌性研究

以丹皮酚为先导,合成了丹皮酚缩1,3-丙二胺、丹皮酚缩2-羟基-1,3-丙二胺和丹皮酚缩糠胺3种丹皮酚席夫碱衍生物。琼脂扩散抑菌试验表明,丹皮酚及其衍生物对受试4种革兰氏阴性菌、阳性菌皆有明显的抑制作用。     

NO供体型丹皮酚衍生物的合成及其生物活性研究

以丹皮酚与溴乙酸为原料制备丹皮酚乙酸,利用其羧基与不同碳数的二溴烷烃反应得到相应的丹皮酚乙酸溴代烷基酯(3a~3e),再与硝酸银反应生成目标化合物NO供体型丹皮酚衍生物4a~4e。目标化合物的结构经过红外光谱、核磁共振氢谱和质谱确证。对合成的NO供体型丹皮酚衍生物进行体外抗血小板聚集及体内调血脂作用的生物活性测试,结果表明,目标化合物均具有一定的体外抗血小板聚集活性及较强的体内降脂作用,其中化合物4c的活性最强。     

无溶剂研磨法合成6-醚基香豆素衍生物及其抑菌活性

[目的]合成6-醚基香豆素衍生物并测试抑菌活性。[方法]邻甲基对苯二酚与乙酰乙酸乙酯经Peachmann缩合得到6-羟基-4,7-二甲基香豆素,随后与取代苄氯无溶剂研磨,合成12个目标化合物4a~4l。[结果]化合物经1H NMR和高分辨质谱鉴定。初步活性试验表明:质量浓度为100 mg/L时,目标化合物对5个靶标真菌有较好的抑菌活性,其中化合物4b、4c和4e对芒果蒂腐病菌的抑制率超过90%。[结论]无溶剂研磨绿色合成了具有较好抑菌活性的6-醚基香豆素衍生物。     

N-苄叉丹皮酚腙的合成及其抗菌活性

以丹皮酚(2-羟基-4-甲氧基苯乙酮)(Ⅰ)为原料,与水合肼反应得到中间体丹皮酚腙(Ⅱ),然后Ⅱ分别与各种取代苯甲醛反应合成了9个N-苄叉丹皮酚腙(Ⅲa~Ⅲi),产率为50.5%~91.9%。利用FTIR、1HNMR、13CNMR、LC-MS对目标化合物的结构进行了表征。初步探索了Ⅱ和Ⅲ的合成条件、测定了Ⅲa~Ⅲi的抗菌活性。结果表明:化合物N-(4-氟苄叉基)丹皮酚腙(Ⅲc)对金黄色葡萄球菌的最低抑菌浓度(MIC)为2 mg/L,化合物N-(2-氟苄叉基)丹皮酚腙(Ⅲb)对大肠杆菌的MIC为8 mg/L,与阳性对照药利福平抗菌效果相当。     

丹皮酚合成过程中抑菌活性的变化研究

研究了在丹皮酚的合成过程中,原料间苯二酚、中间产物2,4-二羟基苯乙酮及主产物丹皮酚对11种植物病原真菌的抑菌活性,并通过抑菌活性的变化来推测影响抑菌活性的主要官能团.结果表明:0.5g·L-1的2,4-二羟基苯乙酮对11种真菌的抑菌率大于或等于同浓度丹皮酚的抑菌率,两者均远远大于同浓度间苯二酚的抑菌率.由此可推测,酚类分子中乙酰基的引入对抑菌活性起到了非常重要的作用,而酚羟基的甲基化的作用却并不显著.该结论对寻求具有更高抑菌活性的酚类衍生物有着非常重要的意义.     

