The aim of the present study was to investigate the extractives of
stem from the sapwood (sW) to heartwood (hW) including the transition zone (tZ) between them by means of quantitative GC-MS, while ...the spatial distribution of four typical compounds was analysed by TOF-SIMS. The focus was on gmelinol, paulownin, 7′-
-ethyl arboreol, and β-sitosterol, which were isolated and purified from hW. The four compounds revealed a characteristic distribution pattern corresponding to their key role in biosynthesis and depending on their susceptibility to secondary reactions in the hW.
Liquefaction of ligno-cellulosic biomass is one of the chemical conversion technologies for developing new materials, adhesives and energy systems. The liquefaction process also provides an ...opportunity to utilize ligno-cellulosic wastes such as saw-dust, woody wastes, branches and twigs, agro-residues, etc. for the development of value added products. This paper presents the liquefaction behaviour of wood meal of twelve tropical hardwood species in phenol as liquefying media to produce chemically active liquid which has potential to be used as a raw material for developing different products. The liquefaction was carried out at 140°C temperatures for 120 minutes at different liquid ratios. In all the cases, a viscous and sticky black liquid was obtained after the stipulated reaction time. The liquefaction efficiency was found to vary with species and liquid ratio. The highest liquefaction efficiency of 93% was achieved in balsa wood at 1:3 (wood: phenol) liquid ratio. The liquefied wood and residues were characterized by FTIR spectroscopy. The liquefied wood was found to be highly acidic in nature. Viscosity of liquefied wood at higher liquid ratio was independent of wood species. Correlation analysis revealed a strong negative relationship between wood basic density and liquefaction efficiency.
The phytochemical investigation, including fractionation and purification of 70% acetone extracts of Juglans sigillata seed husks, an agricultural residue, led to the isolation of five low-molecular ...weight galloyltannins. The structures of the extractives were elucidated as 1,2,6-tri-O-galloyl-β-D-glucose (1), 3,4,6-tri-O-galloyl-β-D-glucose (2), 2,3,4,6-tetra-O-galloyl-β-D-glucose (3), 1,2,3,4,6-penta-O-galloyl-β-D-glucose (4), and tannic acid (5), primarily based on their spectral (NMR and MS) and chemical evidence. Galloyltannins 1-5 showed strong inhibitory activity against mushroom tyrosinase, with IC50 values ranging from 35.27 to 76.37 μM; kojic acid, which was used as a positive control, had an IC50 value of 342.14 μM. It was further found that 1-5 inhibited melanin production and exhibited intracellular tyrosinase activity, as well as down-regulated mRNA and protein expression levels of tyrosinase, in B16F10 mouse melanoma cells. Therefore, the isolated extractives from seed husks of J. sigillata may serve as potential candidates for hyperpigmentation remediation and as skin-whitening agents in the cosmetics industry.
The composition of Scots pine bark, its degradation, and the production of hydrolytic and ligninolytic enzymes were evaluated during 90
days of incubation with
Phanerochaete velutina and
Stropharia ...rugosoannulata. The aim was to evaluate if pine bark can be a suitable fungal substrate for bioremediation applications. The original pine bark contained 45% lignin, 25% cellulose, and 15% hemicellulose. Resin acids were the most predominant lipophilic extractives, followed by sitosterol and unsaturated fatty acids, such as linoleic and oleic acids. Both fungi degraded all main components of bark, specially cellulose (79% loss by
P. velutina). During cultivation on pine bark, fungi also degraded sitosterol, produced malic acid, and oxidated unsaturated fatty acids. The most predominant enzymes produced by both fungi were cellulase and manganese peroxidase. The results indicate that Scots pine bark supports enzyme production and provides nutrients to fungi, thus pine bark may be suitable fungal substrate for bioremediation.
Various types of wound-associated wood, such as discoloured wood including knots of living and dead branches, were sampled from common beech trees (
L.), extracted, and the extracts have been ...analysed by GC and colourimetry assay. Sequential pressurised solvent extraction was applied with cyclohexane and aqueous methanol. The yield of hydrophilic compounds was three to five times higher than that of lipophilic extractives. The fractions differed mainly in their hydrophilic moieties. The lipophilic extractives consisted mainly of free fatty acids, fatty alcohols and free sterols. The yield of fatty acids was slightly higher in reaction zones and knots. The content of free sterols was highest in the reaction zones and in the discoloured wood. The hydrophilic extractives consisted of soluble sugars, various acids and phenolic compounds with catechin as the dominant one. Expectedly, the yield of phenolic extractives and catechin (proanthocyanidins) was highest in knots and wound-wood. Discoloured wood gave rise to lower amounts of catechin.
