Oligolignans in Norway spruce and Scots pine knots and Norway spruce stemwood

Abstract

Oligolignans present in substantial amounts in Norway spruce and Scots pine knots were characterised. The hydrophilic knotwood substances were extracted and different chromatographic methods were applied to obtain fractions for analysis by GC, GC-MS, HR-EI-MS, LC-ESI-MS, NMR, and FTIR. b-O-4-Linked guaiacylglyceryl ethers of hydroxymatairesinol (Ia, Ib, Ic), secoisolariciresinol (II), lariciresinol (III), isolariciresinol (IV), lignan A (V), liovil (VI), conidendrin (VII), and pinoresinol (VIII) were identified in the spruce knotwood extract and b-O-4-linked guaiacylglyceryl ethers of nortrachelogenin (IX) and secoisolariciresinol (II) in the pine knotwood extract. The structures of allo-hydroxymatairesinol-49-guaiacylglyceryl ether (Ia), hydroxymatairesinol-4-guaiacylglyceryl ether (Ib), hydroxymatairesinol-49-guaiacylglyceryl ether (Ic), secoisolariciresisinol-4-guaiacylglyceryl ether (II), and lariciresinol-49-guaiacylglyceryl ether (III) were determined via GC-MS, HR-MS, and 1 H and 13 C NMR analyses. The structures of (Ia), (Ic), (IV), (V), (VI), (VII), and (IX) have not been reported earlier. Spruce stemwood, both heartwood and sapwood, also contained oligolignans in small amounts. In addition, some dilignans with four phenylpropanoid units were tentatively identified in the hydrophilic knotwood substances.

Variation of lignans in Norway spruce (Picea abies [L.] Karst.) knotwood: within-stem variation and the effect of fertilisation at two experimental sites in Finland

“…Lignans have been regarded as end products and non-structural components of phenylpropanoid origin (Lewis and Davin 1999) and it seems that they are not altered in Norway spruce knots after maturation and heartwood formation. However, the formation of sesquilignans and dineolignans in knotwood can probably occur at some point due to the radical scavenging properties of the lignans (Willför et al 2004b(Willför et al , 2005a. Fig.…”

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“…4). On the basis of their spectroscopic data and comparison to reported literature, the compounds were identified as pinoresinol (LH-1) 7 , erythro/threoguaiacylglycerol-8-O-4'-coniferyl alcohol ether (LH-2/3) 8 , erythro/threo-guaiacylglycerol-8-O-4'-coniferyl aldehyde ether (LH-4/5) 9 , balanophonin (LH-6) 10 , 3-(α,4-dihydroxy-3-methoxybenzyl)-4-(4-hydroxy-3-methoxybenzy1) tetrahydrofuran (LH-7), capstemol (LH-8) , picrasmalignan A (LH-9) 11 , Budlenol E (LH-10) 9 , erythro/threoguaiacylglycerol-8-O-4'-pinoresinol ether (LH-11/12) 12 , scopoletin (LH-13) 13 and 2,9-dihydroxy-1(10)-aromadendren-14-oic acid 2, 14-lactone (LH-14) 14 .…”

Chemical characterization of polymerized products formed in the reactions of matairesinol and pinoresinol with the stable radical 2,2-diphenyl-1-picrylhydrazyl

“…A 1 mg ml -1 extract solution in THF was filtered on a 0.45-mm PTFE (polytetrafluoroethylene) syringe filter (VWR International, LLC, Radnor, PA, USA), and 50 ml was injected. The approximate molecular masses at different retention times in the HPSEC-ELSD chromatogram were estimated by comparing with a combination of two calibration curves: one calibration curve based on analysis of polystyrene standards with known molecular masses, and one calibration curve based on the analysis of dehydroabietic acid, pinoresinol, matairesinol, lignan sesquimers isolated from spruce and pine knots (Willför et al 2004), and lignan dimerspentamers in the lower MW GPC fractions. The correlation line of the latter curve was then extrapolated to higher molecular masses regions based on the same slope as obtained for the polystyrene standard curve.…”

“…Several oligolignans have been previously identified in knotwood of Norway spruce and Scots pine (Willför et al 2004) and the probability is high that lignan polymers are also present in wood. This is the reason why the present study is focusing on preparing and chemically characterizing lignan polymers as renewable materials.…”