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Journal of Rare Earths 2010年第6期28卷 847-853页

作者： S. P. Sinha Alfredo M. Simas Gustavo L. C. Moura Scientific Research & Development Departamento de Quimica Fundamental CCEN Universidade Federal de Pernambuco

Theoretical investigation on the structures of the octacoordinated [Nd(CO3)4]5-and the nonacoordinated [Nd(CO3)***2]5-complexes, using the SPARKLE parameters of the lanthanides within MOPAC, revealed that they possessed dodecahedral and square antiprismatic structures respectively with an average Nd-O distance of 0.249 nm. These structures and the Nd-O distances agreed well with those experimentally found in the crystal structures. Replacing the water molecule with a fluoride ion or a mondentatecarbonato ligand resulted in a nonacoordinated distorted square antiprismatic structures where the trans-carbonato groups were twisted. The corresponding decacoordinated structures with two fluoride ions or a bidentatecarbonato group, [Nd(CO3)4·F2]7-and [Nd(CO3)5]7-, were also investigated. In both cases considerable twisting of the transcarbonato groups was observed.

关键词： lanthanides theoretical molecular models octacoordination carbonato complexes adducts MOPAC SPARKLE rare earths

Recent progress in quantitative analysis of DNA adducts of nephrotoxin aristolochic acid

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Science China Chemistry 2009年第10期52卷 1576-1582页

作者： YUE Hao CHAN Wan YU KongJie GUO Lin LIU Ning LIU HuWei CAI ZongWei Department of Chemistry Hong Kong Baptist UniversityHong Kong SARChina Changchun University of Chinese Medicine Changchun 130117China Fujian Entry-Exit Inspection and Quarantine Bureau Fuzhou 350001China Institute of Analytical Chemistry College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Aristolochic acid (AA), a mixture of structure-related nitrophenanthrene carboxylic acid derivatives derived from Aristolochia spp, is associated with nephrotoxin and carcinogen. AA-DNA adducts induced by reductive metabolic activation of AA were detected in tissues of animals and in patients exposed to AA. The DNA adducts were generally used as biomarkers in toxicological study of AA. In this short review, quantitative analysis of AA-DNA adducts in various in vitro and in vivo systems by using 32P-postlabelling assay, HPLC-UV, HPLC-radiation monitor, HPLC-FLD, HPLC-ESI/MS and UPLC-MS/MS methods is discussed. The distribution of AA-DNA adducts in various tissues is also summarized.

关键词： aristolochic acid DNA adducts quantitative analysis short review

Thermochemical Parameters of Tetramethylthiourea adducts of Certain Metal(II) Bromides

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Open Journal of Physical Chemistry 2015年第1期5卷 9-19页

作者： Pedro Oliver Dunstan Instituto de Química Universidade Estadual de Campinas Campinas Brazil

Complexes of the general formula [MBr2(TMTU)n] (where M is Mn, Fe, Co, Ni, Cu, Zn or Cd;TMTU is Tetramethylthiourea;n is 0.75, 2 or 3) were obtained by the reaction of salts and ligand in solution. The bromides were selected among several other salts because they had thermochemical data in the literature. Properties as capillary melting points;C, H, N, Br and metal contents;TG/DTG and DSC curves;and IR and electronic spectra were determined. The values of several thermodynamic parameters for the complexes were found by solution calorimetry. From them, the standard enthalpies of the metal-sulphur coordinated bonds were calculated. The standard enthalpies of the formation of the gaseous phase adducts also were estimated.

