Synthesis of novel 1,2,3-thiadizoles and 1,2,3-selenadiazoles as new antimicrobial agents

Abstract

A series of novel 1,2,3-thiadiazoles and 1,2,3-selenadiazoles having a long alkyl chain were synthesized by reacting semicarbazones with SOCl₂ and SeO₂, respectively. The structures of the target compounds 5–12 were confirmed by spectroscopy (IR, ¹H NMR, ¹³C NMR, and MS) and elemental analysis. Their antibacterial and antifungal activities were evaluated against six bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterococcus faecalis, Staphylococcus epidermidis, Staphylococcus aureus) and three fungi (Candida albicans, Candida parapsilosis, Candida tropicalis). The results of bioassays indicated that the compounds 5-Dodecyl-4-(4-methoxy-phenyl)-[1-3]selenadiazole (7), 4-Methyl-5-tetradecyl-[1-3]selenadiazole (8) and 5-Dodecyl-4-(4-methoxy-phenyl)-[1-3]thiadiazole (11) displayed moderate antibacterial activity against S. Epidermidis. On the other hand, according to antifungal screening results, compounds 5-Dodecyl-4-phenyl-[1-3]selenadiazole (5), 4-p-Tolyl-5-undecyl-[1-3]selenadiazole (6), and 5-Dodecyl-4-(4-methoxy-phenyl)-[1-3]selenadiazole (7) exhibited significant antifungal activities studied yeast strains.     

Synthesis and biological evaluation of novel 1,2,4-triazole containing 1,2,3-thiadiazole derivatives

A series of novel 1,2,4-triazoles containing 1,2,3-thiadiazole derivatives were designed and synthesized. Their structures were confirmed by melting points, IR, 1H NMR, and elemental analysis and ESI-MS or HRMS. Preliminary bioassays indicated that these compounds exhibited very good insecticidal activity against Aphis laburni at 100 μg/mL, with mortality no less than 95%. Compounds 6a, 6c, 6f, 61 showed higher curative activity against TMV and compound 6h showed a higher induction effects against TMV in vivo at 100 μg/mL. Collectively, our data demonstrate a new strategy for control of insects and viruses.     

三芥子酸甘油酯类似物的合成及抑菌活性

以N-(2-溴乙基)邻苯二甲酰亚胺或N-(4-溴丁基)邻苯二甲酰亚胺和硫氢化钠为起始原料,通过取代、肼解、亲核加成等反应合成了10个三芥子酸甘油酯(erucin)类似物,通过核磁共振氢谱、碳谱及质谱对其结构进行了确认。采用比浊法初步测试了其对大肠杆菌、金黄色葡萄球菌、白色葡萄球菌、藤黄八叠球菌、枯草芽孢杆菌、蜡状芽孢杆菌和四联球菌等7种菌的生长抑制活性,测试结果显示,化合物对测试菌种都表现出较好的生长抑制活性,其中苄硫乙基-1-硫代异硫氰酸酯(5e)和苄硫基丁基-1-硫代异硫氰酸酯(5j)活性最高,对大肠杆菌的最低生长抑制浓度仅为7.8μg/m L,对金黄色葡萄球菌的最低生长抑制浓度也仅为15.6μg/m L和31.2μg/m L。     

苄基三苯基季鏻盐的合成及其晶体结构和抗菌活性测定

合成了1种苄基三苯基季鏻盐——氯化苄基三苯基季鏻盐([BzTPP]+Cl-);利用元素分析、红外光谱、电子喷雾质谱和X射线单晶衍射对其进行了组成分析和结构表征;采用二倍稀释法测定了其抗菌活性,并与季鏻盐[BzTPP]2[CoCl4]和[BzTPP]2[MnCl4]进行了对比.结果表明,合成的季鏻盐[BzTPP]+Cl-属于正交晶系,Pbca空间群,晶胞参数为:a=1.388 0(1)nm,b=1.717 0(2)nm,c=1.817 5(2)nm,α=β=γ=90°,V=4.131 3(7)nm3,Z=8,Dc=1.191g/cm3,GOOF=1.002,R1=0.038 4,wR2=0.113 6.该季鏻盐由Cl-离子和[BzTPP]+阳离子组成,阴、阳离子之间存在C-H…Cl氢键.与此同时,三种季鏻盐对大肠杆菌、金葡萄球菌及沙门氏菌均具有较好的抗菌活性.     

Synthesis of novel 1,2,3-triazole based polycarboxylic acid functionalised ligands for MOF systems

Copper catalysed click reactions are excellent tools to generate various 1,2,3-triazole linked polytopic aromatic carboxylates. The general reaction route involves protection of the carboxylates before proceeding with the click reaction. These polycarboxylate azoles are conveniently prepared for potential utility as novel key building blocks for metal organic frameworks. In one case, the ligand crystallises into a solid structure containing 1D, 2D and 3D features, based on a zigzag 1D structure, a ‘chicken mesh’-like 2D structure and a 3D structure with very well-defined channels.     

