Characterization methods for wood extractives

Predstavljene so različne vrste hidrofobnih lesnih lipidov, ki so možni povzročitelji onesnaženja v papirniških sistemih, prav tako pa tudi analitske metode za njihovo karakterizacijo. Podani so rezultati določitve vsebnosti trigliceridov, sterolnih estrov, sterolov, maščobnih in smolnih kislin v smrekovih in bukovih sekancih, ki so pomembna vhodna surovina v celulozno-papirni industriji. Izdelana je primerjava različnih analitskih tehnik, in sicer ekstrakcije na trdni fazi (SPE), tankoplastne kromatografije (TLC), gelske porazdelitvene kromatografije (GPC) in plinske kromatografije (GC)navedene so njihove prednosti in pomanjkljivosti pri določanju kemične sestave in lesnih ekstraktivov.Various types of hydrophobic wood lipids, believed to behave detrimentally in papermaking , are presented, as well as different analytical methods for their chemical characterization. A determination of triglycerides, steryl esters, sterols, fatty and resin acids in spruce and beech chips (important raw materials in pulp and paper industry) was performed. A comparison of results, obtained by solid phase extraction (SPE), thin layer chromatography (TLC), gel permeation chromatography (GPS) and gas chromatography (GC) was made. Advantages and drawbacks of individual analytical techniques were established

Polyphenols in different larch (Larix spp.) species

V članku so predstavljene različne vrste polifenolnih spojin, kot so npr. lignani, oligolignani in flavonoidi, ki jih najdemo v tkivih macesnov, to je dreves iz rodu Larix. Opisana je njihova biosinteza, kemijska struktura in lastnosti, med katerimi je poudarjen predvsem njihov antioksidativni potencial. Predstavljene so metode kvantitativne izolacije iz drevesnih tkiv in kemijske karakterizacije z uporabo sodobnih kromatografskih analiznih tehnik. Raziskave so pokazale, da so največje koncentracije lignanov in flavonoidov v grčah, vejah in skorji dreves. Najpomembnejši med flavonoidi v tkivih macesnov je taksifolin. Glavni predstavnik lignanov, ki jih bomo našli predvsem v grčah, je sekoizolaricirezinol, poleg njega pa sta zastopana tudi laricirezinol in ciklolaricirezinol. Polifenoli so ključnega pomena za obstojnost lesa, saj pomenijo učinkovito kemijsko zaščito pred različnimi okužbami. Zaradi visokih koncentracij bioaktivnih lignanov v grčah iglavcev bi slednje lahko rabile kot vir za tehnološko pridobivanje teh dragocenih komponent.Various types of polyphenolic compounds, such as lignans, oligolignans and flavonoids, which occur in different tissues of wood from the larch (Larix) genus, are presented in the article. Their biosynthesis, chemical structure and properties, including a distinctive antioxidative potential, are described. The methods of quantitative isolation from wood as well as their chemical characterization by means of sophisticated chromatographic analytical techniques are presented. It has been experimentally established that the highest concentrations of lignans and flavonoids are present in knots, branches and bark of trees. The most important flavonoid in larch tissues is taksifolin, while the predominating lignans in knots are secoisolariciresinol and less abundant lariciresinol and cycloisolariciresinol. The presence of polyphenols is crucial for wood durability, as these compounds represent efficient chemical protection of wood against biological decay. Due to high concentrations of bioactive lignans in knots of conifers, the latter represent a suitable source for technological production of valuable substances

Lipofilni ekstraktivi srži europskog ariša (Larix decidua Mill.)

