Study on the spatial structure of brachystemin C, a new cyclic peptide from Brachystemma calycinum

✍ Scribed by Cheng Wang; Li-Li Zhang; Yang Lu; Qi-Tai Zheng; Yong-Xian Cheng; Jun Zhou; Ning-Hua Tan

• Book ID: 103836383
• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 134 KB
• Volume: 688
• Category: Article
• ISSN: 0022-2860
• DOI: 10.1016/j.molstruc.2003.09.012

✦ Synopsis

A new cyclic octapeptide, brachstemin C (the molecular formula: C 38 H 56 N 8 O 9 ), was isolated from the root of Brachystemma calycinum. The types and sequence of the amino acids of the title compound were confirmed by spectral analyses and X-ray diffraction. The stereochemistry of the title cyclic octapeptide was clarified by X-ray crystallographic study. The cyclic octapeptide backbone contains three b-turns. Two of them are type I b-turns and one is type III b-turn (right-handed 3 10 helix). There are intermolecular hydrogen bonds between the cyclic peptide and the solvent molecules which maintained the steady spatial arrangement in crystal.