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1.
J Biol Inorg Chem ; 29(1): 51-73, 2024 02.
Article in English | MEDLINE | ID: mdl-38099936

ABSTRACT

Platinum-based drugs are widely recognized efficient anti-tumor agents, but faced with multiple undesirable effects. Here, four dinuclear platinum(II) complexes, [{Pt(1,2-pn)Cl}2(µ-pydz)]Cl2 (C1), [{Pt(ibn)Cl}2(µ-pydz)]Cl2 (C2), [{Pt(1,3-pn)Cl}2(µ-pydz)]Cl2 (C3) and [{Pt(1,3-pnd)Cl}2(µ-pydz)]Cl2 (C4), were designed (pydz is pyridazine, 1,2-pn is ( ±)-1,2-propylenediamine, ibn is 1,2-diamino-2-methylpropane, 1,3-pn is 1,3-propylenediamine, and 1,3-pnd is 1,3-pentanediamine). Interactions and binding ability of C1-C4 complexes with calf thymus DNA (CT-DNA) has been monitored by viscosity measurements, UV-Vis, fluorescence emission spectroscopy and molecular docking. Binding affinities of C1-C4 complexes to the bovine serum albumin (BSA) has been monitored by fluorescence emission spectroscopy. The tested complexes exhibit variable cytotoxicity toward different mouse and human tumor cell lines. C2 shows the most potent cytotoxicity, especially against mouse (4T1) and human (MDA-MD468) breast cancer cells in the dose- and time-dependent manner. C2 induces 4T1 and MDA-MD468 cells apoptosis, further documented by the accumulation of cells at sub-G1 phase of cell cycle and increase of executive caspase 3 and caspase 9 levels in 4T1 cells. C2 exhibits anti-proliferative effect through the reduction of cyclin D3 and cyclin E expression and elevation of inhibitor p27 level. Also, C2 downregulates c-Myc and phosphorylated AKT, oncogenes involved in the control of tumor cell proliferation and death. In order to measure the amount of platinum(II) complexes taken up by the cells, the cellular platinum content were quantified. However, C2 failed to inhibit mouse breast cancer growth in vivo. Chemical modifications of tested platinum(II) complexes might be a valuable approach for the improvement of their anti-tumor activity, especially effects in vivo.


Subject(s)
Antineoplastic Agents , Breast Neoplasms , Coordination Complexes , Pyridazines , Humans , Animals , Mice , Female , Platinum/pharmacology , Platinum/chemistry , Serum Albumin, Bovine/chemistry , Molecular Docking Simulation , Ligands , DNA/chemistry , Cell Line, Tumor , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Pyridazines/pharmacology , Coordination Complexes/pharmacology , Coordination Complexes/chemistry
2.
J Biol Inorg Chem ; 27(1): 65-79, 2022 02.
Article in English | MEDLINE | ID: mdl-34714401

ABSTRACT

The mechanism of action of most approved drugs in use today is based on their binding to specific proteins or DNA. One of the achievements of this research is a new perspective for recognition of binding modes to DNA by monitoring of changes in measured and stoichiometric values of absorbance at 260 nm. UV-Vis and IR spectroscopy, gel electrophoresis and docking study were used for investigation of binding properties of three dinuclear platinum(II) complexes containing different pyridine-based bridging ligands, [{Pt(en)Cl}2(µ-4,4'-bipy)]Cl2·2H2O (Pt1), [{Pt(en)Cl}2(µ-bpa)]Cl2·4H2O (Pt2) and [{Pt(en)Cl}2(µ-bpe)]Cl2·4H2O (Pt3) to DNA (4,4'-bipy, bpa and bpe are 4,4'-bipyridine, 1,2-bis(4-pyridyl)ethane and 1,2-bis(4-pyridyl)ethene, respectively). In contrast to the system with well-known intercalated ligand (EtBr), covalently bound ligand (cis-Pt) and with minor groove binder (Hoechst 33258), which do not have significant differences in measured and stoichiometric values, the most pronounced deviations are recorded for two dinuclear platinum(II) complexes (Pt1 and Pt2), as a consequence of complex binding to the phosphate backbone and bending of DNA helix. The hydrolysis of complexes and changes in DNA conformation were also analysed as phenomena that may have an impact on the changes in absorbance.


