Reactions catalyzed within inorganic and organic materials and at electrochemical interfaces commonly occur at high coverage and in condensed media, causing turnover rates to depend strongly on interfacial structure and composition, Like 116-31-4, Name is trans-Retinal. In a document, author is Visser, TJ, introducing its new discovery. Formula: https://www.ambeed.com/products/116-31-4.html.
Stereoselective synthesis and biodistribution of potent [C-11]-labeled antagonists for positron emission tomography imaging of muscarinic receptors in the airways
Quantitation of muscarinic receptors in the lungs in vivo with positron emission tomography (PET) is of clinical interest. For that purpose we decided to develop [C-11]-labeled ligands with a high affinity (K-D < 0.1 nM). Three quaternary muscarinic antagonists, racemic N-methylpiperidin-4-yl 2-cyclohexy-2-2-hydroxy-2-phenylacetate methiodide 1a (pK(B) = 10.39), its (R)-isomer 1b (pK(B) = 11.08), and (R,R)-quinuclidin-3-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate methiodide 2 (pK(B) = 11.28), were labeled by reacting [C-11]CH3I With their tertiary amine precursors. The enantiomerically pure tertiary amine precursors were prepared by stereoselective synthesis starting from (R)-(-)-mandelic acid. In vitro binding assay of 1b and 2 demonstrated that both ligands bind with very high affinity to the muscarinic receptor subtypes M(1), M(2), and M(3). They are more potent than the muscarinic antagonist (R)-N-methylquinuclidinyl benzilate ((R)-MQNB). Distribution studies with la, 1b, and 2 in control and atropine-treated male Wistar rats demonstrated significant specific binding (90-99% of total issue uptake) in tissues containing cholinoceptors (heart, intestine, lung, pancreas, spleen, stomach, submandibular gland). Because the tissue/plasma concentration ratios of 1b are most favorable, this ligand was used for further evaluation. Analysis of plasma samples showed a very rapid clearance (t(1/2) = 0.3 min) of the radioligand 1b and a relatively slow appearance of a hydrophilic metabolite. At 15 min postinjection of 1b, analysis of heart, lungs, and liver showed that respectively 99%, 88%, and 8% of the tissue radioactivity corresponded with the parent compound. Ligand 1b appears to be an excellent candidate for PET studies of mAChR receptors in heart and lungs. The reactant in an enzyme-catalyzed reaction is called a substrate. Enzyme inhibitors cause a decrease in the reaction rate of an enzyme-catalyzed reaction.Interested yet? Keep reading other articles of 116-31-4, you can contact me at any time and look forward to more communication. Formula: https://www.ambeed.com/products/116-31-4.html.
Reference:
Quinuclidine – Wikipedia,
,Quinuclidine | C7H13N | ChemSpider