Patrik C Eklund

• PhD
• Lecturer at Åbo Akademi University

Natural stilbenoids, polyphenolic compounds notably found in Scots pine and Norway spruce, have been shown to exhibit analgesic and anti‐inflammatory effects through the TRPA1 channel, making them promising hits for the development of novel agents to treat inflammatory diseases and pain. In this study, we computationally investigated the putative b...

Scots pine knotwood contains valuable amount of stilbenoids such as pinosylvin (Ps) and pinosylvin monomethyl ether (PsMME). The stilbenoids have numerous biological activities. Traditional methods of extracting stilbenoids often yield low quantities and involve complex processes. In the present study, a simple and high-yield method was proposed fo...

The design of lignin nanostructures where interfacial interactions enable enhanced entanglement of colloidal networks can broaden their applications in hydrogel‐based materials and light‐based 3D printing. Herein, an approach for fabricating surface‐active dendritic colloidal microparticles (DCMs) characterized by fibrous structures using nanostruc...

Pinosylvin monomethyl ether (PsMME) is a natural compound known for its valuable bioactive properties, including antioxidant and anti-inflammatory effects. However, PsMME’s susceptibility to photodegradation upon exposure to ultraviolet (UV) radiation poses a significant limitation to its applications in the pharmaceutical field. This study, for th...

Introduction Stilbenoid compounds have been described to have anti-inflammatory properties in animal models in vivo, and have been shown to inhibit Ca2+-influx through the transient receptor potential ankyrin 1 (TrpA1). Methods To study how stilbenoid compounds affect inflammatory signaling in vivo, we have utilized the fruit fly, Drosophila melan...

Fabricating bio‐latex colloids with core–shell nanostructure is an effective method for obtaining films with enhanced mechanical characteristics. Nano‐sized lignin is rising as a class of sustainable nanomaterials that can be incorporated into latex colloids. Fundamental knowledge of the correlation between surface chemistry of lignin nanoparticles...

Thermal transformations of polyphenols from the lignan and stilbene families were investigated at temperatures ranging from 200 ˚C to 250 ˚C, in polyethylene glycol (PEG-400), dimethylformamide (DMF) and in sunflower oil (SO). The polyphenols showed varying degrees of thermal stabilities and in some cases intramolecular transformations were observe...

The aim of this study was to examine the influence of the oxygen atmosphere on hydrothermal fractionation of Norway spruce at 130–160 °C and 1–50 bar. The quantitative kinetics and qualitative aspects of the hemicellulose extraction were studied. The results show that the fractionation can be considerably enhanced already by low concentrations of o...

The influence of oxygen (0-50 bar) on the molar mass and composition of hemicelluloses after hydrothermal treatment of spruce chips was studied in a batch reactor setup at 130 °C-160 °C. Purified galactoglucomannan was studied as a reference. The dissolved oxygen enhanced significantly the depolymerization of hemicelluloses from over 15,000 g/mol t...

A small library of 6-substituted syringyl model compounds with aliphatic, carboxylic, phenylic, benzylic alcohols and brominated substituents were prepared. The influence of the substituents on the chemical shifts of the compounds was analyzed. All of model compounds showed a characteristic increase in the ¹³ C NMR chemical shift of the methoxy gro...

The current work studies the reductive catalytic depolymerization (RCD) of lignin from a novel semi-industrial process. The aim was to obtain aromatic mono-, di-, tri-, and tetramers for further valorization. The substrate and products were characterized by multiple analytical methods, including high pressure size-exclusion chromatography (HPSEC),...

Stilbenes are plant polyphenols that have shown beneficial pharmacological activities in a variety of diseases. The considerable amount of stilbene glucosides in spruce inner bark encouraged us to develop a straightforward and simple method of extraction with high recovery and yield. Stilbene glucosides from fresh inner bark of Norway spruce were e...

The chemical composition of extractives in the sapwood (SW), heartwood (HW), knotwood (KW), and branchwood (BW of silver fir (Abies alba Mill.) was analyzed, and their antifungal and antioxidant properties were studied. In addition, the variability of extractives content in a centripetal direction, i.e., from the periphery of the stem towards the p...

