Synthesis and in vitro Study of Novel Methylenebis(phenyl- 1,5-benzothiazepine)s and Methylenebis(benzofuryl-1,5- benzothiazepine)s as Antimicrobial Agents

A series of methylenebis(phenyl-1,5-benzothiazepine)s 4 and methylenebis(benzofuryl-1,5-benzothiazepine)s 5 were prepared by the reaction of methylene-bis-chalcones 3 with 2-aminothiophenol for 4 and followed by the condensation with chloroacetone for 5. The structures of the synthesized compounds have been confirmed by their IR, 1H NMR, 13C NMR, MS and elemental analyses. All the synthesized compounds were tested for their antimicrobial activity against Gram-positive, Gram-negative bacteria and fungi. To elucidate the essential structural requirements for the antimicrobial activity, the preliminary structure-activity relationship has been described. Among the compounds tested, the dimeric compounds 4f, 4g, 5f and 5g were found to be most active against Bacillus subtilis, Bacillus sphaericus, Staphylococcus aureus, Klebsiella aerogenes and Chromobacterium violaceum. Similarly these dimeric compounds showed potent antifungal activity against Candida albicans, Aspergillus fumigatus, Trichophyton rubrum, and Trichophyton mentagrophytes. It is interesting to note that the dimeric compounds with substituents of heterocyclic ring at the 4th position of benzothiazepine system displayed notable antibacterial activity equal to that of streptomycin and penicillin. Further, the activity of all the dimeric compounds was compared with that of their monomeric compounds, and it is interesting to note that almost all the dimeric compounds showed enhanced activity than their monomeric compounds.     

Design and synthesis of novel triazole antifungal derivatives based on the active site of fungal lanosterol 14a-demethylase （CYP51）

A series of 1-(1H-1,2,4-triazole-1-y1)-2-(2,4-difluorophenyl)-3-(N-isoproyl-N-substituted-amino)-2-propanols have been designed and synthesized on the basis of the active site of lanosterol 14a-demethylase(CYP51).Their structures were confirmed by MS and ~1H NMR.In vitro antifungal activities of these synthesized compounds were evaluated against eight human pathogenic fungi.The results showed that all title compounds exhibited activity against fungi tested to some extent.Compounds 3c,3d,7a,7b and 7c exhi...     

Synthesis,antimicrobial, antiquorum-sensing and cytotoxic activities of new series of benzothiazole derivatives

New series of benzothiazole derivatives were designed and synthesized. The newly synthesized compounds were screened for their antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus cereus. Compounds 6j and 6o showed the highest activity against E. coli and S. aureus. The antifungal activity of these compounds was also tested against Candida albicans and Aspergillus fumigatus293. Compounds 4c, 4g and 6j exhibited the highest activity against C. albicans. In addition, compounds4 a and 6j displayed promising activity against A. fumigatus 293. The same compounds were examined for their antiquorum-sensing activity against Chromobacterium violaceum ATCC 12472, whereas compounds4 a, 6j and 6p showed moderate activity. The in vitro cytotoxicity testing of the synthesized compounds was performed against cervical cancer(Hela) and kidney fibroblast cancer(COS-7) cell lines. Results indicated that all tested compounds have IC50 values 50 mmol/L against both cell lines. Molecular properties, toxicities, drug-likeness, and drug score profiles of compounds 4a–c, 5a, 6g,h, 6j, 6l, 6o and7 c,d were also assessed.     

Syntheses,Spectral Studies and Bioanalyses of Some Triorganotin（IV） Complexes of Cephlaxine

Five novel triorganotin（IV） complexes have been synthesized by refluxing trimethyl, triethyl, tributyl, triphenyl and tribenzyltin chloride with Cephlaxine. These compounds were characterized by spectroscopic （IR, IH, 13C, 119Sn NMR） techniques and elemental analysis. The results obtained through these techniques are in full agreement with the proposed 1：1 stoichiometry. The synthesized compounds were than tested against various microorganisms and fungi. The results of new products obtained showed that the triphenyltin（IV） complex displayed promising activity against all types of bacteria and fungi used while all other compounds showed significant antibacterial and antifungal activity.     