Crystal structures and antibacterial properties of Cu(II) complexes containing an unsymmetrical N2O Schiff base ligand and bidentate N-donor heterocyclic co-ligands

Abstract

Three new Cu(II) Schiff base complexes with bidentate N-donor heterocyclic co-ligands, 2,2'-bipyridine (1), 1,10-phenanthroline (2), and 2,9-dimethyl-1,10-phenanthroline (3), were synthesized and characterized by FT-IR and UV-vis spectroscopy. Molecular structures of [C₂₀H₂₁CuN₄O](ClO₄) (1) and [C₂₄H₂₅CuN₄O](ClO₄) (3) were characterized by single-crystal X-ray crystallography. The Schiff base ligand is an N₂O-type ligand, which is the mono-condensed form of the reaction between 1,3-propanediamine and salicylaldehyde. The antibacterial activities of these complexes were investigated against one gram positive and four gram negative bacteria. Considerable antibacterial activity was obtained against both gram type bacteria. Complexes 2 and 3 with 1,10-phenanthroline and 2,9-dimethyl-1,10-phenanthroline, respectively, showed better antibacterial activity compared to 1 which has the 2,2'-bipyridine co-ligand.     

Synthesis and Antitubercular Evaluation of New Bis-1,2,3-Triazoles Derived from D-Mannitol

Five new bis-1,2,3-triazole derivatives from D-mannitol, namely 2,3,4,5-tetra-O-acetyl-1,6-dideoxy-1,6-bis-(4-substituted-1H-1,2,3-triazol-1-yl)-D-mannitol (4), have been synthesized from 2,3,4,5-tetra-O-acetyl-1,6-diazido-1,6-dideoxy-D-mannitol (3) and alkynes, employing copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC) methodology. Evaluation of their in vitro antitubercular activity against Mycobacterium tuberculosis H₃₇Rv using the Alamar Blue susceptibility test indicated poor activities. However, this study has provided information about the SAR of D-mannitol derivatives in the search for new anti-TB drugs based on this carbohydrate.     

含二氧杂环异黄酮的合成

本文报道含有3', 4'-亚甲二氧基, 3', 4'-亚乙二氧基, 3, 4'-三亚甲二氧基的异黄酮类化合物的合成, 所得25个新化合物的结构经元素分析、^1H NMR谱确证; 紫外光谱表明有异黄酮特征吸收。文中并对反应机理进行了探讨。     

Synthesis,characterization, and antioxidant activity of heterocyclic Schiff bases

Schiff base derivatives have gained great importance due to revealing a great number of biological properties. Schiff bases were synthesized by treatment of 4-amino-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one ( 1 ) with various aldehydes in methanol at reflux. In addition, diamine was reacted with an aldehyde to yield the corresponding Schiff bases. The structures of synthesized Schiff bases were elucidated by spectroscopic methods such as microanalysis, ¹H-NMR, ¹³C-NMR, and FTIR. Antioxidant activities of synthesized Schiff bases were carried out using different antioxidant assays such as 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH^•) scavenging, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging, and reducing power activity. (E)-4-((1H-indol-3-yl)methyleneamino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one ( 3 ), (E)-1,5-dimethyl-4-((2-methyl-1H-indol-3-yl)methyleneamino)-2-phenyl-1H-pyrazol-3(2H)-one ( 5 ), (E)-1,5-dimethyl-2-phenyl-4-(thiophen-2-ylmethyleneamino)-1H-pyrazol-3(2H)-one ( 7 ), (E)-1,5-dimethyl-2-phenyl-4-(quinolin-2-ylmethyleneamino)-1H-pyrazol-3(2H)-one ( 9 ), (1S,2S,N1,N2)-N1,N2-bis((1H-indol-3-yl)methylene)cyclohexane-1,2-diamine ( 11 ), and (1S,2S,N1,N2)-N1,N2-bis((2-methyl-1H-indol-3-yl)methylene)cyclohexane-1,2-diamine ( 12 ) were synthesized in high yields. Compound 5 displayed a good ABTS^•+ activity. Compound 3 revealed the outstanding activity in all assays. Compound 7 has the best-reducing power ability in comparison to other synthesized compounds. Although compounds 5, 11, 12 are new, compounds 3, 7, 9 are known. Due to revealing a good antioxidant activity, the synthesized compounds ( 3, 5, 7 ) have the potential to be used as synthetic antioxidant agents.     

