| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1995: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1994: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1993: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Research Abstract |
Lignans and neolignans are a widely distributed, structurally diverse phytochemical class in gymnosperms and angiosperms, with exhibiting various biological activities.
As a part of our studies to elucidating biosynthetic pathways of lignans in woody plants, we investigated the formation of lignans in Magnolia kobus DC var. borealis Sarg. and Abies sachalinensis Masters.
Based on structural considaratin and possible transformations, we obtained various lignans in recemic ((]SY.+-.]))-form by total synthesis. They were ((]SY.+-.]))-pinoresinol, ((]SY.+-.]))-monomethylpinoresinal, ((]SY.+-.]))-eudesmin, ((]SY.+-.]))-syringaresinol, ((]SY.+-.]))-monomethylsyringaresinol, ((]SY.+-.]))-yangambin, ((]SY.+-.]))-kobusin, ((]SY.+-.]))-fargesin and ((]SY.+-.]))-piperitol. In addition, [9,9-^2H_2, OC^2H_3] coniferyl alcohol and [3-O^<14>CH_3] monomethylpinoresinol were synthesized.
In vivo labelling experiments of M.kobus DC var. borealis, it was established that deuterated coniferyl alcohol had been incorporated into pinoresinol, but not fargesin and kobusin. These results suggested that formation of pinoresinol can occur via coupling of two intact coniferyl alcohol moieties. Next, we examined O-methylation reaction of ((]SY.+-.]))-pinoresinol by incubation with cell-free extracts from M.kobus DC var. borealis. It was shown that M.kobus DC var. borealis cell-free extracts catalysed the O-methylation of pinoresinol, suggesting the conversion of pinoresinol into monomethylpinoresinol and eudesmin in Magnolia.
In the investigation of lignans of Abies sachalinensis various lignans were isolated. it revealed that lignans of Abies sachalinensis were characterized by a preferential occurerence of lactol-type lignans, which mainly distributed in the sap-and heartwood. it was suggested that abiesol A (phenylpropane trimer) was derived from the coupling of lariciresinol (tetrahydrofuran type lignan) and coniferyl alcohlol. (monolignol).
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