The heartwood of two European larch trees was examined for the content of lipophilic extractives. Hexane was used as a solvent for extractions, while gas chromatography with flame ionisation detection and gas chromatography coupled to mass spectrometry were applied for analyses. Different lipophilic groups of compounds, such as fatty acids, resin acids, diterpenoids, sterols, steryl esters and triglycerides were identified and quantitatively evaluated as well as individual low molecular mass components. Distribution of heartwood lipophilics in relation to the trunk heights was also determined and their most likely biological function in wood tissues discussed. The content of hexane extract increased with stem height. Various fatty and resin acids as well as diterpenoid alcohols and sterols were characterized. The predominating lipophilic compounds identified were isopimaric acid and diterpenoid alcohol larixyl acetate. Their average concentrations in examined samples was between 2.0 and 2.5 mg/g. Higher molecular mass lipophilics, e.g. steryl esters and triglycerides, were also present with concentrations between 0.5 and 2.2 mg/g.U radu je prikazan rezultat istraživanja lipofilnih ekstraktivnih tvari u srži dvaju stabala europskog ariša. Kao otapalo za ekstrakciju primijenjen je heksan, a plinska kromatografi ja s plameno-ionizacijskim detektorom i plinska kromatografi ja povezana s masenom spektrometrijom primijenjene su za kemijske analize. Različite lipofilne grupe spojeva, kao masne kiseline, smolne kiseline, diterpenoidi, steroli, sterolni esteri i trigliceridi, identificirane su u uzorcima i kvantitativno su procijenjene. Također su identificirani i procijenjeni pojedini spojevi niskih molekularnih masa. Određena je i raspodjela lipofilnih tvari u srži s obzirom na visinu stabala i objašnjena njihova najvjerojatnija biološka uloga u drvnim tkivima. Sadržaj ekstrakta heksana povećava se s visinom stabla. Različite masne i smolne kiseline, kao i diterpenoidni alkoholi i steroli, također su zastupljeni u srži europskog ariša. Dominantni identificirani lipofilni spojevi jesu isopimarična kiselina i diterpenoidni alkohol. Njihove prosječne koncentracije u ispitivanim uzorcima kreću se između 2,0 i 2,5 mg/g. Lipofilni spojevi veće molekularne mase, npr. sterolni esteri i trigliceridi, također su otkriveni u koncentracijama između 0,5 i 2,2 mg/g

Izoliranje in karakteriziranje eteričnih olj iz storžev navadne smreke (Picea abies Karst.), evropskega macesna (Larix decidua Mill.) in rdečega bora (Pinus sylvestris L.)

Preučevana je bila ekstrakcija eteričnih olj iz svežih storžev navadne smreke, rdečega bora in evropskega macesna ter njihova kemijska karakterizacija z metodo plinske kromatografije. Identificirani so različni monoterpeni in določene njihove relativne koncentracije. Ovrednotene so tudi vsebnosti višjih terpenov in podane razlike v kemijski sestavi posameznih eteričnih olj.Extraction and chemical characterization of essential oils from the cones of Norway spruce, European larch and Scots pine are presented in the article. Various monoterpenes have been identified and their relative concentracions calculated by means of gas chromatograpy. The contents of higher terpenes in individual oils have been also evaluated and the differences in their chemical compositions discussed

Inovativna raba bukovine slabše kakovosti in ostankov

Abundant quantities of beechwood forest residues and industrial residues represent a potentially valuable raw material. Different options for the chemical processing of biomass to marketable products, as well as relevant technologies, are presented in this paper. Beechwood can be efficiently converted to platform chemicals and fuels, such as ethanol and butanol. Sophisticated delignification procedures enable energy efficient and environmentally friendly production of cellulose fibers to be used for paper and textiles, as well as to manufacture nanofibrillated and nanocrystalline cellulose. Wood fibers are suitable for the preparation of wood plastic composites, with a wide range of potential applications. Likewise, hemicellulose and lignin fractions may be conveniently used. Chemical conversion of biomass takes place within biorefineries

Influence of sampling location on sapwood group chemical composition of beech wood (Fagus sylvatica L.)

