3-(2-羟基-4,6-二甲氧基苯基)-5-芳基异噁唑啉的合成及抑菌活性

以查尔酮衍生物为前体, 与盐酸羟胺在碱性条件下反应制得7个3-(2-羟基-4,6-二甲氧基苯基)-5-芳基异噁唑啉化合物(2a~2g), 产物经红外光谱、核磁共振谱、质谱和元素分析表征. 抑菌活性研究结果表明, 化合物2d和2e对大肠杆菌、金黄色葡萄球菌、枯草杆菌和绿脓杆菌均有一定抑制作用, 其中化合物2e对大肠杆菌、金黄色葡萄球菌表现出极好的抑菌活性.     

5′位羟基异戊烯基查尔酮类天然产物的合成及其抗菌活性研究

首次合成了Bartericin A (1), 2’,6’-二羟基-5’-(2’’-羟基-3’’-甲基-3’’-丁烯基)-4’-甲氧基查尔酮(2), Xanthohumol D (3)和Angusticornin B (4) 4个羟基异戊烯基查尔酮类天然产物.为了探讨天然产物中不同官能团对其核心骨架结构抗菌活性的影响,设计合成了衍生物6.所合成的目标产物和未知中间体化合物经过1H NMR、13C NMR、IR、HRMS进行了确证.选取大肠杆菌[CMCC(B)44102]、绿脓杆菌[CMCC(B)10104]、金黄色葡萄球菌[CMCC(B)260003]和枯草芽孢杆菌[CMCC(B)63 501],采用稀释点样法对所合成的4个天然产物及1个新型衍生物进行了抗菌活性评估.结果显示,天然产物1、4和衍生物6对革兰氏阳性菌金黄色葡萄球菌和枯草芽孢杆菌表现出了一定的抑制活性.天然产物3对枯草芽孢杆菌表现出了较为明显的抑制活性,但对其他3种菌株无抑制活性(最小抑菌浓度>200μg/mL).     

Microwave Assisted Green Synthesis of Pyrazole, 1, 2, 3‐ Triazole Based Novel Benzohydrazones and Their Antibacterial Activities

A series of novel pyrazole, triazole based benzohydrazones ( 7a‐l ) were synthesized via conventional and microwave methods in the presence of acetic acid catalyst. Microwave method provided green and economical approach towards the synthesis of novel Schiff bases ( 7a‐l ). Some intermediates and all the final compounds were characterized by NMR, mass, and elemental analysis. The compounds were screened for their in vitro antibacterial activity against Gram‐negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram‐positive bacteria (Staphylococcus aureus and Bacillus cereus). Compounds 7e and 7g showed good antibacterial activity.     

A Facial Synthesis and Anticancer Activity of (Z)‐2‐((5‐(4‐nitrobenzylidene)‐4‐oxo‐4,5‐dihydrothiazol‐2‐yl)amino)‐substituted Acid

In order to explore the anticancer and antimicrobial activity associated with the thiazole framework, we synthesized the new series (Z )‐2‐((5‐(4‐nitrobenzylidene)‐4‐oxo‐4,5‐dihydrothiazol‐2‐yl)amino)‐substituted acid derivatives 6a – l . All the synthesized compounds were evaluated for anticancer and antimicrobial activity in vitro. Among these, the compounds 6a , 6b, 6c , 6e , 6f , 6g , 6h , 6i , 6j , and 6k showed highest antibacterial and antifungal activity. The compound 6a exhibited significant antibacterial activity against Bacillus subtilis , whereas compound 6j displays significant antifungal activity against fungal strains, that is, A. oryzae . The in vitro anticancer studies revealed that 6e , 6g , 6h , 6k , and 6l are the most active compounds against MCF‐7 and BT‐474 human breast cancer cell lines, which can be regarded as the promising drug candidate for development of anticancer drugs.     