4-羟基-3-甲氧基肉桂酸衍生物的除草活性测定

[目的]天然产物4-羟基-3-甲氧基肉桂酸是新型除草剂创制的先导化合物,为了评价其衍生物的除草活性。[方法]试验采用平皿法测定了以4-羟基-3-甲氧基肉桂酸为母体合成的26种衍生物对拟南芥的抑制作用。[结果]17种衍生物具有不同程度的除草活性,其中2-(4-羟基-3-甲氧基亚苄基)丙二酸二乙酯、N-(4-氟苯基)-3-(4-羟基-3-甲氧基苯基)丙烯酰胺、3-溴-4-羟基-5-甲氧基肉桂酸3种衍生物除草活性较高,对拟南芥的抑制中浓度(IC50)分别为9.90、7.53、6.93 mg/L。[结论]4-羟基-3-甲氧基肉桂酸衍生物是开发新型除草剂的重要来源,为新型除草剂的创制奠定了一定的理论基础。     

丹皮酚缩乙醇胺及其镍(Ⅱ)配合物的合成与抑菌性研究

用水蒸气蒸馏法从中药材丹皮中提取活性成分丹皮酚,进而合成丹皮酚与乙醇胺的席夫碱衍生物,并用席夫碱做为配体与Ni(Ⅱ)盐合成了Ni(Ⅱ)配合物,经红外光谱等手段对所合成的席夫碱和配合物进行了结构表征,并对丹皮酚、席夫碱、Ni(Ⅱ)配合物进行了抑菌性研究。     

N-(1,4-二取代吡唑-5-基)-1,2,3-噻二唑酰胺类化合物的合成与杀菌活性研究

设计合成了9个N-(1,4-取代吡唑-5-基)-1,2,3-噻二唑酰胺类化合物,测试了化合物对小麦赤霉病菌(Gibberella zeae)、辣椒枯萎病菌(Fusarium oxysporum)和苹果腐烂病菌(Cytospora mandshurica)的抑制活性。初步结果表明,目标化合物在50μg/mL浓度下对小麦赤霉病菌、辣椒枯萎病菌和苹果腐烂病菌有一定的抑制作用,其中化合物8j对小麦赤霉病菌的抑制率达到47.6%,接近对照药剂恶霉灵;化合物8d对苹果腐烂病菌的抑制率达到56.8%,与对照药剂恶霉灵相当,具有进一步研究的价值。     

Synthesis,Antifungal Activities and Qualitative Structure Activity Relationship of Carabrone Hydrazone Derivatives as Potential Antifungal Agents

Aimed at developing novel fungicides for relieving the ever-increasing pressure of agricultural production caused by phytopathogenic fungi, 28 new hydrazone derivatives of carabrone, a natural bioactive sesquisterpene, in three types were designed, synthesized and their antifungal activities against Botrytis cinerea and Colletotrichum lagenarium were evaluated. The result revealed that all the derivatives synthesized exhibited considerable antifungal activities in vitro and in vivo, which led to the improved activities for carabrone and its analogues and further confirmed their potential as antifungal agents.     

1,2,3-三氮唑桥连水杨醛类席夫碱菊糖衍生物的合成及抑菌活性研究

先对菊糖C-6位的羟基进行溴代激活,形成易离去基团,再用叠氮基亲核置换易离去基团,最后将水杨醛类丙炔胺席夫碱中间体通过Huisgen-Click反应与叠氮代菊糖中间体桥连,得到1,2,3-三氮唑桥连水杨醛类席夫碱菊糖衍生物(4a~4c),通过红外光谱对其结构进行了表征,并测定其抑菌活性。结果表明,与菊糖相比,菊糖衍生物的抑菌活性明显提高,当浓度为1 000μg·mL-1时,化合物4a对黄瓜炭疽病菌(Colletotrichum lagenarium)、西瓜枯萎病菌(Fusarium oxysporium)和芦笋茎枯病菌(Phomopsis asparagi)的抑制率分别为66.7%、42.0%和58.1%。通过对菊糖进行针对性化学修饰,接入具有抑菌活性的基团,可以在一定程度上提高菊糖的抑菌活性,为进一步开发利用菊糖提供了依据。     

