Nectriatide 1a是一种天然存在的环状四肽,已被报道为两性霉素 B (AmB) 活性的增强剂。为了阐明其构效关系,我们在溶液相合成中合成了具有不同氨基酸的nectriatide衍生物,并评估了AmB对白色念珠菌的增强活性。其中, C端和N端受保护的线性肽被发现显示出最有效的 AmB 增强活性。
Synthesis and structure of chiral 2,6-bis[(2-carbamoylphenyl)carbamoyl]pyridine ligands
作者:Qiang Yu、Timothy E. Baroni、Louise Liable-Sands、Arnold L. Rheingold、A.S. Borovik
DOI:10.1016/s0040-4039(98)01486-5
日期:1998.9
The synthesis and structure of a series of enantiomerically pure 2,6-bis[(2-carbamoylphenyl)carbamoyl]-pyridine ligands (H(2)a-c) are described. Appended from the aryl groups are optically active groups which provide a chiral environment around the planar pyridine core. NMR and X-ray diffraction studies show that these ligands contain helical character which is maintained by a network of intramolecular hydrogen bonds. These ligands can bind metal ions through their tridentate diamidato-pyridyl chelate to form optically active metal complexes. The modular design of these ligands offers a variety of chiral environments about the metal chelate that can be useful in the synthesis of metal reagents for asymmetric transformations. (C) 1998 Elsevier Science Ltd. All rights reserved.