关键词： Enthalpies of Formation Thermodynamic Coordinated Bond Enthalpies Solution Calorimetry Dissolution Enthalpies Tetramethylthiourea adducts

Review: adducts and Clusters in Chromatography, Mass Spectrometry and Nature

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International Journal of Analytical Mass Spectrometry and Chromatography 2016年第2期4卷 27-33页

作者： Ilia Brondz Norwegian Drug Control and Drug Discovery Institute (NDCDDI) AS Ski Norway

The word “clusters” in scientific terminology as aggregated molecules or atoms appeared in chemistry relatively recently. The terms clusters have been used intensively since the discovery of fullerenes. The term cluster is not a new one for other branches of science such as astrophysics-star cluster, globular cluster, galaxy cluster, in biology and medicine-cancer cluster, genetic cluster, or in computing-data cluster. adducts in chemistry were known significantly earlier. Both clusters and adducts are assemblies of atoms or molecules that are held together by weak van der Waals or London dispersion forces. Clusters are homogeneous and usually consist of one sort of atom or molecule. Clusters can also be a host for other types of atoms or molecules. adducts usually consist of two different types of molecules, one of which is the host molecule. Both clusters and adducts are well defined by IUPAC. The present short review describes some important phenomena of these intriguing associations, which have interest for chemical extraction, separation, analysis, and for nature in general.

关键词： Clusters adducts Chromatography Mass Spectrometry Icosahedral Structures

Pre-Chelates, Post-adducts and Implexes: A perspective proposal for the future of medicinal chemistry

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Advances in Biological Chemistry 2013年第6期3卷 553-555页

作者： Mario Gosalvez Laboratory and Service of Experimental Biochemistry Clínica and Hospital Universitario Puerta de Hierro Madrid and Majadahonda Comunidad de Madrid Spain

The title of this little assay coins three new words: Pre-Chelates, Post-adducts and Implexes. These, very daring new excursions into the scientific English language, come from the developments of Quelamycin and Sodium L-Thioproline, through our different group studies arriving to cancer reversal by a dual strategy. It is enough to read all our published materials, cites and related papers, dealing more or less with the chemistry and possible mechanism of action of these compounds, to gather somewhat what signified our monomeric-triferric-doxorubicine, as possibly one of the first Pre-Chelates and our Sodium L-Thioproline, probably as one of the first Post-adducts. Both molecules come to the human patients with cancer blood from the exterior. After this indication, it will be proposed a seed concept of a new type of molecules, the “Implexes” in which the metals will be embraced instead of being linked.

关键词： New Chelates and adducts Embracing Metals Future of Medicinal Therapeutics Quelamycin Thioproli

Pyrrolizidine alkaloids-induced hepatic sinusoidal obstruction syndrome: Pathogenesis, clinical manifestations, diagnosis,treatment, and outcomes

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World Journal of Gastroenterology 2019年第28期25卷 3753-3763页

作者： Xiao-Qian Yang Jin Ye Xin Li Qian Li Yu-Hu Song Division of Gastroenterology Union Hospital Tongji Medical college Huazhong University of Science and Technology Wuhan 430022 Hubei Province China Department of Radiology Union Hospital Tongji Medical college Huazhong University of Science and technology Wuhan 430022 Hubei Province China

Hepatic sinusoidal obstruction syndrome (HSOS) can be caused by the intake of pyrrolizidine alkaloids (PAs). To date, PAs-induced HSOS has not been extensively studied. In view of the difference in etiology of HSOS between the West and China, clinical profiles, imaging findings, treatment, and outcomes of HSOS associated with hematopoietic stem cell transplantation or oxaliplatin might be hardly extrapolated to PAs-induced HSOS. Reactive metabolites derived from PAs form pyrrole-protein adducts that result in toxic destruction of hepatic sinusoidal endothelial cells. PAs-induced HSOS typically manifests as painful hepatomegaly, ascites, and jaundice. Laboratory tests revealed abnormal liver function tests were observed in most of the patients with PAs-induced HSOS. In addition, contrast computed tomography and magnetic resonance imaging scan show that patients with PAs-induced HSOS have distinct imaging features, which reveal that radiological imaging provides an effective noninvasive method for the diagnosis of PAs-induced HSOS. Liver biopsy and histological examination showed that PAs-induced HSOS displayed distinct features in acute and chronic stages. Therapeutic strategies for PAs-induced HSOS include rigorous fluid management, anticoagulant therapy, glucocorticoids, transjugular intrahepatic portosystemic shunt, liver transplantation, etc. The aim of this review is to describe the pathogenesis, clinical profiles, diagnostic criteria, treatment, and outcomes of PAs-induced HSOS.

