title: 2-Amino-3-(3-hydroxy-1,2,5-thiadiazol-4-yl)propionic acid: resolution, absolute stereochemistry and enantiopharmacology at glutamate receptors.
abstract: In order to identify new subtype-selective (S)-glutamate (Glu) receptor ligands we have synthesized (RS)-2-amino-3-(3-hydroxy-1,2,5-thiadiazol-4-yl)propionic acid [(RS)-TDPA]. Resolution of (RS)-TDPA by chiral chromatography was performed using a Crownpac CR(+) column affording (R)- and (S)-TDPA of high enantiomeric purity (enantiomeric excess=99.9%). An X-ray crystallographic analysis revealed that the early eluting enantiomer has R-configuration. Both enantiomers showed high affinity as well as high agonist activity at (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors, determined using a [(3)H]AMPA binding assay and an electrophysiological model, respectively. The affinities and agonist activities obtained for (R)-TDPA (IC(50)=0.265 microM and EC(50)=6.6 microM, respectively) and (S)-TDPA (IC(50)=0.065 microM and EC(50)=20 microM, respectively) revealed a remarkably low AMPA receptor stereoselectivity, (S)-TDPA showing the highest affinity and (R)-TDPA the most potent agonist activity. In addition, (S)-TDPA was shown to interact with synaptosomal Glu uptake sites displacing [(3)H](R)-aspartic acid (IC(50 ) approximately 390 microM). An enantiospecific and subtype-selective agonist activity was observed for (S)-TDPA at group I metabotropic Glu (mGlu) receptors (EC(50)=13 microM at mGlu(5) and EC(50)=95 microM at mGlu(1)).
authors: Department of Medicinal Chemistry, NeuroScience PharmaBiotec Research Center, The Royal Danish School of Pharmacy, 2 Universitetsparken, DK-2100 Copenhagen, Denmark.
authors: Tommy N
authors: TN
authors: Johansen
authors: Yves L
authors: YL
authors: Janin
authors: Birgitte
authors: B
authors: Nielsen
authors: Karla
authors: K
authors: Frydenvang
authors: Hans
authors: H
authors: Bräuner-Osborne
authors: Tine B
authors: TB
authors: Stensbøl
authors: Stine B
authors: SB
authors: Vogensen
authors: Ulf
authors: U
authors: Madsen
authors: Povl
authors: P
authors: Krogsgaard-Larsen
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D018360:Crystallography, X-Ray; D018690:Excitatory Amino Acid Agonists / Q000737:chemistry* / Q000494:pharmacology*; D008297:Male; D011422:Propionates / Q000737:chemistry* / Q000494:pharmacology*; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley; D017470:Receptors, Glutamate / Q000187:drug effects* / Q000378:metabolism; D013237:Stereoisomerism; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism
chemical_list: C465521:2-Amino-3-(3-hydroxy-1,2,5-thiadiazol-4-yl)propionic acid; D018690:Excitatory Amino Acid Agonists; D011422:Propionates; D017470:Receptors, Glutamate