Synthesis of novel heptaplatin derivatives and evaluation of their ability to inhibit proliferation of cancer cell lines

A series of novel heptaplatin derivatives were synthesized and evaluated for their ability to inhibit growth of two cancer cell lines: human colon carcinoma cell line HCT-8 and human hepatocarcinoma cell line Bel-7402. Majority of the synthesized compounds demonstrated superior activity against cancer cell lines compared to heptaplatin. Specifically, compounds 5a and 5b (5 µg/mL) had more pronounced efficacy against the HCT-8 cell line while 6b and 6c (0.5 µg/mL) had higher efficacy against Bel-7402 cell line.     

Synthesis,characterization, and cytotoxicity of mixed-ligand complexes of platinum(II) with 2,2′-bipyridine and 4-toluenesulfonyl-L-amino acid dianion

Five new platinum(II) complexes (1–5) with 4-toluenesulfonyl-L-amino acid dianion and 2,2′-bipyridine (bipy) have been synthesized and characterized by elemental analysis, IR, UV, ¹H-NMR, ¹³C-NMR, and mass spectra. The crystal structure of 1 has been determined by X-ray diffraction analysis. Cytotoxicity was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and sulforhodamine B (SRB) assays. The results indicate that 1–5 exert cytotoxic effects with selectivity against tested carcinoma cell lines; 5 displays better cytotoxicity against BGC-823, Bel-7402, and KB cell lines, while 1 has better cytotoxicity against KB cell line. The 4-toluenesulfonyl- L-amino acid dianions have important effects on cytotoxicity; when 4-toluenesulfonyl-L-amino acid dianions are 4-toluenesulfonyl-L-glycine and 4-toluenesulfonyl-L-phenylalanine, the complexes show better cytotoxicity.     

The photocleavage properties of a novel ruthenium(II) complex on liver cancer cells Bel-7402 DNA

A novel ruthenium(II) complex [Ru(bpy)₂DMHPIP] (DMHPIP = 2-(3,5-dimethoxy-4-hydroxyphenyl)imidazo[4,5-f][1,10]phenanthroline) (1) has been synthesized and characterized by elemental analysis, ¹H-NMR and ESI-MS. The DNA binding properties of the complex has also been investigated by electronic spectra and emission spectra, and the results show that complex (1) bind to DNA with high affinity. On the other hand, the photocleavage property of complex (1) on liver cancer cells lines Bel-7402 DNA has been investigated by electrophoresis agarose gels, and the results show that the complex can promote liver cancer cells Bel-7402 DNA from the supercoiled form to the nicked form excellently.     

DNA-binding,antioxidant activity and in vitro cytotoxicity induced by ruthenium(II) complexes containing polypyridyl ligands

Two new ruthenium(II) polypyridyl complexes, [Ru(dmp)₂(maip)](ClO₄)₂ 1 (maip = 2-(3-aminophenyl)imizado[4,5-f][1,10]phenanthroline and [Ru(dmp)₂(paip)](ClO₄)₂ 2 (paip = 2-(4-aminophenyl)imidazo[4,5-f][1,10]phenanthroline, dmp = 2, 9-dimethyl-1,10-phenanthroline) have been synthesized and characterized. The DNA-binding behaviors of complexes 1 and 2 were studied by viscosity measurements, thermal denaturation, and absorption titration. The results show that the two complexes intercalate between the base pairs of DNA. The DNA-binding constants K _b for complexes 1 and 2 were determined to be 3.23 ± 0.16 × 10⁴ M⁻¹ (s = 0.97) and 4.34 ± 0.65 × 10⁴ M⁻¹ (s = 1.13). The cytotoxicity of these complexes has been evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The IC₅₀ values are 35.70, 41.04, 55.25 and 37.50 for complex 1 and 37.02, 103.08, 130.07 and 37.80 for complex 2 against BEL-7402, C-6, HepG-2 and MCF-7 cell lines, respectively. The antioxidant activity against hydroxyl radical (OH•) was also investigated.     

