Bioorthogonal Ligation and Cleavage by Reactions of Chloroquinoxalines with
<i>ortho</i>
‐Dithiophenols
作者:Youshan Li、Zhenbang Lou、Hongyun Li、Haijun Yang、Yufen Zhao、Hua Fu
DOI:10.1002/anie.201913620
日期:2020.2.24
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
extended pi surfaces stabilize the dimer similar to velcrands, while eight hydrogen bonds act like snaps to hold the molecules together. The self-complementary array of hydrogen bonding sites were incorporated on the upper rim of a resorcinarene-based cavitand. A dramatic reorganization of shape and size of the internal cavity was manifested through changes in solvent polarity. Specifically, the equilibrium
Resorcinarene-based cavitands with chiral amino acid substituents for chiral amine recognition
作者:Na Li、Fan Yang、Hillary A. Stock、David V. Dearden、John D. Lamb、Roger G. Harrison
DOI:10.1039/c2ob25613d
日期:——
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.
Synthesis and Conformational Switching of Partially and Differentially Bridged Resorcin[4]arenes Bearing Fluorescent Dye Labels. Preliminary Communication
作者:Vladimir A. Azov、François Diederich、Yoriko Lill、Bert Hecht
DOI:10.1002/hlca.200390172
日期:2003.6
of modified Cram-type cavitands bearing one or two fluorescent labels for single-molecule spectroscopic studies of vasekite conformational switching (Scheme 3). Syntheses were performed by stepwise bridging of the four couples of neighboring H-bonded OH groups of resorcin[4]arene bowls (Schemes 2 and 3). The new substitution patterns enable the construction of a large variety of future functional architectures