Can we improve pollen season definitions by using the symptom load index in addition to pollen counts?

Airborne pollen measurements are the foundation of aerobiological research and provide essential raw data for various disciplines. Pollen itself should be considered a relevant factor in air quality. Symptom data shed light on the relationship of pollen allergy and pollination. The aim of this study is to assess the spatial variation of local, regional and national symptom datasets. Ten pollen season definitions are used to calculate the symptom load index for the birch and grass pollen seasons (2013-2014) in Austria. (1) Local, (2) regional and (3) national symptom datasets are used to examine spatial variations and a consistent pattern was found. In conclusion, national datasets are suitable for first insights where no sufficient local or regional dataset is available and season definitions based on percentages provide a practical solution, as they can be applied in regions with different pollen loads and produce more constant results.

Volatile organic compounds emitted from silver birch of different provenances across a latitudinal gradient in Finland

Climate warming is having an impact on distribution, acclimation and defence capability of plants. We compared the emission rate and composition of volatile organic compounds (VOCs) from silver birch (Betula pendula (Roth)) provenances along a latitudinal gradient in a common garden experiment over the years 2012 and 2013. Micropropagated silver birch saplings from three provenances were acquired along a gradient of 7° latitude and planted at central (Joensuu 62°N) and northern (Kolari 67°N) sites. We collected VOCs emitted by shoots and assessed levels of herbivore damage of three genotypes of each provenance on three occasions at the central site and four occasions at the northern site. In 2012, trees of all provenances growing at the central site had higher total VOC emission rates than the same provenances growing at the northern site; in 2013 the reverse was true, thus indicating a variable effect of latitude. Trees of the southern provenance had lower VOC emission rates than trees of the central and northern provenances during both sampling years. However, northward or southward translocation itself had no significant effect on the total VOC emission rates, and no clear effect on insect herbivore damage. When VOC blend composition was studied, trees of all provenances usually emitted more green leaf volatiles at the northern site and more sesquiterpenes at the central site. The monoterpene composition of emissions from trees of the central provenance was distinct from that of the other provenances. In summary, provenance translocation did not have a clear effect in the short-term on VOC emissions and herbivory was not usually intense at the lower latitude. Our data did not support the hypothesis that trees growing at lower latitudes would experience more intense herbivory, and therefore allocate resources to chemical defence in the form of inducible VOC emissions.

Climate change-induced vegetation change as a driver of increased subarctic biogenic volatile organic compound emissions

Emissions of biogenic volatile organic compounds (BVOCs) have been earlier shown to be highly temperature sensitive in subarctic ecosystems. As these ecosystems experience rapidly advancing pronounced climate warming, we aimed to investigate how warming affects the BVOC emissions in the long term (up to 13 treatment years). We also aimed to assess whether the increased litterfall resulting from the vegetation changes in the warming subarctic would affect the emissions. The study was conducted in a field experiment with factorial open-top chamber warming and annual litter addition treatments on subarctic heath in Abisko, northern Sweden. After 11 and 13 treatment years, BVOCs were sampled from plant communities in the experimental plots using a push-pull enclosure technique and collection into adsorbent cartridges during the growing season and analyzed with gas chromatography-mass spectrometry. Plant species coverage in the plots was analyzed by the point intercept method. Warming by 2 °C caused a 2-fold increase in monoterpene and 5-fold increase in sesquiterpene emissions, averaged over all measurements. When the momentary effect of temperature was diminished by standardization of emissions to a fixed temperature, warming still had a significant effect suggesting that emissions were also indirectly increased. This indirect increase appeared to result from increased plant coverage and changes in vegetation composition. The litter addition treatment also caused significant increases in the emission rates of some BVOC groups, especially when combined with warming. The combined treatment had both the largest vegetation changes and the highest BVOC emissions. The increased emissions under litter addition were probably a result of a changed vegetation composition due to alleviated nutrient limitation and stimulated microbial production of BVOCs. We suggest that the changes in the subarctic vegetation composition induced by climate warming will be the major factor indirectly affecting the BVOC emission potentials and composition.

Ultrafine Betulin Formulation with Biocompatible Carriers Exhibiting Improved Dissolution Rate

The purpose of this research was to develop new methods of increasing dissolution rate and solubility of betulin extracted from birch bark. The ultrafine formulation of betulin with polyethylene glycol and β-glycine was obtained by freeze-drying. The rate of release of betulin from the formulation into water was significantly higher in comparison with the initial betulin sample and its composite with polyethylene glycol obtained by ball-milling.

