%0 Journal Article
%T Building photoswitchable 3,4'-AMPB peptides: Probing chemical ligation methods with reducible azobenzene thioesters
%A Gehad Zeyat
%A Karola R¨¹ck-Braun
%J Beilstein Journal of Organic Chemistry
%D 2012
%I 
%R 10.3762/bjoc.8.101
%X Photoswitchable peptides were synthesized by using cysteine- and auxiliary-based native chemical ligation reactions. For this purpose, the two regioisomeric azobenzene building blocks 3,4'-AMPB thioester 1b and 4,4'-AMPB thioester 2b were employed in the ligation reactions. While 4,4'-AMPB requires the 4,5,6-trimethoxy-2-mercaptobenzyl auxiliary to minimize reduction of the diazene unit, 3,4'-AMPB can be used in combination with the 4,5,6-trimethoxy-2-mercaptobenzyl auxiliary as well as the N¦Á-2-mercaptoethyl auxiliary. Thus, 3,4'-AMPB derivatives/peptides proved to be significantly less prone to reduction by aliphatic and aromatic thiols than were the 4,4'-AMPB compounds.
%K acyl transfer auxiliary
%K azobenzenes
%K ligation
%K molecular switches
%K peptides
%K redox chemistry
%U http://dx.doi.org/10.3762/bjoc.8.101