Novel quinoxaline derivatives for in vivo imaging of β-amyloid plaques in the brain
摘要:
In a search for new probes to detect beta-amyloid plaques in the brain of patients with Alzheimer's disease (AD), we have synthesized and evaluated a series of quinoxaline derivatives containing a '6+6-6' ring system. These quinoxaline derivatives showed excellent affinity for A beta(1) (42) aggregates with K(i) values ranging from 2.6 to 10.7 nM. Autoradiography with sections of brain tissue from an animal model of AD mice (APP/PS1) and AD patients revealed that [(125)I]5 labeled beta-amyloid plaques specifically. In biodistribution experiments using normal mice, [(125)I]5 displayed high uptake (6.03% ID/g at 2 min) into and a moderately fast washout from the brain. Although additional refinements are needed to decrease the lipophilicity and improve the washout rate, the quinoxaline scaffold may be useful as a backbone structure to develop novel beta-amyloid imaging agents. (C) 2011 Elsevier Ltd. All rights reserved.
New hydroxyaminohydrocarbonphosphonic acid derivatives of the formula: ##STR1## wherein R.sup.1 is hydrogen or acyl, R.sup.2 is hydrogen, lower alkyl, ar(lower)alkyl or acyl, and A is lower alkylene, lower alkenylene or hydroxy(lower)alkylene, or the esters at the phosphono group thereof or the pharmaceutical acceptable salt thereof, and production and use thereof.
Microwave-Assisted Palladium-Catalyzed Cross-Coupling of Aryl and Vinyl Halides with H-Phosphonate Diesters
作者:Marcin Kalek、Asraa Ziadi、Jacek Stawinski
DOI:10.1021/ol801935r
日期:2008.10.16
bond was developed. Using a prevalent palladium catalyst, Pd(PPh3)4, a quantitative cross-coupling of various H-phosphonate diesters with aryl and vinyl halides was achieved in less than 10 min. The reactions occurred with retention of configuration at the phosphorus center and in the vinyl moiety. Using this protocol, several C-phosphonates, including those bearing nucleoside and cholesteryl moieties
The present invention is directed to a new method for esterification of P-O components. More specifically, the present invention relates to a new method for esterification of P-O components containing at least one P-O-H functional group, whereby the P-O-H functional group(s) is converted into P-O-R functional group(s). The method according to the invention may find particular use in the manufacture of diesters of phosphorous acid.
Phosphorus is an essential element in living organisms. Evaluating prebiotic processes that lead to phosphorylated biomolecules is an important step toward understanding the origin of life. Schreib...
Various possible methods for synthesis of monoalkyl phosphoroamidities, (RO)(R2′N)P(O)H, starting from tervalent or pentavalentphosphorus derivatives are described and discussed. New experimental results concerning phosphorylation of secondary amines by means of phosphorus acid anhydrides are presented.