Decomposition of birch leaves in heavily polluted industrial barrens: relative importance of leaf quality and site of exposure

The decrease in litter decomposition rate in polluted habitats is well documented, but the factors that explain the observed variation in the magnitude of this pollution effect on litter decomposition remain poorly understood. We explored effects of environmental conditions and leaf quality on decomposition rate of mountain birch (Betula pubescens ssp. czerepanovii) leaves in a heavily polluted industrial barren near the nickel-copper smelter at Monchegorsk. Litter bags filled with leaves collected from two heavily polluted barren sites and from two control forest sites were buried at 2.5-cm depth and exposed for 2 and 4 years at each of these four sites. The relative mass loss of native leaves in the industrial barren during 2 years of exposure was reduced to 49% of the loss observed in the unpolluted forest. We found a similar reduction in mass loss when leaves from control sites were exposed to polluted sites and when leaves from polluted sites were exposed to control sites. We conclude that the reduction in leaf litter decomposition in an industrial barren is caused by pollution-induced changes in both environmental conditions and leaf quality. This reduction is much smaller than expected, given the four-fold decrease in soil microbial activity and nearly complete extinction of saprophagous invertebrates in the polluted soil. We suggest that a longer snowless period and higher spring and summer temperatures at the barren sites have partially counterbalanced the adverse effects caused by the toxicity of metal pollutants.

Ligand Recognition of the Major Birch Pollen Allergen Bet v 1 is Isoform Dependent

Each spring millions of patients suffer from allergies when birch pollen is released into the air. In most cases, the major pollen allergen Bet v 1 is the elicitor of the allergy symptoms. Bet v 1 comes in a variety of isoforms that share virtually identical conformations, but their relative concentrations are plant-specific. Glycosylated flavonoids, such as quercetin-3-O-sophoroside, are the physiological ligands of Bet v 1, and here we found that three isoforms differing in their allergenic potential also show an individual, highly specific binding behaviour for the different ligands. This specificity is driven by the sugar moieties of the ligands rather than the flavonols. While the influence of the ligands on the allergenicity of the Bet v 1 isoforms may be limited, the isoform and ligand mixtures add up to a complex and thus individual fingerprint of the pollen. We suggest that this mixture is not only acting as an effective chemical sunscreen for pollen DNA, but may also play an important role in recognition processes during pollination.

Aceroside VIII is a new natural selective HDAC6 inhibitor that synergistically enhances the anticancer activity of HDAC inhibitor in HT29 cells

The identification of new isoform-specific histone deacetylase inhibitors is important for revealing the biological functions of individual histone deacetylase and for determining their potential use as therapeutic agents. Among the 11 zinc-dependent histone deacetylases that have been identified in humans, histone deacetylase 6 is a structurally and functionally unique enzyme. Here, we tested the inhibitory activity of diarylheptanoids isolated from Betula platyphylla against histone deacetylase 6. Aceroside VIII selectively inhibited histone deacetylase 6 catalytic activity and the combined treatment of aceroside VIII or (-)-centrolobol with A452, another selective histone deacetylase 6 inhibitor, led to a synergistic increase in levels of acetylated α-tubulin. Aceroside VIII, paltyphyllone, and (-)-centrolobol synergistically enhanced the induction of apoptosis and growth inhibition by A452. Consistent with these results, A452 in combination with aceroside VIII, paltyphyllone, or (-)-centrolobol was more potent than either drug alone for the induction of apoptosis. Together, these findings indicate that aceroside VIII is a specific histone deacetylase 6 inhibitor and points to a mechanism by which natural histone deacetylase 6-selective inhibitors may enhance the efficacy of other histone deacetylase 6 inhibitors in colon cancer cells.

Medicinal plants of the genus Betula--traditional uses and a phytochemical-pharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

Trees and shrubs of the genus Betula (Betulaceae) inhabit various ecosystems in temperate and boreal climate zones of the northern hemisphere. The healing properties of Betula bark and bark extracts have been known for a long time in traditional medicine in different parts of the world. Several species of Betula have traditionally been used for the treatment of various inflammatory diseases including arthritis. The purpose of this review is to provide updated, comprehensive and categorized information on the botany, traditional uses, phytochemistry and pharmacological and toxicological research of Betula species in order to explore their therapeutic potential and evaluate future research opportunities.