Synthesis,characterization, crystal structure,and antibacterial evaluation of Ni (II) complex with new dithiophosphorus compound

The reaction of 2,4-bis (4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide (Lawesson^’s reagent) with phenylethylamine produced [H₃NCH₂CH₂C₆H₅]⁺ [(C₆H₅CH₂CH₂NH)(p C₆H₄OMe)PS₂]^? (1). Furthermore, reaction of 1 with NiCl₂ in dry methanol led to the novel complex 2. The compounds were characterized by ¹H and ³¹P NMR, IR spectroscopy, and elemental analysis. A single crystal X-ray structure of complex 2 showed that the nickel complex is square planar. The complex formed a supramolecular structure via intermolecular S1…H7B and O1…H2N2 hydrogen bonds. The X-ray crystallography of complex showed [R²₂](18) and R⁴₄(18) motifs in the monomers were connected to each other via S1…H7B, O1…H2N2 hydrogen bonds with donor–acceptor distance of 2.89 and 2.51 Å, respectively. The new compounds were additionally tested in view of their antibacterial properties.     

One-pot synthesis of novel 1,2,3-triazole-pyrimido[4,5-c]isoquinoline hybrids and evaluation of their antioxidant activity

A series of novel pyrimido[4,5-c]isoquinolines (3a–3h) and 1,2,3-triazole-coupled pyrimido[4,5-c]isoquinolines (4a–4h) were synthesized in good to excellent yields in the one-pot method. The reaction of 6-amino-1,3-dimethyluracil with different 2-iodo benzoyl chlorides using Pd catalyst in dimethylformamide afforded corresponding pyrimido[4,5-c]isoquinolines (3a–3h). One-pot reaction of pyrimido[4,5-c]isoquinolines with propargyl bromide and benzyl azide in THF at room temperature furnished 1,2,3-triazole-coupled pyrimido[4,5-c]isoquinoline (4a–4h). In vitro antioxidant activity examination revealed that compounds 4d and 4c found to exhibit potent antioxidant activity as compared to the standard drug Trolox with IC₅₀ values 6.02?±?0.6 and 12.18?±?0.9?µM, respectively.     

新型N-取代苯甲酰基-N′-(4-甲基苯并噻唑-2-基)硫脲衍生物的合成、晶体结构及抑菌活性

以取代苯甲酸和2-氨基-4-甲基苯并噻唑为原料合成5个新型N-取代苯甲酰基-N′-(4-甲基苯并噻唑-2-基)硫脲衍生物,化合物结构经元素分析、IR、1 H NMR和13 C NMR表征,X-射线单晶衍射测定了N-(4-甲氧苯甲酰基)-N′-(4-甲基苯并噻唑-2-基)硫脲(化合物1)的晶体结构,该晶体为单斜晶系,P21/c空间群,选择广西主要经济作物中常见的病原菌,对目标化合物进行室内抑菌活性测试,实验结果发现该类化合物具有一定的抑菌活性.     

Synthesis and bioactivity evaluation of some novel sulfonamide derivatives

A simple and convenient method for the synthesis of biologically active sulfonamide derivatives was achieved. All the title compounds were characterized by spectral and elemental analysis. They were further screened in vitro for their abilities towards antibacterial, antifungal and antioxidant activities. The compound N,N'-(3,3′-dimethoxybiphenyl-4,4′-diyl)bis(4-fluorobenzenesulfonamide) (5b) and N-(3-(9H-carbazol-4-yloxy)-2-hydroxypropyl)-4-fluoro-N-isopropylbenzenesulfonamide (5e) exhibited good activity when compared to the standard bactericide, Chloramphenicol and fungicide, Ketoconazole respectively. The compounds (2S)-N-((2S,4S)-5-(4-Chloro-phenylsulfonamido)-4-hydroxy-1, 6-diphenylhexan-2-yl)-3-methyl-2-(2-oxotetrahydropyrim-idin-1(2H)-yl)butan-amide (4f) and (2S)-N-((2S,4S)-5-(4-fluorophenylsulfonamido)-4-hydroxy-1,6-diphenyl-hexan-2-yl)-3-methyl-2-(2-oxotetrahydropyrimidin-1(2H)-yl)bu-tana-mide (5f) exhibited good antioxidant activity when compared with standard antioxidant, Ascorbic acid.     

Antifungicidal,antibacterial and antifertility activities of biologically active heterocyclic thiosemicarbazones and their coordination complexes with the dimethylsilicon moiety

Synthetic, structural and biological aspects of trigonal-bipyramidal, Me₂Si(NS)Cl and octahedral, Me₂Si(NS)₂ types of organosilicon (IV) complexes of heterocyclic thiosemicarbazones (N? SH) have been described. The complexes were characterized by elemental analysis, molecular weight determination, conductance measurements and electronic, infrared, ¹H and ¹³C NMR spectral studies. Some ligands and their corresponding dimethylsilicon (IV) complexes have been tested for their effects on several pathogenic fungi and bacteria. Two representative complexes have also been found to act as sterilizing agents by reducing the production of sperm in male mice.     

