Photomodulation of G Protein-Coupled Adenosine Receptors by a Novel Light-Switchable Ligand
摘要:
The adenosinergic system operates through G protein-coupled adenosine receptors, which have become promising therapeutic targets for a wide range of pathological conditions. However, the ubiquity of adenosine receptors and the eventual lack of selectivity of adenosine-based drugs have frequently diminished their therapeutic potential. Accordingly, here we aimed to develop a new generation of light-switchable adenosine receptor ligands that change their intrinsic activity upon irradiation, thus allowing the spatiotemporal control of receptor functioning (i.e., receptor activation/inactivation dependent on location and timing). Therefore, we synthesized an orthosteric, photoisomerizable, and nonselective adenosine receptor agonist, nucleoside derivative MRS5543 containing an aryl diazo linkage on the N6 substituent, which in the dark (relaxed isomer) behaved as a full adenosine A(3) receptor (A(3)R) and partial adenosine A(2A) receptor (A(2A)R) agonist. Conversely, upon photoisomerization with blue light (460 nm), it remained a full A3R agonist but became an A(2A)R antagonist. Interestingly, molecular modeling suggested that structural differences encountered within the third extracellular loop of each receptor could modulate the intrinsic, receptor subtype-dependent, activity. Overall, the development of adenosine receptor ligands with photoswitchable activity expands the pharmacological toolbox in support of research and possibly opens new pharmacotherapeutic opportunities.
Adenosine Analogues as Inhibitors of Trypanosoma brucei Phosphoglycerate Kinase: Elucidation of a Novel Binding Mode for a 2-Amino-N6-Substituted Adenosine
摘要:
As part of a project aimed at structure-based design of adenosine analogues as drugs against African trypanosomiasis, N-6-, 2-amino-N-6-, and N-2-substituted adenosine analogues were synthesized and tested to establish structure-activity relationships for inhibiting Trypanosoma brucei glycosomal phosphoglycerate kinase (PGK), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and glycerol-3-phosphate dehydrogenase (GPDH). Evaluation of X-ray structures of parasite PGK, GAPDH, and GPDH complexed with their adenosyl-bearing substrates led us to generate a series of adenosine analogues which would target all three enzymes simultaneously. There was a modest preference by PGK for NG-substituted analogues bearing the 2-amino group. The best compound in this series, 2-amino-N-6-[2 "-(p-hydroxyphenyl)ethyl]adenosine (46b), displayed a 23-fold improvement over adenosine with an IC50 of 130 muM. 2-[[2 "-(p-Hydroxyphenyl)ethyl]amino]adenosine (46c) was a weak inhibitor of T. brucei PGK with an IC50 of 500 muM. To explore the potential of an additive effect that having the N-6 and N-2 substitutions in one molecule might provide, the best ligands from the two series were incorporated into N-6,N-2-disubstituted adenosine analogues to yield N-6-(2 " -phenylethyl)-2-[(2 " -phenylethyl)amino]adenosine (69) as a 30 muM inhibitor of T. brucei PGK which is 100-fold more potent than the adenosine template. In contrast, these series gave no compounds that inhibited parasitic GAPDH or GPDH more than 10-20% when tested at 1.0 mM. A 3.0 Angstrom X-ray structure of a T, brucei PGK/46b complex revealed a binding mode in which the nucleoside analogue was flipped and the ribosyl moiety adopted a syn conformation as compared with the previously determined binding mode of ADP. Molecular docking experiments using QXP and SAS program suites reproduced this "flipped and rotated" binding mode.
[EN] POLYMERIC HYPERBRANCHED CARRIER-LINKED PRODRUGS<br/>[FR] PROMÉDICAMENTS LIÉS À DES EXCIPIENTS POLYMÉRIQUES HYPERBRANCHÉS
申请人:ASCENDIS PHARMA AS
公开号:WO2013024048A1
公开(公告)日:2013-02-21
The present invention relates to water-soluble carrier-linked prodrugs of formula (I),wherein POL is a polymeric moiety,each Hyp is independently a hyperbranched moiety,each moiety SP is independently a spacer moiety, each L is independently a reversible prodrug linker moiety, m is 0 or 1, each n is independently an integer from 2 to 200 and each x is independently 0 or 1. It further relates to pharmaceutical compositions comprising said water- soluble carrier-linked prodrugs and methods of treatment.
[EN] HIGH-LOADING WATER-SOLUBLE CARRIER-LINKED PRODRUGS<br/>[FR] PROMÉDICAMENTS LIÉS À DES EXCIPIENTS HYDROSOLUBLES DE FORTE CHARGE
申请人:ASCENDIS PHARMA AS
公开号:WO2013024047A1
公开(公告)日:2013-02-21
The present invention relates to water-soluble carrier-linked prodrugs of formula (I), wherein B, A and Hyp form the carrier, B is a branching core, each A is independently a poly(ethylene glycol)-based polymeric chain, each Hyp is independently a branched moiety, each SP is independently a spacer moiety, each L is independently a reversible prodrug linker moiety, each D is independendly a biologically active moiety, each x is independently 0 or 1, each m is independently an integer of from 2 to 64, n is an integer from 3 to 32; or the pharmaceutically acceptable salt thereof. It further relates to pharmaceutical compositions comprising said water-soluble carrier-linked prodrugs, their use asmedicament or diagnostic, and methods of treatment.
[EN] PROTEIN CARRIER-LINKED PRODRUGS<br/>[FR] PROMÉDICAMENTS LIÉS À UN EXCIPIENT PROTÉIQUE
申请人:ASCENDIS PHARMA AS
公开号:WO2013024049A1
公开(公告)日:2013-02-21
The present invention relates to water-soluble protein carrier- linked prodrugs wherein the protein carrier comprises an amino acid sequence consisting of at least 100 amino acid residues forming random coil conformation and comprising alanine, serine and proline residues. It further relates to pharmaceutical compositions comprising said water-soluble protein carrier- linked prodrugs, their use as a medicament as well as methods of treatment and administration.
[EN] HYDROGEL-LINKED PRODRUGS RELEASING MODIFIED DRUGS<br/>[FR] PROMÉDICAMENTS LIÉS À UN HYDROGEL LIBÉRANT DES MÉDICAMENTS MODIFIÉS
申请人:ASCENDIS PHARMA AS
公开号:WO2014173759A1
公开(公告)日:2014-10-30
The present invention relates to a process for the preparation of a hydrogel-linked prodrug releasing a tag moiety-bio logically active moiety conjugate, to a hydrogel-linked prodrug releasing a tag moiety-bio logically active moiety conjugate obtainable by such process, to pharmaceutical compositions comprising said prodrug and their use as a medicament.
Methods for protecting tissues and organs from ischemic damage
申请人:Gensia, Inc.
公开号:US05573772A1
公开(公告)日:1996-11-12
Methods for protecting tissues and organs including the heart central nervous system, and kidney from ischemic damage are described and claimed based upon the recognition that protection against infarction is mediated by A3 rather than A1 adenosine receptors, as was previously thought, and that the receptor mediating protection in other organs and tissues has not been defined. Methods for selectively stimulating A3 adenosine receptors are described and claimed, as such selection is shown to prevent or substantially reduce cell death resulting from ischemia with or without reperfusion in humans. According to this invention, the A3 adenosine receptor is selectively stimulated by administering a compound which is an A3 adenosine receptor-selective agonist. Prevention of tissue death is also achieved by administering a compound which is a non-selective adenosine receptor agonist together with compounds that act as antagonists to the A1 and A2 adenosine receptor.