MATERIALS AND METHODS

All the available information on various species belonging to the genus Betula was collected via electronic search (using Pubmed, SciFinder, Scirus, Google Scholar, JCCC@INSTIRC and Web of Science) and a library search for articles published in peer-reviewed journals.

RESULTS

Although over a hundred Betula species are found distributed globally, about 7 different species of Betula have been documented for their traditional uses. Phytochemical research on Betula species has led to the isolation of triterpenoids, diarylheptanoids, phenylbutanoids, lignans, phenolics and flavonoids. Crude extracts, fractions and phytochemical constituents isolated from Betula showed a wide spectrum of in vitro and in vivo pharmacological activities like immunomodulatory, anti-inflammatory, antimicrobial, antiviral, antioxidant, antidiabetic, dermatological, gastroprotective and hepatoprotective. Antiarthritic and anticancer are the two major areas of research conducted on these species. The anti-carcinogenic effects of Betula bark, betulin as well as betulinic acid have been extensively studied.

CONCLUSIONS

Several species belonging to the genus Betula are widely used in traditional medicine. Betula platyphylla and Betula pendula have specifically been found to be potentially useful in the treatment of degenerative joint disease. There is convincing evidence in experimental animal models in support of their anti-carcinogenic effects. However, it would be worthwhile to investigate the biochemical and physiological mechanisms as well as detailed preclinical toxicity, bioavailability, pharmacokinetics and pharmacodynamics of the different biologically active extracts as well as molecules in sufficient detail. An integrated and holistic approach is required for tapping the full potentials of this important genus.

Biobutanol production by Clostridium acetobutylicum using xylose recovered from birch Kraft black liquor

Acetone-butanol-ethanol (ABE) fermentation was studied using acid-hydrolyzed xylan recovered from hardwood Kraft black liquor by CO2 acidification as the only carbon source. Detoxification of hydrolyzate using activated carbon was conducted to evaluate the impact of inhibitor removal and fermentation. Xylose hydrolysis yields as high as 18.4% were demonstrated at the highest severity hydrolysis condition. Detoxification using active carbon was effective for removal of both phenolics (76-81%) and HMF (38-52%). Batch fermentation of the hydrolyzate and semi-defined P2 media resulted in a total solvent yield of 0.12-0.13g/g and 0.34g/g, corresponding to a butanol concentration of 1.8-2.1g/L and 7.3g/L respectively. This work is the first study of a process for the production of a biologically-derived biofuel from hemicelluloses solubilized during Kraft pulping and demonstrates the feasibility of utilizing xylan recovered directly from industrial Kraft pulping liquors as a feedstock for biological production of biofuels such as butanol.

Betula pendula: A Promising Candidate for Phytoremediation of TCE in Northern Climates

Betula pendula (Silver birch) trees growing on two contaminated sites were evaluated to assess their capacity to phytoscreen and phytoremediate chlorinated aliphatic compounds and heavy metals. Both locations are industrially-contaminated properties in central Sweden. The first was the site of a trichloroethylene (TCE) spill in the 1980s while the second was polluted with heavy metals by burning industrial wastes. In both cases, sap and sapwood from Silver birch trees were collected and analyzed for either chlorinated aliphatic compounds or heavy metals. These results were compared to analyses of the surface soil, vadose zone pore air and groundwater. Silver birch demonstrated the potential to phytoscreen and possibly phytoremediate TCE and related compounds, but it did not demonstrate the ability to effectively phytoextract heavy metals when compared with hyperaccumulator plants. The capacity of Silver birch to phytoremediate TCE appears comparable to tree species that have been employed in field-scale TCE phytoremediation efforts, such as Populus spp. and Eucalyptus sideroxylon rosea.

Characterization of lignin extracted from birch wood by a modified hydrotropic process

In this work an environmentally friendly hydrotropic process was used to extract lignin from industrial birch wood chips. Two hydrotropic treatments were performed, a conventional and a modified process. The lignins were characterized using FTIR, pyrolysis-gas chromatography-mass spectrometry (pyrolysis-GC-MS), (31)P and (1)H-(13)C HSQC NMR, and size exclusion chromatography (SEC). The chemical (carbohydrates, extractives, etc.) and elemental compositions of the lignins were also determined. The yields of both lignins were 16.1% (dry wood basis), and the obtained lignins had very low contents of non-lignin compounds. The treatments resulted in significant changes of the structure of the lignins, a decrease in aliphatic hydroxyls and an increase in phenolic ones. The lignin isolated by the modified treatment underwent more substantial change than the reference one. It is believed that the data presented will facilitate utilization of hydrotropic lignin and promote the adoption of the hydrotropic process in the pulp and biorefinery industry.

