title: Armed-disarmed effect on the stability of cysteine thioglucosides.
abstract: Thioglucosides of cysteine show variable stability depending on the nature of the protecting groups on the glycosyl donor. Armed protecting groups (benzyl) lead to products that decompose readily while disarmed protecting groups (acetyl) lead to more stable products. Since this armed/disarmed effect of the protecting group on the stability of the thioglucosides is more pronounced for cysteine with an unprotected carboxylic group, the proposed mechanism is that decomposition is initiated by an intramolecular protonation of glycosyl sulfide and subsequent displacement of the sulfide by adventitious nucleophiles.
authors.affiliation: Department of Chemistry, Tshwane University of Technology, Pretoria 0001, South Africa. nokwequmg@tut.ac.za
authors.forename: Mbulelo G
authors.initials: MG
authors.lastname: Nokwequ
authors.forename: Comfort M
authors.initials: CM
authors.lastname: Nkambule
authors.forename: David W
authors.initials: DW
authors.lastname: Gammon
mesh_terms: D003545:Cysteine / Q000737:chemistry*; D004355:Drug Stability; D013237:Stereoisomerism; D013863:Thioglucosides / Q000737:chemistry*
chemical_list: D013863:Thioglucosides; D003545:Cysteine