Moenomycin-type transglycosylase inhibitors: Inhibiting activity vs. topology around the phosphoric acid diester group

Combined Fmoc-Alloc strategy for a general SPPS of phosphoserine peptides; preparation of phosphorylation-dependent tau antisera

A block method for the solid phase synthesis (SPPS) of serine phosphopeptides has been developed using a combination of Fmoc and Alloc strategies. Alloc-Ser[PO(OCH2CH CH2)2] OH2, prepared in a one pot procedure from Alloc-Ser-OH, was introduced at the N-terminus of a sequence prepared by standard Fmoc-SPPS. Global cleavage of the allyl ester based protecting groups, followed by coupling of a tripeptide fragment, led to the tau phosphopeptide, 1. Using tau phosphopeptides a series of phosphorylation state-dependent antisera to human tau protein have been raised. These antisera are valuable tools for studying the tau protein which is found in an abnormal, hyperphosphorylated form in Alzheimer's disease brain.

Ceramide-1-phosphate sugars: new types of glycophospholipids

Ceramide-1-phosphate sugars were synthesized by direct glycosyl phosphite/phosphate and O-glycosyl trichloroacetimidate/phosphate exchange reactions, respectively. Thus, ceramide-1-O-phosphoric acid 5 gave with sialyl phosphite 1 as sialyl donor directly beta-linked sialyl phosphate 6; deprotection afforded the corresponding glycophospholipid ceramide-1-phosphate N-acetylneuraminate 7. Similarly, from O-glucosyl- and O-galactosyltrichloroacetimidate 10 and 13 with phosphoric acid derivative 5 glycosyl ceramide-1-phosphate sugars 12 and 15, respectively, were obtained.