4-硫醚基喹唑啉类化合物的合成及抑菌活性研究

以4-氯喹唑啉和巯基化合物为原料, 丙酮作溶剂, 碳酸钾作缚酸剂, 合成了7个新型4-硫醚基喹唑啉类化合物. 采用¹H NMR, ¹³C NMR, IR及元素分析对目标化合物的结构进行了表征. 生物活性测试表明, 化合物1d在50 μg•mL^－1 药剂浓度下对小麦赤霉病菌、辣椒枯萎病菌、苹果腐烂病菌的抑菌活性分别达到69.5%, 71.9%和70.8%, EC₅₀分别为25.88, 17.08和28.77 μg•mL^－1.     

嘧啶类化合物的合成及抗菌活性研究进展

嘧啶类化合物因其广泛的生物活性在医药、农药等领域备受关注. 将不同基团引入嘧啶结构中, 经过结构修饰能产生一系列具有抗菌活性的嘧啶衍生物, 它在新型农药创制中发挥着越来越重要的作用. 对嘧啶类化合物的合成及杀菌活性的研究进行了分类综述, 并展望了它的发展趋势和应用前景.     

芳基肼衍生物的设计、合成及其抑菌活性研究

为了探索具有较高潜力的新型植物病原真菌抑制剂,本文以取代芳胺、3,3-二甲基-2-丁酮和乙酸乙酯为起始原料,采用Claisen缩合、氯代、重氮化、亲核取代等反应合成了16个新型的芳基肼类衍生物(4a～4p),其结构经~1H NMR、~(13)C NMR及ESI-MS确证。初步抑菌活性测试结果表明,目标化合物4d、4g和4j具有潜在的广谱性抑菌作用,其对9种植物病原真菌的平均抑制率分别为64.7%、71.2%和67.8%,显著优于阳性对照药物噁霉灵(50.1%)和百菌清(60.0%)。构效关系研究表明,保持羰基α位氯原子不变,在芳基肼结构中引入甲基、氯、氟、三氟甲氧基等基团能有效提高其抑菌作用。此研究为基于芳基肼骨架的农用抑菌剂结构优化提供了参考。     

Biosynthesis of the Polycyclic System in the Antifungal HSAF and Analogues from Lysobacter enzymogenes

The biocontrol agent Lysobacter enzymogenes produces polycyclic tetramate macrolactams (PoTeMs), including the antifungal HSAF. To elucidate the biosynthesis of the cyclic systems, we identified eleven HSAF precursors/analogues with zero, one, two, or three rings through heterologous expression of the HSAF gene cluster. A series of combinatorial gene expression and deletion experiments showed that OX3 is the “gatekeeper” responsible for the formation of the first 5‐membered ring from lysobacterene A, OX1 and OX2 are responsible for formation of the second ring but with different selectivity, and OX4 is responsible for formation of the 6‐membered ring. In vitro experiments showed that OX4 is an NADPH‐dependent enzyme that catalyzes the reductive cyclization of 3‐dehydroxy alteramide C to form 3‐dehydroxy HSAF. Thus, the multiplicity of OX genes is the basis for the structural diversity of the HSAF family, which is the only characterized PoTeM cluster that involves four redox enzymes in the formation of the cyclic system.     

6-溴-4-烃硫基喹唑啉类化合物的合成及抑菌活性研究

以6-溴-4-巯基喹唑啉和卤代烃为原料, 用相转移催化法合成了10个新的6-溴-4-烃硫基取代喹唑啉类化合物. 化合物经1H NMR, 13C NMR, IR及元素分析证明其结构. 初步生物活性试验结果表明, 在50 mg•L－1浓度下, 化合物6g对小麦赤霉病菌、辣椒枯萎菌、苹果腐烂菌抑制率分别为63.8%, 51.9%, 55.1%, 与对照药剂恶霉灵抑制活性相当.     

含嘧啶氨基的三取代三嗪衍生物的合成及其抗菌、抗肿瘤活性研究

以三聚氯氰为起始原料,合成了系列新的含嘧啶氨基的2,4,6-三取代-1,3,5-三嗪化合物,并测试了化合物抗苹果树腐烂病菌和抑制肿瘤细胞增殖活性.结果表明,化合物2aa～2cb及3aa～3cb对苹果树腐烂病菌具有显著的抑制作用,具有开发为新型植物抗菌剂的潜力.部分化合物,如4ba和4ca分别对胃癌(BGC-823)和宫颈癌(Hela)肿瘤细胞具有较强的抑制活性,IC50分别为10.9和11.3μmol/L.     

Antifungal,anti-inflamatory and neuritogenic activity of newly-isolated compounds from Disporopsis aspersa

Abstract

A new ester (1) and a terpenoid (2) were isolated from the dried whole plant of Disporopsis aspersa (H_UA) E_NGL. ex D_IELS for the first time and their structures were elucidated, as well as their biological activities are described. The two compounds all showed good antifungal activities, especially furanone (2) exhibited better antifungal activity against Pseudoperonospora cubensis and Phytophthora infestans with EC₅₀ value of 22.82, 18.90?μg/mL, respectively. Compound 1 exhibited a significant promotion on the neurite outgrowth in NGF-induced PC-12 cells, and moderate inhibition on the NO production induced by lipopolysaccharide (LPS) in BV-2 microglial cells.     

