Phenolic and Lipophilic Extractives in Scots Pine Knots and Stemwood

Holzforschung ◽  
2003 ◽  
Vol 57 (4) ◽  
pp. 359-372 ◽  
Author(s):  
S. Willför ◽  
J. Hemming ◽  
M. Reunanen ◽  
B. Holmbom

Summary The phenolic and lipophilic extractives in the heartwood of knots from seven Scots pine trees were analysed by GC, GC-MS and HPSEC. The knots contained large amounts of phenolic stilbenes, 1–7% (w/w), and lignans, 0.4–3% (w/w), while the stemwood contained around 1% (w/w) of stilbenes and no detectable lignans. In young trees without stem heartwood the stilbene content in the knots was up to 200 times that in the stem. Some in-tree and between-tree variation was seen in the content of phenolic compounds in the knots. The ratio of pinosylvin monomethyl ether to pinosylvin was higher in the knots than in the stemwood. The most abundant lignan was nortrachelogenin, but also matairesinol, secoisolariciresinol and liovil were present in small amounts in the knots. The knots also contained a complex mixture of lignan-like compounds, here called oligolignans. The flavonoid pinocembrin was present in both stemwood and knots in amounts below 0.02% (w/w). The stilbene concentration in the radial direction, from the pith to the outer branch, decreased or was on the same level inside the stem, while it decreased markedly in the outer branch. The lignan concentration was on the same level or decreased slightly inside the stem, while it decreased markedly in the branches and became almost non-existent within 10 cm out in the branches. The knots contained large amounts (4.5–32% (w/w)) of lipophilic extractives, mainly resin acids. Some in-tree and between-tree variation was seen for the resin acids. The abietane-type resin acids dominated over the pimarane-type acids and abietic acid was the most abundant resin acid in the knots and in stem heartwood. The amount of resin acids in the radial direction decreased or was on the same level inside the stem, while a clear decrease was detected in the branches. The profile of the distribution of resin acids and phenolic compounds was similar. The knots also contained up to 0.5% (w/w) of diterpenyl aldehydes.

Holzforschung ◽  
2002 ◽  
Vol 56 (5) ◽  
pp. 479-486 ◽  
Author(s):  
A. M. Harju ◽  
P. Kainulainen ◽  
M. Venäläinen ◽  
M. Tiitta ◽  
H. Viitanen

Summary The concentration of individual resin acids and the equilibrium moisture content at a relative humidity of 100% were studied in brown-rot resistant and susceptible Scots pine (Pinus sylvestris L.) heartwood. About 90% of the resin acids in the heartwood were of the abietane type, abietic acid being the most abundant. The concentration of resin acids was higher in the decay-resistant heartwood than in the decay-susceptible heartwood. Resin acids are presumably in part responsible for the decay resistance of Scots pine heartwood. However, no clear relationship was found between the concentration of resin acids and the equilibrium moisture content. The role of resin acids may also be ascribed to mechanisms other than their hydrophobic properties alone. The reasons for the slight differences in moisture content between the decay classes require further study.


Holzforschung ◽  
2003 ◽  
Vol 57 (1) ◽  
pp. 27-36 ◽  
Author(s):  
S. Willför ◽  
J. Hemming ◽  
M. Reunanen ◽  
C. Eckerman ◽  
B. Holmbom

Summary The hydrophilic and lipophilic extractives in the heartwood of knots from 7 Norway spruce trees were analysed by GC, GC-MS and HPSEC. The knots contained extremely large amounts of lignans, 6–24% (w/w), with hydroxymatairesinol comprising 65–85% of the lignans. Even the knots of the young trees contained 4–8% (w/w) of lignans. The variation in the amount of lignans was large among knots, both within a single tree and between trees. In addition to the lignans, knots also contained 2–6% (w/w) of a complex mixture of lignan-like compounds with 3, 4 and even up to 6 phenyl propane units, here called oligolignans. The amounts of lignans in the knots were similar in the radial direction from the pith into the outer branch, but decreased dramatically outwards in the branch, almost disappearing after 10–20 cm. The ratio of the 2 epimers of hydroxymatairesinol differed between different knots and even within the knot. A new spruce lignan, nortrachelogenin, or its enantiomer, wikstromol, was detected in knots from trees in northern Finland as opposed to samples from southern Finland. The amount of lipophilic extractives was small compared to the amount of hydrophilic extractives in the knots. Five of the dead knots contained more resin acids and free diterpenyl alcohols than ordinary stemwood. In the other knots, the amount of lipophilic extractives was on the same level as stem heartwood. The stem sapwood contained larger amounts of esterified fatty acids than the knots.


Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 192
Author(s):  
Erkki Verkasalo ◽  
Veikko Möttönen ◽  
Marja Roitto ◽  
Jouko Vepsäläinen ◽  
Anuj Kumar ◽  
...  

This study aimed to identify and quantify phenolic and resin acid extractive compounds in Scots pine stemwood and sawmill residues in four climatic regions of Finland to evaluate their most optimal sources for bio-based chemical biorefining and bioenergy products. The sample consisted of 140 trees from 28 stands, and sawdust lots from 11 log stands. NMR for the overall extractive analysis and HPLC for the quantitative estimation of phenolic and resin acid compounds were employed. Correlation analysis, multivariate factor analysis, principle component analysis and multiple linear regression modelling were applied for statistical analysis. HPLC identified 12 extractive compounds and NMR five more resin acids. Pinosylvin (PS), pinosylvin monomethyl ether (PSMME), and partly neolignans/lignans occurred in the largest concentrations. Wood type caused the most variation, heartwood having larger concentrations than sapwood (sawdust between them). Regional differences in the concentrations were smaller, but factor analysis distinguished the northern and the southern regions into their own groups. The results indicated higher concentrations of PS, PSMME, and vanillic acid in southern regions and those of, e.g., PSMME glycoside, lignan 2, and neolignan 1 in northern regions. The rather low concentrations of extractives in stemwood and sawdust imply value-added products, efficient sorting and/or large raw material volumes.


Holzforschung ◽  
2007 ◽  
Vol 61 (3) ◽  
pp. 317-322 ◽  
Author(s):  
Tor P. Schultz ◽  
Darrel D. Nicholas ◽  
Leonard L. Ingram

Abstract A major consumer concern regarding lumber in above-ground exposure such as decking is the poor dimensional stability that leads to warping, splitting, and checking. One method to increase dimensional stability is to treat lumber with a water repellent. A waterborne water repellent made from the resin acid abietic acid or a commercial source of resin acids, tall oil rosin or TOR, was tested using southern pine sapwood. In laboratory water-swelling tests, the waterborne abietic acid provided water repellency that was almost equivalent to that provided by wax, while no water repellency was observed with solventborne resin acid. Wood treated with waterborne TOR also provided good water repellency in laboratory tests and fair water repellency at up to 13 months of outdoor exposure, but the laboratory efficacy was partially reduced by a water leach. The dimensional stability (cupping and checking) and mold growth on TOR-treated lumber in above-ground exterior exposure was better than for untreated boards, but not as good as for wax-treated lumber. Analysis of the wood in southern pine tree trunks of 14 or 29 years of age of various diameters and sampled at the bottom, middle and top showed that the resin acid content in southern pine wood is quite variable. This may explain the wide variation in natural water repellency and decay resistance previously observed with untreated southern pine sapwood.


Holzforschung ◽  
2003 ◽  
Vol 57 (4) ◽  
pp. 433-439 ◽  
Author(s):  
M. Tiitta ◽  
P. Kainulainen ◽  
A. M. Harju ◽  
M. Venäläinen ◽  
A.-M. Manninen ◽  
...  

Summary This study examined the effects of physical (moisture content, water content and wood density) and chemical properties (concentration of phenolics and resin acids) on the electrical properties of Scots pine (Pinus sylvesteris L.) wood specimens. Complex impedance was measured from heartwood and sapwood specimens using frequencies between 5 kHz and 1 MHz. Significant correlation between density and electrical properties was found at high frequencies with sapwood specimens in which the extractive content was low. Moisture content had an effect on electrical properties over the whole frequency range. Electrical properties of heartwood samples with high extractive content were differently affected by the chemical and physical properties. Electrical properties were sufficient to distinguish between the samples from the brown-rot resistant and susceptible Scots pine trees.


