A new O‐benzylatingreagent, that is, 4‐(4,6‐diphenoxy‐1,3,5‐triazin‐2‐yl)‐4‐benzylmorpholinium trifluoromethanesulfonate (DPT‐BM), has been developed. Benzylcationequivalents are generated from DPT‐BM by dissolving the compound in a solvent at roomtemperature under non‐acidic conditions. The benzylation of various alcohols by using a combination of DPT‐BM and magnesium oxide provided the benzyl
We studied the specific labeling of avidin with biotinylated modular ligand catalysts via MoAL, which we recently established. The labeling yield was found to depend on the linker length connecting the catalytic site to biotin in the modular ligand catalyst 1, and the maximum yield was obtained with 1d possessing octamethylene linker. The labeling reaction reached a maximum rate with only 4 equiv of the ligand catalyst. Presumably, all the subunits of avidin with homotetrameric structure formed a stable complex with 4 equiv of the catalyst because of the extremely high affinity. The ligand catalyst bound to avidin first catalyzed N-triazinylation of the e-amino group of Lys111, and the resulting regenerated catalyst then catalyzed the reaction of Asp108 and CDMT. (C) 2010 Elsevier Ltd. All rights reserved.
Primary-Amine-Specific Lactamization ofω-Amino Acids by an Artificial Cyclotransferase Based on [18]Crown-6
作者:Munetaka Kunishima、Kazuhito Hioki、Takahiro Moriya、Jun Morita、Tomoko Ikuta、Shohei Tani