Subject(s)
Antineoplastic Agents , Platinum , Antineoplastic Agents/chemistry , DNA/chemistry , Ligands , Phosphates , Platinum/chemistry
3.
J Biol Inorg Chem ; 25(3): 395-409, 2020 05.
Article in English | MEDLINE | ID: mdl-32162071

ABSTRACT

New anticancer platinum(II) compounds simultaneously targeting tumor cells and tumor-derived neoangiogenesis, with new DNA interacting mode and large therapeutic window are appealing alternative to improve efficacy of clinical platinum chemotherapeutics. Herein, we describe three novel dinuclear [{Pt(en)Cl}2(µ-L)]2+ complexes with different pyridine-like bridging ligands (L), 4,4'-bipyridine (Pt1), 1,2-bis(4-pyridyl)ethane (Pt2) and 1,2-bis(4-pyridyl)ethene (Pt3), which highly, positively charged aqua derivatives, [{Pt(en)(H2O)}2(µ-L)]4+, interact with the phosphate backbone forming DNA-Pt adducts with an unique and previously undescribed binding mode, called a minor groove covering. The results of this study suggested that the new binding mode of the aqua-Pt(II) complexes with DNA could be attributed to the higher anticancer activities of their chloride analogues. All three compounds, particularly complex [{Pt(en)Cl}2(µ-4,4'-bipy)]Cl2·2H2O (4,4'-bipy is 4,4'-bipyridine) (Pt1), overcame cisplatin resistance in vivo in the zebrafish-mouse melanoma xenograft model, showed much higher therapeutic potential than antiangiogenic drug sunitinib malate, while effectively blocking tumor neovascularization and melanoma cell metastasis. Overall therapeutic profile showed new dinuclear Pt(II) complexes could be novel, effective and safe anticancer agents. Finally, the correlation with the structural characteristics of these complexes can serve as a useful tool for developing new and more effective anticancer drugs.


Subject(s)
Angiogenesis Inhibitors/pharmacology , Antineoplastic Agents/pharmacology , DNA/chemistry , Neovascularization, Pathologic/drug therapy , Organoplatinum Compounds/pharmacology , Pyridines/pharmacology , Angiogenesis Inhibitors/chemical synthesis , Angiogenesis Inhibitors/chemistry , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Binding Sites/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Ligands , Molecular Docking Simulation , Molecular Structure , Neoplasms, Experimental/drug therapy , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/pathology , Neovascularization, Pathologic/metabolism , Neovascularization, Pathologic/pathology , Organoplatinum Compounds/chemical synthesis , Organoplatinum Compounds/chemistry , Pyridines/chemistry , Viscosity , Zebrafish
4.
J Biol Inorg Chem ; 24(7): 1009-1022, 2019 10.
Article in English | MEDLINE | ID: mdl-31385067

ABSTRACT

Three new dinuclear Pd(II) complexes with general formula [{Pd(en)Cl}2(µ-L)](NO3)2 [L is bridging ligand quinoxaline (Pd1), quinazoline (Pd2) and phthalazine (Pd3)] were synthesized and characterized by elemental microanalyses, UV-Vis, IR and NMR (1H and 13C) spectroscopy. The interaction of dinuclear Pd1-Pd3 complexes with calf thymus DNA (CT-DNA) has been monitored by viscosity measurements, UV-Vis and fluorescence emission spectroscopy in aqueous phosphate buffer solution (PBS) at pH 7.40 and 37 °C. In addition, these experimental conditions have been applied to investigate the binding affinities of Pd1-Pd3 complexes to the bovine serum albumin (BSA) by fluorescence emission spectroscopy. In vitro antiproliferative and apoptotic activities of the dinuclear Pd(II) complexes have been tested on colorectal and lung cancer cell lines. All tested Pd(II) complexes had lower cytotoxic effect than cisplatin against colorectal cancer cells, but also had similar or even higher cytotoxicity than cisplatin against lung cancer cells. All complexes induced apoptosis of colorectal and lung cancer cells, while the highest antiproliferative effect exerted Pd2 complex.


Subject(s)
DNA/metabolism , Heterocyclic Compounds/chemistry , Organometallic Compounds/chemistry , Organometallic Compounds/pharmacology , Palladium/chemistry , Serum Albumin, Bovine/metabolism , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Humans , Ligands , Models, Molecular , Molecular Conformation , Organometallic Compounds/metabolism
5.
Rheumatol Int ; 38(5): 715-724, 2018 May.
Article in English | MEDLINE | ID: mdl-29627896

ABSTRACT

When liver damage is present in rheumatoid arthritis (RA) patients, it is sometimes difficult to determine whether it is a hepatic manifestation of RA, associated primary liver disease or hepatotoxic liver disease which developed during the treatment of RA. Liver damage during RA is most common in the form of asymptomatic abnormal liver tests. Occasionally, liver damage may progress to cirrhosis. Patients with RA are more susceptible to an associated autoimmune liver disease. Medications used in rheumatology are often hepatotoxic and it is difficult to differentiate between hepatic manifestations of the primary disease and potential hepatotoxicity of the administered medications. The significance of the paper is in the fact that it includes the most relevant and the latest information on this commonly present problem in clinical practice. The aim of the author is to provide comprehensive but at the same time concise data which will be useful to the doctors who come into contact with RA patients with symptomatic or asymptomatic liver disease. Timely diagnosis and treatment of liver disease in RA patients can significantly influence the course and outcome of rheumatoid arthritis.