Kinetic modeling of multi-feed simultaneous saccharification and co-fermentation of pretreated birch to ethanol

Fed-batch simultaneous saccharification and fermentation (SSF) is a feasible option for bioethanol production from lignocellulosic raw materials at high substrate concentrations. In this work, a segregated kinetic model was developed for simulation of fed-batch simultaneous saccharification and co-fermentation (SSCF) of steam-pretreated birch, using substrate, enzymes and cell feeds. The model takes into account the dynamics of the cellulase-cellulose system and the cell population during SSCF, and the effects of pre-cultivation of yeast cells on fermentation performance. The model was cross-validated against experiments using different feed schemes. It could predict fermentation performance and explain observed differences between measured total yeast cells and dividing cells very well. The reproducibility of the experiments and the cell viability were significantly better in fed-batch than in batch SSCF at 15% and 20% total WIS contents. The model can be used for simulation of fed-batch SSCF and optimization of feed profiles.

Pentacyclic triterpenes in birch bark extract inhibit early step of herpes simplex virus type 1 replication

Antiviral agents frequently applied for treatment of herpesvirus infections include acyclovir and its derivatives. The antiviral effect of a triterpene extract of birch bark and its major pentacyclic triterpenes, i.e. betulin, lupeol and betulinic acid against acyclovir-sensitive and acyclovir-resistant HSV type 1 strains was examined. The cytotoxic effect of a phytochemically defined birch bark triterpene extract (TE) as well as different pentacyclic triterpenes was analyzed in cell culture, and revealed a moderate cytotoxicity on RC-37 cells. TE, betulin, lupeol and betulinic acid exhibited high levels of antiviral activity against HSV-1 in viral suspension tests with IC50 values ranging between 0.2 and 0.5 μg/ml. Infectivity of acyclovir-sensitive and clinical isolates of acyclovir-resistant HSV-1 strains was significantly reduced by all tested compounds and a direct concentration- and time-dependent antiherpetic activity could be demonstrated. In order to determine the mode of antiviral action, TE and the compounds were added at different times during the viral infection cycle. Addition of these drugs to uninfected cells prior to infection or to herpesvirus-infected cells during intracellular replication had low effect on virus multiplication. Minor virucidal activity of triterpenes was observed, however both TE and tested compounds exhibited high anti-herpetic activity when viruses were pretreated with these drugs prior to infection. Pentacyclic triterpenes inhibit acyclovir-sensitive and acyclovir-resistant clinical isolates of HSV-1 in the early phase of infection.

Stimulated production of steroids in Inonotus obliquus by host factors from birch

Steroids was considered as one of the bioactive components in Inonotus obliquus, while this kind of secondary metabolites are less accumulated in cultured mycelia. In this study, effect of extracts from bark and core of host-related species, birch (Betula platyphylla Suk.), on steroid production of I. obliquus in submerged culture were evaluated. The results showed that all dosages (0.01 and 0.1 g/L) of aqueous extracts and methanol extracts from birch bark and birch core possessed significantly stimulatory effect on steroid production of I. obliquus (P < 0.05). Among the eight extracts, the aqueous extract (0.01 g/L) from birch bark gave the highest steroid production (225.5 ± 8.7 mg/L), which is 97.3% higher than that of the control group. The aqueous extract (0.01 and 0.1 g/L) from birch bark could simultaneously stimulated mycelial growth and steroid content, while the methanol extract from birch bark only elevated the steroid content. High performance liquid chromatography analysis showed that productions of betulin, ergosterol, cholesterol, lanosterol, stigmasterol, and sitosterol in I. obliquus simultaneously increased in the presence of aqueous extract and methanol extract from birch bark. The results presented herein indicate that extracts from birch bark could act as an inducer for steroid biosynthesis of I. obliquus.