Discovery of a series of pyridopyrimidine derivatives as potential topoisomerase I inhibitors

A series of new 3-benzoheterocyclic substituted pyridopyrimidines were designed and synthesized. Structures of the compounds were determined by IR, 1H NMR, and elemental analyses. The anti- proliferation activity of 13 novel compounds was evaluated in A549, HL-60, BGC-823 and SMMC-7721 cell lines. Compounds 3, 5, 7, 8, 9,10 showed potent inhibitory activity against the four tested cancer cell lines. These six compounds were examined for Top I inhibition at 100 μmol/L by measuring the relaxation of supercoiled DNA in plasmid pBR322. Most of the tested compounds inhibited the enzyme at this concentration. The most potent compound 9 was as potent as camptothecin.     

Design,synthesis and biological evaluation of sulfenimine cephalosporin sulfoxides as β-lactamase inhibitors

A series of sulfenimine cephalosporin sulfoxide derivatives(7a–v) were designed, synthesized and evaluated for their inhibitory activity against TEM-1 and cephalosporinase in cell-free systems. Some of the tested compounds showed enhanced inhibitory activity against class C b-lactamase cephalosporinase compared with the tazobactam. The most promising compounds 7c and 7n(IC50= 7.6 and8.6 mmol/L, respectively) were further investigated in combination with cefradine against a variety of clinical isolated b-lactamase-producing bacterial strains.     

Synthesis and fungicidal activity study of novel daphneolone analogs with 2,6-dimethylmorpholine

A series of novel daphneolone analogs was designed and synthesized on the basis of natural product 1,5-diphenyl-2-penten-1-one(I) from Stellera chamaejasme L. as lead compound, whereby 2,6-dimethylmorpholine moiety was introduced to replace 1-phenyl group. Their structures were confirmed by IR,1H NMR, and HRMS(ESI) or elemental analysis,13 C NMR for some representative compounds. The two isomers of target compounds were separated and identified by NOESY technique and chemical method.All of the synthesized compounds have been evaluated for anti-plant pathogenic fungi activities. The results showed that some compounds exhibited moderate to good antifungal activities against tested fungi at the concentration of 50 mg/L. Among them, compound 7d, with a 4-bromine-substituted phenyl group and cis-2,6-dimethylmorpholine moiety, displayed best activity with an EC50 of 23.87 mmol/L against Valsa mali, superior to lead compound I. In addition, preliminary structure–activity relationship analysis indicated that, between two isomers of target compounds, the antifungal activities of the isomer with cis-2,6-dimethylmorpholine were better than the trans-isomer.     

Synthesis and biological evaluation of new pyrrolopyrazinone compounds as potential antitumor agents

A series of pyrrolo[1,2-a]pyrazinone compounds(5a-9f) were synthesized,and their cytotoxic activity against SKOV-3,A549.HeLa cells in vitro were evaluated by the MTT method.Some of the compounds showed potential antitumor activity against three tumor cell lines.Among them,compounds 9c and 9d showed the most potent cytotoxic activity.The preliminary mechanism of action was discussed.     

Synthesis and in vitro cytotoxic activities of sorafenib derivatives

A series of novel sorafenib derivatives have been designed and synthesized.The cytotoxic activities of these compounds were tested in three tumor cell lines.Most of the compounds showed potent antiproliferative activity against the tested cell lines with IC50= 0–20 mmol/L.Some compounds demonstrated competitive antiproliferative activities to sorafenib against all three cancer cell lines.Among them,compound 5g demonstrated significant inhibitory activity against A549,ACHN and MDAMB-231 cell lines with IC50values of 1.29,1.99,3.11 mmol/L,respectively.     

Syntheses of Lactam Derivatives of Chenodeoxycholic Acid and in vitro Antiproliferative Activity

With chenodeoxycholic acid as starting material,a series of lactam derivatives of chenodeoxycholic acid was synthesized and their antiproliferative activities against some cancer cells were determined.Among the synthesized derivatives,compounds 6 and 18 displayed distinct antiproliferative activity against PC-3,H-292,SKBR3 and Hey-1B cancer cells,and compounds 10,17 and 18 showed significant antiproliferative activity against SKBR3 cells.Our results reveal that the position of hydroximino on ring A or B of the parental scaffold dramatically affects the antiproliferative activity of these compounds.The conversion of 7-hydroximino to other substituent or 7-hydroximino to 3-hydroximino in the compounds resulted in a dramatic decrease of the antiproliferative activity,suggesting the importance of 7-hydroximino group for the biological activity of the compounds.The structure/activity correlation generated from the studies provides valuable information for the further design of novel chemotherapeutic drugs.     

