Synthesis and antimicrobial activity of some acridone derivatives bearing 1,3,4-oxadiazole moiety

Novel acridone derivatives bearing 1,3,4-moiety were synthesized by intramolecular cyclization of N´-[2-(9-oxoacridin-10(9H)-yl)acetyl]arylhydrazides. Study of antimicrobial activity of the synthesized compounds reveals that some of them are more active than the comparator drug rivanol.     

Novel 1,3,4-oxadiazole thioether and sulfone derivatives bearing a flexible N-heterocyclic moiety: Synthesis,characterization, and anti-microorganism activity

In the search for more efficient and versatile anti-phytopathogen agents, a series of new 1,3,4-oxadiazole thioether/sulfone analogues bearing a flexible N-containing heterocyclic pattern were elaborately prepared, and their bioactivities against plant pathogenic microorganisms were systematically evaluated. Bioassay screening results demonstrated that compounds 32 and 33 significantly inhibited the growth of Xanthomonas oryzae pv. oryzae (Xoo) in vitro (32, EC₅₀ = 5.17 mg L^?1; 33, EC₅₀ = 1.19 mg L^?1), which were significantly surpass commercial bismerthiazol (BT) and thiodiazole copper (TC). Meanwhile, pot experiments confirmed the prospective applications of compound 33 in managing rice bacterial leaf blight and its good safety toward rice plants. Further studies showed that compound 33 interfered with the formation of bacterial biofilms and inhibited bacterial virulence factors. Furthermore, an in vitro antifungal bioassay showed that compound 32 possessed remarkable growth inhibitory activity against Sclerotinia sclerotiorum (S.s., EC₅₀ = 22.16 mg L^?1) and Verticillium dahlia (V.d. EC₅₀ = 32.78 mg L^?1). These results all confirmed that the designed 1,3,4-oxadiazole compounds displayed potential for managing plant microbial diseases through targeting dihydrolipoamide S-succinyltransferase (DLST).     

Synthesis,in vitro antibacterial and antifungal evaluation of novel 1,3,4-oxadiazole thioether derivatives bearing the 6-fluoroquinazolinylpiperidinyl moiety

A series of structurally novel 1,3,4-oxadiazole thioether derivatives(6a-6z) containing a 6-fluoroquinazolinylpiperidinyl moiety were designed and synthesized using pharmacophore hybrid approach,and their structures were fully characterized by ^1H NMR,¹³C NMR and HRMS spectra.Among them,the structure of compound 6 d was further corroborated via single-crystal X-ray diffraction analysis.In vitro antibacterial bioassays showed that compounds 6 a,6 g,6 u and 6 v possessed EC₅₀ values of 30.4,30.6,27.5 and 26.0 μg/mL against phytopathogenic bacterium Xanthomonas oryzae pv.oryzae,respectively,which were significantly superior to that of commercially-available bactericide Bismerthiazol(85.1 μg/mL).Moreover,in vitro antifungal bioassays indicated that seven compounds demonstrated broad-spectrum fungicidal acitivties against six types of phytopathogenic fungi at 50 μg/mL.The present work showed the potential of 1,3,4-oxadiazole thioether derivatives carrying a 6-fluoroquinazolinylpiperidinyl moiety as effective antimicrobial agents for crop protection,deserving further investigations in the future.     

Synthesis and pharmacological evaluation of 9(10H)-acridone bearing 1,3,4-oxadiazole derivatives as antimicrobial agents

In the present study a new acridone derivatives were synthesized. The newly synthesized compounds were characterized by IR, NMR and C, H, N, S analyses. All newly synthesized compounds were screened for their antibacterial (Staphylococcus aureus, Streptococcus viridans and Escherichia coil) and antifungal (Gibberela, Cercospora arachidicola, Physolospora piricola and Fusarium oxysporum) studies. The results revealed that all synthesized compounds have a significant biological activity against the tested microorganisms.     

含1,3,4-噁二唑的葡萄糖苷衍生物的合成及抑菌活性

糖苷类化合物广泛存在于生物体内,并担负着重要生物功能,天然药物及中草药中的许多活性成分是糖苷化合物[1].糖苷类化合物的良好抗菌、抗癌活性激发了广大研究者的浓厚兴趣[2-3],启发人们通过糖苷化反应作为改变或增加生物活性的重要结构修饰方法[4],以增加化合物的水溶性和导向性,改进药理学性质.     

Synthesis,characterization and antibacterial activity of some new thiazole and thiazolidinone derivatives containing phenyl benzoate moiety

4-Formylphenyl benzoate was utilized as a versatile precursor for the construction of new series of heterocyclic scaffolds that contain thiazole and thiazolidin-5-one rings. The antibacterial activity of these scaffolds against two types of bacteria was screened and most of them exhibited good activity. Among the synthesized thiazole derivatives, compounds 5, 6, and 8a showed antibacterial activity close to the standard chemotherapeutic (Ampicillin).     

2,5-双取代-1,3,4-噁二唑类化合物的合成与表征

以3-( 4-氟苯基) -1H-吡唑-5-甲酸乙酯为原料,与H2NNH2?H2O发生肼解生成3-( 4-氟苯基) -1H-吡唑-5-甲酰肼,再与CS2环化生成2-巯基噁二唑中间体,最后在巯基上进行烷基化反应合成了一系列新型的2-硫醚-5-吡唑基-1,3,4-噁二唑类化合物,并利用IR、1H NMR、HRMS等波谱技术对目标化合物结构进行了表征。该合成方法具有原料易得,后处理简便,收率较高的优点。     

Synthesis and antimicrobial activities evaluation of some new thiadiazinone and thiadiazepinone derivatives bearing sulfonamide moiety

A new series of novel functionalized 1,3,4-thiadiazin-5-ones and 1,3,4-thiadi-azepin-5-ones bearing sulfonamide moieties were synthesized via 1,3-dipolar cyclocondensation reaction of nitrilimines with α-mercaptoesters and mercaptosuccinic acid respectively. The structures of the prepared compounds were confirmed by spectral methods (IR, ¹H-NMR, ¹³C-NMR and MS spectroscopy) and elemental analysis. The newly synthesized compounds were screened for their in vitro antimicrobial activity. Some of titled compounds exhibited significant antimicrobial activity on several strains of microbes.     

