Reactions of cytotoxic metallodrugs with lysozyme in pure DMSO explored through UV-Vis absorption spectroscopy and ESI MS.

The reactions of four representative metallodrugs with the model protein HEWL were investigated within a non-aqueous environment-i.e. in pure DMSO- through UV-Vis absorption spectroscopy and ESI MS analysis. Notably, formation of a variety of metallodrug-protein adducts was clearly documented. This is the first example for this kind of protein metalation reactions carried out within a pure organic solvent. It is shown that the applied solution conditions greatly affect the nature of the formed adducts, this being well accounted for by the fact that the overall protein conformation is greatly perturbed within pure DMSO; in addition, the activation profiles of the studied metallodrugs are also highly dependent on the nature of the solvent. The implications of these results are discussed.

Synthesis, characterization and ROS-mediated cytotoxic action of novel (S,S)-1,3-propanediamine-N,N'-di-2-(3-cyclohexyl)propanoic acid and corresponding esters.

This study involves the synthesis and characterization of novel cyclohexyl 1,3-propanediamine-N,N'-diacetate molecules as well as investigation of their cytotoxic action. New acid 1a was synthesized by reaction between (S)-2-amino-3-cyclohexylpropanoic acid and 1,3-dibromopropane, while the esters (1b-1e) derived from this acid were obtained by reaction of the corresponding absolute alcohol, thionyl chloride and synthesized acid. All compounds were characterized by IR, ESI-MS, ((1)H, (13)C and HSQC) NMR spectroscopy and elemental analysis. The cytotoxic activity of all compounds was tested on several tumour cell lines: human (U251) and rat (C6) glioma, human promyelocytic leukaemia (HL-60), human neuroblastoma (SHSY-5Y) and mouse fibrosarcoma (L929) as well as primary rat astrocytes. The present study reveals potent antitumour activity of novel purely organic compounds (1a-1e), which was most pronounced in human glioma (U251) cells. The esterification is required for the novel compounds' cytotoxic action since the n-butyl ester 1e was the most efficient compound. Importantly, n-butyl ester 1e was more toxic to glioma cells in comparison to rat astrocytes, with 24-h IC50 values lower than those for cisplatin. n-Butyl ester 1e induced production of reactive oxygen species (ROS) and caused an oxidative-stress-derived accumulation of glioma cells in the G0/G1 phase of the cell cycle, as well as caspase activation and DNA fragmentation, suggesting that apoptosis induction plays an important role in the novel compounds' antiglioma action.

(S,S)-N,N'-Bis(1-carb-oxy-2-methyl-prop-yl)ethyl-enediammonium dihalide cyclo-penta-nol tetra-solvate (halide = bromide/chloride ≃ 1:12).

In the crystal structure of the title compound, C(12)H(26)N(2)O(4) (2+)·2(Br(0.085)Cl(0.915))(-)·4C(5)H(9)OH, the complete cation is generated by crystallographic twofold symmetry. Contamination of the chloride counter-anion with bromide occured during the preparation, due to the use of 1,2-dibromo-ethane. One of the solvent mol-ecules is disordered, with occupancies 0.53 (3):0.47 (3). The crystal packing is stabilized by an infinite two dimensional ⋯X⋯H-N-H⋯X⋯ hydrogen-bonding network (X: Br(-)/Cl(-) ≃ 1:12). In addition, O-H⋯X and O-H⋯O hydrogen bonds involving solvent mol-ecules are observed.

Synthesis and in vitro antitumoral activity of novel O,O'-di-2-alkyl-(S,S)-ethylenediamine-N,N'-di-2-propanoate ligands and corresponding platinum(II/IV) complexes.

Syntheses of two novel ligand precursors O,O'-diisopropyl- (1a) and O,O'-diisobutyl-(S,S)-ethylenediamine-N,N'-di-2-propanoate dihydrochloride monohydrate (1b) and the corresponding dichloroplatinum(II) (2a and 2b) and tetrachloroplatinum(IV) complexes (3a and 3b) are described here. The substances were characterized by IR, (1)H and (13)C spectroscopy and elemental analysis. Crystal structures were determined for 1a and the corresponding platinum(IV) complex, 3a. In vitro antiproliferative activity was determined against tumor cell lines: human adenocarcinoma HeLa, human myelogenous leukemia K562, human malignant melanoma Fem-x, rested and stimulated normal immunocompetent cells (human peripheral blood mononuclear PBMC cells) using KBR test (Kenacid Blue Dye binding test). The IC(50)(microM) values for the most active compound 3a were: 30.48+/-2.54; 12.26+/-2.60; 13.68+/-3.22; 80.18+/-24.07 and 71.30+/-21.70, respectively.