Novel azo dyes derived from 8-methyl-4-hydroxyl-2-quinolone：Synthesis, UV-vis studies and biological activity

In this study, N,N'-di-(2-methylphenyl)malonamide was synthesized and reacted with polyphosphoric acid to afford 8-methyl-4-hydroxyl-2-quinolone. Eight novel azo disperse dyes were then synthesized by linking diazotized p-substituted aniline derivatives with 8-methyl-4-hydroxyl-2-quinolone. The solvatochromism of these azo dyes in various solvents was evaluated. All the compounds were then evaluated for their antibacterial activity against four bacteria, namely, Bacillus subtilis, Micrococcus luteus, Salmonella enterica, and Pseudomonas aeruginosa. The results showed that some of these compounds have high levels of antibacterial activity.     

Three antibacterial naphthoquinone analogues from cultured mycobiont of lichen Astrothelium sp.

<正>A new naphthoquinone compound named 7-hydroxyl-8-methoxyltrypethelone 3 together with two known compounds trypethelone 1 and trypethelone methyl ether 2 was isolated from cultured mycobiont of Astrothelium sp.The structures were elucidated by 1D and 2D NMR spectroscopic analysis as well as comparison with those reported in literatures.Compound 1 displayed significant antibacterial activity against Bacillus subtilis(ATCC 6633),and showed modest antibacterial activity against Staphylococcus aureus col(MRSA)(CGMCC 1.2465),while compounds 2 and 3 showed modest antibacterial activity against Enterococcus faecalis 850E(CGMCC 1.2135) and S.aureus col(MRSA)(CGMCC 1.2465).     

Antimicrobial and Antimalarial Activity of Novel Synthetic Mononuclear Ruthenium(II) Compounds

The present work was aimed that the two Ruthenium compounds namely, [Ru(A)₂(B)]Cl₂, where A = 1,10‐phenanthroline; B = 2‐NO₂‐phenyl thiosemicarbazone (Compound R₁)/2‐OH‐phenyl thiosemicarbazone (Compound R₂) have been tested for antibacterial activity at the concentrations of 1 mg/mL against various Gram‐Positive organisms (Lactobacillus, Staphylococcus pyrogenes, Bacillus subtilis, Staphylococcus aureus & Bacillus megatarium) and Gram‐Negative organisms (Pseudomonas aeruginosa, Escherichia coli, Proteus vulgaris, Enterobacter aerogenes, Salmonella paratyphi, Klebsiella pneumonia & Proteus mirabilis). The compounds were also tested for antifungal activity against Aspergillus clavatus, Aspergillus niger, Colletotrichum & Penicillium notatum by using agar diffusion assay and antimalarial activity against Plasmodium falciparum (Strain 3D7) using MTT assay. The results concluded that the compound R₁ exhibited significant antibacterial activity than R₂ against Gram‐Negative bacteria with zones of inhibition ranging from 15‐20 mm. and mild antibacterial activity against Gram‐Positive bacteria in comparison to tetracycline, streptomycin and rifampicin. These complexes were found to have moderate antifungal activity with no activity was however observed against Aspergillus niger. The compound, R₁ exhibited antimalarial activity at 10 μg/mL, whereas R₂ did not show antimalarial activity upto 50 μg/mL. Sensitivity to the compounds was greatest in the gram‐negative bacteria, followed by the gram‐positive bacteria and fungi.     

Synthesis, characterization and antibacterial activity of azomethine derivatives derived from 2-formylphenoxyacetic acid

A series of eight new azomethine derivatives were synthesized by reacting 2-formylphenoxyacetic acid with aromatic amines. The chemical structures of these compounds were confirmed by means of 1H-NMR, 13C-NMR, MS and elemental analysis. The compounds were assayed by the disc diffusion method for antibacterial against Staphylococcus aureus and Escherichia coli. Among the compounds tested, 2a, 2b, 2e, 2g and 2h exhibited good antibacterial activity, almost equal to that of Ciprofloxacin used as standard.     

