2002 Fiscal Year Final Research Report Summary
Studies on the production of compounds and regulation of secondary metabolism by the cultures of isolated lichen mycobionts
| Project/Area Number |
13836009
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Institution | Kobe Pharmaceutical University |
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Principal Investigator |
TANAHASHI Takako Kobe Pharmaceutical University, Faculty of Pharmaceutical Sciences, Professor, 薬学部, 教授 (20171811)
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| Co-Investigator(Kenkyū-buntansha) |
HAMADA Nobuo Osaka City Institute of Public Health and Environmental Sciences, Chief Researcher, 研究主任 (40270764)
TAKENAKA Yukiko Kobe Pharmaceutical University, Faculty of Pharmaceutical Sciences, Assistant, 薬学部, 助手 (90289041)
ITOH Atsuko Kobe Pharmaceutical University, Faculty of Pharmaceutical Sciences, Lecturer, 薬学部, 講師 (10223132)
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| Project Period (FY) |
2001 – 2002
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| Keywords | lichen mycobiont / culture of isolated mycobiont / phenolic compounds / structure elucidation / biosynthesis / symbiosis |
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| Research Abstract |
Lichens are symbiotic organisms comprised of a fungus, mycobiont, and a photosynthetic partner, photobiont. In some cases, cultures of lichen mycobionts have an ability under osmotically stressed conditions to produce substances which have never been detected in the lichenized state. It was pointed out that cultures of lichen mycobionts could be new sources of bioactive compounds. In the course of our studies on cultured lichen mycobionts, we cultivated mycobionts of the lichens collected in Japan and investigated their metabolites. From the cultures of Graphis spp., chromones, benzoquinones and a sterol were isolated, while benzofurans, xanthones and aliphatic carboxylic acids were isolated from those of Lecanora spp. From the cultured mycobionts, of Pyrenula spp., a variety of isocoumarin derivatives were obtained. The structures of thirteen new compounds were elucidated.
The biogenetic origin of the carton skeleton in a naphthopyrone and xanthone derivatives was verified by feeding _<13>C-labeled acetate into the cultured mycobionts of Graphis, Lecanora and Pyrenula spp.
A good many of diverse metabolites isolated from the cultured mycobionts have never been detected in the lichenized state but were structurally related to mycotoxins. It might be postulated that the metabolic pathways of these metabolites could be expressed for survival of the mycobiont in pre-lichenized condition, but suppressed in associated lichens because of their toxicity to photobiont. In this context, the effect of some metabolites on the growth of a photobiont, Trebouxia erici were studied to demonstrate that some metabolites inhibit the growth of the photobiont, but the other have no effect. The anti-proliferative activities of some isolated metabolites against a carcinoma cell line were also evaluated.
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Research Products
(8 results)