N,N'-Bis[2-(methoxycarbonyl)ethyl]ethane-1,2-diammonium dichloride.

In the crystal structure of the title compound, C(10)H(22)N(2)O(4) (2+)·2Cl(-) or (H(2)Me(2)eddp)Cl(2) (H(2)Me(2)eddp(2+) is the dimethyl N,N'-di-3-propane-carboxylato-ethane-1,2-diyldiimin-ium cation), the packing is stabilized by an infinite two-dimensional ⋯Cl⋯H-N-H⋯Cl⋯ hydrogen-bonding network. In addition, short C-H⋯Cl contacts are observed.

In vitro and in vivo antimelanoma effect of ethyl ester cyclohexyl analog of ethylenediamine dipropanoic acid.

Melanoma, an aggressive skin tumor with high metastatic potential, is associated with high mortality and increasing morbidity. Multiple available chemotherapeutic and immunotherapeutic modalities failed to improve survival in advanced disease, and the search for new agents is ongoing. The aim of this study was to investigate antimelanoma effects of O,O-diethyl-(S,S)-ethylenediamine-N,N'di-2-(3-cyclohexyl) propanoate dihydrochloride (EE), a previously synthesized and characterized organic compound. Mouse melanoma B16 cell viability was assessed using acid phosphatase, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, sulforhodamine B, and lactate dehydrogenase assays. Apoptosis and autophagy were investigated using flow cytometry, fluorescence and electron microscopy, and western blotting. In vivo antitumor potential was assessed in subcutaneous mouse melanoma model after 14 days of treatment with EE. Tumor mass and volume were measured, and RT-PCR was used for investigating the expression of autophagy-related, proapoptotic, and antiapoptotic molecules in tumor tissue. Investigated organic compound exerts significant cytotoxic effect against B16 cells. EE induced apoptosis, as confirmed by phosphatidyl serine externalisation, caspase activation, and ultrastructural features typical for apoptosis seen on fluorescence and electron microscopes. The apoptotic mechanism included prompt disruption of mitochondrial membrane potential and oxidative stress. No autophagy was observed. Antimelanoma action and apoptosis induction were confirmed in vivo, as EE decreased mass and volume of tumors, and increased expression of several proapoptotic genes. EE possesses significant antimelanoma action and causes caspase-dependent apoptosis mediated by mitochondrial damage and reactive oxygen species production. Decrease in tumor growth and increase in expression of proapoptotic genes in tumor tissue suggest that EE warrants further investigation as a candidate agent in treating melanoma.

Antileukemic action of novel diamine Pt(II) halogenido complexes: Comparison of the representative novel Pt(II) with corresponding Pt(IV) complex.

This study presents the synthesis, characterization, and antitumor action of five new Pt(II) halogenido, chlorido, and iodido complexes with edda type of ligands. (S,S)-Ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoic acid dihydrochloride and its methyl, ethyl, and n-propyl esters were prepared according to the previously reported procedure. All investigated complexes were characterized by IR, ESI-MS (1 H, 13 C, and HMBC) NMR spectroscopy, and elemental analysis. Their cytotoxic action was investigated in four human tumor cell lines: promyelocytic (HL-60) and lymphocytic (REH) leukemia, glioma (U251), and lung carcinoma (H460). Cell viability was assessed by acid phosphatase and LDH assay, while oxidative stress and cell death parameters were analyzed by flow cytometry. The results showed that novel Pt(II) complexes exhibited antitumor action superior to precursor ligands, with iodido complexes being more efficient than corresponding chlorido complexes. Human promyelocytic cell line (HL-60) was the most sensitive to antitumor action of all investigated substances and was used for investigation of the underlying mode of antileukemic action. The investigated Pt(II) complexes showed more potent antileukemic action than corresponding Pt(IV) complex, through induction of oxidative stress and apoptosis, evidenced by caspase (8, 9, and 3) activation and phosphatidylserine externalization.

In Vitro Anticancer Evaluation of Platinum(II/IV) Complexes with Diisoamyl Ester of (S,S)-ethylenediamine-N,N'-di-2-propanoic Acid.