Synthesis,Characterization, and Antimicrobial Screening of 4″‐methyl‐2,2″‐diaryl‐4,2′:4′,5″‐terthiazole Derivatives

A series of novel 4″‐methyl‐2,2″‐diaryl‐4,2′:4′,5″‐terthiazole ( 8a‐p ) derivatives has been synthesized and screened for antibacterial activity against four pathogenic bacteria, Escherichia coli, Pseudomonas flurescence, Staphylococcus aureus, and Bacillus subtilis. Among them, compounds 8a and 8j exhibited excellent antibacterial activity with minimum inhibitory concentration range of 1.0 to 5.3 μg/mL and compounds 8m and 8p exhibited moderate to good antibacterial activity with minimum inhibitory concentration range of 16.9 to 29.7 μg/mL against all tested strains. All the synthesized compounds were screened for their in vitro antifungal activity against Cocinida candida. Most of the compounds reported moderate antifungal activity. This study provides valuable directions to our ongoing endeavor of rationally designing more potent antimicrobial agent.     

Synthesis,antioxidant, and antimicrobial activity of 3-(1H-indole-3-carbonyl)-2H-chromen-2-ones

A simple and convenient method for the one-pot synthesis of 3-(1H-indole-3-carbonyl)-2H-chromen-2-one derivatives from the reaction of 3-cyanoacetyl indole and salicylaldehyde in the presence of Na₂CO₃ in water: methanol (1:1) is described. Wider substrate scope, high yields, operational simplicity, and simple purification process make the protocol highly applicable in the synthesis of 3-(1H-indole-3-carbonyl)-2H-chromen-2-ones. For the first time, in vitro antioxidant and antimicrobial activity was studied. Compounds 5e , 7a , and 7b exhibits good radical scavenging ability against DPPH free radical. Compounds 7b , 5f , and 5g possess lower EC₅₀ values than the Standards AA and BHA and thus proving their high reducing power. Compounds 5d and 5f show good antibacterial activity against gram-positive bacteria (MRSA) while compounds 5c , 7a , and 7b exhibits good antibacterial activity against Bacillus sp. Compounds 5b and 5e show good antibacterial activity against gram negative bacterial strains (Escherichia coli, Klebsiella pneumoniae) and compounds 5g and 5h exhibits good antifungal activity against Candida albicans.     

Synthesis of New 2,4‐Diaryl‐6‐methyl‐5‐nitropyrimidines as Antibacterial and Antioxidant Agents

A new series of 2,4‐diaryl‐6‐methyl‐5‐nitropyrimidines ( 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i ) were synthesized in good yields by Suzuki–Miyaura coupling of 2,4‐dichloro‐6‐methyl‐5‐nitropyrimidine ( 3 ) with various aryl boronic esters ( 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i ) in the presence of 1,1′‐ bis(diphenylphosphino)ferrocene dichloropalladium(II) (Pd(dppf)₂Cl₂). Further, antibacterial and antioxidant properties were screened for the title compounds 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i . Most of the compounds possessed significant activity against Gram‐positive bacteria Staphylococcus aureus and Bacillus subtilis and Gram‐negative bacteria Escherichia coli and Klebsiella pneumoniae. The antioxidant activity of the title compounds showed significant antioxidant activity when compared with vitamin C.     

Design and synthesis of anti-MRSA benzimidazolylbenzene-sulfonamides. QSAR studies for prediction of antibacterial activity

A series of benzimidazolylbenzenesulfonamide compounds containing electron-releasing and electron-withdrawing substituents were synthesized and tested for their in vitro antibacterial activity. Two BZS compounds showed strong antibacterial activity against methicillin-resistant Staphylococcus aureus and Bacillus subtilis. Quantitative studies of their structure-activity relationship using a simple linear regression analysis were applied to explore the correlation between the biological activity and the charges on acidic hydrogen atoms in the synthesized compounds.     

