C-3 Substituted Lawsonemonoximates of Holmium(III): Synthesis, Characterization, and Antimicrobial Activity

A series of five new metal complexes of Ho(III) with C-3 substituted derivatives of lawsonemonexime (2-hydroxy-1,4-naphthalenediene-1-oxime) were synthesized. The compounds were characterized by melting point, elemental analysis, IR spectroscopy and magnetic susceptibility. The antimicrobial activity of the compounds were determined by disk diffusion method and broth micro-dilution techniques using Mueller Hinton medium against the following organisms: S. aureus ATCC 6538P, Klebsiella pneumoniae, NCTC 418, Pseudomonas aeruginosa ATCC 27833, Salmonella typhimurium ATCC 23564, E. coli U 1777, E. coli HB101, Proteus morganii NCIM 2860, Providencia stuartii NCIM 2799 and Acinetobacter baumannii U 24. The chelates of Ho(III) with lawsonemonoxime and Ho(III) with 3-bromolawsonemonoxime showed a variable antimicrobial activity against all organisms tested except Pseudomonas and Klebsiella spp. S. aureus was found more sensitive to all ligands and chelates tested; but the MIC values of chelates were considerably less; thus having more antimicrobial effect.     

Binuclear Rhodium(II) Complexes With Selective Antibacterial Activity

Binuclear rhodium(II) complexes [Rh(2)Cl(2)(mu-OOCR)(2)(N-N)(2)] {R = H, Me; N-N = 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen)} and [Rh(2)(mu-OOCR)(2)(N-N)(2)(H(2)O)(2)](RCOO)(2) (R = Me, Et;) have been synthesized and their structure and properties have been studied by electronic, IR and (1)H NMR spectroscopy. Antibacterial activity of these complexes against Escherichia coli and Staphylococcus aureus has been investigated. The most active antibacterial agents against E. coli were [Rh(2)Cl(2)(mu-OOCR)(2)(N-N)(2)] and [Rh(2)(mu-OOCR)(2)(N-N)(2)(H(2)O)(2)](RCOO)(2) {R = H and Me} which were considerably more active than the appropriate nitrogen ligands. The complexes show low activity against S. aureus. The activity of the complexes [Rh(2)(OOCR)(2)(N-N)(2)(H(2)O)(2)](OOCR)(2) against E. coli decreases in the series: R=H congruent withCH(3)>C(2)H(5)>C(3)H(7) congruent withC(4)H(9). The reverse order was found in the case of S. aureus.     

水杨醛缩对氯苯胺Co(Ⅱ)配合物的合成、表征及其荧光性质研究

以水杨醛和对氯苯胺为原料合成了水杨醛缩对氯苯胺(HL),将其作为主要配体与1,4-对苯二酚以及氯化钴(CoCl2·6H2O)反应生成了Co(Ⅱ)的配合物[Co(C6H4O2)(L)2]n,用元素分析、红外吸收光谱、紫外可见吸收光谱对其结构进行了表征,并通过荧光光谱对配体、配合物荧光发光性质进行了研究。结果表明,配体水杨...     

Properties of Binuclear Rhodium(II) Complexes and Their Antibacterial Activity

Binuclear rhodium(II) complexes [Rh(2)Cl(2)(mu-OOCR)(2)(N-N)(2)], [Rh(2)(mu-OOCR)(2)(N-N)(2)(H(2)O)(2)](RCOO)(2) and [Rh(2)Cl(2)(mu-OOCCH(3))(terpy)(2)](H(3)O)Cl(2).9H(2)O (R = H, Me, Bu(n), ph, PhCHOH; N-N = 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen), 2,9-dimethyl-1,10-phenanthroline (dmp) and 6,7-dimethyl-2,3- di(2-pyridyl)quinoxaline (dmpq); terpy 2,2':6',2'-terpyridine) have been synthesized and their structure and properties have been studied by electronic, IR and (1)H NMR spectroscopy. Antibacterial activity of these complexes against Staphylococcus aureus and Escherichia coli has been investigated. The most active antibacterial agents against S. aureus were [Rh(2)(OOCPh)(2)(phen)(2)(H(2)O)(2)](2+), [Rh(2)(OOCPh)(2)(dmpq)(2)(H(2)O)(2)](2+), [Rh(2)(OOCBu)(2)(phen)(2)(H(2)O)(2)](2+) and [Rh(2)-(OOCBu)(2)(bpy)(2)(H(2)O)(2)](2+) which were considerably more active than the appropriate nitrogen ligands. The complexes show rather low activity against E. coli.     

