34973-28-9Relevant academic research and scientific papers
4-Alkyloxyimino-cytosine nucleotides: Tethering approaches to molecular probes for the P2Y6 receptor
Jayasekara, P. Suresh,Barrett, Matthew O.,Ball, Christopher B.,Brown, Kyle A.,Kozma, Eszter,Costanzi, Stefano,Squarcialupi, Lucia,Balasubramanian, Ramachandran,Maruoka, Hiroshi,Jacobson, Kenneth A.
, p. 1156 - 1165 (2013/08/23)
4-Alkyloxyimino derivatives of pyrimidine nucleotides display high potency as agonists of certain G protein-coupled P2Y receptors (P2YRs). In an effort to functionalize a P2Y6R agonist for fluorescent labeling, we probed two positions (N4 and γ-phosphate of cytidine derivatives) with various functional groups, including alkynes for click chemistry. Functionalization of extended imino substituents at the 4 position of the pyrimidine nucleobase of CDP preserved P2Y6R potency generally better than γ-phosphoester formation in CTP derivatives. Fluorescent Alexa Fluor 488 conjugate 16 activated the human P2Y6R expressed in 1321N1 human astrocytoma cells with an EC50 of 9 nM, and exhibited high selectivity for this receptor over other uridine nucleotide-activated P2Y receptors. Flow cytometry detected specific labeling with 16 to P2Y 6R-expressing but not to wild-type 1321N1 cells. Additionally, confocal microscopy indicated both internalized 16 (t1/2 of 18 min) and surface-bound fluorescence. Known P2Y6R ligands inhibited labeling. Theoretical docking of 16 to a homology model of the P2Y6R predicted electrostatic interactions between the fluorophore and extracellular portion of TM3. Thus, we have identified the N4-benzyloxy group as a structurally permissive site for synthesis of functionalized congeners leading to high affinity molecular probes for studying the P2Y6R.
Pyrimidine ribonucleotides with enhanced selectivity as P2Y6 receptor agonists: Novel 4-alkyloxyimino, (S)-methanocarba, and 5′-triphosphate γ-ester modifications
Maruoka, Hiroshi,Barrett, Matthew O.,Ko, Hyojin,Tosh, Dilip K.,Melman, Artem,Burianek, Lauren E.,Balasubramanian, Ramachandran,Berk, Barkin,Costanzi, Stefano,Harden, T. Kendall,Jacobson, Kenneth A.
experimental part, p. 4488 - 4501 (2010/10/21)
The P2Y6 receptor is a cytoprotective G-protein-coupled receptor (GPCR) activated by UDP (EC50 = 0.30 μM). We compared and combined modifications to enhance P2Y6 receptor agonist selectivity, including ribose ring constraint, 5-iodo and 4-alkyloxyimino modifications, and phosphate modifications such as α,β-methylene and extension of the terminal phosphate group into γ-esters of UTP analogues. The conformationally constrained (S)-methanocarba-UDP is a full agonist (EC 50 = 0.042 μM). 4-Methoxyimino modification of pyrimidine enhanced P2Y6, preserved P2Y2 and P2Y4, and abolished P2Y14 receptor potency, in the appropriate nucleotide. N 4-Benzyloxy-CDP (15, MRS2964) and N4-methoxy-Cp 3U (23, MRS2957) were potent, selective P2Y6 receptor agonists (EC50 of 0.026 and 0.012 μM, respectively). A hydrophobic binding region near the nucleobase was explored with receptor modeling and docking. UTP-γ-aryl and cycloalkyl phosphoesters displayed only intermediate P2Y6 receptor potency but had enhanced stability in acid and cell membranes. UTP-glucose was inactive, but its (S)-methanocarba analogue and N4-methoxycytidine 5′-triphospho-γ-[1]glucose were active (EC50 of 2.47 and 0.18 μM, respectively). Thus, the potency, selectivity, and stability of pyrimidine nucleotides as P2Y6 receptor agonists may be enhanced by modest structural changes.