Ibuprofen (IBU) and diclofenac (DCF) are non-steroidal anti-inflammatory pharmaceuticals. They are frequently detected in wastewater and in the environment. Due to their harmful effect on aquatic organisms, new methods should be developed to enhance their removal from wastewater. One efficient wastewater treatment process is ozonation. In this stud...

Softwood bark is an important by-product of forest industry. Currently, bark is under-utilized and mainly directed for energy production, although it can be extracted with hot water to obtain compounds for value-added use. In Norway spruce (Picea abies [L.] Karst.) bark, condensed tannins and stilbene glycosides are among the compounds that compris...

Improved methods for one-pot propargylation and Claisen rearrangement have been devised for natural lignans – matairesinol and α-conidendrin. The rearrangement was regiospecific, yielding only 2-methylbenzofuran derivatives.

Aiming at tailoring the bonding strength of a thermosetting lignin-containing phenol-formaldehyde (LPF) wood adhesive, different fractions of an industrial hardwood alkaline lignin have been prepared through sequential solvent fractionation (i-PrOH, EtOH, and MeOH). Those fractions were comprehensively characterized by GPC, GC, Py/GC-MS, and NMR te...

The presence of pharmaceuticals in surface water, drinking water, and wastewater has attracted significant concern because of the non-biodegradability, resistance, and toxicity of pharmaceutical compounds. The catalytic ozonation of an anti-inflammatory pharmaceutical, ibuprofen was investigated in this work. The reaction mixture was analyzed and m...

Carbamazepine (CBZ) is a recalcitrant pharmaceutical often detected in wastewater and in the environment. CBZ can be removed from wastewater through advanced oxidation treatment methods such as ozonation. In this study, CBZ and its transformation product 1-(2-benzaldehyde)-(1H,3H)-quinazoline-2,4-dione (BQD) were ozonated, and the formation and tra...

The degradation of the pharmaceutical compound diclofenac in an aqueous solution was studied with an advanced oxidation method, catalytic ozonation. Diclofenac was destroyed in a few minutes by ozonation but several long-lasting degradation by-products were formed. For this reason, the combination of heterogeneous catalysts and ozonation was applie...

Epoxidation of the C=C double bond in unsaturated norlignans derived from hydroxymatairesinol was studied. The intermediate epoxides were formed in up to quantitative conversions and were readily further transformed into tetrahydrofuran, aryltetralin, and butyrolactone products—in diastereomeric mixtures—through ring-closing reactions and intramole...

Bark of Norway spruce (Picea abies [L.] Karst.) trees contains large amounts of polyphenolic stilbene glucosides. Stilbene-rich bark extracts could be utilized as e.g., preservatives due to their antioxidative, antifungal, and antibacterial properties. As stilbenes are photosensitive compounds, ultraviolet (UV) light induces a well-known intramolec...

Carbamazepine (CBZ), a widely used pharmaceutical compound, is one of the most detected drugs in surface waters. The purpose of this work was to identify an active and durable catalyst, which, in combination with an ozonation process, could be used to remove CBZ and its degradation products. It was found that the CBZ was completely transformed afte...

The vast majority of cervical and 75% of oropharyngeal carcinomas are triggered by infection with a type of high-risk oncogenic human papillomavirus (HPV). It is well-known that E6 and E7 oncoproteins are critical for viral-induced cancer, and hence, they represent valuable targets for therapeutic intervention in HPV-mediated cancers. Our earlier r...

The main aim of this study was to chemically characterise the polymeric fraction of birch pulp extractives. We showed that 70–96% of the material in extracts of fully bleached birch kraft elemental chlorine-free (ECF) pulp from three Finnish mills consists of compounds that are undetectable by conventional gas chromatography (GC) analysis, i.e. hig...

Aerobic Pd(AcO)2/pyridine-catalyzed oxidation of unprotected carbohydrate-based terminal alkenes was studied. In accordance with previous reports, the initial reaction step gave methyl ketones. However, our substrates partially gave subsequent α,β-water elimination and alcohol oxidation to α,β-unsaturated 2,5-diketones. Upon increasing the pressure...