Antifungal Effects of Volatile Compounds from Black Zira (<Emphasis Type="Italic">Bunium persicum</Emphasis>) and Other Spices and Herbs

The dish pack method, which measures growth inhibition or promotion effects of volatile compounds on germinating seeds, was applied to measure the antifungal effects of 52 dried samples of spices and herbs against a soil-borne phytopathogenic fungus, Fusarium oxysporum. Black zira showed the strongest effect, followed by cumin and cardamom. Headspace sampling and gas chromatography–mass spectrometry analysis of black zira identified seven volatile compounds, γ-terpinene, limonene, p-cymene, β-pinene, α-pinene, cuminaldehyde, and myrcene. Among these, cuminaldehyde and p-cymene showed the strongest antifungal activities against F. oxysporum, suggesting roles in the antifungal activity of black zira. The same compounds also showed antifungal activities against another soil-borne phytopathogenic fungus, Verticillium dahliae, and foliar phytopathogenic fungi, Botrytis cinerea and Alternaria mali. The total activity calculated from the concentration of cuminaldehyde contained in black zira and its EC₅₀ against F. oxysporum demonstrated that cuminaldehyde is the main antifungal compound detected in black zira.     

Synthesis and antifungal activities of glycosylated derivatives of the cyclic peptide fungicide caspofungin

Diseases caused by systemic fungal infections have become a significant clinical problem in recent decades. A series of glycosyl derivatives of the approved cyclic peptide antifungal drug caspofungin conjugated with β‐D ‐glucopyranose, β‐D ‐galactopyranose, β‐D ‐xylopyranose, β‐L ‐rhamnopyranose, β‐maltose and β‐lactose units were designed, synthesized, and evaluated as new potential antifungal drugs. The compounds were obtained by coupling the corresponding glycosyl amines to the free primary amino groups of caspofungin through a bifunctional glutaryl linker. In contrast to caspofungin, these glycosylated derivatives are soluble in water, but are not hygroscopic and moreover, are more stable than caspofungin under high humidity and temperature. CD studies showed that glycosylation has very little impact on the conformation of the cyclic peptide of caspofungin. In vitro antifungal tests against seven human pathogenic fungi revealed that the caspofungin–monosaccharide conjugates, but not the disaccharide conjugates, have increased antifungal activities against the majority of tested fungus species relative to caspofungin. The β‐D ‐glucopyranosyl derivative 2 a showed the strongest and broadest antifungal activity, providing a lead for further studies.     

Design, synthesis, and biological evaluation of 1-[(biarylmethyl)methylamino]-2-(2,4-difluorophenyl)-3-(1H-1,2,4-triazol-1-yl)propan-2-ols as potent antifungal agents: new insights into structure-activity relationships

We recently reported the design and synthesis of azole antifungal agents with a focus on modifications to the side chain appended to the propanol group. Herein we have identified a series of new 1-[(biarylmethyl)methylamino] derivatives with broad-spectrum antifungal activities against the most prevalent human pathogenic fungi (Candida spp. and Aspergillus fumigatus). Compounds containing a flexible benzylamine moiety were clearly shown to yield the best antifungal activities, without the need for a hydrogen-bond acceptor substituent directly attached to the para position. We were also able to determine that selected compounds are able to overcome gene overexpression and point mutations that lead to reduced susceptibility or resistance against current treatments, such as fluconazole. As the minor differences observed with small structural modifications cannot be explain with only a three-dimensional model of CYP51, adequate physicochemical parameters must be evaluated in terms of antifungal potency, bioavailability, and toxicity. Therefore, structure-activity relationship studies such as these reveal new insights for the development of future antifungal therapies.     

