作者:Viet-Anh Nguyen、Christine L. Willis、William H. Gerwick
DOI:10.1039/b106087m
日期:——
The first total synthesis of the trichlorinated natural
product barbamide is described. The convergent approach involves coupling
(S)-3-trichloromethylbutanoyl chloride with Meldrum’s acid
(2,2-dimethyl-1,3-dioxane-4,6-dione) to give 15 followed by addition of the
novel secondary amine N-methyl-(S)-dolaphenine 2
(prepared in 6 steps and 24% overall yield from
N-Cbz-L-phenylalanine) to give the β-keto amide 16
which was converted directly to the required (E)-enol ether.
Valence Tautomerism in Titanium Enolates: Catalytic Radical Haloalkylation and Application in the Total Synthesis of Neodysidenin
作者:Stéphane Beaumont、Elizabeth A. Ilardi、Lucas R. Monroe、Armen Zakarian
DOI:10.1021/ja910154f
日期:2010.2.10
A direct ruthenium-catalyzed radical chloroalkylation of N-acyloxazolidinones capitalizing on valence tautomerism of titanium enolates has been developed. The chloroalkylation method served as the centerpiece in the enantioselective total synthesis of trichloroleucine-derived marine natural product neodysidenin.
Dragonamide E, a Modified Linear Lipopeptide from <i>Lyngbya majuscula</i> with Antileishmanial Activity
作者:Marcy J. Balunas、Roger G. Linington、Kevin Tidgewell、Amanda M. Fenner、Luis-David Ureña、Gina Della Togna、Dennis E. Kyle、William H. Gerwick
DOI:10.1021/np900622m
日期:2010.1.22
plants and microorganisms from Panama. We have pursued activity-guided isolation from an extract of Lyngbyamajuscula that was found to be active against leishmaniasis. A new modified linear peptide from the dragonamide series was isolated, dragonamide E (1), along with two known modified linear peptides, dragonamide A (2) and herbamide B (3). Dragonamides A and E and herbamide B exhibited antileishmanial
热带寄生虫病和传染病,如利什曼病,对全球健康构成巨大威胁,但在商业药物发现计划中却被很大程度上忽视了。然而,巴拿马国际生物多样性合作小组 (ICBG) 一直致力于通过对巴拿马植物和微生物的调查来确定疟疾、南美锥虫病和利什曼病的新疗法。我们已经从被发现对利什曼病有活性的Lyngbya majuscula提取物中进行了活性引导分离。从龙酰胺系列中分离出一种新的修饰线性肽,龙酰胺 E ( 1 ),以及两种已知的修饰线性肽,龙酰胺 A ( 2 ) 和草本酰胺 B ( 3 ))。Dragonamides A 和 E 以及草本酰胺 B 表现出抗利什曼原虫活性,IC 50值分别为6.5、5.1和 5.9 μM。提供了龙酰胺 E ( 1 ) 和草本酰胺 B ( 3;该物质的光谱和立体化学数据在文献中不完整) 的光谱和立体化学数据以及龙酰胺化合物家族内生物活性的比较。还讨论了具有末端游离酰胺的海洋化合物之间的生物合成差异。
Herbacic Acid, a Simple Prototype of 5,5,5-Trichloroleucine Metabolites from the Sponge <i>Dysidea herbacea</i>
作者:John B. MacMillan、Tadeusz F. Molinski
DOI:10.1021/np990468j
日期:2000.1.1
Dysideaherbacea, collected at Harrier Reef on the Great Barrier Reef, contains the novel metabolite herbacic acid as the major trichloroleucine metabolite. Herbacic acid appears to be an early product of direct free-radical chlorination of leucine and is a prototype for further transformation of the free carboxylic acid group and generation of complex trichloromethyl metabolites, including natural