Characterization and standardization of allergen extracts

This paper summarizes the development of the extraction and characterization of allergens responsible for the induction of immunoglobulin (lg) E-induced allergies from the beginning of the 20th century, including the nomenclature of allergens. The majority of papers characterizing allergens and allergen extracts state that the lack of standardization of allergen extracts is the reason for the paper, and so it has been for more than 100 years. A natural part of that process might be the isolation of an allergen molecule and this starts the speculation of 'what makes that allergen an allergen?' To achieve the perfect standardization is a desirable end that is still awaited. So far none of these problems have been finally solved. I started in allergy shortly after the discovery of IgE in 1967. Since that time the history as I remember it is based on the literature, my interpretation of it, and of course may be a little biased due to personal prejudice! The history of the last 10-15 years has still not matured and it might be a little early to draw conclusions. However, at the end of this chapter I do dare to make a few conclusions after having followed the development in this field for 40 years. As this is history it is not meant to be either comprehensive or technically and scientifically precise in all aspects, but rather draws on some thoughts as to what in my mind have been important developments until now. Specific techniques are only mentioned by name and not intended to be discussed in depth. This activity has, however, pushed me to reflect on my hopes and speculations at the time of my introduction to the field of allergen chemistry. To my surprise I realize that far more than I ever expected at that time has been fulfilled. It has been extremely exciting to be a part of that development.

Antineoplastic agents. 595. Structural modifications of betulin and the X-ray crystal structure of an unusual betulin amine dimer

The lupane-type triterpene betulin (1) has been subjected to a series of structural modifications for the purpose of evaluating resultant cancer cell growth inhibitory activity. The reaction sequence 7→11→12 was especially noteworthy in providing a betulin-derived amine dimer. Other unexpected synthetic results included the 11 and 13/14→17 conversions, which yielded an imidazo derivative. X-ray crystal structures of dimer 12 and intermediate 25 are reported. All of the betulin modifications were examined for anticancer activity against the P388 murine and human cell lines. Significant cancer cell growth inhibition was found for 4, 8, 9, 15/16, 19, 20, 24, and 26, which further defines the utility of the betulin scaffold.

Switchable ionic liquids as delignification solvents for lignocellulosic materials

The transformation of lignocellulosic materials into potentially valuable resources is compromised by their complicated structure. Consequently, new economical and feasible conversion/fractionation techniques that render value-added products are intensely investigated. Herein an unorthodox and feasible fractionation method of birch chips (B. pendula) using a switchable ionic liquid (SIL) derived from an alkanol amine (monoethanol amine, MEA) and an organic super base (1,8-diazabicyclo-[5.4.0]-undec-7-ene, DBU) with two different trigger acid gases (CO2 and SO2 ) is studied. After SIL treatment, the dissolved fractions were selectively separated by a step-wise method using an antisolvent to induce precipitation. The SIL was recycled after concentration and evaporation of anti-solvent. The composition of undissolved wood after MEA-SO2 -SIL treatment resulted in 80 wt % cellulose, 10 wt % hemicelluloses, and 3 wt % lignin, whereas MEA-CO2 -SIL treatment resulted in 66 wt % cellulose, 12 wt % hemicelluloses and 11 wt % lignin. Thus, the MEA-SO2 -SIL proved more efficient than the MEA-CO2 -SIL, and a better solvent for lignin removal. All fractions were analyzed by gas chromatography (GC), Fourier transform infrared spectroscopy (FT-IR), (13) C nuclear magnetic resonance spectroscopy (NMR) and Gel permeation chromatography (GPC).

Effect of betulin-containing extract from birch tree bark on α-amylase activity in vitro and on weight gain of broiler chickens in vivo

In vitro effect of betulin-containing extract from Betula pendula Roth. bark on alpha-amylase activity was studied, the kinetic mechanism of interaction was proposed and in vivo effect of betulin-containing extract on weight gain and meat quality of broiler chickens was evaluated. The highest level of inhibitory activity (20%) was detected in extract concentration of 1,000 mg/L. Increased extract concentration did not lead to increased enzyme inhibition. Using Dixon and Cornish-Bowden coordinates, the competitive mechanism of inhibition was demonstrated. Calculated kinetic parameters were: Km equal to 0.6 mg/mL, Vmax equal to 2.6 and 2.1 mM/min from Lineweaver-Burk and Dixon coordinates, respectively and Ki equal to 3,670 ± 230 mg/mL. The partial inhibition of enzyme indicates the existence of low concentration of active inhibitory form, which reaches saturation level with increased extract concentration in applied suspension. Therefore, Ki has an apparent constant character. This partial inhibition of amylase activity observed in in vitro assay did not affect weight gain and meat quality of broiler chickens during in vivo assay. Rather, the tendency to increase the weight of edible parts and muscles compared to diet without additive suggests that the extract may be a potential food additive in poultry farming. Additionally, it could be a source for further pharmaceutical and pharmacological research.