Synthesis and antimicrobial evaluation of some pyrazolo-thiazolyl alkoxy-1H-isoindole-1, 3(2H)-dione derivatives

1,3-Thiazolidine-2,4-dione 2 has been synthesized by the cyclisation reaction of thiourea and chloroacetic acid in the presence of ethanol. The reaction of compound 2 with substituted aromatic aldehyde afforded the corresponding derivatives of substituted 5-benzylidene-1,3-thiazolidinone-2,4-dione 3a–d, which upon reflux with ω-bromoalkoxyphthalimide gave 2-{[-5-(substituted benzylidine)-2,4-dioxo-1,3-thiazolidine-3-yl]alkoxy} -1H-isoindole-1,3(2H)-dione 4a–i. Further, compounds 4a–i were treated with phenyl hydrazine and 2,4 dinitro phenyl hydrazine in the DMF to yield the title compound 2-[5-oxo-2,3-substituted diphenyl-2H-pyrazolo[3,4-d][1,3]thiazol-6(5H)-yl)alkoxy]-1H-isoindole-1,3(2H)-dione 5a–r. Structures of newly synthesized compounds were established based on elemental analysis, IR, ¹H NMR and mass spectral data. Synthesized compounds have been assayed for their antibacterial activities against B. subtilis, K. pneumoniae, P. aeruginosa and S. aureus and antifungal activities against A. fumigatus and C. albicans.     

Fatty Acids in Heterocyclic Synthesis. Part XIV: Synthesis of Surface Active Agents from Some Novel Class of Oxadiazole,Thiadiazole and Triazole Derivatives Having Microbiological Activities

Reaction of stearic acid with semicarbazide in refluxing POCl₃ afforded 2-amino-5-heptadecyl 1,3,4-oxadiazole. Acylation of the amino group with acetic anhydride, ethyl chloroacetate and chloroacetic acid gave amide and β-amino acid derivatives. These compounds were cyclized to imidazo[2,1-b]oxadiazole derivatives by two different techniques. Treating the starting oxadiazole compound with P₂S₅, hydroxyl amine and hydrazine hydrate in benzene afforded thiadiazole and triazole derivatives. Unexpectedly, triazolo[3,4-b][1,3,4]oxadiazole derivative was obtained when 1,3,4-oxadiazole derivative was refluxed with hydrazine hydrate in ethanol. The biological activities of the synthesized compounds were screened in vitro against some gram positive and gram negative bacteria and fungi. Addition of quantitative amount of propylene oxide units (3, 5, 7 mol) to the synthesized compounds afforded new nonionic surfactants. The physico-chemical and surface properties of the novel synthesized surfactants such as surface and interfacial tension, cloud point, wetting time, emulsion stability, foam height, CMC, resistance to hydrolysis and their biodegradability were investigated. In addition, surface parameters including effectiveness (π _CMC), efficiency (PC₂₀), maximum surface excess (Γ_max) and (A _min) were examined.     

2-取代-4-氯-5-芳基-2H-1,2,3-三唑类化合物的合成及其生物活性

为发现杀菌活性高、抑菌谱广的新化合物，以芳醛、硝基甲烷及叠氮化钠为起始原料，经环化、氯化、烃化反应合成了15个2-取代-4-氯-5-芳基-2H-1,2,3-三唑类新化合物，目标物的分子结构经核磁共振谱、质谱和元素分析进行了确证。采用菌丝生长速率测定法，在25 mg/L的测试浓度下，目标化合物对小麦赤霉病菌、辣椒疫霉病菌、烟草赤星病菌、黄瓜灰霉病菌、水稻纹枯病菌及油菜菌核病菌6种作物病菌进行了离体抑菌活性试验。初步的抑菌活性测试结果表明：化合物4d对小麦赤霉病菌、黄瓜灰霉病菌及油菜菌核病菌的抑制率分别为70.4%、74.1%和72.9%，化合物4k对黄瓜灰霉病菌及油菜菌核病菌的抑制率分别为87.0%及84.7%。4d对辣椒疫霉病菌的抑制率为61.4%，高于商品化品种苯醚甲环唑的42.5%。