Synthesis of 2-amino-5-cyano-1,3,4-oxadiazole and some of its derivatives

Preparative syntheses have been developed for 2-amino-5-cyano-1,3,4-oxadiazole from the semicarbazone of methyl glyoxylate and some of its transformations were studied. This product is an important intermediate in the preparation of its derivatives.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1. 243–246, January, 1991.     

Synthesis and characterization of new thiadiazole derivatives bearing a pyrazole moiety

A series of thidiazole derivatives (4, 7) from pyrazole-3-carboxylic acid chloride (2) and pyrazole-3,4-dicarboxylic acid chloride derivatives (6) were synthesized and characterized. The structures of the new compounds were confirmed byelemental analysis, NMR (¹H and ¹³C) and IR spectra. The molecular and crystal structure of 4-benzoyl-N-[5-(methylthio)-1,3,4-thiadiazol-2-yl]-1,5-di-phenyl-1H-pyrazole-3-carboxamide(4d)was determined by single crystal X-ray diffraction method.     

Synthesis and biological activity of novel 1,3,4-oxadiazole derivatives containing a pyrazole moiety

Research on Chemical Intermediates - Several new 1,3,4-oxadiazole derivatives containing a pyrazole ring were designed and synthesized from ethyl acetoacetate and triethyl orthoformate as starting...     

Synthesis and anti-brucella activity of some new 1,3,4-oxadiazole derivatives containing a ferrocene unit

An isocyanide-based multicomponent reaction between cinnamic acid derivatives or 3-phenyl-2-propynoic acid, (N-isocyanimino)triphenylphosphorane, ferrocenecarbaldehyde, and dibenzylamine has been reported in excellent yields for the preparation of some new ferrocenyl-containing 1,3,4-oxadiazole derivatives. The anti-brucella activities of the products are investigated in in vitro and in vivo assays.     

Synthesis of substituted 1,3,4-oxadiazole derivatives

Monosubstituted oxadiazoles were synthesized by the reaction of hydrazides with triethyl orthoformate. Their reactions with benzoyl chloride gave benzoylcarbohydrazides, which under the action of thionyl chloride were cyclized to the respective 2,5-disubstituted oxadiazoles. 1-Aryl-4-(5-thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)-pyrrolidin-2-ones were synthesized from acid hydrazides using carbon disulfide under basic conditions. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 269-272, February, 2009.     

Synthesis and antibacterial evaluation of new sulfanyltetrazole derivatives bearing piperidine dithiocarbamate moiety

A series of new alkyl or aryl sulfanyltetrazole derivatives containing dithiocarbamate moiety (5a–6e) were synthesized. The structures of the compounds were characterized by IR, ¹H NMR, ¹³C NMR spectra, and elemental analysis data. The present study examines the antibacterial potential of novel synthetic sulfanyltetrazole compounds against clinically important gram-positive and -negative strains. The results of screening showed that attachment of dithiocarbamate to sulfanyltetrazole derivatives results in enhancement of antibacterial activity. The compound 6d showed the best activity among the tested compounds. Also, the less polar 2,5-disubstituted sulfanyltetrazole regioisomers showed an increased antibacterial activity compared with the corresponding more polar regioisomers.     

Synthesis of nitrophenyl derivatives of 1,3,4-oxadiazole

Acylation of nitrobenzhydrazides with nitrobenzoyl chlorides and ethyl chlorocarbonate yielded a number of corresponding 1,2-diacylhydrazines, which were converted by the action of phosphorus oxychloride to nitro-substituted 2,5-diphenyl- and 2-phenyl-5-ethoxy-1, 3,4-oxidazoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 741–743, June, 1977.     

Synthesis and biological activities of benzothiazole derivatives bearing a 1,3,4-thiadiazole moiety

A series of benzothiazole derivatives bearing a 1,3,4-thiadiazole moiety were designed, synthesized and evaluated for their antibacterial, antifungal and antiviral activities. The bioassay results indicated that most of target compounds showed good antiviral activities against tobacco mosaic virus (TMV) and antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo) and Ralstonia solanacearum (Rs). Especially, the anti-Xoo effect of title compounds 5k (N-(5-methoxybenzo[d]thiazol-2-yl)-2-((5-(2-tolyl)-1,3,4-thiadiazol-2-yl)thio)acetamide) and the anti-Rs effect of title compounds 5a (N-(5-nitrobenzo[d]thiazol-2-yl)-2-((5-(4-(trifluorom ethyl)phenyl)-1,3,4-thiadiazol-2-yl)thio)acetmide) respectively reached 52.4% and 71.6% at 100?µg/mL, which are superior to that of bismerthiazol (32.0% and 52.3%). In addition, the protective and inactivation activities of title compound 5i (N-(5-methoxybenzo [d]thiazol-2-yl)-2-((5-(4-nitrophenyl)-1,3,4-thiadiazol-2-yl)thio)acetamide) against TMV were 79.5% and 88.3%, respectively, which are better than that of ningnanmycin (76.4% and 86.8%). The above research showed that benzothiazole derivatives bearing a 1,3,4-thiadiazole moiety may be used as potential molecular templates in searching for highly-efficient antiviral and antibacterial agents.