Synthesis and Antibacterial Screening of 1,3,4‐Thiadiazoles, 1,2,4‐Triazoles,and 1,3,4‐Oxadiazoles Containing Piperazine Nucleus

A series of novel 1,3,4‐thiadiazoles, 1,2,4‐triazoles, and 1,3,4‐oxadiazoles were synthesized by cyclization of substituted 1‐(2‐(2‐chlorophenyl)‐2‐(4‐(2,3‐dichlorophenyl)piperazin‐1‐yl)acetyl)thiosemicarbazide. The structures of all newly synthesized compounds were elucidated on the basis of spectral studies. Some of them were screened for their antibacterial activity. The compounds 6b , 6c , 8e , 9a , and 9b have shown moderate activity towards Bacillus Subtilis and Escherichia Coli .     

Synthesis and structure-activity relationship of rhodomyrtone derivatives as antibacterial agent

To study structure-activity relationship of rhodomyrtone against Gram-positive bacteria,structural modification of rhodo-myrtone was carried out to afford its 10 analogues.All compounds were assayed for their antibacterial potency using broth microdilution method.The results indicated that rhodomyrtone exhibited higher antibacterial activity against all Gram-positive bacteria than its analogues,with the exception of rhodomyrtone 6,8-diacetate(3) and oxime analogues 6 and 7 which demonstrated similar activity as the parent compound against Bacillus subtilis and Staphylococcus epidermidis with minimum inhibitory concentration and minimum bactericidal concentration ranged from 1 to 4μg/mL and 2 to 4μg/mL,respectively.In contrast,all analogues displayed no activity against Acinetobacter baumannii.Hydroxyl and ketone groups of rhodomyrtone were elucidated to be essential for the antibacterial property.     

Synthesis,spectral characterization,and biological studies of 3,5-disubstituted-1,3,4-oxadiazole-2(3H)-thione derivatives

The reaction of 3,4-dichlorophenyl-1,3,4-oxadiazole-2( 3H )-thione with piperidine derivatives via Mannich reaction was used to generate eleven novel compounds in moderate to good yields. Synthesized molecules were characterized according to their structure with ¹H NMR, ¹³C NMR and FT-IR spectral foundations, which were compatible with literature informations. Antimicrobial activity and cytotoxicity studies were done by disc diffusion and NCI-60 sulphordamine B assay methods. The antimicrobial test results revealed that synthesized compounds have better activity against gram-positive species than gram-negative ones. A total analysis of the antibacterial, antifungal, and antiyeast activity revealed that newly synthesized compounds were really active against Bacillus cereus , Bacillus ehimensis, and Bacillus thuringiensis species . For cytotoxicity, among three different cancer cell lines (HCT116, MCF7, HUH7) compounds 5c, 5d, 5e, 5f, 5g, 5i, 5j and 5k were seemed especially effective on HUH7 cancer cell line via moderate to good activity. More significantly, against liver carcinoma cell line (HUH7) most of the compounds of the series ( 5c-5g and 5i-5j ) have better IC₅₀ values (IC₅₀= 18.78 µM) than 5-Florouracil (5-FU) and also compound 5d possessed 10.1 µM value, which represents good druggable cytotoxic activity. Further, the molecules were also screened for in silico chemoinformatic and toxicity data to gather the predicted bioavailibity and safety measurements.     

Synthesis and antibacterial evaluation of some new 4‐substituted‐3‐aryl‐1‐(2,6‐dimethylpyrimidin‐4‐yl)pyrazoles

Synthesis of a series of new 4‐substituted‐3‐aryl‐1‐(2,6‐dimethylpyrimidin‐4‐yl)pyrazoles ( 2a , 2b , 2c , 2d , 2e , 2f , 2g , 3a , 3b , 3c , 3d , 3e , 3f , 3g , and 4a , 4b , 4c , 4d , 4e , 4f , 4g ) is described. All the synthesized compounds were evaluated in vitro for their antibacterial activity against two gram‐positive and two gram‐negative bacteria, namely, Bacillus subtilis (MTCC 8509), Bacillus stearothermophilus (MTCC 8508), Escherichia coli (MTCC 51), and Pseudomonas putida (MTCC 121), and their activity was compared with two commercial antibiotics, streptomycin and chloramphenicol. Two compounds, namely, 3‐(4‐anisyl)‐1‐(2,6‐dimethylpyrimidin‐4‐yl)pyrazole‐4‐carboxaldehyde ( 2b ) and 3‐(2‐thienyl)‐1‐(2,6‐dimethyl pyrimidin‐4‐yl)pyrazole‐4‐carboxaldehyde ( 2g ) were found to be equipotent to streptomycin and chloramphenicol against gram‐negative bacteria, E. coli having minimum inhibitory concentration (MIC) value = 4 μg/mL. Compounds 4b and 4d also displayed good activity against E. coli with MIC = 8 μg/mL. J. Heterocyclic Chem., (2011).     