Synthesis, Characterization and Antiviral Properties of Pd(II) Complexes With Penciclovir

With the aim to improve and extend the antiviral activity of the antiherpic drug penciclovir, to a wider spectrum of viruses, we have synthesized and characterized new binary and ternary complexes of Pd(II) of formulae cis-(pen)(2)PdCl(2) and cis,[(nucl)(2)Pd(pen)(2)]Cl(2), where nucl = guanosine, inosine, cytidine or penciclovir. The characterization was mainly based on IR and (1)H NMR spectroscopy, and the results showed that in all prepared complexes, penciclovir coordinates to the metal through N7. The far-i.r. spectrum of the complex cis-(pen)(2)PdCl(2) confirmed the cis- geometry around Pd(II). All the prepared complexes were markedly active against HSV-1 and HSV-2 strains, but not against thymidine kinase-deficient HSV-1 strains.     

Synthesis of novel pyridazine derivatives as potential antimicrobial agents

A series of novel pyridazine derivatives incorporated with triazole, thiazolidine, imidazolidine, oxazine, and quinazoline moieties was synthesized by the reaction of [6-(4-phenoxyphenyl)pyridazin-3-yloxy]acetyl isothiocyanate with variety of nucleophilic reagents. The structures of all products were confirmed and characterized by the elemental analysis and spectroscopic studies (IR, MS, ¹H NMR). Also, the products were investigated for their antibacterial and antifungal activities and were compared with the standard drugs. Most of the synthesized compounds demonstrated potent to weak antimicrobial activity.     

Poly[(2-Hydroxy-4-Methoxy Benzophenone) Butylene] Resin and its Polychelates with Lanthanides(III): Synthesis and Characterization

ABSTRACT

The resin (polymeric ligand) was prepared from 2-hydroxy-4-methoxy benzophenone with 1,4-butane diol in the presence of polyphosphoric acid as a catalyst at 160°C for 9 h. The poly[(2-hydroxy-4-methoxy benzophenone) butylene] L = H(HMBP-BD) form 1:2, ML₂, complexes with M = La(III), Pr(III), Nd(III), Sm(III), Gd(III), Tb(III), and Dy(III). The polymeric ligand and its polychelates were characterized by elemental analyses, electronic spectra, and magnetic susceptibilities, IR-spectroscopy, NMR, and thermogravimetric analyses. The number average molecular weight (M¯n) of the resin was determined by Vapour Pressure Osmometry (VPO). All the polychelates are paramagnetic in nature. The resins and their polychelates were screened for their antimicrobial activity against E. coli, B. substilis, S. aureus (bacteria), and S. cerevisiae (yeast). It was found that the polychelates show good antimicrobial activity compared to the free polymeric ligand.     

Polymerization of methyl methacrylate catalyzed by mono-/bis-salicylaldiminato nickel(II) complexes and methylaluminoxane

Two types of salicylaldiminato-based nickel complexes, mono-ligated Ni(II) complexes ([O-C₆H₄-o- C(H)=N-Ar]Ni(PPh₃)(Ph) (5), [O-(3,5-Br₂)C₆H₂-o-C(H)=N-Ar]Ni(PPh₃)(Ph) (6), [O-(3-t-Bu)C₆H₃-o-C(H)=N-Ar]Ni(PPh₃)(Ph) (7)) and bis-ligated Ni(II) complexes ([O-(3,5-Br₂)C₆H₂-o-C(H)=N-Ar]₂Ni (8), [O-(3,5-Br₂)C₆H₂-o-C(H)=N-2-C₆H₄(PhO)]₂Ni (9), Ar=2,6-C₆H₃(i-Pr)₂) were synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), mass spectrography (MS) and elemental analysis (EA). In the presence of methylaluminoxane (MAO) as cocatalyst, all the nickel complexes exhibited high activities for the polymerization of methyl methacrylate (MMA) and syndiotactic-rich poly(methyl methacrylate) (PMMA) was obtained. The complexes with less bulky substituents on salicylaldiminato framework possessed higher activities, while with the same salicylaldiminato, the mono-ligated nickel complexes showed higher catalytic activity than bis-ligated ones.     