The amount of hydroxyl groups is a crucial parameter when characterizing lignin as a raw material and when developing lignin-based applications. Currently, the most common method used for quantitative hydroxyl group determination is 31 P nuclear magnetic resonance (NMR) spectroscopy after phosphitylation of the hydroxyl groups. The method relies on...

In this work we have analyzed the pine and spruce softwood lignin fraction recovered from a novel pressurized hot water extraction pilot process. The lignin structure was characterized using multiple NMR techniques and the thermal properties were analyzed using thermal gravimetric analysis. Acetylated and selectively methylated derivatives were pre...

Numerous oxidative transformations of lignan structures have been reported in the literature. In this paper we present an overview on the current findings in the field. The focus is put on transformations targeting a specific structure, a specific reaction, or an interconversion of the lignan skeleton. Oxidative transformations related to biosynthe...

Lignin has the potential to become a significant resource of renewable aromatics for the chemical industry. The current work studies pulsed corona discharge (PCD) as an alternative method for lignin modification. The effect of initial lignin concentration and gas phase composition on aldehydes formation was studied experimentally. Kraft lignin was...

In this work we have characterized a mild soda pulped birch (betula pendula) lignin after a novel pressurized hot water extraction pilot process. In the process hemicelluloses are first isolated from woods chips with hot water at oxygen-starved conditions, followed by mild alkali pulping at oxygen-starved conditions to remove lignin from the cellul...

The presence of pharmaceutical compound residues in water bodies is becoming an increasingly serious problem. Various pharmaceuticals have been detected in raw municipal wastewaters, after wastewater treatment plant processes, and even in drinking water. Many common pharmaceuticals are bio-accumulating and they can have a harmful impact on aquatic...

The identification of compounds in Scots pine (Pinus sylvestris L.) knotwood (KnW), obtained by extracting with hydrophilic organic solvents, has been performed previously almost exclusively by gas chromatography-mass spectrometry (GS-MS) equipped with long GC columns (≥25 m). That means that the molar mass (MM) of the majority of the identified co...

Methods for the preparation of phosphites and phosphates from chiral diols based on lignan backbones were developed. Four novel phosphites and one phosphate were synthesized and characterized. Sterically hindered diols showed diastereoselectivity in formations of phosphites, whereas non-hindered diols showed no selectivity.

In our upper-level undergraduate laboratory course in organic chemistry we focus on a research-oriented task in a context-based and problem-based learning approach. The course starts with a preliminary training period where the students learn how to safely and independently perform synthesis and purification procedures and to operate the most commo...

The structures of the naturally occurring lignan hydroxymatairesinol (HMR) and TADDOL-like -conidendrin-based chiral 1,4-diols (LIGNOLs) have been studied at DFT/B3LYP/TZVP level of theory, for the first time applying the density functional dispersion correction (DFT-D3) [1] and employing the BJ-damping (-D3(BJ)) [2]. This study establishes the nec...

Abstract Nanofibrillated cellulose (NFC)-Norway spruce O-acetyl-galactoglucomannan (GGM) composite films were coated either with a novel succinic ester of GGM or with native GGM. NFC films were made for reference. The succinic ester of GGM was synthesised at low (GGM-Su1) and high (GGM-Su2) degree of substitution to obtain different level of water...

Highly efficient methods for synthetic modifications of the natural lignan hydroxymatairesinol into chiral diphosphines similar to DIOP were developed. Catalytic activity and induction of enantioselectivity for the prepared phosphines were evaluated in rhodium catalyzed hydrogenations of different functionalized alkenes. High catalytic activities w...

A major enhancement of grease and water vapor barrier properties was accomplished with a 1–10 g/m2 coating of O-acetyl galactoglucomannan (GGM) ester or with GGM coatings applied as water dispersions on cartonboard. GGMs were esterified with phthalic and benzoic anhydrides, respectively. The novel phthalic esters of GGM (GGM-Ph) were characterized...

