Synthesis and antibacterial activity of hydroxylated 2-arylbenzothiazole derivatives

Abstract

N-acyliminium reagents formed in situ from benzothiazole and alkyl chloroformates react with hydroxyarenes in a Friedel-Crafts manner, providing access to 2-(hydroxyaryl)-benzothiazolines with antibacterial properties.     

Synthesis and antibacterial activity of lactivicin derivatives

The chemical modification of the 4-acetylamino group on the cycloserine moiety of lactivicin (1a) was carried out. The lactivicin derivatives (1d, k--p and w) having heterocyclic acylamino groups which have been often utilized in beta-lactam antibiotics showed potent antibacterial activities. Ester prodrugs (7a--d) of lactivicin derivatives were also prepared in order to improve the bioavailability on oral administration. The pivaloyloxymethyl (POM) esters (7a and 7b) and 1-ethoxycarbonyloxyethyl (EOE) ester (7c) were found to have slightly improved protective effect in vivo compared with their parent compounds 1c and 1k.     

1,2,4-噁二唑类化合物的合成及抗菌活性研究

以对溴苯腈为原料,通过多步反应合成了一系列3-(吗啉苯基)-5-取代-1,2,4-异噁唑类化合物和3-(吗啉苯基)-5-取代-4,5-二氢-1,2,4-噁二唑类化合物,并用1HNMR、13C NMR和MS进行了结构确证。这些化合物对测试的部分革兰氏阳性菌,如金黄色葡萄球菌、耐甲氧西林金黄色葡萄球菌、表皮葡萄球菌、粪肠球菌显示出一定的抗菌活性,但与噁唑烷酮类上市药物利奈唑胺相比,抗菌活性有明显下降。这一结果表明对于化合物的抗菌活性,1,2,4-噁二唑杂环不如噁唑烷酮结构有效。     

芝麻酚酰胺类衍生物的合成及抑菌活性

以芝麻酚为原料,经醚化、硝化、还原和酰胺化合成了9个未见报道的新型芝麻酚酰胺衍生物.其结构经~1H NMR和IR表征,并测定了其抑菌活性.初步生物活性测试结果表明,目标化合物对所有供试病菌均有一定的抑菌活性.4a_4对番茄灰霉病菌、棉花枯萎病菌、小麦赤霉病菌有较好的抑菌活性.4b_1对小麦赤霉病菌的抑制率达到95%;4b_2对番茄灰霉病菌和棉花枯萎病菌的抑制率达到90%以上;4b_3对番茄早疫病菌、番茄灰霉病菌、苹果腐烂病菌和棉花枯萎病菌的抑制率达到90%以上;4b_4对芹菜早疫病菌、番茄灰霉病菌、棉花枯萎病菌和小麦赤霉病菌的抑制率达到90%以上;4c_1对芹菜早疫病菌、番茄早疫病菌、番茄灰霉病菌、苹果腐烂病菌和棉花枯萎病菌的抑制率达到均达到90%以上.     

Sulfonylamidine-substituted derivatives of avibactam: Synthesis and antibacterial activity

Avibactam is a clinically approved non-β-lactam based β-lactamase inhibitor. Derivatization of this scaffold with improved inhibition profile is the demand of the day to cope with the future challenges. We successfully synthesized new derivatives of avibactam containing sulfonylamidine moieties at C2 position of the diazabicyclooctane ring. We tested in vitro antibacterial activities of newly synthesized compounds against 10 bacterial strains expressing variable β-lactamases. All compounds did not exhibit antimicrobial profile when assayed individually; however, all compounds minimized the MIC value of the imipenem in combination. Compound 5l proved most potent against all 10 bacterial strains, and showed improved inhibition against six bacterial strains as compared with the control inhibitor, relebactam. The compound 5l may be a lead hit for future development.     

Synthesis of 5-phenylproline derivatives with antibacterial activity

Methyl esters of 5-phenylprolines with the vinylsulfonyl or cyano group in the 4-position of the pyrrolidine ring have been synthesized. X-ray crystallography shows that all substituents in the vinylsulfonyl derivatives are cis to each other. All compounds are inhibitors of Staphylococcus aureus sortase SrtA.     

Synthesis and antibacterial activity of some novel pyrazolopyridine derivatives

Eight pyrazolo[3,4-b]pyridine derivatives have been synthesized by Friedl?nder condensation of 5-aminopyrazole-4-carbaldehyde with active methylene compounds in basic medium. These compounds have been screened for their antibacterial activity against two Gram-negative and two Gram-positive bacterium. Pyrazolopyridines having the carboxamide group at the 5-position showed moderate to good activity against P. aeruginosa, E. coli, S. pneumoniae, and B. cereus.     

Synthesis and antibacterial activity of C-2(S)-substituted pleuromutilin derivatives

<正>In order to probe the effect of C-2(S)-substituted groups in the antibacterial activity,a series of novel C-2(S)-substituted pleuromutilin analogues of SB-225586 were synthesized and evaluated for their in vitro antibacterial activity.The results of antibacterial activities indicated that C-2(S)-substituted pleuromutilin derivatives retained appreciable antibacterial activity,and the 2-fluorination compounds 6a and 6b are more potent than the corresponding 2-hydroxylation analogues 7a and 7b.     

