Journal of Glycobiology
Open Access

Glycolipids and glycopeptides: Minimally competent Lewis acid catalysis produces surfactants for use ex vivo and in vivo

Glycobiology World Congress

August 10-12, 2015 Philadelphia, USA

Robin Polt

Posters-Accepted Abstracts: J Glycobiol

Abstract :

Use of minimally competent main group Lewis acids such as InBr3 and Bi (OSO2CF3)3 permit the formation of glycosides
in high yield and purity from simple sugar per-acetates at room temperature or above with remarkable �?±/�?²-selectivity.
Classical reactions rely on very reactive glycosyl donors in conjunction with metal promoters (Hg++, Ag+ etc). Newer methods
have used trichloroacetimidates and strong Bronsted or Lewis acids or thioglycosides in conjunction with oxidative or
thiophilic activators. Use of the more stable glycosyl per acetates in conjunction with stoichiometric amounts of strong Lewis
acids (BF3.Et2O, FeBr3 etc) has been explored with limited success. The use of â�?�?minimally competentâ�? Lewis acids has allowed
us to perform glycosidation reactions with catalytic amounts of InBr3 or Bi (OTfl)3 well above room temperature and without
significant decomposition of the glycoside products. We will discuss the exploitation of these methods to produce glycolipid
surfactants from renewable resources as well as glycopeptide drugs that penetrate the blood-brain barrier (BBB). These
â�?�?biousian glycopeptidesâ�? are not subject to â�?�?Lipinskiâ�?�?s rulesâ�? that would otherwise eliminate them as CNS drug candidates.
Glycosylated amphipathic helices or â�?�?address segmentsâ�? have been used to target G-protein coupled receptors (GPCRs) in
the brain after intravenous administration. The addition of glycosides to endogenous peptide neurotransmitters and peptide
hormones imparts favorable pharmacokinetic and pharmacodynamics (PK/PD) properties and enables penetration of the BBB
which is not constrained by molecular weight.