Evaluation of a 7-Methoxycoumarin-3-carboxylic Acid Ester Derivative as a Fluorescent, Cell-Cleavable, Phosphonate Protecting Group.
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 Vγ9Vδ2 T cell activation. The fluorescent ester displayed low cellular toxicity (IC50 >100 μm) and strong T cell activation (EC50 =0.018 μm) relative to the unprotected anion (EC50 =23 μm). 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.
['Wiemer|Andrew J|AJ|', 'Shippy|Rebekah R|RR|', 'Kilcollins|Ashley M|AM|', 'Li|Jin|J|', 'Hsiao|Chia-Hung Christine|CH|', 'Barney|Rocky J|RJ|', 'Geng|M Lei|ML|', 'Wiemer|David F|DF|']
D003374:Coumarins D004305:Dose-Response Relationship, Drug D005456:Fluorescent Dyes D006801:Humans D020014:K562 Cells D015394:Molecular Structure D063065:Organophosphonates D013329:Structure-Activity Relationship D013601:T-Lymphocytes
prodrugs antigens butyrophilin coumarin phosphorus