Synthesis of C-Linked Triazole-Containing AFGP Analogues and Their Ability to Inhibit Ice Recrystallization
摘要:
C-Linked antifreeze glycoprotein (C-AFGP) analogues have been shown to have potent ice recrystallization inhibition (IRI) activity. However, the lengthy synthesis of these compounds is not amenable to large-scale preparation for the many commercial, industrial, and medical applications that exist. This paper describes the synthesis of triazole-containing AFGPs using a convergent solid-phase synthesis (SPS) approach in which multiple carbohydrate derivatives are coupled to a resin-bound synthetic peptide in a single step. Modified "Click" conditions using dry DMF as solvent with catalytic Cu(II), sodium ascorbate, and microwave radiation afforded the synthesis of AFGP analogues 9-12 in 16-54% isolated yield. Compound 9 demonstrated no IRI activity, while compounds 10, 11, and 12 were moderate inhibitors of ice recrystallization. These results suggest that, while the triazole group is a structural mimetic of an amide bond, the amide bond in C-AFGP analogue 3 is an essential structural feature necessary for potent IRI activity.
We present the first synthesis of calix[4]arene-based S-glycoclusters via photoinduced multiple thiolâene coupling of tetra- and octa-allyl calix[4]arenes with peracetylated glucosyl thiol (67â88% yields). Moreover we describe the dual clustering at the upper and lower rim of a calix[4]arene with two different sugars (galactose and glucose) via sequential copper(I)-catalyzed azideâalkyne cycloaddition and photoinduced thiolâene coupling.