From a traditional medicinal plant to a rational drug: understanding the clinically proven wound healing efficacy of birch bark extract

BACKGROUND

Birch bark has a long lasting history as a traditional medicinal remedy to accelerate wound healing. Recently, the efficacy of birch bark preparations has also been proven clinically. As active principle pentacyclic triterpenes are generally accepted. Here, we report a comprehensive study on the underlying molecular mechanisms of the wound healing properties of a well-defined birch bark preparation named as TE (triterpene extract) as well as the isolated single triterpenes in human primary keratinocytes and porcine ex-vivo wound healing models.

METHODOLOGY/PRINCIPAL FINDINGS

We show positive wound healing effects of TE and betulin in scratch assay experiments with primary human keratinocytes and in a porcine ex-vivo wound healing model (WHM). Mechanistical studies elucidate that TE and betulin transiently upregulate pro-inflammatory cytokines, chemokines and cyclooxygenase-2 on gene and protein level. For COX-2 and IL-6 this increase of mRNA is due to an mRNA stabilizing effect of TE and betulin, a process in which p38 MAPK and HuR are involved. TE promotes keratinocyte migration, putatively by increasing the formation of actin filopodia, lamellipodia and stress fibers. Detailed analyses show that the TE components betulin, lupeol and erythrodiol exert this effect even in nanomolar concentrations. Targeting the actin cytoskeleton is dependent on the activation of Rho GTPases.

CONCLUSION/SIGNIFICANCE

Our results provide insights to understand the molecular mechanism of the clinically proven wound healing effect of birch bark. TE and betulin address the inflammatory phase of wound healing by transient up-regulation of several pro-inflammatory mediators. Further, they enhance migration of keratinocytes, which is essential in the second phase of wound healing. Our results, together with the clinically proven efficacy, identify birch bark as the first medical plant with a high potential to improve wound healing, a field which urgently needs effective remedies.

Structure and function of the peanut panallergen Ara h 8

The incidence of peanut allergy continues to rise in the United States and Europe. Whereas exposure to the major allergens Ara h 1, 2, 3, and 6 can cause fatal anaphylaxis, exposure to the minor allergens usually does not. Ara h 8 is a minor allergen. Importantly, it is the minor food allergens that are thought to be responsible for oral allergy syndrome (OAS), in which sensitization to airborne allergens causes a Type 2 allergic reaction to ingested foods. Furthermore, it is believed that similar protein structure rather than a similar linear sequence is the cause of OAS. Bet v 1 from birch pollen is a common sensitizing agent, and OAS results when patients consume certain fruits, vegetables, tree nuts, and peanuts. Here, we report the three-dimensional structure of Ara h 8, a Bet v 1 homolog. The overall fold is very similar to that of Bet v 1, Api g 1 (celery), Gly m 4 (soy), and Pru av 1 (cherry). Ara h 8 binds the isoflavones quercetin and apigenin as well as resveratrol avidly.

Bioaccumulation of arsenic and cadmium in birch and lime from the Bor region

Copper production in the Bor region (east Serbia) during the last 100 years has influenced the quality of soil, water, and air. This pollution has endangered not only the biotope but all living organisms, including humans. Contents of arsenic (As) and cadmium (Cd) were analyzed in Betula sp. (birch) and Tillia sp. (lime) within the Bor region with the aim to investigate the bioaccumulation of these highly toxic, nonessential trace elements in selected plants, which may be important for biomonitoring and bioremediation purposes. The results of statistical data analysis showed that several factors influenced the bioaccumulation of trace elements in the examined plants, of which soil pH, soil content, and mechanism of accumulation were the main factors. The greatest As and Cd concentrations were found in plant material from the Bor center sampling site in the urban/industrial zone, which is in close proximity to the pollution source, due to the greatest metal concentrations in soil and the lowest soil pH. The low values of biological accumulation coefficients (bioconcentration factor <1, mobility ratio <1) pointed to a low rate of uptake and accumulation of As and Cd in lime and birch. Trace elements showed different patterns of behavior and accumulation in the trees. Lime showed a high ability of assimilation through leaves, whereas birch showed a better potential to express a linear correlation between concentrations in plant parts and soil.