Polymer constructs are often applied in nanoparticulate systems to expand their applicability. One such common macromolecular modifier is poly(ethylene imine) - poly(ethylene glycol) copolymers. Despite their quite widespread use, and considering that interaction and stabilization mechanisms when combining a polyelectrolyte with a non-charged polym...

Galactose units of spruce galactoglucomannan (GGM), guar galactomannan (GM), and tamarind (galacto)xyloglucan (XG) were selectively allylated. Firstly aldehyde functionalities were formed at the C-6 position via enzymatic oxidation by galactose oxidase. The formed aldehydes were further derivatized by an indium mediated Barbier-Grignard type reacti...

Water-soluble O-acetyl-galactoglucomannans (GGMs) can be obtained from Norway spruce by hot-water-extraction of the wood or as a side product by ultrafiltration of mechanical pulping waters. Cationic and amphiphilic polysaccharides and their derivatives are of interest for a number of applications and thus quaternary nitrogen moieties with cationic...

Modified spruce O-acetyl galactoglucomannans (GGMs) can be used as molecular anchors to alter the surface properties or to activate the surface of cellulose. To selectively introduce functionalities, GGMs were oxidized on C-6 of hexoses by 2,2,6,6-tetramethylpiperidin-1-oxyl-mediated oxidation. Different degrees of oxidation were successfully obtai...

The extraction conditions have been evaluated concerning the recovery of specific polyphenols from Scots pine (Pinus sylvestris) knots by means of an accelerated solvent extractor. The composition of the extracts was determined by gas chromatography, gas chromatography-mass spectrometry, and high-performance size-exclusion chromatography. The main...

Methods for synthetic modifications of the natural dibenzylbutyrolactone lignan hydroxymatairesinol into chiral 1,4-diols with different lignan-derived backbones have been developed. A stepwise procedure, involving alkylation and oxidation, was shown to be successful and several highly substituted 1,4-diols were prepared. Some substituted butyrolac...

A class of nonionic polysaccharides-based surfactants were synthesised from O-acetyl galactoglucomannan (GGM), water-soluble hemicelluloses from spruce, using naturally-occurring saturated fatty acids, CH3(CH2)nCOOH (n = 7, 12, and 16). Hemicelluloses can be recovered from waste-streams of papermaking and agricultural processes or isolated by hot w...

The antimicrobial effects of the wood-associated polyphenolic compounds pinosylvin, pinosylvin monomethyl ether, astringin, piceatannol, isorhapontin, isorhapontigenin, cycloXMe, dHIMP, ArX, and ArXOH were assessed against both Gram-negative (Salmonella) and Gram-positive bacteria (Listeria monocytogenes, Staphylococcus epidermidis, Staphylococcus...

The readily available natural lignan hydroxymatairesinol was transformed into sterically hindered and optically pure diphenyl, di-2-naphthyl, and tetramethyl 1,4-diol derivatives via arylation/alkylation of the aryltetralinbutyrolactone lignan (−)-conidendrin. In addition, the diastereoselective formation of stable hemiketals from the highly substi...

Molecular dynamics (MD) simulations were performed on sterically hindered α-conidendrin-based chiral 1,4-diols (LIGNOLs) from the naturally occurring lignan hydroxymatairesinol (HMR) using the GROMACS software. The aim of this study was to explore the conformational behaviour of the LIGNOLs in aqueous solution adopting the TIP4P model. The topologi...

Galactoglucomannan (GGM) is a polysaccharide mainly consisting of mannose, glucose, and galactose. GGM is the most abundant hemicellulose in the Norway spruce (Picea abies), but is also found in the cell wall of flax seeds, tobacco plants, and kiwifruit. Although several applications for GGM polysaccharides have been developed in pulp and paper man...

In seed extracts of five oilseed species, in bran extracts of three cereal species, and in seed and/or whole berry extracts of 10 berry species, the concentrations of a large number of lignans and the enantiomeric composition of selected lignans were determined. In the case of sesame and hemp seeds, the lignan content and composition of the whole s...