酰胺类喹唑啉酮衍生物的合成及抗菌活性

本文设计并合成了23个含酰胺结构单元的新型喹唑啉酮类化合物,经1 H NMR、13 C NMR和HRMS确证结构.在100μg·mL-1和50μg·mL-1浓度下,评价了它们对水稻白叶枯病菌、猕猴桃溃疡病菌和柑橘溃疡病菌的抑菌活性.结果表明,化合物对柑橘溃疡病菌有较强的抑制活性,并测定了6个化合物对柑橘溃疡病菌的EC5...     

Synthesis, antibacterial and antifungal activity of some derivatives of 2-phenyl-chromen-4-one

Some derivatives of 2-phenyl-chromen-4-one (flavone ring) have been synthesized and tested for antibacterial and antifungal activities along with their chalcone precursors against four human pathogenic bacteria and five plant mould fungi. The structures of the synthesized compounds were elucidated by UV, IR and¹H NMR spectroscopic techniques, and elemental analysis. The antibacterial and antifungal screens of the synthesized compounds were performed in vitro by the filter paper disc diffusion method and the poisoned food technique.     

Synthesis of some sulfonamide derivatives with potential antibacterial activity

Some new quinoxaline-6-sulfonamide and phthalazine-6-sulfonamide derivatives were synthesized. The majority of the prepared compounds showed antibacterial activity.Faculty of Pharmacy, University of Tanta, Egypt. Fax: 002 040 335466Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 523–528, April, 2000.     

Synthesis and antibacterial activity of chalcone derivatives containing thioether triazole

The infection of Xanthomonas oryzae pv. Oryzae (Xoo), Ralstonia solanacearum (Rs), and Xanthomonas axonopodis pv. Citri (Xac) has become a major problem in agricultural production. In this study, a series of novel chalcone derivatives containing thioether triazoles were designed and synthesized. The structures of the novel compounds were systematically characterized via ¹H-NMR, ¹³C-NMR, and HRMS. Moreover, the antibacterial activity results showed that E₁₀, E₁₁, E₁₅, and E₁₆ have adequate antibacterial activities against Xoo, Rs, and Xac. Among the different compounds, E₁₅ exhibited remarkable inhibitory effect against Xac with an EC₅₀ of 9.1 μg.mL^-1, which was better than that of commercial agent bismerthiazol (54.9 μg.mL^-1). In addition, the possible antibacterial mechanism of the target compound E₁₅ against Xac was studied via scanning electron microscopy (SEM).     

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 and antibacterial activity of four natural chalcones and their derivatives

Four natural chalcones bearing hydroxyisoprenyl or prenyl groups, named Paratocarpin E (2), Xanthoangelol D (3), Angusticornin A (4) and Kanzonol C (5), were prepared by employing the Claisen-Schmidt condensation as the key step. In an attempt to investigate the effect of the hydroxyisoprenyl group on biological activity, two of their derivatives were also prepared for antibacterial activity research. The synthesized compounds were investigated for their expected antibacterial activities against Gram positive bacteria (Bacillus subtilis, Staphylococcus aureus) as well as Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa). Paratocarpin E (2) was found to be the most potent against two Gram positive bacteria while the majority of the remaining compounds showed promising activity as well. However, all of the compounds were inactive against both Gram-negative bacteria.     

Synthesis and antibacterial activity of betulonic acid amides with piperazine derivatives

New betulonic acid amides with piperazine derivatives were synthesized by the acid-chloride method and characterized using spectral data. It was shown that synthesized compounds 2–7 exhibited varied antibacterial activity. The most active of them was betulonic acid amide of 1-(3,4-dichlorophenyl)piperazine (3) and 1-(4-trifluoromethylphenyl)piperazine (7).     

Synthesis of hydrazone derivatives of benzofuran and their antibacterial and antifungal activity

A series of benzofuran hydrazones 6a–6n were synthesized from benzofuran aldehyde and substituted aromatic hydrazides 5a–5n. Structures of all compounds were confimed by IR, ¹H and ¹³C NMR, and Mass spectral data. These compounds were evaluated for their antibacterial activity against gram-negative bacteria (Escherichia coli, –ve), gram-positive bacteria (Bacillus Subtillis, +ve), and antifungal activity against Candida albicans. All compounds demonstrated considerable activity against bacteria and fungi.     

Synthesis and PPAR-gamma ligand-binding activity of the new series of 2'-hydroxychalcone and thiazolidinedione derivatives

Fifteen chalcones and three thiazolidinedione (TZD) chalcones were prepared to evaluate their peroxisome proliferator-activated receptor-gamma (PPAR-gamma) ligand-binding activities. Among the three TZDs, one compound possessed PPAR-gamma transactivation potential, while the others showed antagonistic activity against PPAR-gamma transactivation. Among the chalcones, compound 5 was the most potent, and structure-activity relationship studies indicated that a methoxyl group in position C-4 and hydroxyl group in position C-4' or 5' in chalcone plays a key role in determining the potency of PPAR-gamma activation.