62671-38-9Relevant articles and documents
Metallo-β-lactamase-catalyzed hydrolysis of cephalosporins: Some mechanistic insights into the effect of heterocyclic thiones on enzyme activity
Tamilselvi,Mugesh, Govindasamy
, p. 749 - 756 (2011)
The hydrolysis of β-lactam antibiotics using zinc-containing metallo-β-lactamases (mβl) is one of the major bacterial defense systems. These enzymes can catalyze the hydrolysis of a variety of antibiotics including the latest generation of cephalosporins, cephamycins, and imipenem. It is shown in this paper that the cephalosporins having heterocyclic-SR side chains are less prone to mβl-mediated hydrolysis than the antibiotics that do not have such side chains. This is partly due to the inhibition of enzyme activity by the thione moieties eliminated during hydrolysis. When the enzymatic hydrolysis of oxacillin was carried out in the presence of heterocyclic thiones such as MTT, MDT, DMETT, and MMA, the catalytic activity of the enzyme was inhibited significantly by these compounds. Although the heterocyclic-SR moieties eliminated from the β-lactams upon hydrolysis undergo a rapid tautomerism between thione and thiol forms, these compounds act as thiolate ligands toward zinc(II) ions. The structural characterization of two model tetranuclear zinc(II) thiolate complexes indicates that the-SR side chains eliminated from the antibiotics may interact with the zinc(II) metal center of mβl through their sulfur atoms.
Efficient dye-sensitized photovoltaic wires based on an organic redox electrolyte
Pan, Shaowu,Yang, Zhibin,Li, Houpu,Qiu, Longbin,Sun, Hao,Peng, Huisheng
, p. 10622 - 10625 (2013)
An organic thiolate/disulfide redox couple with low absorption in the visible region was developed for use in fabricating novel dye-sensitized photovoltaic wires with an aligned carbon nanotube (CNT) fiber as the counter electrode. These flexible wire devices achieved a maximal energy conversion efficiency of 7.33%, much higher than the value of 5.97% for the conventional I-/I3- redox couple. In addition, the aligned CNT fiber also greatly outperforms the conventional Pt counter electrode with a maximal efficiency of 2.06% based on the thiolate/disulfide redox couple.
COMPOUND HAVING HEPTAMETHINE STRUCTURE, SENSITIZING DYE AND PHOTOELECTRIC CONVERSION ELEMENT
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Paragraph 0118, (2014/01/23)
Provided is a compound having a heptamethine structure represented by the following general formula (1) used as a sensitizing dye for a photoelectric conversion device, and a photoelectric conversion device using the compound as a sensitizing dye, which may solve the problems of the related art. In the general formula (1), R1 and R2 each represent a hydrogen atom, an alkyl group or an aryl group; R3 to R6 each represent an alkyl group having from 1 to 18 carbon atoms; X represents a halogen atom; Y represents a monovalent anion; Z represents an alkyl group, an alkoxy group or an aryl group when R3 to R6 each have from 1 to 5 carbon atoms, or a hydrogen atom, an alkyl group, an alkoxy group or an aryl group when R3 to R6 each have from 6 to 18 carbon atoms; and m and n each represent an integer of from 1 to 12.
Redox chemistry between graphene oxide and mercaptan
Fan, Deqin,Zhang, Chao,He, Junpo,Hua, Rong,Zhang, Yang,Yang, Yuliang
experimental part, p. 18564 - 18571 (2012/10/08)
We report here redox reactions between graphene oxide (GO) and mercaptans, which reduces GO to reduced graphene oxide (RGO) and oxidizes mercaptans into disulfides. The reduction processes of GO using various mercaptans as the reducing agents are investigated through XPS, TGA, FT-IR, Raman and EA analysis. The degree of reduction of RGO depends on molecular structure of mercaptans and is controlled by the reaction time. The redox reaction is also employed to oxidize mercaptans into disulfides in medium to high yields under moderate conditions. The mechanism of the redox reaction may involve nucleophilic ring opening of oxirane on GO by alkylthio moiety, followed by addition of another alkylthio group, leaving the resulting disulfide. The reduction of the hydroxy group could be more complex, involving both radical and anionic processes.
