植物抗生素的研究进展

本文综述了植物抗生素在植物防御机制中的作用途径,对其进行了化学分类,并从化学生态学的角度概括了植物抗生素的产生以及与病原虫之间的关系。     

Phytoalexins of woody plants

Summary Phytoalexins accumulated in selected woody plants in response to microbial attack or stress are reviewed and listed with respect to their chemical structure and probable biogenetic origin. The host-pathogen systems from which they have been isolated are described. The review also considers the antimicrobial activity of the phytoalexins to the causal pathogens and other microorganisms.     

Phytoalexins in defense against pathogens

Plants use an intricate defense system against pests and pathogens, including the production of low molecular mass secondary metabolites with antimicrobial activity, which are synthesized de novo after stress and are collectively known as phytoalexins. In this review, we focus on the biosynthesis and regulation of camalexin, and its role in plant defense. In addition, we detail some of the phytoalexins produced by a range of crop plants from Brassicaceae, Fabaceae, Solanaceae, Vitaceae and Poaceae. This includes the very recently identified kauralexins and zealexins produced by maize, and the biosynthesis and regulation of phytoalexins produced by rice. Molecular approaches are helping to unravel some of the mechanisms and reveal the complexity of these bioactive compounds, including phytoalexin action and metabolism.     

剑叶龙血树树脂中的植物防卫素

１引言剑叶龙血树（Ｄｒａｃａｅｎａｃｏｃｈｉｎｃｈｉｎｅｎｓｉｓ）系龙舌兰科龙血树属,常绿乔木或灌木,在云南主要分布于勐连、勐腊、思茅、普洱、沧源、景东等县．在广西也有分布．剑叶龙血树现已成为我国传统中药血竭的主要基源植物之一［３］．近几年,对血竭化...     

Phytoalexins from Brassicaceae: News from the front

The chemical structures, syntheses, metabolism and biological activities of the cruciferous phytoalexins discovered to date, with particular focus on the latest results dealing with their biosynthesis and detoxification are reviewed.     

Phytoalexins and stress metabolites in the sapwood of trees

A wide range of organic compounds, many of them fungitoxic or fungistatic, appear in the sapwood of trees after wounding, injury or fungal attack. There is evidence that most of these compounds are formed by dying parenchyma cells and they therefore can be considered to be phytoalexins. In many cases such compounds accumulate in narrow ‘reaction zones’ which serve to impede further progress of pathogens.     

Tenualexin,Other Phytoalexins and Indole Glucosinolates from Wild Cruciferous Species

In general, the chemodiversity of phytoalexins, elicited metabolites involved in plant defense mechanisms against microbial pathogens, correlates with the biodiversity of their sources. In this work, the phytoalexins produced by four wild cruciferous species (Brassica tournefortii, Crambe abyssinica (crambe), Diplotaxis tenuifolia (sand rocket), and Diplotaxis tenuisiliqua (wall rocket)) were identified and quantified by HPLC with photodioarray and electrospray mass detectors. In addition, the production of indole glucosinolates, biosynthetic precursors of cruciferous phytoalexins, was evaluated. Tenualexin, (=2‐(1,4‐dimethoxy‐1H‐indol‐3‐yl)acetonitrile), the first cruciferous phytoalexin containing two MeO substituents in the indole ring, was isolated from D. tenuisiliqua, synthesized, and evaluated for antifungal activity. The phytoalexins cyclobrassinin and spirobrassinin were detected in B. tournefortii and C. abyssinica, whereas rutalexin and 4‐methoxybrassinin were only found in B. tournefortii. D. tenuifolia, and D. tenuisiliqua produced 2‐(1H‐indol‐3‐yl)acetonitriles as phytoalexins. Because tenualexin appears to be one of the broad‐range antifungals occurring in crucifers, it is suggested that D. tenuisiliqua may have disease resistance traits important to be incorporated in commercial breeding programs.     

Maldi-mass Spectrometry Imaging for Phytoalexins Detection in RD6 Thai Rice

Applied Biochemistry and Microbiology - Phytoalexin production has been extensively studied using multiple methods. However, this is the first report on the use of matrix-assisted laser...     

Phytoalexins from crucifers: synthesis, biosynthesis, and biotransformation

Phytoalexins play a significant role in the defense response of plants. These secondary metabolites, which are synthesized de novo in response to diverse forms of stress, including fungal infection, are part of the plants' chemical and biochemical defense mechanisms. Phytoalexins from crucifers are structurally and biogenetically related, but display significantly different biological activities. Here, we review work reporting the chemical structures, synthesis, biosynthesis and metabolism of cruciferous phytoalexins, as well as their biological activity towards different microorganisms.     

Phytoalexins from Pinus strobus bark infected with pinewood nematode, bursaphelenchus xylophilus

From the bark of Pinus strobus infected with pinewood nematode, Bursaphelenchus xylophilus, a stilbenoid 3-O-methyldihydropinosylvin and a flavanone (2S)-pinocembrin were isolated as active principles of inducibly produced antifungal compounds. The structures of the compounds were determined on the basis of spectroscopic analyses. Close investigations of spectroscopic analyses led to the complete assignment of 13C NMR and 1H NMR chemical shifts for the former compound and to the determination of the stereochemistry of the latter compound from P. strobus to be 2S. Furthermore, the distribution and time course accumulation of the identified compounds were investigated. The former compound was demonstrated to be nematocidal and the concentrations of the compound in the inoculated branches were sufficient enough to inactivate the pinewood nematode within one week after inoculation.     

植物抗毒素研究进展及其作为食品功能性成分的应用前景

植物抗毒素是植物受到外界刺激或感染病菌后合成并积累的具有抗逆活性的小分子化合物.过去对它的研究集中在其生成机理以及作为植物免疫体系组成成分、起到抗病作用等方面.新近的研究表明,植物抗毒素对人体同样具有多重生物学功效,如抗氧化、抗炎、抗癌等.由此,植物抗毒素作为植物次生代谢产物的重要组成部分,在功能食品和膳食补充剂领域有着广阔的应用前景.本文综述了近年来关于植物抗毒素的种类、活性及在植物体内诱生和积累等方面的研究,为食品功能因子的选择性拓展提供依据和指导.