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

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

  • Chembiochem. 2016 Jan 1;17(1):52-5. doi: 10.1002/cbic.201500484.
Andrew J Wiemer 1 Rebekah R Shippy 2 Ashley M Kilcollins 3 Jin Li 1 Chia-Hung Christine Hsiao 1 Rocky J Barney 4 M Lei Geng 5 David F Wiemer 6
Affiliations

Affiliations

  • 1 Department of Pharmaceutical Sciences, Institute for Systems Genomics, University of Connecticut, 69 N. Eagleville Rd Unit 3092, Storrs, CT, 06269, USA.
  • 2 Department of Chemistry, University of Iowa, E531 Chemistry Building, Iowa City, IA, 52242, USA.
  • 3 Department of Physiology and Neurobiology, University of Connecticut, 75 N. Eagleville Rd Unit 3156, Storrs, CT, 06269, USA.
  • 4 Department of Chemistry, Western Wyoming Community College, 1204-A, Rock Springs, WY, 82901, USA.
  • 5 Department of Chemistry, Optical Science and Technology Center, University of Iowa, 330 IATL, Iowa City, IA, 52242, USA.
  • 6 Department of Chemistry, University of Iowa, E531 Chemistry Building, Iowa City, IA, 52242, USA. david-wiemer@uiowa.edu.
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 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.

Keywords

antigens; butyrophilin; coumarin; phosphorus; prodrugs.

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