Latent pH-responsive ratiometric fluorescent cluster based on self-assembled photoactivated SNARF derivatives

We have developed a self-assembled fluorescent cluster comprising a seminaphthorhodafluor (SNARF) derivative protected by a photoremovable o-nitrobenzyl group. Prior to UV irradiation, a colorless and nonfluorescent cluster was spontaneously assembled in aqueous solution. After UV irradiation, the self-assembled cluster remained intact and showed a large enhancement in pH-responsive fluorescence. The unique pH responsive fluorescent cluster could be used as a dual-emissive ratiometric fluorescent pH probe not only in the test tube but also in HeLa cell cultures.</p

Synthesis of the New Mannosidase Inhibitors, Diversity-Oriented 5-Substituted Swainsonine Analogues, via Stereoselective Mannich Reaction

5α-Substituted swainsonine analogues were synthesized by Mannich reaction of an in situ generated (−)-swainsonine iminium ion intermediate. 5α-Substituted swainsonine analogues were epimerized to their 5β-isomers in protic solvent

Synthesis of the New Mannosidase Inhibitors, Diversity-Oriented 5-Substituted Swainsonine Analogues, via Stereoselective Mannich Reaction

5α-Substituted swainsonine analogues were synthesized by Mannich reaction of an in situ generated (−)-swainsonine iminium ion intermediate. 5α-Substituted swainsonine analogues were epimerized to their 5β-isomers in protic solvent