Synthesis,structure, and antitumor properties of platinum(iv) complexes with aminonitroxyl radicals

The platinum(iv) complexes cis,trans,cis-Pt^IV(RNH₂)(NH₃)(OH)₂Cl₂, where R is 2,2,6,6-tetramethyl-1-oxyl-4-piperidinyl (1) or 2,2,5,5-tetramethyl-1-oxyl-3-pyrrolidinyl (2), were prepared by oxidation of the corresponding cis-Pt^II(RNH₂)(NH₃)Cl₂ complexes with hydrogen peroxide. The reactions are catalyzed by tungstate salts, which makes it possible to carry out oxidation under mild conditions. The resulting complexes were characterized by elemental analysis, HPLC, and IR, UV, and ESR spectroscopy. The structure of complex 1 was established by X-ray diffraction analysis. Complex 1 exhibits the highest antitumor activity in an experimental tumor, viz., in P388 leukemia. The resistance of the tumor to this complex developed much slower than that to Cisplatin.     

Meso位单取代卟啉及其配合物的合成、表征和光谱性质

设计合成了一系列新型的meso位N,N-二甲氨基苯基或N-苯基咔唑基单取代卟啉（5a~c）及其锌配合物（6a~c）,用高分辨质谱、¹H NMR、紫外-可见光谱及X射线单晶衍射方法等对结构进行了表征;研究了卟啉化合物及其配合物的热稳定性及荧光性质。结果表明,这些卟啉化合物及其锌配合物在400~410 nm之间具有强的吸收且具有很好的热稳定性,荧光量子产率在0.05~0.09;另外还分析了meso位不同取代基对光谱性质的影响。     

两个取代苄基锡配合物的合成、抗癌活性及其与DNA相互作用

利用二(2,4-二氯苄基)二氯化锡分别与对甲基苯甲酰肼或对叔丁基苯甲酰肼、丙酮酸钠在甲醇中发生反应,合成了2个二(2,4-二氯苄基)锡配合物(C1、C2),通过元素分析、IR、¹H NMR、¹³C NMR、¹¹⁹Sn NMR、HRMS以及X射线单晶衍射表征了配合物结构。测试了配合物C1、C2的热稳定性以及配合物对NCI-H460(人肺癌细胞)、HepG2(人肝癌细胞)和MCF7(人乳腺癌细胞)的体外抑制活性,发现配合物C1对癌细胞均表现较好的抑制作用。利用UV-Vis光谱、荧光光谱以及黏度法研究了2个配合物与ct-DNA之间的相互作用,结果表明配合物是以经典的嵌入模式与DNA结合。     

Platinum(IV) complexes with N-alkylphenothiazines: synthesis,characterization, and antibacterial activity

Two new platinum(IV) complexes (1, trifluoperazinehydrochloride-aquapentachloridoplatinate(IV) and 2, chlorpromazine-chlorpromazinehydrochloridepentachloridoplatinate(IV)) were synthesized in the reaction of K₂[PtCl₆] with trifluoperazine dihydrochloride (TF·2HCl) or chlorpromazine hydrochloride (CP·HCl). The complexes were characterized by elemental analysis, molar conductivity measurement, and spectral (IR, ¹H, ¹³C, 2D ¹H–¹³C heteronuclear correlation spectra, ¹⁹⁵Pt NMR, and MS) methods. Outer-coordination sphere was proposed for 1; while in 2, the ligand was coordinated to the metal. The complexes exhibit antibacterial effect on strains of Bacillus subtilis, Bacillus cereus, Bacillus pumilus, and methicillin-resistant Staphylococci as Gram-positive bacteria and an Escherichia coli as Gram-negative bacteria, as well as the reference strains.     