[Spatial variation of non-structural carbohydrates in Betula platyphylla and Tilia amurensis stems]

Taking the two diffuse-porous tree species Betula platyphylla and Tilia amurensis in a temperate forest in Northeast China as test objects, this paper studied the spatial variation of the non-structural carbohydrates (NSC) concentrations in the stem xylem after leaf-fall. For the two tree species, the concentrations of total non-structural carbohydrate (TNC, soluble sugars plus starch) and soluble sugars in the stem xylem decreased gradually with the increasing depth from cambium to pith, whereas the starch concentration showed little radial variation. There was still a substantial amount of NSC in the inner wood close to pith. The concentrations of the NSC in the two species stems decreased gradually from the stump to the breast height, and then increased vertically. The maximum concentrations of the TNC, soluble sugars, and starch occurred at different heights, depending on the species and the TNC components. The ratio of sugar to starch showed a contrasting vertical trend for the two species, i. e., increasing from the stump to the top for B. platyphylla, but decreasing for T. amurensis. The estimation error of the stem NSC storage was mainly from the axial variation, and then, from the radial variation of NSC concentration. The TNC concentration (1.0% dry mass) in the stem of shade-intolerant species B. platyphylla was significantly lower than that (4.3% dry mass) of shade-tolerant species T. amurensis, which could be related to their different life-history strategies. Applying the sampling protocols considering the axial and radial variations of NSC could effectively reduce the potential uncertainty in estimating the NSC storage at tree or stand level.

From soil to leaves--aluminum fractionation by single step extraction procedures in polluted and protected areas

The paper presents the fractionation of aluminum in the samples of soil and plants of different species using a selective single-step extraction method. The study was conducted in the area located near a chemical plant, which for many years served as a post-crystallization leachate disposal site storing chemical waste (sector I), and in the area around the site: in Wielkopolski National Park, Rogalin Landscape Park and toward the infiltration ponds at the "Dębina" groundwater well-field for the city of Poznań (Poland) (sector II). The results of aluminum fractionation in samples of soil, leaves and plants showed heavy pollution with aluminum, especially in the water soluble aluminum fraction - Alsw (maximum concentration of aluminum in soil extract was 234.8 ± 4.8 mg kg(-1), in the leaves of Betula pendula it was 107.4 ± 1.8 mg kg(-1) and in the plants of Artemisia vulgaris (root) and Medicago sativa (leaves) it amounted to 464.7 ± 10.7 mg kg(-1)and 146.8 ± 1.2 mg kg(-1) respectively). In addition, the paper presents the problem of organic aluminum fractionation in biological samples and it shows the relationship between aluminum concentration in soil and the analysed woody and herbaceous species.

[Spatial structure of acid properties of litter in the succession row of swamp birch woods ]

The general potential, exchange, and actual (pH) acidities were investigated in the litter of the succession row of swamp birch woods. Their variabilities constitute, respectively, 75.9-174.4, 3.7-25.8 mmol (+)/100 g of the sampling, 3.7-5.5. For the first time, using the methods ofgeostatistics, their spatial variability was analyzed and the contributions of the trend, autocorrelation component, and the radius of the spatial correlation were estimated. It was established that in combination with the tree waste, which is uniformly distributed along the ecological profile, the specific composition of the grass-moss tier, which corresponds to the humidity of edaphon, forms the picture of the spatial structure of acid properties of the litter. It was noted that the prime cause of variability consists in the particularities of the water regime of the habitats of swamp birch woods.

Xylooligosaccharides from hardwood and cereal xylans produced by a thermostable xylanase as carbon sources for Lactobacillus brevis and Bifidobacterium adolescentis

To compare xylans from forestry with agricultural origins, hardwood xylan (birch) and cereal arabinoxylan (rye) were hydrolyzed using two variants of the xylanase RmXyn10A, full-length enzyme and catalytic module only, from Rhodothermus marinus . Cultivations of four selected bacterial species, using the xylooligosaccharide (XOS) containing hydrolysates as carbon source, showed selective growth of Lactobacillus brevis DSMZ 1264 and Bifidobacterium adolescentis ATCC 15703. Both strains were confirmed to utilize the XOS fraction (DP 2-5), whereas putative arabinoxylooligosaccharides from the rye arabinoxylan hydrolysate were utilized by only B. adolescentis. Escherichia coli did not grow, despite its capability to grow on the monosaccharides arabinose and xylose. It was also shown that Pediococcus parvulus strain 2.6 utilized neither xylose nor XOS for growth. In summary, RmXyn10A or its catalytic module proved suitable for high-temperature hydrolysis of hardwood xylan and cereal arabinoxylan, producing XOS that could qualify as prebiotics for use in functional food products.