关键词： Hepatic sinusoidal obstruction syndrome Pyrrolizidine alkaloids Hepatic sinusoidal endothelial cells Pyrrole-protein adducts Diagnostic criteria Symptomatic treatment Anticoagulant therapy

<i>Gsta</i>4 Null Mouse Embryonic Fibroblasts Exhibit Enhanced Sensitivity to Oxidants: Role of 4-Hydroxynonenal in Oxidant Toxicity

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Open Journal of Apoptosis 2013年第1期2卷 1-11页

作者： Kevin E. McElhanon Chhanda Bose Rajendra Sharma Liping Wu Yogesh C. Awasthi Sharda P. Singh Central Arkansas Veterans Healthcare System Little Rock USA Department of Molecular Biology and Immunology University of North Texas Health Science Center Fort Worth USA Department of Pharmacology and Toxicology University of Arkansas for Medical Sciences Little Rock USA

The alpha class glutathione s-transferase (GST) isozyme GSTA4-4 (EC2.***.1.18) exhibits high catalytic efficiency towards 4-hydroxynon-2-enal (4-HNE), a major end product of oxidative stress induced lipid peroxidation. Exposure of cells and tissues to heat, radiation, and chemicals has been shown to induce oxidative stress resulting in elevated concentrations of 4-HNE that can be detrimental to cell survival. Alternatively, at physiological levels 4-HNE acts as a signaling molecule conveying the occurrence of oxidative events initiating the activation of adaptive pathways. To examine the impact of oxidative/electrophilic stress in a model with impaired 4-HNE metabolizing capability, we disrupted the Gsta4 gene that encodes GSTA4-4 inmice. The effect of electrophile and oxidants on embryonic fibroblasts (MEF) isolated from wild type (WT) and Gsta4 null mice were examined. Results indicate that in the absence of GSTA4-4, oxidant-induced toxicity is potentiated and correlates with elevated accumulation of 4-HNE adducts and DNA damage. Treatment of Gsta4 null MEF with 1,1,4-tris(acetyloxy)-2(E)-nonene [4-HNE(Ac)3], a pro-drug form of 4-HNE, resulted in the activation and phosphorylation of the c-jun-N-terminal kinase (JNK), extracellular-signal-regulated kinases (ERK 1/2) and p38 mitogen activated protein kinases (p38 MAPK) accompanied by enhanced cleavage of caspase-3. Interestingly, when recombinant mammalian or invertebrate GSTs were delivered to Gsta4 null MEF, activation of stress-related kinases in 4-HNE(Ac)3 treated Gsta4 null MEF were inversely correlated with the catalytic efficiency of delivered GSTs towards 4-HNE. Our data suggest that GSTA4-4 plays a major role in protecting cells from the toxic effects of oxidant chemicals by attenuating the accumulation of 4-HNE.

关键词： Glutathione Transferase Protein adducts Lipid Peroxidation Oxidants Stress Kinases

Drug-Excipient Interactions: Case Studies and Overview of Drug Degradation Pathways

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American Journal of Analytical Chemistry 2016年第1期7卷 107-140页

作者： Kishore Kumar Hotha Swapan Roychowdhury Veerappan Subramanian Novel Laboratories Inc. Somerset NJ USA

The objective of the current research article is to provide a comprehensive review of excipients impact on the stability of the drug product and their implications during the product development. Recent developments in the understanding of the degradation pathways further impact methodologies used in the pharmaceutical industry for potential stability assessment. The formation of drug excipient adducts was very common based on the sensitive chemical moieties in the drugs and the excipients. The formation of the impurities was not limited to drug related impurities but there were several possibilities of the drug-excipient adduct formations as well as excipient impurities reaction with Active Pharmaceutical Ingredients. Identification of drug degradation in presence of excipients/excipient impurities requires extensive knowledge and adequate analytical characterization data. Systematic literature review and understanding about the drug formulation process, give you a smooth platform in establishing the finished product in the drug market. This paper discusses mechanistic basis of known drug-excipient interactions with case studies and provides an overview of common underlying themes in solid, semisolid and parenteral dosage forms.

