title: Total Synthesis and Stereochemical Assignment of Nostosin B.
abstract: Nostosins A and B were isolated from a hydrophilic extract of Nostoc sp. strain from Iran, which exhibits excellent tryps inhibitory activity. Nostosin A was the most potent natural tripeptide aldehyde as trypsin inhibitor up to now. Both R- and S-2-hydroxy-4-(4-hydroxy-phenyl) butanoic acid (Hhpba) were prepared and incorporated into the total synthesis of nostosin B, respectively. Careful comparison of the NMR spectra and optical rotation data of synthetic nostosin B (1a and 1b) with the natural product led to the unambiguous identification of the R-configuration of the Hhpba fragment, which was further confirmed by co-injection with the authentic sample on HPLC using both reversed phase column and the chiral AD-RH column.
authors.affiliation: School of Life Science, Jiangxi Science and Technology Normal University, Nanchang 330013, China. professorwxj@163.com.
authors.forename: Xiaoji
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Life Science, Jiangxi Science and Technology Normal University, Nanchang 330013, China. mengy@pkusz.edu.cn.|Laboratory of Chemical Genomics, Engineering Laboratory for Chiral Drug Synthesis, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, University Town of Shenzhen, Xili, Nanshan District, Shenzhen 518055, China. mengy@pkusz.edu.cn.
authors.forename: Junmin
authors.initials: J
authors.lastname: Feng
authors.affiliation: Laboratory of Chemical Genomics, Engineering Laboratory for Chiral Drug Synthesis, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, University Town of Shenzhen, Xili, Nanshan District, Shenzhen 518055, China. xuzs@pkusz.edu.cn.
authors.forename: Zhengshuang
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Laboratory of Chemical Genomics, Engineering Laboratory for Chiral Drug Synthesis, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, University Town of Shenzhen, Xili, Nanshan District, Shenzhen 518055, China. tao_ye35@hotmail.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Ye
authors.affiliation: Laboratory of Chemical Genomics, Engineering Laboratory for Chiral Drug Synthesis, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, University Town of Shenzhen, Xili, Nanshan District, Shenzhen 518055, China. mengy@pkusz.edu.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Meng
authors.affiliation: State Intellectual Property of the People's Republic of China, Keyuan Road, Guang Zhou 510000, China. 13246888828@163.com.
authors.forename: Zhiyu
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D001688:Biological Products / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D009842:Oligopeptides / Q000737:chemistry*; D013237:Stereoisomerism; D014357:Trypsin / Q000378:metabolism; D014361:Trypsin Inhibitors / Q000737:chemistry
chemical_list: D001688:Biological Products; D009842:Oligopeptides; D014361:Trypsin Inhibitors; C000601919:nostosin B; D014357:Trypsin
keywords: nostosin B;  stereochemical assignment;  total synthesis