Synthesis and Antifungal Activity of Chimonanthus praecox Derivatives

To search for efficient agricultural antifungal lead compounds, 39 Chimonanthus praecox derivatives were designed, synthesized, and evaluated for their antifungal activities. The structures of target compounds were fully characterized by ¹H NMR, ¹³C NMR, and MS spectra. The preliminary bioassays revealed that some compounds exhibited excellent antifungal activities in vitro. For example, the minimum inhibitory concentration (MIC) of compound b15 against Phytophthora infestans was 1.95 µg mL⁻¹, and the minimum inhibitory concentration (MIC) of compound b17 against Sclerotinia sclerotiorum was 1.95 µg mL⁻¹. Therefore, compounds b15 and b17 were identified as the most promising candidates for further study.     

Antifungal activities and active ingredients of Melodinus suaveolens Champ. ex Benth.

Four Melodinus species with antifungal activity were found in survey of the floral resources, in Shiwan Mountain Natural Reserve, Guangxi Province, China. Crude methanolic extracts of the twigs and leaves of Melodinus suaveolens exhibited potent antifungal activities against the plant pathogenic fungi Colletotrichum musae, Colletotrichum graminicola, Colletotrichum gloeosporioides and Alternaria musae, and the ethyl acetate fraction inhibited these pathogens at rates of 85.37, 91.47, 72.77 and 89.87%, respectively (5 mg/mL). A new compound, (2R, 3S, 5S, 6R)-1-O-methyl- chiro-inositol was isolated from the ethyl acetate fraction, along with 15 known compounds. The antifungal activities of compounds (1–16) were evaluated for the first time. Compound (4) had potent antifungal activity against C. gloeosporioides, C. graminicola and A. musae.     

Design,Synthesis and Biological Evaluation of Lophanic Acid Derivatives as Antifungal and Antibacterial Agents

In order to discover more promising antifungal and antibacterial agents, a series of new derivatives were designed and synthesized by structure modification based on the naturally occurring antimicrobial compound lophanic acid. The structures of all the target compounds were well characterized by spectroscopic data. The stereochemistry of these compounds was further determined through the X-ray diffraction analysis of 6a. The synthetic compounds were evaluated for their antimicrobial activities against filamentous fungi (T. rubrum, T. mentagrophytes), yeasts (C. neoformans, C. albicans) and Gram-positive and Gram-negative bacteria (MRSA, S. mutans, S. sobrinus, and E. coli). Among them, 3d and 3i are found as the most promising leads that showed potent inhibitory effects against all the tested fungal and bacterial strains except for E. coli. The presence of the C-20 carboxylic ester groups and the free hydroxy group at C-13 was found to be essential for the antifungal and antibacterial activities of the lophanic acid derivatives.     

5-乙氧羰基甲硫基-1,2,4-三唑席夫碱的合成及杀菌活性

以3-甲基-4-氨基-5-乙氧羰基甲硫基-1,2,4-三唑为原料,与取代芳醛合成9种3-甲基-4-(X-取代基苯亚甲基氨基)-5-乙氧羰基甲硫基-1,2,4-三唑席夫碱化合物a～i。 产物结构经1H NMR、IR和MS等技术手段确证。 其中化合物3-甲基-4-(4-羟基苯亚甲基氨基)-5-乙氧羰基甲硫基-1,2,4-三唑h进一步经X射线单晶衍射得到其晶体结构（CCDC：910927）：C14H16N4O3S,Mr=320.37,Orthorhombic,P2(1)2(1)2(1)/n,a=0.9220(10) nm,b=1.5823(17) nm,c=2.1667(2) nm,V=3.161(6) nm3,Z=8,F(000)=1344。 化合物对4种植物病原菌的初步生物活性测试结果(EC95值)表明,化合物d、e、f对供试菌种西瓜枯萎病和小麦赤霉病的抑菌活性优于对照原药三唑酮。     

C(2)-酰胺基-4-芳基-1,5-苯并硫氮杂的合成及抑菌活性的研究

设计合成了三类C(2)酰胺基取代的1,5-苯并硫氮杂衍生物:2-酰胺基(N-芳基)-4-芳基-1,5-苯并硫氮杂、2-酰胺基(N-烷基)-4-芳基-1,5-苯并硫氮杂和2-酰胺基(N,N-二烷基)-4-芳基-1,5-苯并硫氮杂,其结构用元素分析,IR,MS及1H NMR确证.测定了目标化合物的抑真菌活性,结果表明部分化合物对新生隐球菌具有中等强度的抑真菌活性.还研究了2-酰胺基-4-芳基-1,5-苯并硫氮杂的合成反应条件.     