Synthesis and biological activities of novel 2-amino-1,3-thiazole-4-carboxylic acid derivatives

A series of novel 2-amino-1, 3-thiazole-4-carboxylic acid derivatives were designed and synthesized. Their structures were confirmed by melting points, IR, ¹H NMR, ¹³C NMR, and HRMS or elemental analysis. Biological activities of all title compounds including fungicidal activity and antivirus activity were evaluated systematically. Preliminary bioassays indicated that these compounds exhibited good fungicidal activity at 50 μg/mL, compounds 4b and 4i exhibited over 50% activity against six fungi tested. Most compounds showed good activity against TMV with different models in vivo at 100 μg/mL. Compounds 4c and 4e stood out with high effects against TMV in vivo in all models tested, including protective, inactivative, curative, and inductive activities. These data demonstrate a new strategy for fungi and virus control.     

3-S-(β-D-吡喃葡萄糖基)-1,2,4-三唑的合成及抗菌活性

以自制的5-取代芳基-4-氨基-3-巯基-1,2,4三唑为底物, 经糖基修饰后, 在甲醇钠/甲醇/二氯甲烷体系中经水解脱除糖环上的乙酰基, 得到9个新化合物5-取代苯基-4-氨基-3-S-(β-D-吡喃葡萄糖基)-1,2,4-三唑(6a~6i), 其结构经核磁共振波谱(¹H NMR, ¹³C NMR), 红外光谱(IR)和高分辨质谱(HRMS)确认. 生物活性测试结果表明, 目标化合物对大肠杆菌、 金黄色葡萄球菌、 枯草芽孢杆菌和白色念珠菌均显示出良好的抑菌活性. 化合物6g对大肠杆菌、 金黄色葡萄球菌、 枯草芽孢杆菌和白色念珠菌的最小抑菌浓度分别达到2, 8, 32和8 μg/mL, 抑菌效果接近或优于对照药物三氯生和氟康唑. 利用Autodock程序研究了目标化合物(6a~6i)与大肠杆菌烯脂酰还原酶(FabⅠ)受体蛋白分子的相互作用和结合自由能变化规律.     

Design,Syntheses and Biological Activities of Novel Sulfonylureas Containing an Oxime Ether Moiety

Since sulfonylurea is one of the most potent acetohydroxyacid synthase(AHAS) inhibitors, a series of novel sulfonylureas containing an oxime ether moiety was designed and synthesized and their chemical structures were determined by means of ¹H nuclear magnetic resonance(NMR), ¹³C NMR and high-resolution mass spectrometry(HRMS). In the herbicidal bioassay, several compounds showed moderate to good herbicidal activities against dicotyledons, but their activities against monocotyledons decreased. The in vitro antifungal activity was tested at a dosage of 50 mg/L. And the results show that compounds 7l, 7m and 7n exhibit promising antifungal activities against six common plant pathogenic fungi. Further investigations on molecular modification are in progress.     

含有2,4-二卤代联苯基的新型唑类衍生物的合成及其抗真菌活性

以2,4-二卤代联苯为原料,经傅-克酰基化、还原、取代等反应步骤,合成了含有2,4-二卤代联苯基的新型唑类目标化合物3a~3k,其结构用红外光谱(IR)、高分辨质谱(HMRS)、核磁共振氢谱(¹H NMR)、核磁共振碳谱(¹³C NMR)等技术手段进行了表征。 测试了目标化合物的体外抗真菌活性,结果表明,所有目标化合物对所测试的致病真菌均有一定程度的抗真菌活性。 其中化合物3a~3k对红色发癣菌和石膏样毛癣菌的抗真菌活性和两性霉素B相当,化合物3b、3c、3e、3f、3h、3i、3k对白色念珠菌的抗真菌活性优于或等于酮康唑。     

Synthesis and Biological Evaluation of Novel Anthranilic Diamides Containing N-H/CH3-1H-Pyrazole

In order to systematically study the structure-activity relationship of anthranilic diamides and develop insecticides with simple structure and high efficiency, a series of novel anthranilic diamides containing N-H/CH₃-1H-pyrazole was designed and synthesized. Their chemical structures were characterized by ¹H NMR spectra, high resolution mass spectrometry(HRMS) or ¹³C NMR spectra. The preliminary bioassay results indicated that all title compounds displayed moderate insecticidal activity against oriental armyworm(Mythimna separata) at 200 mg/L and fungicidal activities against six kinds of fungi at 50 mg/L, especially compound 5i showed 50% insecticidal activity at 25 mg/L. In addition, some compounds exhibited certain antitumor activities. It was demonstrated that the introduction of CH₃ group into pyrazole ring was superior to H for the insecticidal activity.     

