caa a22 4500 463247930 CHVBK 20180405153331.0 cr unu---uuuuu 170326e20070401xx s 000 0 eng 10.1007/s10086-006-0833-0 doi (NATIONALLICENCE)springer-10.1007/s10086-006-0833-0 Stereochemistry and biosynthesis of (+)-lyoniresinol, a syringyl tetrahydronaphthalene lignan in Lyonia ovalifolia var. elliptica II: feeding experiments with 14C labeled precursors [Elektronische Daten] [MD. Rahman, Takeshi Katayama, Toshisada Suzuki, Yuka Yoshihara, Takashi Nakagawa] To clarify the biosynthetic pathway for syringyl lignans, especially syringyl tetrahydronaphthalene lignans and formation of the C2-C7′ linkage, production of (+)-lyoniresinol (LYR) and its predicted intermediates [syringaresinol (SYR), 5,5′-dimethoxylariciresinol (DMLR), and 5,5′-dimethoxysecoisolariciresinol (DMSLR)] in Lyonia ovalifolia var. elliptica was investigated by means of feeding experiments with radiolabeled precursors. Following individual administration of l-[U-14C]phenylalanine (Phe), [8-14C]sinapyl alcohol (SA), and [8,8′-14C]SYR to excised young shoots of L. ovalifolia and their subsequent metabolism, free [14C]lignans and [14C]lignan glycosides were extracted with methanol from stems and leaves and were divided into ethyl acetate-soluble fractions (lignans) and aqueous fractions (lignan glycosides), respectively. Using a combination of xylanase, cellulase, and β-glucosidase, the glycosides were hydrolyzed to liberate [14C]lignans as aglycones. l-[U-14C]Phe was incorporated into (+)-[14C]SYR [stem 0.38%, 8% enantiomeric excess (e.e.)], (−)-[14C]SYR (leaves 2.75%, 72% e.e.), (+)-[14C]DMLR (stem 0.07%, 18% e.e. and leaves 0.009%, 58% e.e.), (−)-[14C]DMSLR (stem 0.03%, 46% e.e. and leaves 0.05%, 20% e.e.), (+)-[14C]LYR (leaves 0.013%, 22% e.e.) and glycosides of (+)-[14C]LYR (stem 0.036%, 50% e.e.) in 24h. Based on the percent incorporation and enantiomeric composition of the lignans, the biosynthetic pathway of (8R,8′R)-(+)-LYR was proposed as follows: a nonselective dehydrogenative dimerization of sinapyl alcohol yields (±)-SYR, which is reduced with low specificity to give (8R,8′R)-(+)-DMLR. This is cyclized to directly give (+)-LYR as well as reduced again to (8R,8′R)-(−)-DMSLR. Although further transformation of (−)-DMSLR also leads to the formation of (+)-LYR, cyclization could be a main pathway for (+)-LYR biosynthesis. The Japan Wood Research Society, 2007 Syringyl lignan nationallicence Lyonia ovalifolia var. elliptica nationallicence Biosynthesis nationallicence 5,5′-Dimethoxylariciresinol nationallicence Lyoniresinol nationallicence Rahman MD Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, 761-0795, Kagawa, Japan aut Katayama Takeshi Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, 761-0795, Kagawa, Japan aut Suzuki Toshisada Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, 761-0795, Kagawa, Japan aut Yoshihara Yuka Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, 761-0795, Kagawa, Japan aut Nakagawa Takashi Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, 761-0795, Kagawa, Japan aut Journal of Wood Science Springer-Verlag 53/2(2007-04-01), 114-120 1435-0211 53:2<114 2007 53 10086 https://doi.org/10.1007/s10086-006-0833-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10086-006-0833-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Rahman MD Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, 761-0795, Kagawa, Japan aut NATIONALLICENCE 700 1- Katayama Takeshi Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, 761-0795, Kagawa, Japan aut NATIONALLICENCE 700 1- Suzuki Toshisada Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, 761-0795, Kagawa, Japan aut NATIONALLICENCE 700 1- Yoshihara Yuka Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, 761-0795, Kagawa, Japan aut NATIONALLICENCE 700 1- Nakagawa Takashi Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, 761-0795, Kagawa, Japan aut NATIONALLICENCE 773 0- Journal of Wood Science Springer-Verlag 53/2(2007-04-01), 114-120 1435-0211 53:2<114 2007 53 10086 Metadata rights reserved Springer special CC-BY-NC licence nationallicence SWISSBIB 463247884 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer