Design, Synthesis, and Bioactivation of O-Glycosylated Prodrugs of the Natural Nitric Oxide Precursor Nω-Hydroxy-l-arginine
摘要:
Naturally occurring N-omega-hydroxy-L-arginine (NOHA, 1) is the best substrate of NO synthases (NOS). The development of stable and bioavailable prodrugs would provide a pharmacologically valuable strategy for the treatment of cardiovascular diseases that are associated with endothelial dysfunction. To improve NOHAs druglike properties, we demonstrate that O-substitution by (glycosylic) acetal formation greatly increased the chemical stability of the hydroxyguanidine moiety and provided a nontoxic group that could be easily bioactivated by glycosidases. A straightforward synthetic concept was devised and afforded a series of diversely substituted prodrugs by O-conjugation of the hydroxyguanidine moiety with different monosaccharides. Systematic exploration of their bioactivation profile revealed that glucose-based prodrugs were more efficiently bioactivated than their galactose counterparts. NOS-dependent cytosolic NO release was quantified by automated fluorescence microscopy in a cell-based assay with murine macrophages. Glucose-based prodrugs performed particularly well and delivered cellular NO levels comparable to 1, demonstrating proof-of-concept.
The Use of Differential Receptors to Pattern Peptide Phosphorylation
作者:Tianzhi Zhang、Nicola Y. Edwards、Marco Bonizzoni、Eric V. Anslyn
DOI:10.1021/ja9041675
日期:2009.8.26
the receptors, three metal ions and three pH indicators are used to create a suite of 45 indicator displacement assays. The colorimetric data from the 45 sensing ensembles is collected in a 96-well plate reader, and linear discriminant analysis gives patterns resulting in 100% classification of the peptides. The approach demonstrates a generalizable principle to create pattern-basedrecognition protocols
Synthesis of protected guanidinium linked dinucleoside incorporable into an oligonucleotide using solid phase DNA methodology
作者:Dinesh A. Barawkar、Barry Linkletter、Thomas C. Bruice
DOI:10.1016/s0960-894x(98)00251-0
日期:1998.6
The synthesis of novel fully protected guanidinium linked dinucleoside for incorporation into oligonucleotide using solid-phase DNA synthesis methodology was developed. The three different protecting groups selected allow different deprotection conditions.
A nine-step (!) solid-phase synthesis and subsequent cleavage with cyclization from the polymeric support were the keys to preparing high-quality molecular libraries of thiazolylhydantoines 1 from modified amino acid building blocks. Each step in the synthesis is different. Because the final cyclization cleaves only molecules that have been successfully constructed, the products obtained are pure. R1 , R2 =alkyl; R3 =aryl, arylO; R4 =allyl.