In a hydrophilic extract of Norway spruce knotwood, the domi-nating lignan, 7-hydroxymatairesinol, was partially removed by precipitation, and the resulting mixture was fractionated by fl ash chromatography and preparative high-performance liquid chromatography (HPLC). In the HPLC fractions, 7 S -and 7 R -todolactol A, 7 ′ -hydroxylariciresinol, an...

The forest industries are developing new innovative products in addition to the traditional bulk products. A promising raw material for added-value products consists of lignans that are extracted in chemical pulping from residual knots. The anticarcinogenic and antioxidative lignan hydroxymatairesinol (HMR) is found in large amounts in the knots of...

Polymerization reactions of the lignans matairesinol and pinoresinol with the stable radical 2,2-diphenyl-1-picrylhy-drazyl (DPPH) were studied. The reactions were rapid and almost quantitative. The molecular weight distribution (MWD) of the formed lignan dimers and polymers was determined by high-performance size-exclusion chromatog-raphy (HPSEC)...

Galactoglucomannans (GGMs) are water-soluble polysaccharides released and accumulated in process waters in the production of thermomechanical pulp. The general trend in the forestry industry is moving towards bio-refineries, for example utilizing these hemicelluloses as bioactive substances. At present, there is no industrial use of wood-derived ma...

In seed extracts of five oilseed species, in bran extracts of three cereal species, and in seed and/or whole berry extracts of 10 berry species, the concentrations of a large number of lignans and the enantiomeric composition of selected lignans were determined. In the case of sesame and hemp seeds, the lignan content and composition of the whole s...

The structures of TADDOL-like α-conidendrin-based chiral 1,4-diols (LIGNOLs) have been studied at molecular mechanics, Hartree-Fock (HF)/6-31G* and DFT/B3LYP/TZVP level of theory. The molecules included were 1,1-diphenyl, two diastereomers of 1,1,4-triphenyl, 1,1,4,4-tetraphenyl, and 1,1,4,4-tetramethyl 1,4-diol. Several conformers of each molecule...

Phytoestrogens are plant-derived food ingredients assumed to contribute to the prevention of hormone-dependent cancers, osteoporosis, cardiovascular disease, and menopausal symptoms. Lignans occur in numerous food plants and various structures; they are common constituents of human diet, and estrogen activity has been assessed for lignan metabolite...

The model complex [(64)Cu((S)-p-NH(2)-Bn-NOTA)](-) ([(64)Cu]1) was used to study the isomerism of [(64)Cu-NOTA-Bn]-labeled radiotracers. Two complex isomers [(64)Cu]1a and [(64)Cu]1b, which were formed at a ratio of 1:9 during the complexation of [(64)Cu]Cu(2+) with (S)-p-NH(2)-Bn-NOTA, were separated using ion pair chromatography. To study the int...

Natively acetylated galactoglucomannans (GGMs) is the main hemicellulose type in most softwood species and can be utilised as, for example, bioactive polymers, hydrocolloids, papermaking chemicals, or coating polymers. In this study, carboxymethylated GGMs (CM-GGMs) were prepared and characterised by GC-MS, 1H 13C NMR and FTIR spectroscopy, and SEC...

Multidrug resistance protein 1 (MRP1/ABCC1) is one of the drug efflux pumps mediating multidrug resistance in several cancer types. Efficient nontoxic inhibitors of MRP1-mediated transport are sought to potentially sensitise cancer cells to anticancer drugs. This study examined the potency of a series of plant lignans and norlignans of various stru...

A convenient semi-synthesis of (8R,8'R)-matairesinol 4,4'-di-O-beta-d-glucopyranoside (MDG), found in the stems of Trachelospermum asiaticum var. intermedium, is described starting from the readily available starting materials d-glucose and hydroxymatairesinol. By this approach the synthesis of MDG can be accomplished in six steps with an overall y...

The C-6 unit of methyl α-D-galactopyranoside was selectively modified by combining enzymatic oxidation with an indium-mediated allylation reaction. The Barbier-Grignard type reaction, where a carbonyl group reacts with an allyl halide, proceeds in aqueous solution, even with water as the only solvent; thus carbohydrates can be modified without the...