The amount and composition of lipophilic and hydrophilic extractives, including proanthocyanidins, has been analysed as a first screening in the bark of six Pakistani coniferous tree species, namely ...Pinus wallichiana, Pinus roxburghii, Pinus gerardiana, Abies pindrow, Taxus fuana and Cedrus deodara. The predominant lipophilic extractives were common fatty and resin acids, fatty alcohols and sterols. In all bark samples, short-chain fatty acids were more abundant than long-chain fatty acids. Generally, the amount of free fatty acids was also larger than the amount of triglycerides. Oleic acid was the most common fatty acid, except in C. deodara, where lignoceric acid dominated. The largest amounts of fatty acids and fatty alcohols were found in P. wallichiana and P. gerardiana. P. gerardiana contained an exceptionally large amount of resin acids, approximately 3% of the bark weight, compared to the other species. The amount of free sterols was approximately at the same level or larger than the amount of steryl esters in most samples. In addition to proanthocyanidins, different known lignans, stilbenes, ferulates and flavonoids were generally predominant amongst the hydrophilic extractives. Resveratrol glycoside was abundant in P. wallichiana, while C. deodara and P. gerardiana contained large amounts of lignans and lignan derivatives. All bark extracts contained large amounts of proanthocyanidin-related catechin and its derivatives. Furthermore, C. deodara and P. roxburghii contained quite large amounts of taxifolin. In particular, P. wallichiana and A. pindrow are potential rich sources of proanthocyanidins, representing approximately 16% and 5% of the bark weight, respectively.
Microbiological degradation of wood and wood products is one of the most important of disadvantage which reduce its useful life. There are various methods to increase the natural durability of wood ...and wood products and most of them using chemical reagents. In the past, the thermal modification has been used as a ecofriendly method in many times. In this research the effects of steam pretreatment on the fungal durability of particleboard were studied. Steam pre-treatment was applied on the poplar wood particles using a stainless steel reactor at four temperature levels (155, 165, 175 and 185 ºc) and three retention times (15, 30 and 45 min). The amount of hemicelluloses, acetone extractives of wood particles as well as EMC and Mass loss of test panels were measured.The results indicated that the steam pretreatment significantly decreased the amount of hemicelluloses of wood particles, EMC and mass loss of test samples where as the amount of extractives of wood particles increased.According to the results, the variation of Mass loss of particleboard test samples showed a significant correlation to the variation of EMC of test samples, hemicelluloses and extractives amount of wood particles when the wood particles thermally pre-treated at 165ºC for 30 minutes
Flavonoids represent a large group of polyphenols that have been recognized to exert a wide range of biological effects, such as anticancer, inflammation inhibition, anti-aging, and neuroprotective ...activities. In the forest industry, tree twigs have been treated as residues; however, tree twigs could be a rich source of high-value added compounds, which have been relatively unexplored. In this study, an investigation into the chemical constituent of extractives from S. japonica twigs resulted in the isolation of a new (Z)-caffeoyl flavonol glycoside that was elucidated as myricetin 3-O-(4′′-(Z)-caffeoyl)-α-rhamnopyranoside (IV). The structure of the new compound was established mostly on the basis of extensive spectroscopic techniques and other physiochemical evidences. Among the three known flavonoids extracted in this work, including isoquercitrin (I), isorhamnetin 3′-O-β-D-glucopyranoside (II), and myricitrin (III), II and III have never been previously reported in the Sophora genus.
This article reports the first study of the influence of the Brazilian process of thermal modification called VAP HolzSysteme® on the chemical composition of Eucalyptus wood. Flatsawn boards of ...Eucalyptus grandis juvenile wood were tested for four treatment levels: untreated and thermally modified at final cycle temperatures of 140, 160 and 180 °C. Chemical analyses were carried out according to the standards of the Technical Association of the Pulp and Paper Industry and encompassed total extractives, insoluble lignin, holocellulose (cellulose + hemicelluloses) and solvent soluble extractives in water (cold and hot) and ethanol:toluene (1:2 v.v.) mixture. The chemical composition of thermally modified Eucalyptus grandis juvenile wood was significantly changed by the VAP HolzSysteme® process compared to untreated wood. Only the wood thermally modified at final cycle temperature of 180 °C was significantly different for all the chemical analyses performed compared to untreated wood.
The research results of the Siberian larch needle extractives are presented in paper. The content of extractive substances from green and yellow needles extracted by organic solvents with different ...polarities is determined. It is found out that the double increase of the yellow needle extractive substances content soluble in hydrocarbon extractant is observed, whereas it is decreased by 30%, when extracted with propan-2-ol. The group composition of needle extracts derived from isopropanol extract by petroleum ether is determined. The neutral substances content in both needle collections is practically the same, although the yellow needles contain less “bound” acids in the form of esters. High wax content is noted in the needles, which mainly consist of secondary nonacosanol-10 alcohol. The composition of free and “bound” acids in Siberian larch needles at various vegetation periods is established. The groups of higher unsaturated C18 fatty acids prevail in the needles. The resin acids are represented by isopimaric acids (isopimaric and sandaracopimaric) and abietic acids: abietic, dehydroabietic and levopiric acids. The dehydroabietic acid content is increased quadrupled in yellow needles and the hydroxy acids are identified: 15-hydroxyabietic acid and 15-hydroxyhydroabietic acids. The tri- and tetraenic C20 acids are identified among higher fatty acids.
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