Synthesis and biological evaluation of novel bispyridinium salts containing naphthalene-2,7-diylbis(oxy) spacer

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Syntheses,Crystal Structures and Antibacterial Activities of Two Heterocyclic Schiff Base Compounds

Two heterocyclic Schiff bases were synthesized via the condensation reactions of primary amines with carbonyl compounds. 2-[(4-pyridylmethylene)-amino] phenol(compound 1) was synthesized by the interaction of 4-pyridinecarboxaldehyde with o-aminophenol in ethanol solvent; N,N‘-bis(3-(furan-2-yl)allylidene)benzene-1,4-diamin(compound 2) was synthesized by the interaction of 3-(2-furyl)acrolein with p-phenylenediamine in ethanol medium. The compounds were characterized by elemental analysis, IR, MS and single-crystal X-ray diffraction. Compound 1(C12H10N2O) crystallizes in the monoclinic system, space group P21/c with a = 7.0771(7), b = 7.2820(7), c = 19.849(2),β= 96.3390(10)°, V = 1016.66(17) ?3, Z = 4, Mr = 198.22, Dc = 1.295 g/cm3, F(000) = 416, GOOF = 1.060, μ= 0.085 mm-1, the final R = 0.0371 and wR = 0.0929 for 1497 observed reflections with I 2σ(I). Compound 2(C20H16N2O2) crystallizes in the orthorhombic system, space group Fdd2 with a = 26.344(15), b = 48.50(3), c = 5.293(3), V = 6764(7) ?3, Z = 16, Mr = 316.35, Dc = 1.243 g/cm3, F(000) = 2656, GOOF = 1.043, = 0.081 mm-1, the final R = 0.0526 and wR = 0.1267 for 2059 observed reflections with I 2σ(I). 1 and 2 molecules are connected through hydrogen bonds to generate a 2D network and a 1D chain structure, respectively. The preliminary antibacterial activity results showed that the title compounds display excellent antibacterial activities to Escherichia coli, Staphylococcus aureus and Bacillus subtilis.     

Synthesis,crystal structure and antibacterial activity of manganese(III) and cobalt(III) complexes containing pentadentate Schiff bases of a common amine and thiocyanate

Abstract

Four new mononuclear Schiff base manganese(III) and cobalt(III) complexes viz. [Mn(L¹)(NCS)] (1), [Mn(L²)(NCS)] (2), [Co(L³)(NCS)] (3), and [Co(L⁴)(NCS)]·0.5CH₃OH·0.5H₂O (4), containing thiocyanate as a common pseudohalide ion are reported. The pentadentate Schiff base ligands H₂L¹, H₂L², H₂L³, and H₂L⁴ were obtained by the condensation of substituted salicylaldehydes with N-(3-aminopropyl)-N-methylpropane-1,3-diamine. The syntheses of the complexes have been achieved by the reaction of manganese(II) perchlorate or cobalt(II) perchlorate with the respective Schiff bases in the presence of thiocyanate in methanol medium. Complexes 1–4 have been characterized by microanalytical, spectroscopic, single-crystal X-ray diffraction and other physicochemical studies. Structural studies reveal that 1–4 adopt nearly similar structures containing the MN₄O₂ (M?=?Mn, Co) chromophore in which each central M(III) ion adopts a distorted octahedral geometry. Weak intermolecular H-bonding interactions are operative in these complexes to bind the molecular units. The antibacterial activity of 1–4 and their constituent Schiff bases has been tested against some common bacteria.     

富氮杂环配位超分子化合物的合成、结构及光谱特征

以2,6-二(5-甲基-1H-吡唑-3-基)吡啶(简写为H2L)为第一配体,以均苯四甲酸和乙酸为第二配体,合成了2个新的配位超分子化合物[Ni(H2L)2]·(Me O-H2BTA)2(1)和Mn(H2L)(Ac)2(2)(H4BTA∶均苯四甲酸,HAc∶乙酸),并由元素分析、红外光谱、紫外-可见光谱以及X射线单晶衍射等对其进行了表征,分析了其光谱及结构特征。晶体结构分析表明,化合物1属于正交晶系,Pbcn空间群,a=0.95747(8)nm,b=1.99273(13)nm,c=2.50175(13)nm,α=90°,β=90°,γ=90°,V=4.773 3(6)nm3,Z=4;化合物2属于单斜晶系,Cc空间群,a=1.11300(13)nm,b=2.0239(2)nm,c=0.97308(12)nm,α=90°,β=118.555(16)°,γ=90°,V=1.9253(4)nm3,Z=4。