title: Accumulation of Isohemigossypolone and Its Related Compounds in the Inner Bark and Heartwood of Diseased Pachira aquatica.
abstract: Isohemigossypolone (1) and 2-O-methylisohemigossypolone (2), major fungitoxins of Pachira aquatica, were found to accumulate locally in the outer bark of the swollen trunk, whereas the inner bark and heartwood contained only a trace amount of them. From P. aquatica that was infected with a phytopathogenic bacterium, we detected significant amounts of 1 and 2 from browned inner tissues of the swollen trunk. According to a quantitative analysis by a gas-chromatograph, the concentration of 1 in the diseased inner tissues was calculated to be approximately 780 μg/g f.w., which was the same level as that in the outer bark of healthy individuals. These findings suggest that the inner tissues inducibly produced and accumulated antifungals 1 and 2 during infection events, as do many plants with phytoalexins. 11-Nor-2-O-methylisohemigossypolone (3), showing approximately equivalent fungitoxic activity to that of 1 and 2, was also isolated from the infected inner tissues. We screened pathogenic bacteria from the infected tissue, and isolated a rod-shaped bacterium that was tentatively identified as Pseudomonas sp. which promoted tissue-browning on sectioned disks of P. aquatica trunks.
authors: a Department of Applied Bioscience, Faculty of Agriculture, Hokkaido University.
authors: M
authors: M
authors: Shibatani
authors: Y
authors: Y
authors: Hashidoko
authors: S
authors: S
authors: Tahara
mesh_terms: D000935:Antifungal Agents / Q000378:metabolism* / Q000494:pharmacology; D035161:Bombacaceae / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D002849:Chromatography, Gas; D006072:Gossypol / Q000031:analogs & derivatives / Q000096:biosynthesis* / Q000494:pharmacology; D024301:Plant Bark / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D057865:Plant Immunity; D011549:Pseudomonas / Q000187:drug effects / Q000254:growth & development; D004718:Saccharomycetales / Q000187:drug effects / Q000254:growth & development; D014934:Wood / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology
chemical_list: D000935:Antifungal Agents; D006072:Gossypol
keywords: Pachira aquatica; cadinane sesquiterpenes; isohemigossypolone; norcadinane; phytoalexin