Synthesis and antitumor activity of some new pyrazolo[1,5-a] pyrimidines

New series of pyrazolo[1,5-a]pyrimidine derivatives 7a-i, 11a-c and Schiff bases 13a-c were synthesized and screened for their in vitro antitumor activity against three human carcinoma cell lines, namely colorectal carcinoma (HCT116), prostate adenocarcinoma (PC-3) and liver carcinoma (HepG-2) using MTT cytotoxicity assay at 100 μg/mL. Some of the tested compounds displayed good anticancer activities against HCT-116 and PC-3 cells. Whereas, compounds 7d and 11a showed better antitumor activity than the rest of the compounds against both cell lines. A structure-activity relationship (SAR) has been discussed and structures of the newly synthesized compounds were confirmed by different spectral data (MS, IR, ¹H NMR and ¹³C NMR) and elemental analysis.     

Design,Synthesis and Antifungal Activity of Novel Thioureas Containing 1,3,4-Thiadiazole and Thioether Skeleton

To find new lead compounds with high antifungal activity, a series of new thiourea derivatives containing 1,3,4-thiadiazole and thioether skeleton was designed via linking the active sub-structures. The target compounds were prepared via three steps from the commercially available thiosemicarbazide. Their structures were characterized by means of HRMS, ¹H NMR, ¹³C NMR and IR spectroscopy. The preliminary results indicate that the title compounds show various antifungal activity against the tested fungi. Compounds 4c, 4g, 4h, 4k, 4n, 4o, 4p, 4q and 4r display excellent antifungal activities against one or more tested fungi with inhibitory efficiencies of 90%-100% at 200 μg/mL. Especially, compound 4o shows the best inhibitory effect against Curvularia lunata, Cotton Fusarium Wilt, P. P. var nicotianae and Fusarium spp. with the EC₅₀ values of 28.12, 30.41, 15.2 and 6.22 μg/mL, respectively, which are even superior to those of triadimefon(98.73, 96.58, 105.37 and 102.18 μg/mL). The preliminary structure-activity relationship indicates that allyl and aromatic groups are favorable to their antifungal activities.     

Synthesis and biological evaluation of 4-methyl-1,2,3- thiadiazole-5-carboxaldehyde benzoyl hydrazone derivatives

To find new lead compounds with high biological activity,a series of novel 4-methyl-1,2,3-thiadiazole-5-carboxaldehyde benzoyl hydrazone derivatives were designed and synthesized.Their structures were confirmed by ~1H NMR,~(13)C NMR,IR spectrum and elemental analysis.Preliminary bioassay indicated that the title compounds exhibited moderate to strong fungicidal activity against six fungi in vitro at50 μg/mL.Moreover,some of the title compounds exhibited good curative activity against TMV in vivo at500 μg/mL.The structure-activity relationship analysis of compounds against Valsa mali showed that compounds containing halogen at the para position on phenyl exhibited the best activity.Especially compound 8k showed broad spectrum fungicidal activities against Valsa mali,Botrytis cinerea,Pythium aphamdermatum,Rhizoctonia solani,Fusarium moniliforme and Altemaria solani with the EC_(50) values of8.20,24.42,15.80,40.53,41.48,and 34.16 μg/mL,respectively.     

Synthesis and biological activities of(E)-β-farnesene analogues containing 1,2,3-thiadiazole

In order to discover novel compounds with high-activity to control aphid,a series of novel(E)-β-farnesene analogues containing 1,2,3-thiadiazole were designed and synthesized,and their structures were confirmed by IR,~1H NMR,~(13)C NMR,and HRMS(ESI).The stability of representative compounds was studied by HPLC and ~1H NMR techniques.Repellent activity results indicated that compounds 8h and 8j displayed 60.3%and 62.0%repellent rates,respectively.The aphicidal bioassay results showed that most analogues exhibited considerable aphicidal activity against Myzus persicae.Especially,analogues 81,8s and 8t exhibited high activity with LC_(50) values of 33.4 μg/mL,50.2 μg/mL and 61.8 μg/mL,respectively,which were higher than the lead compound(E)-β-farnesene,but lower than commercial insecticide pymetrozine with a LC_(50) of 7.1 μg/mL