Subject(s)
Arthritis, Rheumatoid , Liver Diseases , Antirheumatic Agents/adverse effects , Arthritis, Rheumatoid/diagnosis , Arthritis, Rheumatoid/drug therapy , Arthritis, Rheumatoid/epidemiology , Arthritis, Rheumatoid/immunology , Chemical and Drug Induced Liver Injury/diagnosis , Chemical and Drug Induced Liver Injury/epidemiology , Chemical and Drug Induced Liver Injury/immunology , Chemical and Drug Induced Liver Injury/therapy , Early Diagnosis , Humans , Liver Diseases/diagnosis , Liver Diseases/epidemiology , Liver Diseases/immunology , Liver Diseases/therapy , Liver Function Tests , Predictive Value of Tests , Prognosis , Risk Factors
6.
Bioorg Chem ; 72: 190-198, 2017 06.
Article in English | MEDLINE | ID: mdl-28460361

ABSTRACT

Two dinuclear palladium(II) complexes, [{Pd(en)Cl}2(µ-pz)](NO3)2 and [{Pd(en)Cl}2(µ-pydz)](NO3)2, have been synthesized and characterized by elemental microanalysis and spectroscopic (1H and 13C NMR, IR and UV-vis) techniques (en is ethylenediamine; pz is pyrazine and pydz is pyridazine). The square planar geometry of palladium(II) metal centers in these complexes has been predicted by DFT calculations. The chlorido complexes were converted into the corresponding aqua complexes, [{Pd(en)(H2O)}2(µ-pz)]4+ and [{Pd(en)(H2O)}2(µ-pydz)]4+, and their reactions with N-acetylated l-histidylglycine (Ac-l-His-Gly) and l-methionylglycine (Ac-l-Met-Gly) were studied by 1H NMR spectroscopy. The palladium(II)-aqua complexes and dipeptides were reacted in 1:1 M ratio, and all reactions performed in the pH range 2.0

Subject(s)
Amides/chemistry , Dipeptides/chemistry , Histidine/chemistry , Methionine/chemistry , Organometallic Compounds/chemistry , Dimerization , Dose-Response Relationship, Drug , Hydrolysis , Molecular Structure , Palladium/chemistry , Platinum/chemistry , Pyrazines/chemistry , Pyridazines/chemistry , Structure-Activity Relationship
7.
Article in English | MEDLINE | ID: mdl-34747416

ABSTRACT

Almost all drugs, including some plant-based compounds, can have adverse effects, about 10% of which are expressed at the level of the digestive tract and in some cases resemble gastrointestinal diseases. Most commonly manifest as difficult and/or painful swallowing, nausea, vomiting, diarrhea and constipation. In rare cases, lesions caused by medications may be complicated by bleeding, strictures and perforations and can manifest in all segments of the gastrointestinal tract (GIT). The diagnosis is made from a detailed medical history and clinical examination inter alia. and best confirmed by proximal or distal endoscopy.


Subject(s)
Gastrointestinal Diseases , Mouth , Diarrhea/etiology , Esophagus , Humans
8.
Chem Biol Interact ; 351: 109708, 2022 Jan 05.
Article in English | MEDLINE | ID: mdl-34666020

ABSTRACT

Herein, the stability, lipophilicity, in vitro cytotoxicity, and influence on acetylcholinesterase of five dinuclear platinum(II) complexes with the general formula [{Pt(en)Cl}2(µ-L)]2+ (L is a different aromatic nitrogen-containing heterocyclic bridging ligands pyrazine (pz, Pt1), pyridazine (pydz, Pt2), quinoxaline (qx, Pt3), phthalazine (phtz, Pt4) and quinazoline (qz, Pt5), while en is bidentate coordinated ethylenediamine) were evaluated. The most active analyzed platinum complexes induced time-dependent growth inhibition of A375, HeLa, PANC-1, and MRC-5 cells. The best efficiency was achieved on HeLa and PANC-1 cells for Pt1, Pt2, and Pt3 at the highest concentration, while Pt1 was significantly more potent than cisplatin at a lower concentration. Additionally, a lower effect on normal cells was observed compared to cisplatin, which may indicate potentially fewer side effects of these complexes. Selected complexes induce reactive oxygen species and apoptosis on tumor cell lines. The most potent reversible acetylcholinesterase (AChE) inhibitors were Pt2, Pt4, and Pt5. Pt1 showed similar inhibitory potential toward AChE as cisplatin, but a different type of inhibition, which could contribute to lower neurotoxicity. Docking studies revealed that Pt2 and Pt4 were bound to the active gorge above the catalytic triad. In contrast, the other complexes were bound to the edge of the active gorge without impeding the approach to the catalytic triad. According to this, Pt1 represents a promising compound with potent anticancer properties, high selectivity, and low neurotoxicity.


