Development of Potent μ-Opioid Receptor Ligands Using Unique Tyrosine Analogues of Endomorphin-2
摘要:
Six analogues of tyrosine, which contained alkyl groups at positions 2', 3', and 6', either singly or in combination on the tyramine ring, were investigated for their effect on the opioid activity of [Xaa(1)]endomorphin-2 (EM-2). The opioid analogues displayed the following characteristics: (i) high mu-opioid receptor affinity [K-i(mu) = 0.063-2.29 nM] with selectivity [K-i(delta)/Ki(mu)] ranging from 46 to 5347; (ii) potent functional mu-opioid agonism [GPI assay (IC50 = 0.623-0.924 nM)1 and with a correlation between delta-opioid receptor affinities and functional bioactivity using MVD; (iii) intracerebroventricular administration of [Dmt(1)]- (14) and [Det(1)]EM-2 (10) produced a dose-response antinociception in mice, with the former analogue more active than the latter; and (iv) a marked shift occurred from the trans-orientation at the Tyr(1)-Pro(2) bond to a cis-conformer compared to that observed previously with [Dmt(1)]EM-2 (14) (Okada et al. Bioorg. Med. Chem. 2003, 11, 1983-1984) except [Mmt(1)]EM-2 (7). The active profile of the [Xaa(1)]EM-2 analogues indicated that significant modifications on the tyramine ring are possible while high biological activity is maintained.
A process for making 2,6-disubstituted tyrosine by the noble metal coupling of a disubstituted aromatic halide or diazonium salt with an amino-protected 2-aminoacrylic acid to form a (Z)-.beta.-(disubstituted phenyl)-.alpha.-acylaminoacrylate, and asymmetrically hydrogenating the acrylate to produce the 2,6-disubstituted tyrosine.
Gas-chromatographic identification of products formed in iodination of methyl phenols by retention indices
作者:I. V. Gruzdev、I. M. Kuzivanov、I. G. Zenkevich、B. M. Kondratenok
DOI:10.1134/s1070427212090108
日期:2012.9
Iodination reaction followed by conversion of iodine-substituted methylphenols to the corresponding trifluoroacetates was suggested for improving the sensitivity of the gas-chromatographic determination of phenol and its methyl-substituted derivatives (al isomers of mono-and diethylphenols, 2,3,5-, 2,3,6-, and 3,4,5-trimethylphenols) in aqueous media. Acylation products of iodo methylphenols (104 compounds) were identified by linear-logarithmic retention indices on a standard nonpolar polydimethylsiloxane stationary phase, and the pattern of their variation with the number and nature of substituents were characterized. A procedure for identification of methyl-substituted phenols in water in their gas-chromatographic determination with an electron-capture detector was developed.
Synthesis of some new hindered biaryls
作者:Harry W. Gibson、F. C. Bailey
DOI:10.1021/jo00865a033
日期:1976.2
GIBSON H. W.; BAILEY F. C., J. ORG. CHEM. <JOCE-AH>, 1976, 41, NO 3, 557-560