59715-45-6Relevant articles and documents
Bioorthogonal Ligation and Cleavage by Reactions of Chloroquinoxalines with ortho-Dithiophenols
Fu, Hua,Li, Hongyun,Li, Youshan,Lou, Zhenbang,Yang, Haijun,Zhao, Yufen
supporting information, p. 3671 - 3677 (2020/02/04)
A bioorthogonal ligation and cleavage method via reactions of chloroquinoxalines (CQ) and ortho-dithiophenols (DT) is presented. Double nucleophilic substitutions of ortho-dithiophenols to chloroquinoxalines provide conjugates containing tetracyclic benzo[5,6][1,4]dithiino[2,3-b]quinoxaline with strong built-in fluorescence together with release of the other functional molecules. Three cleavable linkers were designed and successfully used in release of the molecules containing biotin from the protein conjugates. The CQ-DT bioorthogonal reactions can be applied for the bioorthogonal ligations, bioorthogonal cleavages, and trans-tagging of proteins, and show advantages of readily accessible unnatural orthogonal groups, appealing reaction kinetics (k2≈1.3 m?1 s?1), excellent biocompatibility of orthogonal groups, and high stability of conjugates. This complements previous bioorthogonal reactions and is a new route for protein-fishing applications and in-gel fluorescence analysis.
Resorcinarene-based cavitands with chiral amino acid substituents for chiral amine recognition
Li, Na,Yang, Fan,Stock, Hillary A.,Dearden, David V.,Lamb, John D.,Harrison, Roger G.
scheme or table, p. 7392 - 7401 (2012/10/08)
Resorcinarene-based deep cavitands alanine methyl resorcinarene acid (AMA), alanine undecyl resorcinarene acid (AUA) and glycine undecyl resorcinarene acid (GUA), which contain chiral amino acids, have been synthesized. The upper rim of the resorcinarene host is elongated with four identical substituents topped with alanine and glycine groups. The structures of the new resorcinarenes were elucidated by nuclear magnetic resonance (NMR), mass spectrometry (MS) and the sustained off-resonance irradiation collision induced dissociation (SORI-CID) technique in FTICR-MS. These studies revealed that eight water molecules associate to the cavitand, two for each alanine group. The alanine substituent groups are proposed to form a kite-like structure around the resorcinarene scaffold. The binding of AMA, AUA, and GUA with chiral R- and S-methyl benzyl amines was studied by 1H NMR titration, and compared to that of a binary l-tartaric acid and the monoacid phthalyl alanine (PA). The results show that these compounds interact with amine guests; however, with four carboxylic acid groups, they bind several amine molecules strongly while the binary l-tartaric acid only binds one amine guest strongly. The simple compound PA, which contains one carboxylic group, shows weak binding to the amines. The 1H NMR titration of AUA with primary, secondary, and tertiary chiral amines showed that it can discriminate between these three types of amines and showed chiral discrimination for chiral secondary amines.
Permanganate Oxidation of Quinoxaline and Its Derivatives
Obafemi, Craig A.,Pfleiderer, Wolfgang
, p. 1549 - 1556 (2007/10/02)
The oxidation reaction of a series of quinoxaline derivatives, using KMnO4 in the presence or absence of NaOH, are described.Neutral oxidation of 2-chloro- and 2,3-dichlorodioxalines 2-4 afforded the corresponding chloro- and dichloropyrazinedicarboxilic acids 13 and 14 in good yield.On the other hand, oxidation of quinoxalin-2(1H)-one and 1,4-dihydroquinoxaline-2,3-dione derivatives in alkaline medium gave different products, with the quinoxalin-2(1H)-one (5) forming 1,4-dihydroquinoxaline-2,3-dione (9), while various substituted quinoxalin-2,3-dione derivatives (see 9-11) gave a new type of dimeric products.The structural assignments for the new compounds were based on spectroscopic data.
