Structures of the Dimeric and Monomeric Chromanones, Gonytolides A–C, Isolated from the Fungus Gonytrichum sp. and Their Promoting Activities of Innate Immune Responses
摘要:
Innate Immunity is the front line of self-defense against microbial infection. After searching for natural substances that regulate innate immunity using an ex vivo Drosophila culture system, we identified a novel dimeric chromanone, gonytolide A, as an Innate immune promoter from the fungus Gonytrichum sp. along with gonytolides B and C. Gonytolide A also increased TNF-alpha-stimulated production of IL-8 in human umbilical vein endothelial cells.
A Convergent Synthesis of Gonytolide C Using an Intramolecular Oxa-Michael Addition
作者:Freda F. Li、Darcy J. Atkinson、Daniel P. Furkert、Margaret A. Brimble
DOI:10.1002/ejoc.201501402
日期:2016.2
of a convergent total synthesis of gonytolide C is reported. The assembly of the natural product core relies on a Horner–Wadsworth–Emmons (HWE) olefination followed by an intramolecular oxa-Michael addition. Robust and efficient preparations of both HWE coupling partners were established. The synthesis enabled further investigation of an asymmetric oxa-Michael cyclisation to prepare gonytolide C, demonstrating
Asymmetric Synthesis of Gonytolide A: Strategic Use of an Aryl Halide Blocking Group for Oxidative Coupling
作者:Xiaowei Wu、Takayuki Iwata、Adam Scharf、Tian Qin、Kyle D. Reichl、John A. Porco
DOI:10.1021/jacs.8b02535
日期:2018.5.9
The first synthesis of the chromanone lactone dimer gonytolide A has been achieved employing vanadium(V)-mediated oxidative coupling of the monomer gonytolide C. An o-bromine blocking group strategy was employed to favor para- para coupling and to enable kinetic resolution of (±)-gonytolide C. Asymmetric conjugate reduction enabled practical kinetic resolution of a chiral, racemic precursor and the
色满酮内酯二聚体 gonytolide A 的首次合成是利用钒 (V) 介导的单体 gonytolide C 的氧化偶联实现的。采用邻溴封闭基团策略有利于对位偶联并实现 ( ±)-gonytolide C。不对称缀合物还原能够实现手性、外消旋前体的实际动力学拆分以及 (+)-gonytolide A 及其阻转异构体的不对称合成。
Asymmetric synthesis of chromanone lactones <i>via</i> vinylogous conjugate addition of butenolide to 2-ester chromones
The scope of Michael acceptors includes a variety of substituted chromones at different positions, and the desired chromanone lactones upon reduction are afforded in good yield and diastereoselectivity, and excellent enantioselectivity (up to 99% ee). The strategy could be used in the concise synthesis of blennolide C and gonytolide A, C and G.
手性色满酮内酯是一类具有重要生物活性的天然产物。我们报道了丁烯内酯与2-酯取代的色酮的直接非对映和对映选择性插烯共轭加成。在低至 1 mol% 的手性N , N'-二氧化物/Sc III络合物、3 Å MS 和催化量的六氟异丙醇 (HFIP) 的存在下,转化顺利进行。迈克尔受体的范围包括各种不同位置取代的色酮,还原后得到所需的色酮内酯,具有良好的产率和非对映选择性,以及优异的对映选择性(高达99% ee)。该策略可用于blennolide C和gonytolide A、C和G的简捷合成。
New dimeric and monomeric chromanones, gonytolides D–G, isolated from the fungus Gonytrichum sp.
In the course of the screening of innate immune regulators from natural resources, we isolated new dimeric and monomeric chromanones, gonytolides D G (4-7), from Gonytrichum sp. along with a known innate immune promoter, gonytolide A (1). The structures of these compounds were determined by spectral analysis, chemical conversion, and biogenetic consideration. The compounds 4-7 were evaluated on the innate immune response, indicating that the 8,8'-linked bischromanone rings were crucial for innate immune-promoting activity. (C) 2012 Elsevier Ltd. All rights reserved.
Total synthesis of (+)-blennolide C and (+)-gonytolide C via spirochromanone
We report the asymmetric total synthesis of (+)-blennolide C and (+)-gonytolide C isolated from endophytic fungi. The synthesis involved construction of a spirochromanone with a chiral quaternary carbon by the aldolreaction of o-hydroxyacetophenones and optically active α-oxygenated cyclohexenone, followed by cyclization under acidic conditions. Oxidative cleavage of the alkene moiety of the spirochromanone