Synthesis,characterization, and cytotoxicity of platinum(II)/palladium(II) complexes with 4-toluenesulfonyl-L-amino acid dianion and diimine/diamine

Eight new platinum(II)/palladium(II) complexes with 4-toluenesulfonyl-L-amino acid dianion and diimine/diamine ligands, [Pd(en)(Tsile)]·H₂O (1), [Pd(bipy)(Tsile)] (2), [Pd(bipy)(Tsthr)]·0.5H₂O (3), [Pd(phen)(Tsile)]·0.5H₂O (4), [Pd(phen)(Tsthr)]·H₂O (5), [Pd(bqu)(Tsthr)]·1.5H₂O (6), [Pt(en)(Tsser)] (7), and [Pt(en)(Tsphe)]·H₂O (8), have been synthesized and characterized by elemental analyses, ¹H NMR and mass spectrometry. The crystal structure of 7 has been determined by X-ray diffraction. Cytotoxicities were tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and sulforhodamine B assays. The complexes exert cytotoxicity against HL-60, Bel-7402, BGC-823, and KB cell lines with 4 having the best cytotoxicity against HL-60, Bel-7402, and BGC-823 cell lines; the compounds are less cytotoxic than cisplatin.     

Cytotoxic and DNA-binding properties of two ruthenium(II) porphyrin complexes

Two ruthenium(II) porphyrin complexes [Ru(L)₂Cl(PTP)]⁺ (L = bpy, 1, phen; 2; PTP = 5-(3′-pyridyl)-10,15,20-trimethylphenylporphyrin) have been synthesized and their antitumor activities have been evaluated by MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) methods. Both complexes exhibit high inhibitory activity against the growth of human cervical carcinoma cell line HeLa, both with and without light treatment. However, when treated with light, the inhibitory activity for both complexes increases at low drug concentration. Spectroscopic studies show that both complexes can bind to HeLa DNA tightly with apparent binding constants of 1.54(±0.07) × 10⁵ and 1.01(±0.02) × 10⁵ M⁻¹ for 1 and 2, respectively.     

Platinum(II) complexes of reduced amino acid ester Schiff bases: synthesis, characterization, and antitumor activity

A series of platinum(II) complexes of reduced amino acid esters Schiff bases were synthesized as potential anticancer agents and characterized by ¹H NMR, EA, IR, and molar conductivity. These compounds were tested for their DNA interaction with salmon sperm DNA by ultraviolet spectrum and CD spectrum, and their in vitro anticancer activities have been validated against HL-60, KB, BGC-823, and Bel-7402 cell lines by MTT assay. The cytotoxicity of complexes 5d and 5f are better than cisplatin against Bel-7402 cell lines, and show a close cytotoxic effect against HL-60 cell line.     

Stereochemistry and solid-state circular dichroism spectroscopy of eight-coordinate chiral lanthanide complexes

Eight-coordinate chiral lanthanide complexes [Eu(dbm)₃L ^RR ] (1), [Eu(dbm)₃L ^SS ] (2) and [Tb(dbm)₃L ^RR ] (3) (L ^RR /L ^SS = (-)-/(+)-4,5-pineno-2,2′-bipyridine, Hdbm = dibenzoylmethane) were synthesized stereoselectively, which were characterized by UV-vis, CD spectra and X-ray single-crystal diffraction. The mirror-image structure features of complexes 1 and 2 were obtained by combination of the solid-state CD spectra and the crystal structure analysis. After further comparison with the solid-state CD spectra of six-coordinate and seven-coordinate metal complexes containing β-diketone ligands, the CD spectra-absolute configuration correlation rule for the eight-coordinate β-diketonate lanthanide complexes was proposed through the exciton chirality method for the first time. The Δ or Λ absolute configurations of complexes 1–3 with the distorted square antiprism geometry were confirmed by the X-ray single-crystal analysis.     

Synthesis of Novel Phosphoramide-Tegafur Derivatives Containing Aminopropylsilatrane

Abstract

A series of novel phosphoramide-tegafur derivatives containing γ-aminopropyl silatrane were synthesized via the condensation reactions of phosphoryl dichloride with N¹-(2-furanidyl)-N³-(hydroxyethyl)-5-fluorouracil, followed by condensation with γ-aminopropyl silatrane. The structures of the products were confirmed by ¹H NMR, ³¹P NMR, IR, MS, and elemental analysis. The results of preliminary bioassay showed that the new compounds had an inhibition effect against HCT-8 and Bel-7402 cell lines.     