Subject(s)
Antineoplastic Agents/pharmacology , Cholinesterase Inhibitors/pharmacology , Coordination Complexes/pharmacology , Acetylcholinesterase/chemistry , Acetylcholinesterase/metabolism , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Apoptosis/drug effects , Binding Sites , Cell Line, Tumor , Cholinesterase Inhibitors/chemistry , Cholinesterase Inhibitors/metabolism , Coordination Complexes/chemistry , Coordination Complexes/metabolism , Drug Screening Assays, Antitumor , Humans , Ligands , Molecular Docking Simulation , Molecular Structure , Platinum/chemistry , Protein Binding , Reactive Oxygen Species/metabolism , Structure-Activity Relationship
9.
J Inorg Biochem ; 231: 111773, 2022 06.
Article in English | MEDLINE | ID: mdl-35279446

ABSTRACT

Four Pt(II) complexes of the general formula [Pt(L)(5,6-epoxy-1,10-phen)], where L is an anion of either malonic acid (mal, Pt1), 2-methylmalonic acid (Me-mal, Pt2), 2,2-dimethylmalonic acid (Me2-mal, Pt3) or 1,1-cyclobutanedicarboxylic acid (CBDCA, Pt4) and 5,6-epoxy-1,10-phen is 5,6-epoxy-5,6-dihydro-1,10-phenanthroline, were synthesized and characterized by elemental microanalysis and different spectroscopic techniques. The crystal structure of anhydrous Pt3 complex was determined by single crystal X-ray diffraction. The in vitro anticancer activity of the platinum(II) complexes was investigated in human and murine cancer cell lines as well as in a normal murine cell line by MTT assay. The results show that the investigated platinum(II) complexes exhibit potent cytotoxic activity against murine breast carcinoma cells (4T1), human (HCT116) and murine (CT26) colorectal carcinoma cells. The Pt3 complex shows stronger selectivity against cancer cells compared to other platinum(II) complexes tested and thus exhibits beneficial antitumor activity, mainly by inducing apoptosis and inhibiting cell proliferation and migration. The Pt3 complex also exhibits significant in vivo antitumor activity in the orthotopical 4T1 tumor model without detected liver, kidney, lung, and heart toxicity. All the results indicate that these novel platinum(II) complexes have good antitumor activity on breast and colorectal cancer and have the potential to become possible candidates for cancer treatment.


Subject(s)
Antineoplastic Agents , Coordination Complexes , Animals , Antineoplastic Agents/chemistry , Cell Line, Tumor , Coordination Complexes/chemistry , Drug Screening Assays, Antitumor , Humans , Malonates/pharmacology , Mice , Platinum/chemistry , Platinum/pharmacology
10.
J Inorg Biochem ; 225: 111619, 2021 12.
Article in English | MEDLINE | ID: mdl-34597886

ABSTRACT

The antitumour potential of nine dinuclear platinum(II) complexes of the type [{Pt(L)Cl}2(µ-X)]2+(where L represents two NH3 or different bidentantly coordinated diamine ligand - ethylenediamine, en; (±)-1,2-propylenediamine, 1,2-pn; isobutylenediamine, ibn; trans-(±)-1,2-diaminocyclohexane, dach; 1,3-propylenediamine, 1,3-pd; 2,2-dimethyl-1,3-propylenediamine, 2,2-diMe-1,3-pd; (±)-1,3-pentanediamine,1,3-pnd, and X is a bridging pyrazine (pz) or pyridazine (pydz) ligand) were determined by in vitro and in vivo assays using the CT26 cell line and a murine model of heterotopic colon cancer tumour induced in immunocompetent BALB/c mice. This study concludes that complexes Pt1, Pt2 and Pt7 possess significant in vitro cytotoxic activity against mouse colon carcinoma CT26 cells, while all these complexes show moderate apoptotic effect. Complexes Pt1 and Pt7 arrested CT26 cells in G2/M phase of cell cycle, while, evaluated by detection of Ki67 expressing cells, complexes Pt5 and Pt6 exerted the highest antiproliferative effect. Complexes Pt1 and Pt2 exerted significant in vivo antitumour effects. These complexes reduced the growth of primary tumour and the incidence of lung and liver metastases without causing the significant hepato- and nephro- toxicity. Our data indicate considerable antitumour activity of platinum(II) complexes against CT26 cells in vitro and in vivo and imply possible further investigations on their role as potential chemotherapeutic agents.


