Evaluation of a 7-Methoxycoumarin-3-carboxylic Acid Ester Derivative as a Fluorescent, Cell-Cleavable, Phosphonate Protecting Group.

ABSTRACT: Cell-cleavable protecting groups often enhance cellular delivery of species that are charged at physiological pH. Although several phosphonate protecting groups have achieved clinical success, it remains difficult to use these prodrugs in live cells to clarify biological mechanisms. Here, we present a strategy that uses a 7-methoxycoumarin-3-carboxylic acid ester as a fluorescent protecting group. This strategy was applied to synthesis of an (E)-4-hydroxy-3-methyl-but-2-enyl diphosphate (HMBPP) analogue to assess cellular uptake and human V?9V?2 T?cell activation. The fluorescent ester displayed low cellular toxicity (IC50 >100 ?m) and strong T cell activation (EC50 =0.018 ?m) relative to the unprotected anion (EC50 =23 ?m). The coumarin-derived analogue allowed no-wash analysis of biological deprotection, which revealed rapid internalization of the prodrug. These results demonstrate that fluorescent groups can be applied both as functional drug delivery tools and useful biological probes of drug uptake.

SUBMITTER: Wiemer AJ 

PROVIDER: S-EPMC4746711 | biostudies-other | 2016 Jan

REPOSITORIES: biostudies-other