Novel dihydropyrazole derivatives linked with multi（hetero）aromatic ring： Synthesis and antibacterial activity

Eight novel heterocycle-substituted dihydropyrazole derivatives were synthesized and characterized by ESI-MS,~1H NMR and ~(13)C NMR.All of the compounds have been screened for their antibacterial potential in vitro against Bacillus subtilis, Staphylococcus aureus,Escherichia coli and Pseudomonas aeruginosa.The results show that compounds 9b,9g and 9h displayed significant activity with MIC values in the range of 0.39-1.562μg/mL against B.subtilis.     

Ionic Liquid Mediated Green Synthesis of Spirooxindoles from N‐methyl Quinolones and Their Anti Bacterial Activity

Three‐component reaction involving condensation of 1‐methyl quinoline‐2,4(1H ,3H )‐dione 1 , isatins 2(a–e) , and malononitrile/cyanoacetic ester 3(a–b) in the task‐specific ionic liquid [DBU][Ac] (1,8‐diazabicyclo[5.4.0]‐undec‐7‐en‐8‐ium acetate) leading to the spirooxindole derivatives 4(a–j) is described. This approach is affords the products in high yields without use of column chromatography and resulting compounds were evaluated for antibacterial activity against both gram positive and gram negative bacteria (Staphylococcus aureus , Escherichia coli , Bacillus cereus, Bacillus subtilis, Salmonella typhimurium, and Klebsiella pneumonia ). Among the all compounds, four compounds, that is, 4b, 4e, 4f, 4g, 4j exhibited moderate activity against all the strains as compared with the standard used.     

Synthesis,Characterization and Antibacterial Activity of New 5-Aryl Pyrazole Oxime Ester Derivatives

Eleven new 1-{5-[4-（benzyloxy）phenyl]-3-methyl-4,5-dihydropyrazol-l-yl} oxime ester dcrivatives were synthesized and characterized by elemental analysis, HRMS, ^1H NMR data. All the compounds were screened for their antibacterial potential in vitro against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The results indicate that compounds 8c and 8f possess potent activity with the minimum inhibitory concentrations（MIC） of 1.562--3.125 ug/mL against all the four bacteria. Compounds 8c, 8e and 8f show moderate inhibition against the DNA gyrase（IC50=1.9--2.5 ug/mL）. On the basis of the biological activities, structure-activity relationship was discussed.     

含哌嗪片段的噻吩查尔酮衍生物的合成及其抗菌活性

查尔酮是一类具有多种生物活性的1,3-二苯基丙烯酮化合物.以4-氟苯乙酮和2-噻吩甲醛为原料出发,经取代、Aldol反应和衍生化,合成得到16个未见文献报道的含哌嗪片段的噻吩查尔酮衍生物.以氧氟沙星、左氧氟沙星、莫西沙星作阳性对照,采用K-B纸片扩散法测试了目标化合物对金黄色葡萄球菌(Staphylococcus aureus Rosenbach)、大肠埃希菌(Escherichia coli)和枯草芽孢杆菌(Bacillus subtilis)的抑菌活性.结果表明,(E)-1-[4-(4-肉桂酸甲酯甲基哌嗪基)苯基]-3-(噻吩-2-基)丙-2-烯酮(4b)和(E)-1-{4-[4-(2-氧亚基苯乙基)哌嗪基]苯基}-3-(噻吩-2-基)丙-2-烯酮(4e)对枯草芽孢杆菌高度敏感,且最低抑菌浓度为4.0μg/m L.