Facile syntheses of 3-halo and mixed 3,5-dihalo analogues of N-acetyl-l-tyrosine via sulfonic acid-catalysed regioselective monohalogenation
摘要:
The combination of catalytic amounts of p-toluenesulfonic acid and 1 equiv of N-halosuccinimide afforded highly selective ring-halogenation of N-acetyl-L-tyrosine, furnishing either N-acetyl-3-halo-L-tyrosine analogues or mixed 3,5-dihalo derivatives in a one-pot reaction with excellent yields at room temperature. (C) 2008 Elsevier Ltd. All rights reserved.
inhibitor of angiotensin I converting enzyme (K-13) has been synthesized from N-acetyl-3,5-dichloro-L-tyrosyl-O-benzyl-L-tyrosyl-3,5-diiodo-L-tyrosine methyl ester, whose oxidation with thallium trinitrate (TTN) as a key step followed by zinc reduction affords the corresponding diphenyl ether with the same heterocyclic skelton as that of K-13, indicating that K-13 is biosynthesized from three molecules of
Method for determination of likelihood of occurrence of preterm labor in pregnant females
申请人:Woods James
公开号:US20060166295A1
公开(公告)日:2006-07-27
The presence of 3-chlorotyrosine in vaginal secretions in a predictor of the likelihood preterm premature rupture of the fetal membranes, i.e., the chorioamnion and/or the occurrence of the risk of preterm labor. 3-chlorotyrosine is a marker for the excessive production of hypochlorous acid which causes focal areas of increased collagen destruction in the chorioamnion, preterm premature rupture of membranes, or increased production of postaglandin and preterm labor. The inventive method comprises determining the likelihood of the occurrence of preterm premature rupture of membranes or increased production of postaglandin and preterm labor in a pregnant female by obtaining a sample of the females vaginal secretions, and analyzing the secretions for the presence and amount of 3-chlorotyrosine in the sample. Various antibody-based tests can be used to measure 3-chlorotyrosine, and a number of neoantigens, useful in raising antibodies to 3-chlorotyrosine, are disclosed.