Subject(s)
Antineoplastic Agents/therapeutic use , Coordination Complexes/therapeutic use , Neoplasms/drug therapy , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Coordination Complexes/chemistry , Coordination Complexes/pharmacology , Drug Screening Assays, Antitumor , G2 Phase Cell Cycle Checkpoints/drug effects , Ligands , Male , Mice, Inbred BALB C , Molecular Structure , Neoplasm Metastasis/prevention & control , Platinum/chemistry
11.
Bioorg Chem ; 38(4): 144-8, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20359733

ABSTRACT

Proton NMR spectroscopy was applied to study the reactions of the dipeptides glycyl-glycine (Gly-Gly) and glycyl-L-alanine (Gly-L-Ala) with hydrogen tetrachloridoaurate(III) (H[AuCl(4)]). All reactions were performed at pH 2.0 and 3.0 and at 40 degrees C. The final products in these reactions were [Au(Gly-Gly-kappa(3)N(G1),N(G2),O(G2))Cl] and [Au(Gly-L-Ala-kappa(3)N(G),N(A),O(A))Cl] complexes. Tridentate coordination of the corresponding dipeptides and square-planar geometry of these Au(III) complexes was confirmed by NMR ((1)H and (13)C) spectroscopy. This study showed that at pH<3.0 the Au(III) ion was able to deprotonate the amide nitrogen atom. However this displacement reaction was very slow and the total concentration of the corresponding Au(III)-peptide complex formed after 5 days was less than 60% for the Gly-L-Ala or 70% for the Gly-Gly dipeptide. The kinetic data of the reactions between the Gly-Gly and Gly-L-Ala dipeptides and [AuCl(4)](-) were compared with those for the histidine-containing Gly-l-His dipeptide. The differences in the reactivity of these three dipeptides with the Au(III) ion are discussed.


Subject(s)
Dipeptides/chemistry , Glycylglycine/chemistry , Gold Compounds/chemistry , Magnetic Resonance Spectroscopy
12.
Acta Crystallogr C ; 66(Pt 2): m51-4, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20124681

ABSTRACT

Crystallographic analysis of a solid solution of two diastereoisomers, i.e. ({(1S,R)-1-carboxy-3-[(R,S)-methylsulfinyl]propyl}aminocarbonyl)methanaminium tetrachloridoaurate(III) and ({(1S,R)-1-carboxy-3-[(S,R)-methylsulfinyl]propyl}aminocarbonyl)methanaminium tetrachloridoaurate(III), (C(7)H(15)N(2)O(4)S)[AuCl(4)], has shown that in the presence of gold(III), the methionine part of the Gly-D,L-Met dipeptide is oxidized to sulfoxide, and no coordination to the Au(III) cation through the S atom of the sulfoxide is observed. In view of our observation, literature reports that methionine acts as an N,S-bidentate donor ligand forming stable gold(III) complexes require verification. Moreover, it has been demonstrated that crystallization of the oxidation product leads to a substantial 77:23 excess of both S-methionine/R-sulfoxide and R-methionine/S-sulfoxide over S-methionine/S-sulfoxide and R-methionine/R-sulfoxide. The presence of two different diastereoisomers at the same crystallographic site is a source of static disorder at this site.


Subject(s)
Dipeptides/chemistry , Gold/chemistry , Safrole/analogs & derivatives , Crystallography, X-Ray , Isomerism , Models, Molecular , Oxidation-Reduction , Safrole/chemistry
13.
J Inorg Biochem ; 210: 111158, 2020 09.
Article in English | MEDLINE | ID: mdl-32622215

ABSTRACT

Three new dinuclear palladium(II) complexes with general formula [{Pd(en)Cl}2(µ-L)]2+ (L is pyridine-based bridging ligand 4,4'-bipyridine (4,4'-bipy, 1), 1,2-bis(4-pyridyl)ethane (bpa, 2), 1,2-bis(4-pyridyl)ethylene (bpe, 3) and en is bidentate coordinated ethylenediamine) were synthesized and characterized by elemental microanalyses, NMR (1H and 13C), IR and UV-Vis spectroscopy. In vitro cytotoxic activity of these complexes against human A549 and murine LLC1 lung cancer cells, as well as two human HCT116 and SW480 and one murine CT26 colon cancer cells was investigated using MTT assay (MTT is 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). The potential of complexes 1-3 to induce apoptosis was tested by flow cytometric analysis of Annexin V and propidium iodide stained treated cells, while their antiproliferative activity was analyzed by detection of Ki67 expression in treated cancer cells. The DNA binding affinity of complexes 1-3 was evaluated by UV-Vis, fluorescence emission spectroscopy and by viscosity measurements in aqueous phosphate buffer solution at pH 7.40. Furthermore, interaction of these complexes with bovine serum albumin was investigated by fluorescence spectrometry. The present study showed that the nature of pyridine-based bridging ligand (L) in dinuclear [{Pd(en)Cl}2(µ-L)]2+ complex has an influence on the complex preference for the cytotoxic activity and CT-DNA/BSA (CT-DNA is calf thymus DNA and BSA is bovine serum albumin) binding affinity.