Synthesis,characterization, antimicrobial,DNA binding,and oxidative cleavage activities of Cu(II) and Co(II) complexes with 2-(2-hydroxybenzylideneamino)isoindoline-1,3-dione

(E)-2-(2-hydroxybenzylideneamino)isoindoline-1,3-dione (Hbid) was prepared by condensation of N-aminophthalimide and salicylaldehyde and characterized by elemental analysis, IR, ¹H-NMR, and mass spectral studies. Mononuclear complexes [(phen)Cu^II(μ-Hbid)₂H₂O] (1), [(phen)Co^II(Cl)₂(μ-Hbid)]6H₂O (2) (phen?=?1,10-phenanthroline) and binuclear complexes [Cu^II(μ-Hbid)]₂ (3), and [Co^II(μ-Hbid)]₂ (4) with Hbid were prepared and characterized by elemental analysis, IR, UV-Vis, molar conductance, and thermogravimetric (TG) techniques. DNA-binding properties of 1–4 were investigated by UV spectroscopy, fluorescence spectroscopy, and viscosity measurements. The results suggest that 1 and 2 bind to DNA by partial intercalation, whereas 3 and 4 find different groove-binding sites. The cleavage of these complexes with super coiled pUC19 has been studied using gel electrophoresis; all the complexes displayed chemical nuclease activity in the absence and presence of H₂O₂ via an oxidative mechanism. Complexes 1–4 inhibit the growth of both Gram-positive and Gram-negative bacteria.     

乙烯聚合水杨醛亚胺锆配合物的合成、结构和固定化

合成和表征了2个锆的配合物：Bis[N-(3-tert-butylsalicylidene) allylaminato] zirconium dichloride (4)和Bis[N-(3-tert-butylsali-cylidene)-iso-butylaminato] zirconium dichloride (5)，并且得到了配合物4的单晶结构。在引发剂的作用下，配合物4和苯乙烯进行自由基共聚，得到高分子化催化剂6。在助催化剂MMAO的存在下，4，5和6都可以催化乙烯聚合。最高活性为3.7×10⁶ g PE·(mol Zr)^-1·h^-1。     

Synthesis,spectroscopic characterization,crystal structure,and anti-bacterial activity of diorganotin(IV) complexes with 5-bromo-2-hydroxybenzaldehyde-N(4)-ethylthiosemicarbazone

Three new diorganotin(IV) complexes, [Me₂Sn(BDET] (2), [Bu₂Sn(BDET)] (3), and [Ph₂Sn(BDET)] (4), were synthesized by reacting R₂SnCl₂ (R = Me, Bu, and Ph) with 5-bromo-2-hydroxybenzaldehyde-N(4)-ethylthiosemicarbazone [H₂BDET, (1)] in the presence of KOH in absolute methanol. The newly synthesized complexes were characterized by elemental analysis, molar conductivity, UV–vis, FT-IR, ¹H, ¹³C, and ¹¹⁹Sn NMR spectroscopies. The molecular structure of 4 was confirmed by X-ray crystallography. X-ray crystallography revealed that the doubly deprotonated O,N,S-tridentate thiosemicarbazone coordinates to tin(IV), resulting in a distorted trigonal bipyramidal geometry. Their ¹H, ¹³C, and ¹¹⁹Sn NMR spectra support a five-coordinate tin(IV) in solution for all complexes, in accord with the solid-state X-ray structure determined for 4. Compounds 1–4 were evaluated for their antibacterial activities against Staphylococcus aureus, Enterobacter aerogenes, Escherichia coli, and Salmonella typhi. The results exhibited that 2–4 were active with comparable potency compared to the standard drug. Antibacterial studies also indicated that the complexes have potential for biological evaluation.     