2020 ◽  
Author(s):  
Tiina Belt ◽  
Martti Venäläinen ◽  
Michael Altgen ◽  
Anni Harju ◽  
Lauri Rautkari

Abstract The heartwood of many wood species is rich in extractives, which improve the wood material’s resistance to biological attack. Their concentration is generally higher in outer than inner heartwood, but the exact radial changes in aging heartwood remain poorly characterized. This investigation studied these radial changes in detail in Scots pine (Pinus sylvestris L.), using radial sample sequences prepared from three different trees. Stilbene and resin acid contents were first measured from bulk samples, after which the extractive contents of individual heartwood annual rings were investigated using Raman spectroscopy and fluorescence microscopy. Raman imaging and fluorescence microscopy were also used to study the cellular level distributions of extractives in different annual rings. Although there were substantial differences between the trees, the content and distribution of stilbenes seemed to follow a general radial trend. The results suggest that stilbenes are absorbed into heartwood tracheid cell walls from small stilbene-rich extractive deposits over several years and then eventually transform into non-extractable compounds in aging heartwood. Resin acids followed no consistent radial trends, but their content was strongly connected to the frequency of large extractive deposits in latewood tracheid lumens. The results highlight the variability of heartwood extractives: their content and distribution vary not only between trees but also between and even within the annual rings of a single tree. This high variability is likely to have important effects on the properties of heartwood and the utilization of heartwood timber.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Michelle Nordkvist ◽  
Maartje J. Klapwijk ◽  
La rs Edenius ◽  
Christer Björkman

AbstractMost plants are subjected to damage from multiple species of herbivores, and the combined impact on plant growth can be non-additive. Since plant response to herbivores tends to be species specific, and change with repeated damage, the outcome likely depend on the sequence and number of attacks. There is a high likelihood of non-additive effects on plant growth by damage from mammals and insects, as mammalian herbivory can alter insect herbivore damage levels, yet few studies have explored this. We report the growth response of young Scots pine trees to sequential mammal and insect herbivory, varying the sequence and number of damage events, using an ungulate-pine-sawfly system. Combined sawfly and ungulate herbivory had both additive and non-additive effects on pine growth—the growth response depended on the combination of ungulate browsing and sawfly defoliation (significant interaction effect). Repeated sawfly herbivory reduced growth (compared to single defoliation) on un-browsed trees. However, on browsed trees, depending on when sawfly defoliation was combined with browsing, trees exposed to repeated sawfly herbivory had both higher, lower and the same growth as trees exposed to a single defoliation event. We conclude that the sequence of attacks by multiple herbivores determine plant growth response.


2006 ◽  
Vol 34 (6) ◽  
pp. 1209-1214 ◽  
Author(s):  
B. Hamberger ◽  
J. Bohlmann

Diterpene resin acids, together with monoterpenes and sesquiterpenes, are the most prominent defence chemicals in conifers. These compounds belong to the large group of structurally diverse terpenoids formed by enzymes known as terpenoid synthases. CYPs (cytochrome P450-dependent mono-oxygenases) can further increase the structural diversity of these terpenoids. While most terpenoids are characterized as specialized or secondary metabolites, some terpenoids, such as the phytohormones GA (gibberellic acid), BRs (brassinosteroids) and ABA (abscisic acid), have essential functions in plant growth and development. To date, very few CYP genes involved in conifer terpenoid metabolism have been functionally characterized and were limited to two systems, yew (Taxus) and loblolly pine (Pinus taeda). The characterized yew CYP genes are involved in taxol diterpene biosynthesis, while the only characterized pine terpenoid CYP gene is part of DRA (diterpene resin acid) biosynthesis. These CYPs from yew and pine are members of two apparently conifer-specific CYP families within the larger CYP85 clan, one of four plant CYP multifamily clans. Other CYP families within the CYP85 clan were characterized from a variety of angiosperms with functions in terpenoid phytohormone metabolism of GA, BR, and ABA. The recent development of EST (expressed sequence tag) and FLcDNA (where FL is full-length) sequence databases and cDNA collections for species of two conifers, spruce (Picea) and pine, allows for the discovery of new terpenoid CYPs in gymnosperms by means of large-scale sequence mining, phylogenetic analysis and functional characterization. Here, we present a snapshot of conifer CYP data mining, discovery of new conifer CYPs in all but one family within the CYP85 clan, and suggestions for their functional characterization. This paper will focus on the discovery of conifer CYPs associated with diterpene metabolism and CYP with possible functions in the formation of GA, BR, and ABA in conifers.


1991 ◽  
Vol 27 (1) ◽  
pp. 89-93 ◽  
Author(s):  
Tero Kuoksa ◽  
Anja Hohtola
Keyword(s):  

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