Subject(s)
Antineoplastic Agents/pharmacology , Coordination Complexes/pharmacology , DNA/metabolism , Pyridines/pharmacology , Serum Albumin, Bovine/metabolism , Animals , Antineoplastic Agents/metabolism , Apoptosis/drug effects , Cattle , Cell Line, Tumor , Cell Proliferation/drug effects , Coordination Complexes/metabolism , Drug Screening Assays, Antitumor , Drug Stability , Humans , Ligands , Mice , Palladium/chemistry , Protein Binding , Pyridines/metabolism
14.
Bioorg Chem ; 37(5): 173-9, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19656547

ABSTRACT

(1)H NMR spectroscopy was applied to study the reactions of cis-[Pd(L)(H(2)O)(2)](2+) complexes (L is en, pic and dpa) with the N-acetylated tripeptides L-methionylglycylglycine, MeCOMet-Gly-Gly, and glycyl-L-methionyl-glycine, MeCOGly-Met-Gly. All reactions were performed in the pH range 2.0-2.5 with equimolar amounts of the cis-[Pd(L)(H(2)O)(2)](2+) complex and the tripeptide at 60 degrees C. The hydrolytic reactions of the cis-[Pd(en)(H(2)O)(2)](2+), cis-[Pd(pic)(H(2)O)(2)](2+) and cis-[Pd(dpa)(H(2)O)(2)](2+) complexes with MeCOMet-Gly-Gly were regioselective and only the amide bond involving the carboxylic group of methionine was cleaved. However, in the reactions of these three Pd(II) complexes with MeCOGly-Met-Gly, two amide bonds, Met-Gly and MeCO-Gly, were cleaved. From UV-Vis spectrophotometry studies, it was found that the rate-determining step of these hydrolytic reactions is the monodentate coordination of the corresponding Pd(II) complex to the sulfur atom of the methionine side chain. The rate of the cleavage of these amide bonds is dependent on the nature of the bidentate coordinated diamine ligand L (en>pic>dpa). The hydrolytic reaction of cis-[Pd(L)(H(2)O)(2)](2+)-type complexes with MeCOMet-Gly-Gly, containing the methionine side chain in the terminal position of the peptide, is regioselective while in the reaction of these Pd(II) complexes with MeCOGly-Met-Gly, none selective cleavage of the peptide occurs. This study contributes to a better understanding of the selective cleavage of methionine-containing peptides employing palladium(II) complexes as catalysts.


Subject(s)
Amides/chemistry , Methionine/chemistry , Peptides/chemistry , Catalysis , Hydrolysis , Nuclear Magnetic Resonance, Biomolecular , Spectrophotometry, Ultraviolet
15.
Bioorg Chem ; 36(3): 161-4, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18400244

ABSTRACT

The reaction of the monofunctional [Pt(Gly-Gly-N,N',O)I](-) complex, in which Gly-Gly is the dipeptide glycyl-glycine coordinated through two nitrogen and oxygen atoms, with the N-acetylated dipeptide L-methionyl-L-histidine (MeCOMet-His) studied by (1)H NMR spectroscopy. All reactions were carried out in 50mM phosphate buffer at pD 7.4 and at 25 degrees C. In the initial stage of the reaction, the platinum(II) complex forms the kinetically favored [Pt(Gly-Gly-N,N',O)(MeCOMet-His-S)](-) complex, with unidentate coordination of the MeCOMet-His dipeptide through the sulfur atom of the methionine residue. In the second stage of the reaction, complete intramolecular migration of the [Pt(Gly-Gly-N,N',O)] unit from the sulfur to the N3 nitrogen atom of imidazole was observed and a new platinum(II)-peptide complex, [Pt(Gly-Gly-N,N',O)(MeCOMet-His-N3)](-) was formed. In comparison with previous results obtained for the reaction of [Pt(dien)Cl](+) with different methionine- and histidine-containing peptides, this migration reaction was sufficiently fast and strongly selective to the N3 atom of the imidazole ring of the histidine side chain. This study is an important step in the development of new platinum(II) complexes for selective covalent modification of peptides and proteins.


