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Containing Compounds (containing + compound)
Selected AbstractsNitrogen-Rich Compounds of the Lanthanoids: Highlights and SummaryHELVETICA CHIMICA ACTA, Issue 2 2010Georg Steinhauser Abstract In this third part of our research on the 5,5,-azobis[1H -tetrazol-1-ides] (ZT) of the lanthanoids, we present two compounds with La2(ZT)3 moieties with very different coordination modes between the cations and the anions. One La2(ZT)3 -containing compound is interesting, because it contains trimeric La3(ZT)3III cations, which are arranged in a windmill-like structure. Moreover, the first double salt of a ZT compound, namely the carbonate compound La2(ZT)2(CO3),12 H2O, is presented and discussed. Another highlight of nitrogen chemistry is the first molecular structure of a 5-azido-2H -tetrazole (CHN7) molecule, in the form of the spectacular compound Dy2(ZT)3,4 CHN7,24 H2O. This is the first known complete molecular structure of an azidotetrazole molecule (the organic molecule with the highest nitrogen-content: 88.3% N). All compounds have been characterized completely including elemental analyses, vibrational (IR and Raman) spectroscopy, and X-ray crystal-structure determination. We summarize our ,nitrogen-rich compounds of the lanthanoids' project and extensively discuss selected literature on this topic and compare previously published results with ours. [source] Effects of chromium on the immune systemFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2002Richa Shrivastava Abstract Chromium is a naturally occurring heavy metal found commonly in the environment in trivalent, Cr(III), and hexavalent, Cr(VI), forms. Cr(VI) compounds have been declared as a potent occupational carcinogen among workers in chrome plating, stainless steel, and pigment industries. The reduction of Cr(VI) to Cr(III) results in the formation of reactive intermediates that together with oxidative stress oxidative tissue damage and a cascade of cellular events including modulation of apoptosis regulatory gene p53, contribute to the cytotoxicity, genotoxicity and carcinogenicity of Cr(VI)-containing compounds. On the other hand, chromium is an essential nutrient required to promote the action of insulin in body tissues so that the body can use sugars, proteins and fats. Chromium is of significant importance in altering the immune response by immunostimulatory or immunosuppressive processes as shown by its effects on T and B lymphocytes, macrophages, cytokine production and the immune response that may induce hypersensitivity reactions. This review gives an overview of the effects of chromium on the immune system of the body. [source] Novel regioselective synthesis of 3,H,4H -spiro[chromene-3,2,-[1,3,4]thiadiazol]-4-one containing compoundsJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2006Mohamed I. Hegab A variety of 3,,5,-diaryl-3,H,4,H -dispiro[cyclohexane-1,2,-chromene-3,,2,-[1,3,4]thiadiazol]-4,-ones 3a-c were synthesized regioselectively through the reaction of 4,H,5H -trispiro[cyclohexane-1,2,-chromene-3,,2,-[1,3,4]oxadithiino[5,6- c]chromene-5,,1,,-cyclohexan]-4,-one (1) with nitrilimines (generated in situ via triethylamine dehydrohalogenation of the corresponding hydrazonoyl chlorides 2a-c) in refluxing dry toluene. Single crystal X-ray diffraction studies of 3a,b add support for the established structure. Similarly, 3,,5,-diaryl-2,2-dimethyl-3,H,4H -spiro[chromene-3,2,-[1,3,4]thiadiazol]-4-ones 5a-c were obtained in a regioselective manner through the reaction of 2,2,5,,5,-tetramethyl-4H,5,H -spiro[chromene-3,2,-[1,3,4]oxadithiino[5,6- c]chromen]-4-one (4a) with nitrilimines under similar reaction conditions. On the other hand, reaction of 2,5,-diethyl-2,5,-dimethyl-4H,5,H -spiro[chromene-3,2,-[1,3,4]oxadithiino-[5,6- c]chromen]-4-one (4b) with nitrilimines in refluxing dry toluene afforded the corresponding 3,,5,-diaryl-2-ethyl-2-methyl-3,H,4H -spiro[chromene-3,2,-[1,3,4]thiadiazol]-4-ones 5d-f as two unisolable diastereoisomeric forms. [source] Synthesis of functionalized compounds containing pyridazine and related moietiesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2005Jurij Svete 3-Aminopyridazines 17 and 3-hydrazinopyridazines 18 were used as building blocks for the preparation of various types of functionalized, pyridazine ring containing compounds. 