Synthesis,DNA-binding,and antitumor activity of polypyridyl-ruthenium(II) complexes [Ru(L)2(DClPIP)] (L = bpy,phen; DClPIP = 2-(2,4-dichlorophenyl)-1H-imidazo[4,5-f][1, 10]phenanthroline)

Abstract

Two new ruthenium(II) complexes, [Ru(bpy)₂(DClPIP)](ClO₄)₂ (1) and [Ru(phen)₂(DClPIP)](ClO₄)₂ (2) (bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline, and DClPIP = 2-(2,4-dichlorophenyl)-1H-imidazo[4,5-f][1, 10]phenanthroline), have been prepared in high yield by using microwave-assisted synthesis technology. The anticancer activity of the two ruthenium(II) complexes against A549, C6, CNE-1 and MDA-MB-231 cell lines has been evaluated by MTT assay and results showed that 2 exhibited higher antitumor activity than 1 toward all the selected tumor cell lines. Besides, A549 cell line was sensitive to both ruthenium(II) complexes, especially to 2 (IC₅₀ = 8.01?±?0.36?μM). Meanwhile, 2 showed low toxicity against MCF-10A human normal cells. Furthermore, the DNA-binding properties of the two new ruthenium(II) complexes with CT-DNA have been investigated by electronic absorption titration, luminescence spectra, circular dichroism spectra and viscosity measurements. The results suggested that 1 and 2 were able to interact with CT-DNA via intercalative mode with a strong binding affinity in the order 2?>?1. All of these results suggested that anticancer activity of both ruthenium(II) complexes could be closely related to their interaction with DNA.     

Cytotoxicity,apoptosis, interaction with DNA,cellular uptake,and cell cycle arrest of ruthenium(II) polypyridyl complexes containing 4,4′-dimethyl-2,2′-bipyridine as ancillary ligand

Two new ruthenium(II) polypyridyl complexes, [Ru(dmb)₂(DNPIP)](ClO₄)₂ (1) (DNPIP?=?2-(2,4-dinitrophenyl)imidazo[4,5-f][1,10]phenanthroline, dmb?=?4,4′-dimethyl-2,2′-bipyridine) and [Ru(dmb)₂(DAPIP)](ClO₄)₂ (2) (DAPIP?=?2-(2,4-diaminophenyl)imidazo[4,5f][1,10]phenanthroline), were synthesized and characterized. The DNA-binding behaviors of these complexes have been studied by UV-Vis absorption titration, viscosity measurements, and photocleavage. The DNA-binding constants are 7.39 (±0.16)?×?10⁴ (s?=?2.68) and 2.73 (±0.16)?×?10^4?(mol?L^?1)^?1 (s?=?0.64) for 1 and 2, respectively. Their evaluation as cytotoxic agents on different cancer cell lines was investigated with IC₅₀ values of 59.5, 51.3, and 70.3?µmol?L^?1 for 1, >100, 87.9, and 77.9?µmol?L^?1 for 2 against BEL-7402, HepG-2, and MCF-7 cells, respectively. Complex 1 is more active than 2 against selected cancer cell lines. The apoptosis induced by these complexes was studied. Cellular uptake showed that these complexes could enter into the cytoplasm and accumulate in the nuclei. The cell cycle arrest and antioxidant activity against hydroxyl radicals were also investigated.     

Cytotoxicity, cellular uptake, cell cycle arrest, apoptosis, reactive oxygen species and DNA-binding studies of ruthenium(II) complexes

Three ruthenium(II) polypyridyl complexes [Ru(dmb)₂(dadppz)]²⁺ 1, [Ru(bpy)₂(dadppz)]²⁺ 2 and [Ru(phen)₂(dadppz)]²⁺ 3 were synthesized and characterized by elemental analysis, ES-MS, ¹H NMR and ¹³C NMR. Their DNA-binding behaviors were investigated by absorption titration, fluorescence spectroscopy and viscosity measurements. Cytotoxicity in vitro, apoptosis, cell cycle arrest, cellular uptake and reactive oxygen species assays were performed. The complexes were found to show moderate DNA-binding affinities and high cytotoxicities toward A549, BEL-7402, MG-63 and SKBR-3 cell lines. These complexes can effectively induce apoptosis of BEL-7402. In cell cycle assays, the complexes induced S-phase arrest on BEL-7402 cells and G0/G1-phase arrest on SKBR-3 cells. The DNA-binding experiments showed that the three complexes interact with CT-DNA through an intercalative mode.     