基于多羧酸烟酸配体的镝、钬、铒和铥配合物的合成及荧光、磁学性质的表征

以5-(4-羧基苯氧基)烟酸配体(H₂cpna)和稀土金属离子Dy³⁺、Ho³⁺、Er³⁺和Tm³⁺为原料,采用水热法合成了4种稀土金属配合物[M(Hcpna)(cpna)(H₂O)₃]_n,其中M=Dy(1)、Ho (2)、Er (3)、Tm (4)。单晶X射线衍射分析表明配合物1、2、3和4为同构配合物,均为一维链状结构。通过红外、元素分析以及粉末X射线衍射对所得配合物进行了表征,同时对配合物的荧光和磁学性质开展了研究。荧光测试结果表明,配合物1～4的荧光强度均低于配体H2cpna的荧光强度。在2～300 K温度范围内1 kOe直流电场下测试了配合物1～4的磁性,结果表明配合物1、2、3和4的χ_mT值分别为14.04、14.15、11.08和6.83 cm³·mol^-1·K,与文献理论值相符合。     

One-Pot,Multicomponent Condensation Reaction in Neutral Conditions: Synthesis,Characterization, and Biological Studies of Fused Thiazolo[2,3-b]quinazolinone Derivatives

A new series of 12-(2-chloro-6-quinoline-3-yl)-3,3,8-substituted-2,3,4,12-tetrahydro-benzo[4,5]thiazolo[2,3-b]quinazolin-1-ones 4 was synthesized in one pot by condensing various 2-chloro-3-formylquinolines 1, 2-amino-6-substituted-benzothiazoles 2, and 1,3-cyclohexanedione 3 in ethanol. All the compounds were characterized by IR, ¹H NMR, ¹³C NMR spectra and elemental analysis. All the synthesized compounds were screened for their antibacterial activity against Grampositive bacterial species Bacillus cereus and Bacillus substilus, Gram-negative bacterial species Escherichia coli, and their fungicidal activity against Aspergillus niger, Fuserium oxisporum, and Rhizopus species.     

Preparation and structural,spectroscopic, thermal,and electrochemical characterizations of iron(III) compounds containing dipicolinate and 2-aminopyrimidine or acridine

Two new iron(III) compounds, (Hamp)[Fe(pydc)₂]?·?2H₂O (1) and (Hacr)[Fe(pydc)₂]?·?2H₂O (2) (pydc^2??=?pyridine-2,6-dicarboxylic acid, amp?=?2-aminopyrimidine, acr?=?acridine), have been hydrothermally synthesized. Both compounds were characterized by spectroscopic methods (IR, UV/Vis), and their molecular and crystal structures were determined by X-ray crystal structure analysis and their thermal stability by thermogravimetric analysis/differential thermal analysis (TGA/DTA) methods. Compound 1 consists of Hamp⁺ cation and [Fe(pydc)₂]^? anion and 2 consists of Hacr⁺ cation and [Fe(pydc)₂]^? anion. Crystallographic characterization revealed an octahedron as a coordination polyhedron for the complex anion in 1 and 2 and the same O,N,O′-chelated coordination mode of pyridine-2,6-dicarboxylate. The crystal structures of 1 and 2 are stabilized by a complicated network of hydrogen bonds between the crystallization water molecules, counter ion, and carboxylates of pydc^2?. Thermogravimetric (TG) analyses of the two compounds were carried out to examine their thermal stabilities. Cyclic voltammetric response of bare glassy carbon electrode surface in 0.10?mol?L^?1 phosphate buffer containing 1 and 2 at different pH values indicated that they have the same voltammograms at all pH values and the electrochemical behavior of 1 and 2 has not been affected by different ion pairs. The formal potential of the solutions of 1 and 2 at the glassy carbon electrode surface was also pH-dependent with a slope of ?57.0?mV/pH unit at 25°C. This shows that the number of electrons and protons involved in the electrode process is equal.     

