Zoosporicidal Activity of Polyflavonoid Tannin Identified in Lannea coromandelica Stem Bark against Phytopathogenic Oomycete Aphanomyces cochlioides
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- 作者：Md. Tofazzal Islam ; Toshiaki Ito ; Mitsuyoshi Sakasai ; and Satoshi Tahara
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2002
- 出版时间：November 6, 2002
- 年：2002
- 卷：50
- 期：23
- 页码：6697 - 6703
- 全文大小：203K
- 年卷期：v.50,no.23(November 6, 2002)
- ISSN：1520-5118
文摘
In a survey of nonhost plant secondary metabolites regulating motility and viability of zoospores ofthe Aphanomyces cochlioides, we found that stem bark extracts of Lannea coromandelica remarkablyinhibited motility of zoospores followed by lysis. Bioassay-guided fractionation and chemicalcharacterization of Lannea extracts by MALDI-TOF-MS revealed that the active constituents wereangular type polyflavonoid tannins. Commercial polyflavonoid tannins, Quebracho and Mimosa, alsoshowed identical zoosporicidal activity. Against zoospores, the motility-inhibiting and lytic activitieswere more pronounced in Lannea extracts (MIC 0.1 
g/mL) than in Quebracho (MIC 0.5 g/mL) andMimosa (MIC 0.5 g/mL). Scanning electron microscopic observation visualized that both Lanneaand commercial tannins caused lysis of cell membrane followed by fragmentation of cellular materials.Naturally occurring polyflavonoid tannin merits further study as potential zoospore regulating agentor as lead compound. To the best of our knowledge, this is the first report of zoosporicidal activity ofnatural polyflavonoid tannins against an oomycete phytopathogen.Keywords: Lannea coromandelica; polyflavonoid tannins; motility-inhibiting activity; Aphanomycescochlioides; zoospore lysis
g/mL) than in Quebracho (MIC 0.5 g/mL) andMimosa (MIC 0.5 g/mL). Scanning electron microscopic observation visualized that both Lanneaand commercial tannins caused lysis of cell membrane followed by fragmentation of cellular materials.Naturally occurring polyflavonoid tannin merits further study as potential zoospore regulating agentor as lead compound. To the best of our knowledge, this is the first report of zoosporicidal activity ofnatural polyflavonoid tannins against an oomycete phytopathogen.Keywords: Lannea coromandelica; polyflavonoid tannins; motility-inhibiting activity; Aphanomycescochlioides; zoospore lysis