Antifungal Activity and In Silico Studies on 2-Acylated Benzo- and Naphthohydroquinones

The high rates of morbidity and mortality due to fungal infections are associated with a limited antifungal arsenal and the high toxicity of drugs. Therefore, the identification of novel drug targets is challenging due to the several resemblances between fungal and human cells. Here, we report the in vitro antifungal evaluation of two acylphenols series, namely 2-acyl-1,4-benzo- and 2-acyl-1,4-naphthohydroquinones. The antifungal properties were assessed on diverse Candida and filamentous fungi strains through the halo of inhibition (HOI) and minimal inhibitory concentration (MIC). The antifungal activities of 2-acyl-1,4-benzohydroquinone derivatives were higher than those of the 2-acyl-1,4-naphthohydroquinone analogues. The evaluation indicates that 2-octanoylbenzohydroquinone 4 is the most active member of the 2-acylbenzohydroquinone series, with MIC values ranging from 2 to 16 μg/mL. In some fungal strains (i.e., Candida krusei and Rhizopus oryzae), such MIC values of compound 4 (2 and 4 μg/mL) were comparable to that obtained by amphotericin B (1 μg/mL). The compound 4 was evaluated for its antioxidant activity by means of FRAP, ABTS and DPPH assays, showing moderate activity as compared to standard antioxidants. Molecular docking studies of compound 4 and ADMET predictions make this compound a potential candidate for topical pharmacological use. The results obtained using the most active acylbenzohydroquinones are promising because some evaluated Candida strains are known to have decreased sensitivity to standard antifungal treatments.     

含1,2,3-三氮唑结构的1,5-苯并硫氮杂[艹卓]的合成及其抑真菌活性

设计合成了三类含1,2,3-三氮唑结构的1,5-苯并硫氮杂[艹卓]化合物3-(1H-1,2,3-三氮唑)-4-芳基-2,5-二氢-1,5-苯并硫氮杂[艹卓](5a^5f)、3-(2H-1,2,3-三氮唑)-4-芳基-2,3-二氢-1,5-苯并硫氮杂[艹卓](6a^6f)和3-(1H-1,2,3-三氮唑)-4-芳基-2,3,4,5-四氢-1,5-苯并硫氮杂[艹卓](7a^7f).研究了中间体及目标产物的合成条件,分离出其中两个副产物并进行了结构确定.目标产物的抑真菌活性测试表明,化合物5a^5f对真菌具有良好的抑制作用,对新生隐球菌的抑制效果尤为突出.初步抑真菌构效关系研究表明, 1H-1,2,3-三氮唑环和C=C双键是化合物5a^5f抑真菌活性的关键官能团.     

新型丙烯海松酸基双噻二唑化合物的合成及其抗真菌活性

松香与丙烯酸经Diels-Alder环加成反应制得丙烯海松酸(1); 将1转化为双酰氯后与2-氨基-5-取代苯基-1,3,4-噻二唑经-N-酰化反应合成了8个新型的丙烯海松酸基双噻二唑化合物(4a~4h),其结构经¹H NMR, ¹³C NMR, IR和元素分析表征。抗真菌活性测试结果表明,在用药量为50 μg·mL^-1时,4d(R=m-Cl)对苹果轮纹病菌、花生褐斑病菌和小麦赤霉病菌的抑制率分别为66.9%, 57.8%和52.9%。     

2,3-二苯基-4-噻唑酮类衍生物的合成及抑菌活性研究

本文以取代苯甲醛、苯胺及巯基乙酸为原料,合成了一系列2,3-二苯基-4-噻唑酮类衍生物,其结构经~1H NMR和MS确证。抑菌活性试验显示,所有目标化合物表现出中等抑菌活性,其中化合物4g对苹果腐烂病菌的抑菌活性最高,能达到62.7%。构效关系研究表明在2,3-二苯基-4-噻唑酮的苯基上引入甲基能增强活性。     

Antifungal Effects and Active Components of Ligusticum chuanxiong

The separation of chemical components from wild plants to develop new pesticides is a hot topic in current research. To evaluate the antimicrobial effects of metabolites of Ligusticum chuanxiong (CX), we systematically studied the antimicrobial activity of extracts of CX, and the active compounds were isolated, purified and structurally identified. The results of toxicity measurement showed that the extracts of CX had good biological activities against Botrytis cinerea, Sclerotinia sclerotiorum, Alternaria alternata and Pythium aphanidermatum, and the value of EC₅₀ were 130.95, 242.36, 332.73 and 307.29 mg/L, respectively. The results of in vivo determination showed that under the concentration of 1000 mg/L, the control effect of CX extract on Blumeria graminis was more than 40%, and the control effect on Botrytis cinerea was 100%. The antifungal active components of CX were identified as Senkyunolide A and Ligustilide by mass spectrometry and nuclear magnetic resonance. The MIC (minimum inhibitory concentration) value of Senkyunolide A and Ligustilide against Fusarium graminearum were 7.81 and 62.25 mg/L, respectively. As a new botanical fungicide with a brightly exploitative prospect, CX extract has potential research value in the prevention and control of plant diseases.