Acetylated galactoglucomannans (GGMs) are the main hemicellulose type in most softwood species and can be utilized as, for example, bioactive polymers, hydrocolloids, papermaking chemicals, or coating polymers. Acetylation of spruce GGM using acetic anhydride with pyridine as catalyst under different conditions was conducted to obtain different deg...

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been shown to be selectively pro-apoptotic in cancer cells, with minimal toxicity to normal tissues. Although this feature makes TRAIL a promising anticancer agent, not all cancer cell types are sensitive to TRAIL-induced apoptosis despite abundant expression of TRAIL receptors. Th...

X-ray structures of two compounds isolated from wood knots of coniferous trees, namely dihydrokaempferol (3,5,8,13-tetrahydroxyflavanon) and lariciresinol (3,14-dimetoxy-7,10-epoxylignan-4,15,19-triol), are presented here. Diffraction data for the dihydrokaempferol crystals were collected on a CAD4 diffractometer and on a synchrotron for the larici...

We report here the first selective de-O-methylation of a large panel of guaiacyl lignans to the corresponding catechol derivatives by using IBX as primary oxidant under green conditions (dimethyl carbonate-H(2)O solvent) through an in situ reduction procedure. The influence of the catechol moiety on the cytotoxicity and genotoxicity of new lignan d...

Highly oxidized lignans produced during the cytochrome P-450 metabolism in the cells show biological activities significantly different from those of their parent natural compounds. Lignans precursors of mammalian enterolignans were treated with a methyltrioxorhenium/hydrogen peroxide catalytic system to afford new compounds oxidized at benzylic as...

Lignans are natural bioactive polyphenols widely distributed in the plant kingdom. To determine the amount and composition of lignans in plant materials, you first separate them from the plant matrix using solvent extraction. The outcome of the analysis is highly dependent on the sampling procedure and pretreatment [1]. Another crucial step is the...

Knots in trees, i.e. the branch bases inside stems, contain extraordinary high amounts of polyphenols, which are potent natural antioxidants and biocides. Studies of more man 50 tree species have shown that knots, in most of the studied species, contain remarkably higher amounts of polyphenols titan the adjacent stemwood, for many species 20-100 ti...

The fragmentation pattern of 30 compounds belonging to different classes of the lignan family was studied by liquid chromatography-electrospray ionization ion-trap mass spectrometry. On the basis of the observed fragmentation patterns, identification of different types of lignans was achieved. For example, dibenzylbutyrolactone lignans showed a cha...

Geheimnisse der Kiefernrinde: Das Spirodienon-Sesquineolignan Pinobatol (1), eine seit langem vermutete Monomereinheit von Lignin, wurde nach Extraktion der Rinde von Pinus sylvestris L. mit 70 % wässrigem Aceton isoliert. Die Struktur von 1 wurde durch hochauflösende EI-Massenspektrometrie und eine Kombination von NMR-Spektroskopietechniken bestim...

Barking up the right tree: The spirodienone sesquineolignan pinobatol (1), a long-time speculated monomeric unit of lignin, was isolated from the 70 % aqueous acetone extract of pine (Pinus sylvestris L.) bark. Its structure was determined by high-resolution electron ionization mass spectrometry and a variety of NMR spectroscopic techniques.

Flavonoids have recently been found in large amounts in knotwood and stemwood of several tree species. Six flavonoids, two flavonoid glucosides, and one cinnamic acid derivative were isolated from Jack pine and European aspen knotwood and structurally characterised using GC-MS, HR-MS, and NMR spectroscopic analyses. Isolated compounds were further...

Twenty-four plant lignans were analyzed by high-performance liquid chromatography−tandem mass spectrometry in bran extracts of 16 cereal species, in four nut species, and in two oilseed species (sesame seeds and linseeds). Eighteen of these were lignans previously unidentified in these species, and of these, 16 were identified in the analyzed sampl...

