Synthesis of a Bioreversibly Masked Lipophilic Adenosine Diphosphate Ribose Derivative

Abstract

The design of a bioreversibly protected lipophilic sugar nucleotide as a potential membrane-permeable precursor of adenosine diphosphate ribose (ADPR) is described. ADPR is the most potent activator of the transient receptor potential melastatin 2 (TRPM2) ion channel. Membrane-permeable, lipophilic derivatives of ADPR are of great interest as tools for study of the mechanism of TRPM2. The approach described here was based on our recently disclosed "DiPPro" and "TriPPPro" prodrug approaches developed for the intracellular delivery of nucleotides. A lipophilic, bioreversibly masked ADPR analogue containing an enzymatically cleavable 4-pentanoyloxybenzyl (PB) mask at the phosphate moiety next to the 5'-position of adenosine, together with O-acetyl groups, was prepared in high yields. Chemical and enzymatic hydrolysis studies in phosphate buffer (pH 7.3) were performed to assess chemical stability and possible (selective) enzymatic demasking of the ADPR analogue. HPLC-MS revealed that the PB group was readily cleaved enzymatically. In addition, the formation of partially deacetylated ADPR compounds and also of fully unprotected ADPR was observed.

Chemo-enzymatic synthesis of the exocyclic olefin isomer of thymidine monophosphate

“…Phosphorylation of compound 10 proved to be challenging with POCl 3 38 or (H 3 CO) 3 P 39 reagents due to varying degrees of isomerization under different reaction conditions. It is possible that strategies based on other P(III) reagents 40 still could be employed to accomplish a chemical formation of the desired monophosphate, but we turned to enzymatic methods instead. When an enzymatic reaction was attempted, phosphorylation of compound 10 was achieved by a pyrimidine kinase to obtain the desired compound 2 in high yield.…”

Prodrugs of pyrophosphates and bisphosphonates: disguising phosphorus oxyanions

“…45 Lastly Pahnke and Meier used a 4-pentanoyloxybenzyl group to mask adenosine diphosphate ribose (ADPR) 24 , a potent activator of the TRPM2 ion channel. 46 This protection was shown to be reversible in a solution containing pig liver esterase.…”

Membrane-Permeable Octanoyloxybenzyl-Masked cNMPs as Novel Tools for Non-Invasive cell Assays

“…[14] Further, the concept was expanded on compound classes like sugar nucleotides. [18] The broad synthetic applicability of the AB masking group is complimented by meeting the essential features of a prodrug concept: i) high chemical stability, ii) efficient enzymatic activation and iii) sufficient lipophilicity to enable the passage through cell membranes. Moreover, the two-part composition of the AB-masks allows variation of e.g lipophilicity or enzymatic cleavability which adds further versatility to the concept.…”