3-Aminopyridazines were employed in the synthesis of 3-(6-chloroimidazo[1,2- b]pyridazin-2-yl)alanines 26, 27 and for the preparation of 3-amino-4H -pyrimido[1,2- b]pyridazin-4-ones 103, intermediates in the ,ring switching' synthesis of alkyl 1-pyridazin-3-yl-1,2,3-triazole-4-carboxylates 106. On the other hand, hydrazinopyridazines 18 were employed in a two-step preparation of 3-functionalized 1,2,4-triazolo[4,3- b]pyridazines via condensation with functionalized aldehydes and their enamino analogs followed by oxidative cyclization of the intermediate hydrazones. In this manner, 1,2,4-triazolo[4,3- b]pyridazin-3-yl substituted alanines 29, 30, polyols 33, 39,48, C -nucleosides 49, 50, and terpenes 58, 62, 64,69 were prepared. In another general approach, 3-hydrazinopyridazines 18 were treated with functionalized enaminones as 1,3-dielectrophiles to give the 1-(substituted pyridazin-3-yl)-1H -pyrazole derivatives containing an ester 72, 73, 75, 76, alanine 79, 84, 85, 87, 2-phenylethylamine 97, 99, and ,-amino alcohol functional element 98, 100. In the reaction of 4-oxohomoglutamate 82 with hydrazine hydrate and methyl hydrazine, chiral functionalized tetrahydropyridazinones 88a,b were obtained. [source] Hyperbranched polyethers by ring-opening polymerization: Contribution of activated monomer mechanismJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 4 2003Przemys, aw Kubisa Abstract Propagation in the cationic ring-opening polymerization of cyclic ethers involves nucleophilic attack of oxygen atoms from the monomer molecules on the cationic growing species (oxonium ions). Such a mechanism is known as the active chain-end mechanism. If hydroxyl groups containing compounds are present in the system, oxygen atoms of HO groups may compete with cyclic ether oxygen atoms of monomer molecules in reaction with oxonium ions. At the proper conditions, this reaction may dominate, and propagation may proceed by the activated monomer mechanism, that is, by subsequent addition of protonated monomer molecules to HO terminated macromolecules. Both mechanisms may contribute to the propagation in the cationic polymerization of monomers containing both functions (i.e., cyclic ether group and hydroxyl groups) within the same molecule. In this article, the mechanism of polymerization of three- and four-membered cyclic ethers containing hydroxymethyl substituents is discussed in terms of competition between two possible mechanisms of propagation that governs the structure of the products,branched polyethers containing multiple terminal hydroxymethyl groups. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 457,468, 2003 [source] Longitudinal Brain Metabolic Characterization of Chronic Alcoholics With Proton Magnetic Resonance SpectroscopyALCOHOLISM, Issue 9 2002Mitchell H. Parks Background Proton magnetic resonance spectroscopy may elucidate the molecular underpinnings of alcoholism-associated brain shrinkage and the progression of alcohol dependence. Methods Using proton magnetic resonance spectroscopy, we determined absolute concentrations of N -acetylaspartate (NAA), creatine/phosphocreatine (Cr), and choline (Cho)-containing compounds and myo -inositol (mI) in the anterior superior cerebellar vermis and frontal lobe white matter in 31 alcoholics and 12 normal controls. All patients were examined within 3 to 5 days of their last drink. Patients who did not relapse were again studied after 3 weeks and 3 months of abstinence by using an on-line repositioning technique that allows reliable localization of volumes of interest (VOIs). Results At 3 to 5 days after the last drink, frontal white matter metabolite concentrations were not significantly different from those of normal controls, whereas brain tissue in the VOI was reduced. Cerebellar [NAA] and [Cho] and brain and cerebellar volumes were decreased, but [Cr], [mI], and VOI brain tissue volume were not significantly different. Eight patients relapsed before 3 weeks (ER), 12 relapsed between 3 weeks and 3 months (LR), and 11 did not relapse (NR) during 3 months. Cerebellar [NAA] was reduced only in ER patients, despite the fact that ER patients drank for significantly fewer years and earlier in life than LR or NR patients. After 3 months, in the 11 continuously abstinent patients, cerebellar [NAA] and brain and cerebellar volumes increased; cerebellar [Cho], [Cr], and [mI] and VOI brain tissue did not change significantly. Conclusions Decreased [NAA] and [Cho] in cerebellar vermis indicate a unique sensitivity to alcohol-induced brain injury. Cerebellar [NAA] increased with abstinence, but reduced [Cho] persisted beyond 3 months. Further studies are needed to determine whether low cerebellar [NAA] is a risk factor for, or consequence of, malignant, early-onset alcoholism. [source] | |||||||||||||