N-Primary-amine tetrapeptide-catalyzed highly asymmetric Michael addition of aliphatic aldehydes to maleimides
作者:Zhi-Hong Du、Wen-Juan Qin、Bao-Xiu Tao、Meng Yuan、Chao-Shan Da
DOI:10.1039/d0ob01457e
日期:——
highly asymmetric Michaeladdition reaction between maleimides and aliphatic aldehydes catalyzed by low-loading β-turn tetrapeptides with excellent yields and enantioselectivities at room temperature was reported. α-Branched and α-unbranched aldehydes both are suitable nucleophiles. N-Aryl, alkyl and hydrogen maleimides all are well tolerated and led to high yields and enantioselectivities. The transformation
Spin-labelled diketopiperazines and peptide–peptoid chimera by Ugi-multi-component-reactions
作者:Haider N. Sultani、Haleh H. Haeri、Dariush Hinderberger、Bernhard Westermann
DOI:10.1039/c6ob02194h
日期:——
For the first time, spin-labelled coumpounds have been obtained by isonitrile-based multi component reactions (IMCRs). The typical IMCR Ugi-protocols offer a simple experimental setup allowing structural variety by which labelled diketopiperazines (DKPs) and peptide–peptoid chimera have been synthesized. The reaction keeps the paramagnetic spin label intact and offers a simple and versatile route to
As an antitumor drug which is excellent in terms of antitumor effect and safety and has an excellent therapeutic effect, there is provided an antibody-drug conjugate in which an antitumor compound represented by the following formula is conjugated to an anti-HER2 antibody via a linker having a structure represented by the formula: L1-L2-LP-NH-(CH2)n1-La-Lb-Lc or -L1-L2-LP-wherein the anti-HER2 antibody is connected to the terminal L1, and the antitumor compound is connected to the terminal Lc or LP with the nitrogen atom of the amino group at position 1 as the connecting position.
As an antitumor drug which is excellent in terms of antitumor effect and safety and has an excellent therapeutic effect, there is provided an antibody-drug conjugate in which an antitumor compound represented by the following formula is conjugated to an anti-HER2 antibody via a linker having a structure represented by the formula: L1-L2-LP-NH—(CH2)n1-La-Lb-Lc or -L1-L2-LP- wherein the anti-HER2 antibody is connected to the terminal L1, and the antitumor compound is connected to the terminal Lc or LP with the nitrogen atom of the amino group at position 1 as the connecting position.
Subtilisin, alpha-chymotrypsin and papain catalyzed hydrolyses of alpha-trifluoromethyl substituted N-benzyloxycarbonyl amino acid methylesters (Z-TFM-Xaa-OMe) 1 can be achieved only in the case of 3,3,3-trifluoroalanine. Enzymatic incorporation of Z-TFM amino acids 2 into N-terminal position of dipeptides also fails. In contrary, dipeptides with a TFM amino acid moiety in N-terminal position, e. g. TFM-Phg-L-Phe-OMe 5, react with H-Leu-NH2 to give the corresponding tripeptides 6 in high yield. Z protected dipeptide derivatives 8 with N-terminal TFM amino acids can be obtained via 4-trifluoromethyl-5-(4H)-oxazolones 7.