[EN] METAL-CATALYZED OXIDATIVE COUPLING OF THIOLS<br/>[FR] COUPLAGE OXYDATIF CATALYSÉ PAR UN MÉTAL DE THIOLS
申请人:ECOLAB USA INC
公开号:WO2017024092A1
公开(公告)日:2017-02-09
Disclosed are methods for preparing disulfide compounds through oxidative coupling of thiol compounds. Thiols are oxidized to the corresponding disulfide compound in high yield in presence of a base and a metal salt. The method uses low catalyst loadings and provides organic disulfide compounds with little to no byproducts.
[EN] REDUCTION SENSITIVE BIODEGRADABLE POLYESTERAMIDES<br/>[FR] RÉDUCTION DE POLYESTERAMIDES BIODÉGRADABLES SENSIBLES
申请人:DSM IP ASSETS BV
公开号:WO2016020545A1
公开(公告)日:2016-02-11
The present invention relates to biodegradable polyesteramides (PEAs) comprising hydrophobic alpha -amino acids, diols, aliphatic dicarboxylic acids and optionally diamines whereby at least one of the dicarboxylic acids, diols or diamines comprises disulphide linkages. The present invention also relates to the use of the polyesteramides in medical applications such as cancer treatment, ophthalmic applications, therapeutic cardiovascular applications, veterinary applications, pain management applications, MSK applications and vaccine delivery compositions. The present invention also relates to a drug delivery composition comprising the PEA's and to a drug delivery system such as micro-or nanoparticles, micelles, liposomes, polymerosomes, micro- and nanogels, polymerosomes or nanotubes.
Dynamic Kinetic Resolution of Amines Involving Biocatalysis and in Situ Free Radical Mediated Racemization
作者:Stéphane Gastaldi、Stéphanie Escoubet、Nicolas Vanthuyne、Gérard Gil、Michèle P. Bertrand
DOI:10.1021/ol063062o
日期:2007.3.1
[reaction: see text] The association of lipase-catalyzed enzymatic resolution with in situracemization mediated with the thiyl radical enables the dynamic kineticresolution of non-benzylic amines. It leads to (R)-amides with high enantioselectivities. It can be applied either to the conversion of racemic mixtures or to the inversion of (S)-enantiomers.
METHOD FOR PRODUCING 3-MERCAPTOPROPIONIC ACID, AND METHODS USING SAME FOR PRODUCING CARBOXYLIC ACID ESTER COMPOUND HAVING MERCAPTO GROUP AND THIOURETHANE-BASED OPTICAL MATERIAL
申请人:KOC SOLUTION CO., LTD.
公开号:US20180179154A1
公开(公告)日:2018-06-28
A method for producing 3-mercaptopropionic acid and methods using same for producing a carbonic acid ester compound having a mercapto group and a thiourethane-based optical material. The present invention improves a process during the production of 3-mercaptopropionic acid, significantly increases yield, and reduces the temperature and time during vacuum distillation, thereby preventing the destruction of a product and significantly increasing productivity. The present invention allows high-purity 3-mercaptopropionic acid having an excellent color to be finally yielded; accordingly, by using same, a high-purity carbonic acid ester compound having an excellent color and a mercapto group can be inexpensively obtained. A thiourethane-based polymeric composition and a thiourethane-based optical material obtained by polymerizing same can likewise be inexpensively obtained by using said carbonic acid ester compound. Such carbonic acid ester compound can be used for the production of inexpensive thiourethane optical lenses; consequently, inexpensive optical lenses having an excellent color can be obtained.
The mechanism of nitric oxide formation from S-nitrosothiols (thionitrites)
作者:D. Lyn H. Williams
DOI:10.1039/cc9960001085
日期:——
S-Nitrosothiols (RSNO) are easily made by electrophilic nitrosation of thiols and are a convenient source of nitric oxide. Reaction occurs readily (in many cases) in aqueous buffer at pH 7.4 to give in addition the corresponding disulfide RSSR. If oxygen is not rigorously excluded from the solution, then the nitric oxide is converted quantitatively to nitrite ion, whereas in the absence of oxygen nitric oxide can be detected using a commercial NO-probe. Reaction, however, only occurs (apart from the photochemical pathway) if Cu2+ is present. There is often enough Cu2+ in the distilled water–buffer components to bring about reaction, but decomposition is halted if Cu2+ is complexed with EDTA. Experiments with the specific Cu+ chelator neocuproine however show that the true effective reagent is Cu+, formed by reduction of Cu2+ with thiolate ion. Kinetic experiments show that the most reactive nitrosothiols are those which can coordinate bidentately with Cu+, and there is a wide range of reactivity amongst the structures studied. Reactivity is crucially dependent on the concentrations of Cu2+ and RS–.Reaction also occurs, although somewhat more slowly, if the source of copper is the CuII complex with the tripeptide diglycyl-L-histidine (GGH) or as the CuII complex with human serum albumin (HSA). This allows the possibility that nitrosothiols could in principle generate nitric oxide in vivo using the naturally occurring sources of CuII.Rapid exchange of the NO-group in RSNO with thiols occurs, again in aqueous buffer at pH 7.4. This reaction has been established as a nucleophilic substitution reaction by the thiolate ion at the nitroso nitrogen atom.The implications of these results with regard to possible involvement of nitrosothiols in vivo are discussed.