Synthesis,antimicrobial activity and QSAR studies of 2,5-disubstituted benzoxazoles

In this study, a new series of 2,5-disubstituted benzoxazoles was synthesized and their structures were elucidated by elemental analysis, MASS, ¹H-NMR, ¹³C-NMR and IR spectral data. Newly and previously synthesized 2,5-disubstituted benzoxazole derivatives were evaluated for antibacterial and antifungal activity against standard strains and their drug-resistant isolates. Microbiological results showed that the compounds presented a large spectrum of activity having MIC values of 250–7.8 µg mL^?1 against the tested microorganisms. Among the newly synthesized derivatives 3–22, compound 11 was the most active against Candida krusei out of all; however, it was one dilution less potent than standard drug fluconazole. In addition, all the new and previous compounds were more active than standard drugs ampicillin trihydrate and rifampicin against Pseudomonas aeruginosa and its gentamicin-resistant isolate. The 2D-QSAR (Quantitative Structure–Activity Relationship) analysis of a set of newly and previously synthesized benzoxazoles tested for growth inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA) was also performed by using multivariable regression analysis. The activity contributions for substituent effects of these compounds were determined from the correlation equation for predictions of the lead optimization.     

Synthesis,structural characterization,and cytotoxic activity of new spirocyclic octachlorocyclotetraphosphazenes

Octachlorocyclotetraphosphazene, N₄P₄Cl₈, (1) was reacted with N, N′-dibenzylethylenediamine to synthesize partially substituted monospiro- (2), dispiro- (5) and tetraspirocyclotetraphosphazene (8) derivatives. The reactions of 2 and 5 with excess pyrrolidine and morpholine produced fully substituted pyrrolidino (3 and 6) and morpholino (4 and 7) spirocyclotetraphosphazenes. The structures of the compounds were determined with 1D (¹H, ¹³C, ³¹P, and DEPT) NMR, 2D (HSQC) NMR, ESI-MS, FTIR, and elemental analysis. The solid-state structures of 6 and 7 were examined by X-ray crystallography. In 7, intramolecular C-H…O hydrogen bonds link the molecules into centrosymmetric dimmers. The cytotoxic activity of all the compounds against human cervix carcinoma cell lines (HeLa) was investigated. The study showed that these compounds exert limited cytotoxic, apoptotic and necrotic effects on HeLa cancer cell lines.     

Synthesis,spectral, catalytic,and thermal studies of vanadium complexes with quadridentate schiff bases

The paper reports the synthesis and characterization of vanadium complexes of N,N′-(±)-trans-bis(2,4-dihydroxyacetophenone)-1,2-cyclohexanediamine (H₂L¹) and N,N′-(±)-trans-bis(2,4-dihyroxy-5-nitroacetophenone)-1,2-chyclohexanediamine (H₂L²). All the complexes were characterized by elemental analysis, magnetic susceptibility measurements, infrared and electronic spectra, and thermogravimetric analysis. The X-ray patterns of the [VO(L¹)] · H₂O (I) and [VO(L²)] · H₂O (II) complexes show the monoclinic system with the unit cell parameters a = 26.1352, b = 11.7149, c = 6.0401 β = 115.38° and a = 29.3787, b = 12.9398, c = 5.9175 β = 96.84°, respectively. The complexes I and II catalyze the oxidation of styrene in the presence of hydrogen peroxide.     

Synthesis,characterization, and crystal structure of three cobalt(II) complexes with Schiff bases derived from rimantadine

By condensation of rimantadine and substituted salicylaldehyde, three new Schiff bases, HL¹, HL² and HL³, were synthesized. Then, a mixture of one of the new ligands and cobalt(II) chloride hexahydrate in ethanol led to 1, 2, and 3, respectively. These complexes were characterized by melting point, elemental analysis, infrared spectra, molar conductance, thermal analysis, and single-crystal X-ray diffraction analysis. X-ray diffraction analysis reveals that 1 crystallizes in the orthorhombic system, Pbcn space group; each asymmetric unit consists of one cobalt(II) ion, two deprotonated ligands, and one lattice water. The central cobalt is four coordinate via two nitrogens and two oxygens from the corresponding Schiff base ligand, forming a distorted tetrahedral geometry. Complexes 2 and 3 crystallize in the monoclinic system, P2₁/c space group; each asymmetric unit consists of one cobalt(II), two corresponding deprotonated ligands, one lattice water, and one methanol. The central cobalt is also four-coordinate via two nitrogens and two oxygens from the corresponding Schiff base ligand, forming a distorted tetrahedral geometry.     