2-取代-7-苄氧基-4,5-二氢-[1,2,4]三氮唑[4,3-a]喹啉-1(2H)-酮的合成及其抗癫痫活性研究

为了寻找具有更好抗惊厥活性及低神经毒性的化合物,文章以6-羟基-3,4-二氢-2(1H)-喹啉酮为起始原料合成了4个2-取代-7-苄氧基-4,5-二氢-[1,2,4]三氮唑[4,3-a]喹啉-1(2H)-酮衍生物,对目标化合物,采用小鼠最大电惊厥实验(MES),皮下戊四唑实验(sc-PTZ)测定了其抗惊厥活性,采用旋转法测定了神经毒性.药理实验结果显示目标化合物表现出了较强的抗惊厥话性,该结论证明喹啉并三氮唑化合物具有被开发为新型癫痫治疗药的优良品质.     

几种Salen双肟类衍生物及其配合物的合成与表征

以12,-二胺氧乙烷、1,3-二胺氧丙烷、1,4-二胺氧丁烷及3种水杨醛衍生物为原料,以无水乙醇为溶剂,在常压、55℃条件下合成了9种新型的Salen双肟类衍生物,与过渡金属盐类作用制备了其配合物。用元素分析、红外光谱、核磁共振及差热-热重等测试技术对化合物的结构进行了表征。结果表明,所合成的新型Salen双肟类衍生物均为四齿含氮配体并与过渡金属离子有较强的配位能力,反应条件温和,收率较高。     

N-[2-[(4,6-二甲氧基嘧啶-2-基)(羟基)甲基]苯基]取代甲酰胺类衍生物的合成及除草活性研究

以2-(2-硝基苯基)乙腈为起始原料,设计合成了13个新型的N-[2-[(4,6-二甲氧基嘧啶-2-基)(羟基)甲基]苯基]取代甲酰胺类化合物,通过1HNMR、MS和元素分析对所合成的化合物结构进行了表征。初步的生物活性测试结果表明,在150 g/hm2的有效成分用量条件下,合成化合物都没有表现出除草活性。     

β-环糊精-Cu(Ⅱ)配合物催化氧化邻苯二酚及其反应动力学

以β-环糊精(β-CD)作为骨架,经磺酰化反应、卤代反应和与L-组氨酸的亲核取代反应,得到了两种β-环糊精-组氨酸衍生物配体,再将配体与Cu(Ⅱ)配位,合成了具有多酚氧化酶催化活性的β-环糊精-Cu(Ⅱ)配合物。采用元素分析、傅里叶变换红外光谱、核磁共振波谱和原子吸收光谱等方法对配体和配合物的结构进行了表征。以O₂为氧化剂,用分光光度法测定了它们催化邻苯二酚氧化反应的性能,并考察了反应温度、pH值等因素对催化反应速率的影响。结果表明：β-环糊精-Cu(Ⅱ)配合物具有良好的催化性能;C-2位修饰得到的环糊精类金属衍生物因为活性基团与反应中心之间相对位置适宜,表现出较大的加速效果;反应动力学表明组胺基配位Cu(Ⅱ) 、β- CD疏水空腔和碱催化作用是反应加速的3个因素。     

Oxidation of catechol catalyzed by β-cyclodextrin-Cu(Ⅱ) complexes and its reaction kinetics

以β-环糊精(β-CD)作为骨架,经磺酰化反应、卤代反应和与L-组氨酸的亲核取代反应,得到了两种β-环糊精-组氨酸衍生物配体,再将配体与Cu(Ⅱ)配位,合成了具有多酚氧化酶催化活性的β-环糊精-Cu(Ⅱ)配合物。采用元素分析、傅里叶变换红外光谱、核磁共振波谱和原子吸收光谱等方法对配体和配合物的结构进行了表征。以O₂为氧化剂,用分光光度法测定了它们催化邻苯二酚氧化反应的性能,并考察了反应温度、pH值等因素对催化反应速率的影响。结果表明：β-环糊精-Cu(Ⅱ)配合物具有良好的催化性能;C-2位修饰得到的环糊精类金属衍生物因为活性基团与反应中心之间相对位置适宜,表现出较大的加速效果;反应动力学表明组胺基配位Cu(Ⅱ) 、β- CD疏水空腔和碱催化作用是反应加速的3个因素。     

Design,Synthesis, in vitro and in silico Characterization of 2-Quinolone-L-alaninate-1,2,3-triazoles as Antimicrobial Agents

