1.Chiral resolution and stereospecificity of 6-phenyl-4-phenylethynyl- 1,4-dihydropyridines as selective A(3) adenosine receptor antagonists.
Jiang J1, Li AH, Jang SY, Chang L, Melman N, Moro S, Ji X, Lobkovsky EB, Clardy JC, Jacobson KA. J Med Chem. 1999 Aug 12;42(16):3055-65.
Racemic 6-phenyl-4-phenylethynyl-1,4-dihydropyridine derivatives have been shown to be highly selective A(3) adenosine receptor antagonists (Jiang et al. J. Med. Chem. 1997, 40, 2596-2608). Methods for resolving the optical isomers at the C4 position, involving selective crystallization or chromatographic separation of diastereomeric ester derivatives, have been developed. Optically pure glycerol and threitol derivatives were used as chiral auxiliary groups for ester formation at the 3-position, resulting in diastereomeric mixtures of dihydropyridines. Esterification of a 6-phenyl-4-phenylethynyl-1,4-dihydropyridine derivative at the 3-position with a chiral, protected glycerol moiety, (S)-(+)-2, 2-dimethyl-1,3-dioxolane-4-methanol, allowed the selective crystallization of a pure diastereomer, 9. The (1)H NMR spectrum of 9 using the lanthanide shift reagent Eu(fod)(3) indicated optical purity, and the (4S,2'R)-configuration was assigned using X-ray crystallography.
2.Rigid Dipeptide Mimics: Synthesis of Enantiopure 5- and 7-Benzyl and 5,7-Dibenzyl Indolizidinone Amino Acids via Enolization and Alkylation of delta-Oxo alpha,omega-Di-[N-(9-(9-phenylfluorenyl))amino]azelate Esters.
Polyak F1, Lubell WD. J Org Chem. 1998 Aug 21;63(17):5937-5949.
Azabicyclo[X.Y.0]alkane amino acids are tools for constructing mimics of peptide structure and templates for generating combinatorial libraries for drug discovery. Our methodology for synthesizing these conformationally rigid dipeptides has been elaborated such that alkyl groups can be appended onto the heterocycle to generate mimics of peptide backbone and side-chain structure. Inexpensive glutamic acid was employed as chiral educt in a Claisen condensation/ketone alkylation/reductive amination/lactam cyclization sequence that furnished alkyl-branched azabicyclo[4.3.0]alkane amino acid. Enantiopure 5-benzyl-, 7-benzyl-, and 5,7-dibenzylindolizidinone amino acids 2-4 were stereoselectively synthesized via efficient reaction sequences featuring the alkylation of di-tert-butyl alpha,omega-di-[N-(PhF)amino]azelate delta-ketone 5. A variety of alkyl halides were readily added to the enolate of ketone 5 to provide mono- and dialkylated ketones 6 and 7.
3.Microdetermination of bioethanomethrin.
George DA, McDonough LM. J Assoc Off Anal Chem. 1975 Jul;58(4):781-4.
A microanalytical method was developed for the determination of the experimental synthetic pyrethroid insecticide Bioethanomethrin ((5-benzyl-3-furyl) methyl trans-(+)-3-(cyclopentylidenemethyl) -2,2-dimethylcyclopropanecarboxylate). After saponification, trichloroacetyl chloride is used to form an ester from the acid moiety. Infrared and mass spectral data support the expected structures of the derivatives formed. Nanogram sensitivity is realized by utilizing a gas chromatograph with an electron capture detector.
4.Adenosine receptor, protein kinase G, and p38 mitogen-activated protein kinase-dependent up-regulation of serotonin transporters involves both transporter trafficking and activation.
Zhu CB1, Hewlett WA, Feoktistov I, Biaggioni I, Blakely RD. Mol Pharmacol. 2004 Jun;65(6):1462-74.
Serotonin (5-hydroxytryptamine; 5-HT) transporters (SERTs) are critical determinants of synaptic 5-HT inactivation and the targets for multiple drugs used to treat psychiatric disorders. In support of prior studies, we found that short-term (5-30 min) application of the adenosine receptor (AR) agonist 5'-N-ethylcarboxamidoadenosine (NECA) induces an increase in 5-HT uptake Vmax in rat basophilic leukemia 2H3 cells that is enhanced by pretreatment with the cGMP phosphodiesterase inhibitor sildenafil. NECA stimulation is blocked by the A3 AR antagonist 3-ethyl-5-benzyl-2-methyl-phenylethynyl-6-phenyl-1,4(+/-)dihydropyridine-3,5-dicarboxylate (MRS1191), by the phospholipase C inhibitor 1-(6-[[17beta-3-methoxyestra-1,3,5(10)-trien-17-yl] amino]hexyl)-1H-pyrrole-2,5-dione (U73122), by the intracellular Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester, and by the guanyl cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one.