AIMS: Platinum(II) and platinum(IV) complexes [PtCln{(S,S)-(i-Am)2eddip}] (n = 2, 4: 1, 2, respectively; (S,S)-(i-Am)2eddip = O,O'-diisoamyl-(S,S)-ethylenediamine-N,N'-di-2-propanoate) were synthesized and characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy and mass spectrometry. METHOD: Quantum chemical calculations were used to predict formed isomers of 1 and 2. Furthermore, reduction of 2 with ascorbic acid was followed by time-dependant 13C NMR spectroscopy in order to enable assignation of the formed isomers for complex 1. In vitro cytotoxic activity was determined for 1 and 2 on a panel of five human tumor cell lines derived from cervix adenocarcinoma (HeLa), alveolar basal adenocarcinoma (A549), breast adenocarcinoma (MDA-453), colorectal cancer (LS 174), erythromyeloblastoid leukemia (K562), as well as one non-malignant human lung fibroblast cell line (MRC-5), using MTT assay. RESULT: Both complexes exhibited high (2 against K562: IC50 = 5.4 µM), more active than cisplatin, to moderate activity (1). Both complexes caused considerable decrease of cell number in K562 cells in G1, S and G2 phases, concordantly increasing subpopulation in sub-G1 fraction. Morphological analysis of K562 cell death induced by platinum(II/IV) complexes indicate apoptosis.

In vitro antitumor activity, metal uptake and reactivity with ascorbic acid and BSA of some gold(III) complexes with N,N'-ethylenediamine bidentate ester ligands.

Four novel gold(III) complexes of general formulae [AuCl2{(S,S)-R2eddl}]PF6 (R2eddl=O,O'-dialkyl-(S,S)-ethylenediamine-N,N'-di-2-(4-methyl)pentanoate, R=n-Pr, n-Bu, n-Pe, i-Bu; 1-4, respectively), were synthesized and characterized by elemental analysis, UV/Vis, IR, and NMR spectroscopy, as well as high resolution mass spectrometry. Density functional theory calculations pointed out that (R,R)-N,N'-configuration diastereoisomers were energetically the most favorable. Duo to high cytotoxic activity complex 3 was chosen for stability study in DMSO, no decomposition occurs within 24h, and for the reaction with ascorbic acid in which was reduced immediately. Additionally, 3 interacts with bovine serum albumin (BSA) as proven by UV/Vis spectroscopy. In vitro antitumor activity was determined against human cervix adenocarcinoma (HeLa), human myelogenous leukemia (K562), and human melanoma (Fem-x) cancer cell lines, as well as against non-cancerous human embryonic lung fibroblast cells MRC-5. The highest activity was observed against K562 cells (IC50: 5.04-6.51µM). Selectivity indices showed that these complexes are less toxic than cisplatin. 3 had a similar viability kinetics on HeLa cells as cisplatin. Drug accumulation studies in HeLa cells showed that the total gold uptake increased much faster than that of cisplatin pointing out that 3 more efficiently enters the cells than cisplatin. Furthermore, morphological and cell cycle analysis reveal that gold(III) complexes induced apoptosis in time- and dose-dependent manner.

Activity of some platinum(II/IV) complexes with O,O-n-butyl-and O,O-n-pentyl-ethylenediamine-N,N'-di-3-propanoate and halogeno ligands against HeLa and K562 cell lines and human PBMC.

This paper reports on syntheses and characterization of chlorotribromo(O,O-n-butyl-ethylenediamine-N,N'-di-3-propanoate)platinum(IV) [II], dichlorodiiodo(O,O-n-butyl-ethylenediamine-N,N'-di-3-propanoate)platinum(IV) [III], and dichloro(O,O-n-butyl-ethylenediamine-N,N'-di-3-propanoate)platinum(II) [V] complexes, with the formulae [Pt(dbeddp)Br(3)Cl], [Pt(dbeddp)Cl(2)I(2)] and [Pt(dbeddp)Cl(2)], respectively. The complexes were characterized by elemental analysis, infrared, (1)H and (13)C NMR spectroscopy and electrospray mass spectrometry. In the aim to assess the selectivity in the antitumor action of these complexes, as well, as tetrachloro(O,O-n-butyl-ethylenediamine-N,N'-di-3-propanoate)platinum(IV) [I] and tetrachloro(O,O-n-pentyl-ethylenediamine-N,N'-di-3-propanoate)platinum(IV) [IV], the antiproliferative action of these compounds was determined to human adenocarcinoma HeLa cells, to human myelogenous leukemia K562 cells and to normal immunocompetent cells, i.e., on human peripheral blood mononuclear PBMC cells.