Due to the ever-increasing antimicrobial resistance there is an urgent need to continuously design and develop novel antimicrobial agents. Inspired by the broad antibacterial activities of various heterocyclic compounds such as 2-quinolone derivatives, we designed and synthesized new methyl-(2-oxo-1,2-dihydroquinolin-4-yl)-L-alaninate-1,2,3-triazole derivatives via 1,3-dipolar cycloaddition reaction of 1-propargyl-2-quinolone-L-alaninate with appropriate azide groups. The synthesized compounds were obtained in good yield ranging from 75 to 80 %. The chemical structures of these novel hybrid molecules were determined by spectroscopic methods and the antimicrobial activity of the compounds was investigated against both bacterial and fungal strains. The tested compounds showed significant antimicrobial activity and weak to moderate antifungal activity. Despite the evident similarity of the quinolone moiety of our compounds with fluoroquinolones, our compounds do not function by inhibiting DNA gyrase. Computational characterization of the compounds shows that they have attractive physicochemical and pharmacokinetic properties and could serve as templates for developing potential antimicrobial agents for clinical use.     

Synthesis,Spectroscopy, Single-Crystal Structure Analysis and Antibacterial Activity of Two Novel Complexes of Silver(I) with Miconazole Drug

In a previous article, we reported on the higher toxicity of silver(I) complexes of miconazole [Ag(MCZ)₂NO₃ (1)] and [Ag(MCZ)₂ClO₄ (2)] in HepG2 tumor cells compared to the corresponding salts of silver, miconazole and cisplatin. Here, we present the synthesis of two silver(I) complexes of miconazole containing two new counter ions in the form of Ag(MCZ)₂X (MCZ = 1-[2-(2,4-dichlorobenzyloxy)-2-(2,4-dichlorophenyl)ethyl]-1H-imidazole]; X = BF₄⁻ (3), SbF₆⁻ (4)). The novel silver(I) complexes were characterized by elemental analysis, ¹H NMR, ¹³C NMR and infrared (IR) spectroscopy, electrospray ionization (ESI)-MS spectrometry and X-ray-crystallography. In the present study, the antimicrobial activity of all obtained silver(I) complexes of miconazole against six strains of Gram-positive bacteria, five strains of Gram-negative bacteria and yeasts was evaluated. The results were compared with those of a silver sulfadiazine drug, the corresponding silver salts and the free ligand. Silver(I) complexes exhibited significant activity against Gram-positive bacteria, which was much better than that of silver sulfadiazine and silver salts. The highest antimicrobial activity was observed for the complex containing the nitrate counter ion. All Ag(I) complexes of miconazole resulted in much better inhibition of yeast growth than silver sulfadiazine, silver salts and miconazole. Moreover, the synthesized silver(I) complexes showed good or moderate activity against Gram-negative bacteria compared to the free ligand.     

The Interaction of the Antitumor Complexes Na[trans-RuCl(4) (DMSO)(Im)] and Na[trans-RuCl(4)(DMSO)(Ind)] With Apotransferrin: a Spectroscopic Study

The interaction of two antitumor ruthenium(III) complexes,-Na[trans-RuCl(4)(DMSO)(Im)] and Na[trans-RuCl(4)(DMSO)(Ind)]- with human serum apotransferrin (apoTf) was investigated through a number of spectroscopic techniques such as UV-Vis absorption, CD and (1)H NMR spectroscopy. Interestingly, the hydrolysis profiles of these complexes in a physiological buffer are markedly affected by the presence, in solution, of apoTf suggesting the occurrence of a specific interaction of their respective hydrolysis products with the protein. The formation of stable adducts with apotransferrin has been demonstrated by CD spectroscopy, and additional information obtained through (1)H NMR of the hyperfine shifted signals. The bound ruthenium(III) species may be detached from these adducts by addition of excess citrate at low pH. The behavior of the investigated ruthenium(III) complexes with apoTf is compared with that of the recently described and strictly related ru-im and ru-ind antitumour complexes, and discussed in the frame of general strategies of drug targeting.     