Ruthenium(II) complexes: synthesis,cytotoxicity in vitro,apoptosis, DNA-binding,photocleavage, and antioxidant activity studies

Two new ruthenium(II) complexes, [Ru(dmp)₂(APIP)](ClO₄)₂ (1) (APIP?=?2-(2-aminophenylimidazo[4,5-f][1,10]phenanthroline), dmp?=?2,9-dimethyl-1,10-phenanthroline) and [Ru(dmp)₂(HAPIP)](ClO₄)₂ (2) (HAPIP?=?2-(2-hydroxyl-5-aminophenyl)imidazo[4,5-f][1,10]phenanthroline), were synthesized and characterized. The DNA-binding properties of these complexes were investigated by absorption titration, viscosity measurements, and photoactivated cleavage. The DNA-binding constants for 1 and 2 have been determined to be 2.3 (±?0.3)?×?10⁴ (mol?L^?1)^?1 and 3.3 (±?0.4)?×?10⁴ (mol?L^?1)^?1. The results indicate that 1 and 2 interact with DNA through intercalative mode. The cytotoxicities of 1 and 2 were assessed against BEL-7402, HepG-2 and MCF-7 cell lines using standard MTT assay. The apoptosis induced by these complexes was studied with the acridine orange/ethidium bromide staining method. The antioxidant activity on hydroxyl radical was also investigated.     

DNA-binding and photocleavage, cytotoxicity, apoptosis and antioxidant activity studies of ruthenium(II) complexes

Two ruthenium(II) polypyridyl complexes, namely [Ru(phen)₂(DMDPPZ)](ClO₄)₂ 1 (phen = 1,10-phenanthroline, DMDPPZ = 3,6-dimethyldipyrido[3,2-a:2′,3′-c]phenazine) and [Ru(dmp)₂(DMDPPZ)](ClO₄)₂ 2 (dmp = 2,9-dimethyl-1,10-phenanthroline), have been synthesized and characterized. The DNA-binding properties of the complexes were investigated by spectrophotometric methods, viscosity measurements, and photoactivated cleavage studies. The DNA-binding constants for complexes 1 and 2 have been determined as 8.78 (±0.94) × 10⁵ M⁻¹ (s = 3.02) and 1.26 (±0.35) × 10⁵ M⁻¹ (s = 1.69), respectively. The results suggest that these complexes bind to calf thymus DNA through intercalation. When irradiated at 365 nm, the complexes promote the photocleavage of pBR322 DNA, and complex 1 cleaves DNA more effectively than complex 2 under comparable experimental conditions. The cytotoxicities of complexes 1 and 2 have been evaluated by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) method. Complex 2 shows higher anticancer potency than complex 1 against four tumor cell lines. The apoptosis-inducing activity was assessed by acridine orange/ethidium bromide staining assay, and the antioxidant activities of these complexes against hydroxyl radical were also explored.     

Synthesis and in vitro cytotoxicity of platinum(II) complexes with chiral N-monosubstituted 1,2-cyclohexyldiamine derivatives as the carrier groups

Eight platinum(II) complexes with the new chiral ligands, (1R,2R)-N ¹-(pyridine-2-ylmethyl) cyclohexane-1,2-diamine (R) or (1S,2S)-N ¹-(pyridine-2-ylmethyl) cyclohexane-1,2-diamine (S) as the carrier groups were designed, synthesized, and spectrally characterized. All platinum(II) complexes showed much better aqueous solubility than cisplatin and oxaliplatin. In vitro cytotoxicity of the compounds against human HepG-2, MCF-7, A549, and HCT-116 cell lines was evaluated. Results indicate that all compounds with R as the carrier group showed cytotoxicity against HCT-116, A549, and MCF-7 cell lines; however, all compounds with S as carrier group exhibited disappointing cytotoxicity against tested cell lines. Compound R2, bearing ClCH₂COO^- as leaving group, exhibited better cytotoxicity than that of carboplatin against A549 and MCF-7 cell lines and also showed close activity to oxaliplatin against HCT-116 cell line.     

Synthesis and in vitro cytotoxicity of novel dinuclear platinum(II) complexes containing a chiral tetradentate ligand

A series of novel dinuclear platinum(II) complexes with a chiral tetradentate ligand, (1R,1′R,2R,2′R)-N¹,N¹′-(1,2-phenylenebis(methylene))dicyclohexane-1,2-diamine (HL), and mono-carboxylic acid derivatives as ligands have been designed, synthesized, and characterized. In vitro cytotoxicity evaluation of synthesized complexes against human HepG-2, A549, HCT-116, and MCF-7 cancer cell lines has been conducted by MTT assays. All compounds showed antitumor activity to HepG-2 and HCT-116 cell lines. Compound L2 exhibited better cytotoxicity than that of carboplatin against HepG-2 and A549 cell lines and also showed comparable activity against HCT-116 cell line.     