Screening of 400 Streptomyces strains for biotransformation of the natural lignan matairesinol led to the identification of Streptomyces sp. LS136, capable of producing a single metabolite in moderate yields. Isolation and purification by preparative HPLC, followed by structural analyses by LC-MS and NMR, established the structure as matairesinol-4...

The lignans matairesinol (MAT) and secoisolariciresinol (SECO) were fed to Min mice at 0.02% (w/w) in diet to study their effects on intestinal tumor development. The mean number (67 vs. 51, P=0.052) and size (1.4 vs. 1.2 mm, P=0.011) of tumors in the MAT group was elevated when compared with the control group. Tumor formation of the SECO group did...

The antioxidant activity, in terms of radical scavenging capacity, of altogether 15 different lignans was measured by monitoring the scavenging of the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). The effect of differences in skeletal arrangement or the degree of oxidation of the lignans was investigated in a structure-activity relationship st...

A few lignans, that is, 7-hydroxymatairesinol, secoisolariciresinol, lariciresinol, and nortrachelogenin, predominate in a large proportion of the industrially important softwood species used. Some other lignans, of which some still are unidentified, are also present in lower amounts. Softwood knots, i.e., the branch bases inside tree stems, common...

Recently it was found that cell cultures and plants of Linum species contain lignans of various chemical structures. The stereochemistry of these compounds differ among species. Cell cultures of L. album accumulate (-)-podophyllotoxin together with pure (-)-secoisolariciresinol. The presence of both enantiomers of the precursor pinoresinol indicate...

Ten potential lignan metabolites were quantified in rat urine extracts using liquid chromatography-tandem mass spectrometry. The rats were orally administered with the plant lignans 7-hydroxymatairesinol, matairesinol, lariciresinol or secoisolariciresinol, or with the mammalian lignan enterolactone. The samples were enzymatically hydrolysed and so...

The natural lignan hydroxymatairesinol was hydrogenolysed to a potential anticarcinogenic substance matairesinol over different carbon-supported palladium catalysts. The reaction was conducted in 2-propanol at 70C under hydrogen flow in a stirred glass reactor. The catalysts were characterised by N2-physisorption, CO pulse chemisorption and pH meas...

Research in our group has revealed that softwood knots, i.e. the branch bases inside tree stems, commonly contain 5-10% (w/w) of free lignans. A few lignans dominate in most industrially important softwood species, the most common lignans being 7-hydroxymatairesinol, secoisolariciresinol, lariciresinol, and nortrachelogenin. In addition, some minor...

The chemical properties and synthetic modifications of the natural lignan hydroxymatairesinol in basic and acidic nucleophilic media were studied. Hydroxymatairesinol presumably reacts via a quinone methide and a carbonium ion mechanism under basic and acidic conditions, respectively. In these conditions the benzylic hydroxyl group was displaced by...

When the natural lignan hydroxymatairesinol (1) was treated with an alkaline aqueous solution, it partially rearranged to isomeric forms of a lariciresinol-type butyrolactone lignan. The two major diastereomers formed (2 and 3) were isolated by column and medium-pressure chromatography, and their structures were elucidated by MS and NMR techniques....

Conformations of the two diastereomers of the natural lignan hydroxymatairesinol (HMR) from Norway Spruce (Picea abies), their interactions with alkali metal cations Na+ and K+, and the mechanism and some other aspects of the dehydrogenation reaction between HMR and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) were studied computationally with m...

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. beta-O-4-Linked guaiacylglyceryl ethers of hydroxymatairesinol...

The antioxidant potency and the radical scavenging capacity of superoxide and peroxyl radicals were assessed for 13 hydrophilic knotwood extracts of commercially important wood species, or fractions thereof, as well as for five pure wood-derived lignans and the flavonoid taxifolin. The chemical composition of the knotwood extracts was determined by...

The oxidative transformation of the two isomers of the natural lignan hydroxymatairesinol from Norway Spruce (Picea abies) by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), has been studied. Significant differences in the outcome of the reactions were observed when the pure isomers of hydroxymatairesinol were reacted with DDQ under the same condi...