Hydroxynaphthoquinone metal complexes as antitumor agents x: synthesis, structure, spectroscopy and in vitro antitumor activity of 3-methyl-phenylazo lawsone derivatives and their metal complexes against human breast cancer cell line mcf-7

The C-3 substituted phenylazo derivatives of lawsone (2-hydroxy-l,4 p-naphthoquinone, III) were synthesized and characterized. The X-ray crystal structure was determined for the ligand 3-(3'-methyl phenylazo) lawsone. The copper complexes of these derivatives were found to possess 1:2 metal stoichiometry and square planar geometries with intermolecular stackings, resulting in antiferromagnetic exchange interactions. The in vitro activity of all the synthesized compounds was examined against human breast cancer cell-line, MCF-7, which revealed enhanced activities for the metal complexes, the highest activity being observed for the copper compound of 3-(3'-methyl phenylazo) lawsone.     

SOD mimic activity,DNA binding and in-vitro antibacterial studies of drug based copper(II) complexes

Square pyramidal complexes [Cu^II(PFL)(bpa)Cl]?5H₂O (1) and [Cu^II(LFL)(bpa)Cl]?5H₂O (2) have been synthesized and characterized. Compounds were checked for their in-vitro antimicrobial activity against two Gram^(+ ve) and three Gram^(–ve) bacterial species. Intrinsic binding constant (K_b) of complexes with CT DNA were determined using absorption titration. Viscosity measurement suggests that complexes bind with CT DNA through partial nonclassical intercalative mode. Superoxide dismutase (SOD) like activity of the complexes was also compared with previously reported compounds.     

Synthesis and characterization of novel phenyl‐substituted poly(p‐phenylene vinylene) derivatives

Two novel phenyl‐substituted poly(p‐phenylene vinylene) derivatives, poly{2‐[3′,4′‐(2″‐ethylhexyloxy)(3″,7″‐dimethyloctyloxy)benzene]‐1,4‐phenylenevinylene} (EDP‐PPV) and poly{2‐[3′,4′‐(2″‐ethylhexyloxy)(3″,7″‐dimethyloctyloxy)benzene]‐5‐methoxy‐1,4‐phenylenevinylene} (EDMP‐PPV), and their copolymer, poly{2‐[3′,4′‐(2″‐ethylhexyloxy)(3″,7″‐dimethyloctyloxy)benzene]‐1,4‐phenylene‐vinylene‐co‐2‐[3′,4′‐(2″‐ethylhexyloxy)(3″,7″‐dimethyloctyloxy)benzene]‐5‐methoxy‐1,4‐phenylenevinylene} (EDP‐co‐EDMP‐PPV; 4:1, 1:1, and 1:4), were successfully synthesized according to the Gilch route. The structures and properties of the monomers and the resulting conjugated polymers were characterized with ¹H‐NMR, ¹³C‐NMR, elemental analysis, gel permeation chromatography, thermogravimetric analysis, ultraviolet–visible absorption spectroscopy, and photoluminescence and electroluminescence (EL) spectroscopy. The EL polymers possessed excellent solubility in common solvents and good thermal stability with a 5% weight loss temperature of more than 380°C. The weight‐average molecular weights and polydispersity indices of EDP‐PPV, EDMP‐PPV, and EDP‐co‐EDMP‐PPV were 1.40–2.58 × 10⁵, and 1.19–1.52, respectively. Double‐layer light‐emitting diodes with the configuration of indium tin oxide/polymer/tris(8‐hydroxyquinoline)aluminum/Al devices were fabricated, and EDP‐co‐EDMP‐PPV (1:1) showed the highest EL performance and exhibited a maximum luminance of 1050 cd/m² at 19.5 V. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1259–1266, 2005     

Novel Poly(Styrene) Attached Schiff Bases for Uptake Mn(II) and Ni(II) Ions and as Antimicrobial Agent against Micrococcus luteus

In this study, three novel poly(styrene) attached Schiff bases (AMP–SB) were synthesized from condensation reaction of (aminomethyl)polystyrene with 2-hydroxy-5-bromobenzaldehyde, 2-hydroxy-5-methylbenzaldehyde and 2-hydroxy-5-chlorobenzaldehyde for uptake from solutions containing Mn(II) and Ni(II) ions and as antimicrobial agent against Micrococcus luteus. Furthermore coordination polymers were synthesized including Mn(II) and Ni(II) ions for understand to geometric structure of uptake ions. Polymers attached Schiff bases and coordination polymers were characterized by means of elemental analyses, magnetic measurements, FTIR, UV-GB, TG/DTA and ¹H-NMR. The Ni(II) and Mn(II) contents in the metal-containing polymer complexes were determined by the ICP-MS technique. Antibacterial activities of the polymers attached Schiff bases and their complexes were studied by the well-diffusion method against M. luteus (ATCC-9341).