Subject(s)
Dipeptides/chemistry , Organoplatinum Compounds/chemistry , Histidine , Kinetics , Magnetic Resonance Spectroscopy , Peptides , Proteins
16.
Bioinorg Chem Appl ; 2018: 3294948, 2018.
Article in English | MEDLINE | ID: mdl-29853829

ABSTRACT

Dinuclear platinum(II) complexes, [{Pt(en)Cl}2(µ-qx)]Cl2·2H2O (1), [{Pt(en)Cl}2(µ-qz)](ClO4)2 (2), and [{Pt(en)Cl}2(µ-phtz)]Cl2·4H2O (3), were synthesized and characterized by different spectroscopic techniques. The crystal structure of 1 was determined by single-crystal X-ray diffraction analysis, while the DFT M06-2X method was applied in order to optimize the structures of 1-3. The chlorido Pt(II) complexes 1-3 were converted into the corresponding aqua species 1a-3a, and their reactions with an equimolar amount of Ac-L-Met-Gly and Ac-L-His-Gly dipeptides were studied by 1H NMR spectroscopy in the pH range 2.0 < pH < 2.5 at 37°C. It was found that, in all investigated reactions with the Ac-L-Met-Gly dipeptide, the cleavage of the Met-Gly amide bond had occurred, but complexes 2a and 3a showed lower catalytic activity than 1a. However, in the reactions with Ac-L-His-Gly dipeptide, the hydrolysis of the amide bond involving the carboxylic group of histidine was observed only with complex 1a. The observed disparity in the catalytic activity of these complexes is thought to be due to different relative positioning of nitrogen atoms in the bridging qx, qz, and phtz ligands and consequent variation in the intramolecular separation of the two platinum(II) metal centers.

17.
Turk J Gastroenterol ; 29(4): 488-493, 2018 07.
Article in English | MEDLINE | ID: mdl-30249565

ABSTRACT

BACKGROUND/AIMS: Thrombin Activatable Fibrinolysis Inhibitor (TAFI), in addition to suppressing fibrinolysis, can be involved as a natural anti-inflammatory molecule in the inflammatory process in acute pancreatitis (AP). The goal of this study was to discover the significance of early determination of the values of TAFI in the assessment of the severity of AP. MATERIALS AND METHODS: The prospective study included 92 patients with AP. In accordance with the revised Atlanta classification, we divided all patients into 3 groups (I-mild AP, II- moderate AP and III-severe AP). All patients were further classified into group A (mild AP) and group B (moderate and severe AP) with the aim of separating the patients with complicated and potentially bad prognosis. Biochemical markers, inflammatory biomarkers, coagulation parameters and TAFI were analyzed in all patients. RESULTS: The level of TAFI were significantly higher among the patients with the complicated form (group B) of AP (p=0.002). The analysis of the ROC curve in regard to the inflammatory biomarkers (fibronectin and CRP) has shown that TAFI possesses the best discriminatory ability for complicated forms of AP (AUC=0.724, p=0.013), with the sensitivity of 83.30% and the specificity of 56.00%. CONCLUSION: The level of TAFI in plasma is higher in patients with moderate or severe AP. Determining the level of TAFI as a single parameter has a greater significance in the early estimation of the severity of AP than inflammatory biomarkers that we have analyzed.


Subject(s)
Carboxypeptidase B2/blood , Pancreatitis/blood , Pancreatitis/diagnosis , Severity of Illness Index , Acute Disease , Adult , Aged , Area Under Curve , Biomarkers/blood , C-Reactive Protein/analysis , Female , Humans , Male , Middle Aged , Prospective Studies , ROC Curve , Sensitivity and Specificity
18.
Article in English | MEDLINE | ID: mdl-29358788

ABSTRACT

Irritable bowel syndrome (IBS) is a chronic and relapsing functional gastrointestinal disorder that affects 9-23% of the population across the world. Patients with IBS are often referred to gastroenterology, undergo various investigations, take various medicines, take time off work and have a poor quality of life. The pathophysiology of IBS is not yet completely understood and seems to be multifactorial. Many pathogenetic factors, in various combinations, and not all necessarily present in each patient, can play an important role. Discomfort or abdominal pain relieived by defacation, asociated with a change in stool form, is a typical clinical manifestation of IBS. Many factors, such as emotional stress and eating, may exacerbate the symptoms. A timely diagnosis of IBS is important so that treatment which will provide adequate symptomatic relief (diarrhoea, constipation, pain and boaring) can be introduced. The diagnosis of IBS is not confirmed by a specific test or structural abnormality. It is made using criteria based on clinical symptoms such as Rome criteria, unless the symptoms are thought to be atypical. Today the Rome Criteria IV is the current gold-standard for the diagnoses of IBS. Treatment of patients with IBS requires a multidisciplinary approach. Some patients respond well to non-pharmacological treatment, while others also require pharmacological treatment. This review will provide a summary of pathophysiology, diagnostic criteria and therapies for IBS.