关键词： Drug Excipients Forced Degradation Impurities adducts Degradation Pathways HPLC LC-MS/MS Synthesis Chemistry Characterization

Studies on the Thiol Components of Isolated Nuclei

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Journal of Analytical Sciences, Methods and Instrumentation 2020年第1期10卷 36-42页

作者： Michael Gronow Cambridge Cancer Research Fund Laboratory 7 The Maltings Cottenham Cambridge England UK

The thiol components of the nonhistone proteins prepared from isolated nuclei from rat liver, regenerating liver and hepatoma 223 cells have been investigated after reaction with radio labelled N-ethylmaleimide and 5-5’-dithiobis-(2-nitrobenzoic acid) (DTNB). The labelled adducts formed were examined by isoelectric focusing analysis in polyacrylamide gel and the distribution of the radiolabels within sliced portions of the gels determined. In the case of the 14C labelled NEM adduct the label was found to be spread amongst numerous protein components within the gel however, in the case of the 35S labelled DTNB adducts, only a small proportion of the label was found in the protein material which was retained in the acidic isoelectric point (pI) region of the gel. The bulk of the 35S labelled adduct (56% - 60%) was found to have migrated into the anode solution (10 mM phosphoric acid). This could be adsorbed onto a hydrophobic resin (XAD2) resin and eluted with methanol. Gel filtration chromatographic analysis of this adduct material on BioGel P2, (exclusion limit 1500 daltons) showed low molecular weight components to be present. Slightly different patterns were obtained for these nuclei, each containing several 35S components with molecular weights greater than the Ellman reagent itself. These 35S labelled thiol components did not contain any protein, peptide or amino acid components indicating strongly that a novel species of thiols could be present in these nuclei bound within the non-histone protein matrices.

关键词： Thiols Isolated Cell Nuclei Radiolabelled Thiol adducts Isoelectric Focusing Analysis

Characterization, XPS and Toxicological Study of Organothallium (III) Compounds with Schiff Base Ligands

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Crystal Structure Theory and Applications 2012年第3期1卷 97-99页

作者： Gyanendra Kumar Gaur Shekhar Srivastava Scientific Officer Forensic Science Laboratory Gwalior India

Many Organothallium Compounds have been used in medicine, industry and antibacterial activity. Optical properties are among the most fascinating and useful properties of many complexes and have been extensively studied using a variety of optical spectroscopic techniques. A basic understanding of the optical properties and related spectroscopic techniques is essential for characterization about semiconductors, insulators or metal. Optical properties are related to other properties and functionalities (e.g. electronic, magnetic, and thermal) that are of fundamental importance to many technological applications, such as energy conversion, chemical analysis, biomedicine, opto-electronics, communication, and radiation detection. The fundamental importance of Thallium is the ability to accept electrons due to empty d-orbitals and thus establish additional bonds (σ bond and π bond) in chemistry. The Thallium metal, which has outer electronic configuration 6 s2, 6 p1 shows oxidation states of Thallium (III) and Thallium (I). This research paper explains that Thallium (III) and Thallium (I) accepts lone pairs from various bi-dentate tetra-dentate Schiff base ligands due to p-orbital and vacant d-orbital. This research paper explains the Characterization, XPS and Toxicological Study of Or- ganothallium (III) Compounds with Schiff base ligands by physiochemical technique. X-Ray photoelectron spectrogra- phy (XPS) study of Thallium (III) complexes with Schiff Base ligands also reported in this paper. XPS study shows a single symmetrical peak without any splitting in photoelectron peak, which confirms diamagnetic nature of all prepared molecular adducts. All prepared complexes with Schiff base ligands show toxicological effect.

关键词： Oxidation Ligand Diamagnetic Organothallium Compound Molecular adducts