Interaction of cobalt(III) polypyridyl complexes containing asymmetric ligands with DNA

Four asymmetric cobalt(III) complexes, [Co(bpy)₂(aip)]³⁺, [Co(bpy)₂(pyip)]³⁺, [Co(phen)₂(aip)]³⁺, and [Co(phen)₂(pyip)]³⁺ (bpy = 2,2,bipyridine, phen = 1,10-phenathroline), (pyip = 2-(1-pyrenyl)-1H-imidazo[4,5-f][phen], (aip = 2-(9-anthryl)-1H-imidazo[4,5,-f][phen], have been synthesized and characterized. Their interaction with calf thymus DNA (CT-DNA) was investigated by physico-chemical methods and photocleavage. The size and shape of the ligands have a marked effect on the DNA-binding affinity of the complexes. Irradiation of pBR322 DNA with these novel cobalt(III) complexes results in nicking of the plasmid DNA. Toxicity and induced cell death investigations revealed that the complexes of pyip had higher toxicity than those of aip. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Preparation and in vitro cytotoxicity of oxaliplatin derivatives with chiral amino acid as the carrier group

Eight oxaliplatin derivatives with chiral amino acid, 2-{[(1R,2R)-2-aminocyclohexyl]amino}propanoic acid, as the carrier group, were designed, synthesized, and spectrally characterized by IR, ¹H NMR, MS spectra, and microanalyses. In vitro cytotoxicities against human HepG-2, MCF-7, A549, and HCT-116 cell lines were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazo-liumbromide assay. Results indicated that all compounds exhibited sensitivity to HepG-2 cell line, and among them, compounds P3 and P4 which have CH₃(CH₂)₆COO^– and CH₃(CH₂)₈COO^– as the leaving groups, respectively, gave better antitumor activity than carboplatin against HepG-2 and A549 cell lines.     

苯并咪唑衍生的单核钴（Ⅱ）和单核镍（Ⅱ）配合物与DNA和蛋白质的结合反应性及细胞毒活性研究

利用紫外吸收光谱、荧光光谱、圆二色光谱（CD）等各种光谱手段对比地研究了由苯并咪唑衍生的单核钴配合物[Co（EDTB）]²⁺（1）和单核镍配合物[Ni（EDTB）]²⁺（2）（这里EDTB为N,N,N’,N’-四（2-苯并咪唑甲基）-1,2-乙二胺）与小牛胸腺DNA（CT-DNA）和牛血清白蛋白（BSA）的相互作用。结果表明,在生理条件下,配合物1和2均能通过插入方式较强的与CT-DNA结合,诱导DNA构象的改变;且配合物1对DNA的结合能力略强于2,其结合常数分别为K_b（1）=3.23×10⁴L·mol^-1和K_b（2）=2.40×10⁴L·mol^-1。配合物与BSA相互作用的研究表明,1和2均能与BSA发生较强的相互作用,结合常数均处在10⁴~10⁵L·mol^-1;该结合引起了BSA微环境和构象发生变化,且使BSA内源荧光被淬灭,淬灭机理为静态淬灭。利用MTT法研究了配合物1和2对小鼠白血病细胞株P388和人非小细胞肺癌细胞株A-549的体外细胞毒活性,实验结果表明,配合物1和2对P388不敏感,对A-549在高浓度（10^-4~10^-5mol·L^-1）下表现出与顺铂相当的细胞毒活性。     

DNA-binding properties of ruthenium(II) complexes with the bidentate ligand 5-chloro-2-(phenylazo)pyridine

A bidentate ligand, 5-chloro-2-(phenylazo)pyridine (Clazpy), and its two polypyridyl ruthenium(II) complexes, [Ru(Clazpy)₂bpy]Cl₂·7H₂O (1) and [Ru(Clazpy)₂phen]Cl₂·8H₂O (2), were synthesized and characterized. The DNA-binding properties of these complexes with DNA, the breast cancer susceptibility gene 1 (BRCA1), and the pBIND plasmid DNA were probed by photocleavage, electronic absorption titration, ethidium bromide quenching, and thermal denaturation. Both complexes were found to bind to the BRCA1 fragment through the intercalative mode into the base pairs of DNA, and the DNA-binding constants (K_b) for 1 and 2 were 7.0 × 10⁴ M⁻¹ and 5.1 × 10⁵ M⁻¹, respectively. In addition, both complexes enhanced the single-stranded cleavage of the plasmid DNA. Under comparable experimental conditions, 2 cleaved DNA more effectively than 1, in a dose–response manner. The data indicated that the binding affinity of these two complexes to DNA was dependent on the aromatic planarity and hydrophobicity of the intercalative polypyridyl ligand.