The structures of syringolides 1 and 2, novel C-glycosidic elicitors from Pseudomonas syringae pv. tomato
摘要:
The isolation and structure determination of two bacterial signal molecules which elicit active plant defense responses are reported. The production of these molecules by Gram-negative bacteria requires the action of a virulence gene D (avrD), cloned from Pseudomonas syringae pv. tomato. The structures of syringolide 1 (1a) and syringolide 2 (1b) are determined by a combination of NMR experiments, biosynthetic arguments, molecular modeling, and X-ray crystallography. A proposed biosynthetic scheme based on the condensation of D-xylulose with a beta-ketoalkanoic acid is presented. Further cyclization of the biosynthetic intermediates leads to C-glycosides with a novel tricyclic ring system. These are the first nonproteinaceous specific elicitors of a plant hypersensitive response.
Biomimetic synthesis of the microbial elicitor syringolide 2
作者:Julian P. Henschke、Rodney W. Rickards
DOI:10.1016/0040-4039(96)00611-9
日期:1996.5
Syringolide2 (1; n=2), an elicitor metabolite of the bacterial plant pathogen Pseudomonas syringae pv. tomato, has been synthesised in four steps from D-xylulose. The key stage involves triple cyclisation of the putative biosynthetic intermediate 1-(3′-oxodecanoyl)-D-xylulose (9), and provides evidence for the biosynthesis of the syringolides.
丁香酚2(1; n = 2),是细菌性植物病原体丁香假单胞菌pv的激发子代谢产物。番茄,是由D-木酮糖经四个步骤合成的。关键阶段涉及推定的生物合成中间体1-(3'-氧十二烷酰基)-D-木酮糖(9)的三环化,并为丁香内酯的生物合成提供了证据。
enantioselective synthesis of (−)-syringolides 1 and 2 which were isolated as specific elicitors produced by Pseudomonas syringae pv. tomato was accomplished in 11 steps from diethyl d tartrate. The specific rotations of synthetic samples were in good accord with those of the natural syringolides, and synthetic syringolide2 showed almost the same biological activity as that of natural syringolide2.
The enantioselective synthesis of syringolide2, one of the two elicitors produced by Pseudomonas syringae pv. tomato, was accomplished in 11 steps from diethyl d-tartrate.
Efficient synthesis of syringolides, secosyrins, and syributins through a common approach
作者:Anastasia-Aikaterini C. Varvogli、Ioannis N. Karagiannis、Alexandros E. Koumbis
DOI:10.1016/j.tet.2008.11.079
日期:2009.1
A new common synthetic approach toward the elicitors syringolides and their related natural products, secosyrins and syributins, is described here. This uses d-arabinose as starting material and efficiently delivers the targeted compounds through a sequential tandem HWE olefination–lactonization process and an IHMA reaction.
An improved synthesis of (−)-syringolides and X-ray structural characterization of synthetic (−)-syringolide 1
作者:Pei Yu、Qi-Guang Wang、Thomas C.W. Mak、Henry N.C. Wong
DOI:10.1016/s0040-4020(97)10401-x
日期:1998.2
On treatment with 10% HF, butenolides 4a and 4b afforded enantiopure (−)-syringolides 1 (1a) and 2 (1b) respectively in much higher yields. Unprecedentedly, the cyclic acetal 5a was also converted to 1a by reacting with an excess of p-TsOH. The structure of the synthetic (−)-syringolide 1 (1a) was substantiated by an X-ray crystallographic study.