Urumamide, a novel cyclic depsipeptide that contains a β-aminoacid, was isolated from a marine cyanobacterium Okeania sp. Its gross structure was determined by spectroscopic analyses, and the absolute configuration was established based on Marfey’s analyses and chiral HPLC analyses of hydrolysis products. Biologically, urumamide inhibited the growth of human cancer cells. In addition, urumamide inhibited
prenylation is an outstanding modification in alkaloid and peptide biosynthesis, but its enzymaticbasis has remained elusive. We report the isolation of argicyclamides, a new class of cyanobactins with unique mono- and bis-prenylations on guanidine moieties, from Microcystis aeruginosa NIES-88. The genetic basis of argicyclamide biosynthesis was established by the heterologous expression and in vitro characterization
Application of 3D NMR for Structure Determination of Peptide Natural Products
作者:Fan Zhang、Navid Adnani、Emmanuel Vazquez-Rivera、Doug R. Braun、Marco Tonelli、David R. Andes、Tim S. Bugni
DOI:10.1021/acs.joc.5b01486
日期:2015.9.4
in NMR, structuredetermination is often slow and constitutes a bottleneck in natural products discovery. Removal of this bottleneck would greatly improve the throughput for antibiotic discovery as well as other therapeutic areas. Overall, faster structure methods for structuredetermination will serve the natural products community in a broad manner. This report describes the first application of
尽管核磁共振技术取得了进步,但结构测定通常很慢,并且构成了天然产物发现的瓶颈。消除这一瓶颈将大大提高抗生素发现以及其他治疗领域的吞吐量。总体而言,用于结构测定的更快的结构方法将以广泛的方式服务于天然产物界。本报告描述了 3D NMR 首次应用于阐明两种具有新颖结构的微生物产生的肽天然产物。这些方法具有成本效益,并且大大提高了对所提出结构的信心。
Highly Sensitive Labeling Reagents for Scarce Natural Products
amino acid labelingreagents were drastically enhanced in LC–MS analysis. These advanced labelingreagents enabled the detection of infinitesimal amounts of amino acids and peptide hydrolysates. This sensitivity-enhancement design concept was also applicable to reagents for labeling saccharides and reactivity-guided isolation of electrophilic natural products. Details of these reagents, including their
octadepsipeptides, octaminomycins A (1) and B (2), were isolated from a microbial metabolite fraction library of Streptomyces sp. RK85-270 based on Natural Products Plot screening. Their structures were elucidated on the basis of HRESIMS, 1D and 2D NMR spectroscopic data, and MS/MS experiments for sequence analysis. The absoluteconfigurations of the constituent amino acid residues were determined by a combination