[EN] SYNTHESIS OF A PEG-6 MOIETY FROM COMMERCIAL LOW-COST CHEMICALS<br/>[FR] SYNTHÈSE D'UNE FRACTION DE PEG-6 À PARTIR DE PRODUITS CHIMIQUES INDUSTRIELS À FAIBLE COÛT
申请人:GE HEALTHCARE LTD
公开号:WO2009108484A1
公开(公告)日:2009-09-03
The present invention provides novel synthesis's for obtaining a protecting group aminoxy PEG-6 linker from cost effective, and readily available starting materials and chemicals or modified polyethylene glycols. More specifically, a novel synthesis of obtaining a modified Boc-protected aminoxy PEG-6 linker was achieved so that said linker may be attached to a vector such as a peptide based fragment.
To investigate the formation process of high carbon number (>C32) sedimentary porphyrins, heating experiments of several porphyrins were performed. Chromic acid oxidation of the heating products of protoporphyrin IX dimethyl ester afforded 2-methyl-3-n-propylmaleimide as the predominant product among the side-chain extension products formed. On the other hand, saturated substituents of etioporphyrin were also extended on heating to slowly form normal and branched homologs. These results may suggest that the transalkylation of porphyrin side chains proceeds mainly by a regioselective mechanism involving alkyl radical addition to a vinyl group of chlorophylls or their diagenetic products.
Maleimide index: a paleo-redox index based on fragmented fossil-chlorophylls obtained by chromic acid oxidation
作者:Kenta Asahina、Satoshi Takahashi、Ryosuke Saito、Kunio Kaiho、Yasuhiro Oba
DOI:10.1039/d2ra04702k
日期:——
understanding paleo-environmental changes. Fossilized chlorophylls present in sedimentary rocks can be detected by their conversion into maleimides and phthalimides. This can be achieved through the chromic acid oxidation of sedimentary rocks. Since the maleimides and phthalimides are derived from the pyrrole skeleton of fossil chlorophylls, their composition reflects the composition of paleo-photosynthetic