Norfloxacin La(III)-based complex: synthesis,characterization, and DNA-binding studies

A La(III) complex, [La^IIICl₂(NOR)₂]Cl (2), containing norfloxacin (NOR) (1), a synthetic fluoroquinolone antibacterial agent, has been synthesized and characterized by elemental analysis, IR, UV–vis spectra and ¹H NMR spectroscopy, and molar conductance measurements. The interaction between 2 and CT-DNA was investigated by steady-state absorption and fluorescence techniques in different pH media, and showed that 2 could bind to CT-DNA presumably via non-intercalative mode and the La(III) complex showed moderate ability to bind CT-DNA compared to other La(III) complexes. The binding site number n, and apparent binding constant K_A, corresponding thermodynamic parameters ΔG^#, ΔH^#, ΔS^# at different temperatures were calculated. The binding constant (K_A) values are 0.23 ± 0.05, 0.56 ± 0.05, and 0.18 ± 0.08 × 10⁵ L mol^?1 for pH 4, 7, and 11, respectively. It was also found that the fluorescence quenching mechanism of CT-DNA by La(III) complex was a static quenching process.     

Synthesis,characterization, antiproliferative,and antimicrobial activity of osmium(II) half-sandwich complexes

New osmium(II)-arene complexes [(η⁶-C₆H₆)OsCl(C₅H₄N-2-CH=N-C₆H₅X)](PF₆) (X = p-flouro (1), p-chloro (2), p-methyl (3)) were synthesized by reaction of the corresponding bidentate N,N′-ligands with the osmium-arene precursor [(η⁶-C₆H₆)Os(μ-Cl)Cl]₂ in a 2:1 ratio. These complexes were characterized by UV–Vis, IR, ¹H, ¹³C NMR spectroscopy, and elemental analysis and, for compound 1, a single crystal X-ray structure was also obtained. The complexes were investigated for antiproliferative activity in vitro against MCF-7 (human breast adenocarcinoma), Caco-2 (human epithelial colorectal adenocarcinoma), and HepG2 (human hepatocellular carcinoma) tumor cell lines. To test their selectivity, the non-tumor HEK293 (human embryonic kidney) cell line was used. The compounds were selective toward the tumor cell lines when compared to the known anticancer drug 5-fluorouracil which displayed low selectivity. The compounds were substantially more active against Caco-2 than 5-fluorouracil. They also showed moderate activity against the other two tumor cell lines. In addition, the antimicrobial activity of complex 2 was explored against a panel of antimicrobial-susceptible and -resistant Gram-negative and Gram-positive bacteria. Complex 2 showed anti-mycobacterial activity against Mycobacterium smegmatis and bactericidal activity against drug-resistant Enterococcus faecalis and methicillin-resistant Staphylococcus aureus ATCC 43300.     

Iron(II) complexes containing the 2,6-bis-iminopyridyl moiety. Synthesis,characterization, reactivity,and DNA binding

Two iron(II) complexes, [Fe^II(py^tBuN₃)₂](FeCl₄) (1) and [Fe^II(py^tBuMe₂N₃)Cl₂] (2), with sterically constrained py^tBuN₃ and py^tBuMe₂N₃ chelate ligands (py^tBuN₃ = 2,6-bis-(aldiimino)pyridyl; py^tBuMe₂N₃ = 2,6-bis-(ketimino)pyridyl), have been synthesized and characterized by elemental analysis, IR, UV–vis spectra, and preliminary X-ray single-crystal diffraction. The latter revealed that Fe(II) in 1 is six-coordinate by six nitrogen donors from two bisiminopyridines in a distorted octahedron. Complex 2 reacts with thiourea with a second-order rate constant k₂ = (2.50 ± 0.05) × 10^?3 M^?1 s^?1 at 296 K, and the reaction seemed to be slow. In a similar way, the interaction of 2 and DNA was studied by fluorescence and absorption spectroscopy. The results revealed that 2 caused fluorescence quenching of DNA through a dynamic quenching procedure. The binding constants K_A, K_app, and K_SV as well as the number of binding sites between 2 and DNA were determined.     