Subject(s)
Genetic Predisposition to Disease , Irritable Bowel Syndrome/diagnosis , Risk Reduction Behavior , Stress, Psychological/complications , Diet , Exercise , Fecal Microbiota Transplantation , Humans , Irritable Bowel Syndrome/etiology , Irritable Bowel Syndrome/physiopathology , Irritable Bowel Syndrome/therapy , Laxatives , Parasympatholytics , Patient Education as Topic , Practice Guidelines as Topic , Prevalence , Probiotics , Quality of Life , Risk Factors
19.
Dalton Trans ; 47(42): 15091-15102, 2018 Oct 30.
Article in English | MEDLINE | ID: mdl-30303498

ABSTRACT

The synthesis, spectroscopic characterization, cytotoxic activity and DNA binding evaluation of seven new dinuclear platinum(ii) complexes Pt1-Pt7, with the general formula [{Pt(L)Cl}2(µ-1,5-nphe)](ClO4)2 (1,5-nphe is 1,5-naphthyridine; while L is two ammines (Pt1) or one bidentate coordinated diamine: ethylenediamine (Pt2), (±)-1,2-propylenediamine (Pt3), trans-(±)-1,2-diaminocyclohexane (Pt4), 1,3-propylenediamine (Pt5), 2,2-dimethyl-1,3-propylenediamine (Pt6), and 1,3-pentanediamine (Pt7)), were reported. In vitro cytotoxic activity of these complexes was evaluated against three tumor cell lines, murine colon carcinoma (CT26), murine mammary carcinoma (4T1) and murine lung cancer (LLC1) and two normal cell lines, murine mesenchymal stem cells (MSC) and human fibroblast (MRC-5) cells. The results of the MTT assay indicate that all investigated complexes have almost no cytotoxic effects on 4T1 and very low cytotoxicity toward LLC1 cell lines. In contrast to the effects on LLC1 and 4T1 cells, complexes Pt1 and Pt2 had significant cytotoxic activity toward CT26 cells. Complex Pt1 had a much lower IC50 value for activity on CT26 cells compared with cisplatin. In comparison with cisplatin, all dinuclear Pt1-Pt7 complexes showed lower cytotoxicity toward normal MSC and MRC-5 cells. In order to measure the amount of platinum(ii) complexes taken up by the cells, we quantified the cellular platinum content using inductively coupled plasma mass spectrometry (ICP-QMS). Molecular docking studies performed to evaluate the potential binding mode of dinuclear platinum(ii) complexes Pt1-Pt7 and their aqua derivatives W1-W7, respectively, at the double stranded DNA showed that groove spanning and backbone tracking are the most stable binding modes.


Subject(s)
Antineoplastic Agents/pharmacology , DNA/chemistry , Naphthyridines/pharmacology , Organoplatinum Compounds/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Binding Sites/drug effects , Cattle , Cell Proliferation/drug effects , Cells, Cultured , Drug Screening Assays, Antitumor , Humans , Ligands , Mice , Molecular Docking Simulation , Molecular Structure , Naphthyridines/chemistry , Organoplatinum Compounds/chemical synthesis , Organoplatinum Compounds/chemistry
20.
Sao Paulo Med J ; 135(1): 71-75, 2017.
Article in English | MEDLINE | ID: mdl-27982294

ABSTRACT

CONTEXT:: Boerhaave syndrome consists of spontaneous longitudinal transmural rupture of the esophagus, usually in its distal part. It generally develops during or after persistent vomiting as a consequence of a sudden increase in intraluminal pressure in the esophagus. It is extremely rare in clinical practice. In 50% of the cases, it is manifested by Mackler's triad: vomiting, lower thoracic pain and subcutaneous emphysema. Hematemesis is an uncommon yet challenging presentation of Boerhaave's syndrome. Compared with ruptures of other parts of the digestive tract, spontaneous rupture is characterized by a higher mortality rate. CASE REPORT:: This paper presents a 64-year-old female patient whose vomit was black four days before examination and became bloody on the day of the examination. Her symptoms included epigastric pain and suffocation. Physical examination showed hypotension, tachycardia, dyspnea and a swollen and painful abdomen. Auscultation showed lateral crackling sounds on inspiration. Ultrasound examination showed a distended stomach filled with fluid. Over 1000 ml of fresh blood was extracted by means of nasogastric suction. Esophagogastroduodenoscopy was discontinued immediately upon entering the proximal esophagus, where a large amount of fresh blood was observed. The patient was sent for emergency abdominal surgery, during which she died. An autopsy established a diagnosis of Boerhaave syndrome and ulceration in the duodenal bulb. CONCLUSION:: Boerhaave syndrome should be considered in all cases with a combination of gastrointestinal symptoms (especially epigastric pain and vomiting) and pulmonary signs and symptoms (especially suffocation).


Subject(s)
Esophageal Perforation/diagnosis , Mediastinal Diseases/diagnosis , Fatal Outcome , Female , Humans , Middle Aged , Rupture, Spontaneous/diagnosis
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