U radu je istraživan utjecaj lokaliteta uzorkovanja na grupni kemijski sastav bijeli bukovine (Fagus sylvatica L.) standardnim metodama izolacije glavnih kemijskih drvnih komponenata. Dosadašnja su istraživanja upućivala na zaključak da postoje različitosti u kemijskom sastavu uzoraka iste vrste drva s različitih lokaliteta uzorkovanja na temelju fitocenoloških kriterija (tip tla i fitocenoza), što je u ovom radu i dokazano. Dobiveni rezultati, u usporedbi s dosadašnjim istraživanjima, pokazuju povećani sadržaj akcesornih tvari i lignina, smanjeni sadržaj drvnih polioza, dok je sadržaj pepela i celuloze ostao u istim granicama. Istraživanja su pokazala, usporedbom istih kemijskih komponenata svakog lokaliteta i njihovim odnosom, da se lokaliteti uzorkovanja međusobno statistički značajno razlikuju po sadržaju akcesornih tvari i celuloze, dok se po sadržaju pepela, lignina i drvnih polioza neznatno razlikuju. Jednako su tako, na temelju fitocenoloških kriterija pojedinih lokaliteta uzorkovanja, rezultati istraživanja pokazali statističke značajne razlike samo u sadržaju akcesornih tvari.This paper deals with the influence of sampling locations on sapwood group chemical composition of beech wood (Fagus sylvatica L.) determined by standard isolation methods for major wood chemical components. Previous researches came to the conclusion that chemical composition varies between samples of the same wood species from different sampling locations based on phytocoenological criteria (soil type and phytocoenoses). This has been confirmed by this paper. Compared to previous studies, the results obtained show the increase of accessory material and lignin content, decrease of wood polyoses content, while ash and cellulose content remain unchanged. It has been shown by comparison of each location with identical chemical components and their correlation that sampling locations differ between themselves significantly (in terms of statistics) in accessory material and cellulose content, while the difference in ash, cellulose and wood polyoses content is negligible. Likewise, based on phytocoenological criteria of each sampling location, research results only show statistically significant differences in the accessory material content

Characterization methods for wood extractives

Various types of hydrophobic wood lipids, believed to behave detrimentally in papermaking , are presented, as well as different analytical methods for their chemical characterization. A determination of triglycerides, steryl esters, sterols, fatty and resin acids in spruce and beech chips (important raw materials in pulp and paper industry) was performed. A comparison of results, obtained by solid phase extraction (SPE), thin layer chromatography (TLC), gel permeation chromatography (GPS) and gas chromatography (GC) was made. Advantages and drawbacks of individual analytical techniques were established

Possibilities for Chemical Conversion of Beech Wood

This article presents chemical composition of beech wood as well as various possibilities for its chemical conversion. The useful components of beech biomass are primarily cellulose fibers, xylan and lignin. Some of the most important technological procedures for wood fractionation are described, as for example hydrolysis, fermentation, pyrolysis and extraction, together with marketable products which are produced in the processes. The greatest potential for the future is ascribed to the production of nanofibrilated cellulose, which is considered to become the raw material of the future. Recent research has indicated that beech wood and bark contain high added value bioactive compounds, while seeds are extremely reach source of high quality oil. Beech wood, including waste such as bark and sawdust, represent reach raw material which might be conveniently converted to different marketable products

Polyphenols in different larch (Larix spp.) species

Various types of polyphenolic compounds, such as lignans, oligolignans and flavonoids, which occur in different tissues of wood from the larch (Larix) genus, are presented in the article. Their biosynthesis, chemical structure and properties, including a distinctive antioxidative potential, are described. The methods of quantitative isolation from wood as well as their chemical characterization by means of sophisticated chromatographic analytical techniques are presented. It has been experimentally established that the highest concentrations of lignans and flavonoids are present in knots, branches and bark of trees. The most important flavonoid in larch tissues is taksifolin, while the predominating lignans in knots are secoisolariciresinol and less abundant lariciresinol and cycloisolariciresinol. The presence of polyphenols is crucial for wood durability, as these compounds represent efficient chemical protection of wood against biological decay. Due to high concentrations of bioactive lignans in knots of conifers, the latter represent a suitable source for technological production of valuable substances