Synthesis,characterization, and fluorescence properties of dinuclear cadmium(II) complexes

Four dinuclear cadmium(II) complexes, [Cd₂(L¹)(μ₂-Cl)Cl₂] (1), [Cd₂(L²)(μ₂-Cl)Cl₂] (2), [Cd₂(L³)(μ₂-Cl)Cl₂] (3), and [Cd₂(L⁴)₃ClO₄] (4), where HL¹ = 4-methyl-2,6-bis(1-(2-piperidinoethyl)iminomethyl)-phenol, HL² = 4-methyl-2,6-bis(1-(2-pyrrolidinoethyl)iminomethyl)-phenol, HL³ = 4-methyl-2,6-bis(1-(2-morpholinoethyl)iminomethyl)-phenol and HL⁴ = 4-methyl-2,6-bis(cyclohexylmethyl)iminomethyl)-phenol, were synthesized. They were characterized by elemental analysis, FT-IR, UV–Vis, fluorescence and electronspray ionization mass spectroscopy. Complexes 1 and 4 were also characterized by single crystal X-ray analysis. The cadmiums atoms in 1 are linked by μ₂-chloride in a distorted square pyramidal geometry, whereas cadmium atom in 4 is in a distorted octahedral environment. The complexes show emission bands around 500 nm with excitation at 395 nm.     

三个二羧酸配体配位聚合物的合成、结构表征和荧光性质

以羧酸配体 2,2''-(1,4-亚苯基双(亚苯基))双(硫二基)二苯甲酸(H₂L¹)和 2,2''-(2,3,5,6-四甲基-1,4-亚苯基)双(亚甲基）双(硫二基)二苯甲酸(H₂L²)分别与金属盐反应,通过溶剂热方法合成了 3个配位聚合物：{[Ni(L¹)(H₂O)₄]·2H₂O}_n (1)、[Zn(L¹)(DMA)₂]_n(2)和[Co(L²)(DMF)₂]_n (3),其中DMA=N,N-二甲基乙酰胺,DMF=N,N-二甲基甲酰胺。对配合物1~3进行了单晶X射线衍射、元素分析、红外光谱、热重分析、粉末X射线衍射和固体紫外可见光谱测试和表征。单晶X射线衍射表明：3个配合物均为一维锯齿形链状结构,并通过氢键作用形成三维骨架,且配体均表现为反式构象。此外,对配合物2固态荧光性质进行了研究。     

2-取代硫醚-5-(3,4,5-三甲氧基苯基)-1,3,4-噻二唑类化合物的合成、结构与体外抗癌活性

以天然产物没食子酸为原料经醚化、酯化、酰肼化、成盐、闭环、硫醚化六步反应合成了6个2-取代硫醚-5-(3,4,5-三甲氧基苯基)-1,3,4-噻二唑类衍生物, 釆用铟催化下水相合成目标化合物8, 具有反应条件温和, 合成收率高的特点; 用IR, ¹H NMR, ¹³C NMR和元素分析对各化合物进行了表征及结构确证, 并用X射线单晶衍射法测定了化合物8a [2-(2-氯-5-吡啶甲基)硫醚-5-(3,4,5-三甲氧基苯基)-1,3,4-噻二唑]的晶体结构, 采用MTT法进行了新化合物抑制PC3和BGC-823癌细胞体外试验, 结果表明在5μmol•L^－1浓度下化合物8e对PC3的抑制活性为55.71%. 化合物8b对BGC-823细胞抑制活性为66.21%.