Evaluation of the mechanism of gelation of an oleogel based on a triterpene extract from the outer bark of birch

Oleogels are known for their high physical, chemical, and mechanical stability and good in vivo efficacy, which make them appropriate vehicles for dermal drug delivery and skin care for very dry skin. Modern formulation research focusses on well tolerated and sustainable formulation concepts. This paper deals with an innovative oleogel, which is based on a triterpene dry extract from the outer bark of birch (TE). In this formulation TE does not only act as an excipient but provides interesting pharmacological properties at the same time. The oleogel was formulated using solely Simmondsia Chinensis seed oil (jojoba oil) and TE. Fluorescence microscopy and confocal Raman microscopy showed that suspended TE particles arrange in a three-dimensional gel network. Infrared spectroscopy revealed that the formation of hydrogen bonds between TE particles is responsible for the self-assembly of TE in oil. Moreover, the influence of TE concentration and morphology of the TE particles on the viscoelasticity of the resulting oleogels was analyzed. Gel strength increased with TE concentration and was critical to the specific surface area of the TE particles.

Potential of hot water extraction of birch wood to produce high-purity dissolving pulp after alkaline pulping

The potential of hot water extraction of birch wood to produce highly purified dissolving pulp in a subsequent soda-anthraquinone pulping process was evaluated. After intermediate extraction intensities, pulps with low xylan content (3-5%) and high cellulose yield were successfully produced. Increasing extraction intensity further decreased the xylan content in pulp. However, below a xylan content of 3%, the cellulose yield dramatically decreased. This is believed to be due to cleavage of glycosidic bonds in cellulose during severe hot water extractions, followed by peeling reactions during alkaline pulping. Addition of sodium borohydride as well as increased anthraquinone concentration in the pulping liquor increased the cellulose yield, but had no clear effects on pulp purity and viscosity. The low intrinsic viscosity of pulps produced after severe extraction intensities and soda-anthraquinone pulping corresponded to the viscosity at the leveling-off degree of polymerization, suggesting that nearly all amorphous cellulose had been degraded.

Quantitative structures and thermal properties of birch lignins after ionic liquid pretreatment

The use of ionic liquid (IL) in biomass pretreatment has received considerable attention recently because of its effectiveness in decreasing biomass recalcitrance to subsequent enzymatic hydrolysis. To understand the structural changes of lignin after pretreatment and enzymatic hydrolysis process, ionic liquid lignin (ILL) and subsequent residual lignin (RL) were sequentially isolated from ball-milled birch wood. The quantitative structural features of ILL and RL were compared with the corresponding cellulolytic enzyme lignin (CEL) by nondestructive techniques (e.g., FTIR, GPC, quantitative (13)C, 2D and (31)P NMR). The IL pretreatment caused structural modifications of lignin (cleavage of β-O-4 ether linkages and formation of condensed structures). In addition, lignin fragments with lower S/G ratios were initially extracted, whereas the subsequently extracted lignin is rich in syringyl unit. Moreover, the maximum decomposition temperature (T(M)) was increased in the order ILL < RL < CEL, which was related to the corresponding β-O-4 ether linkage content and molecular weight (M(w)). On the basis of the results observed, a possible separation mechanism of IL lignin was proposed.

Effect of different steam explosion conditions on methane potential and enzymatic saccharification of birch

Birch (Betula pubescens) was steam exploded at 13 different conditions with temperatures ranging from 170 to 230 °C and residence times ranging from 5 to 15 min. Increasing severity in the pretreatment led to degradation of xylan and formation of pseudo-lignin. The effect of the pretreatments was evaluated by running enzymatic saccharification and anaerobic digestion followed by analysis of sugar and methane yields, respectively. Enzymatically released glucose increased with pretreatment severity up to 220 °C for 10 min and levels of solubilized glucose reached 97% of the theoretical maximum. The highest methane yield (369 mL gVS(-1)) was obtained at a severity factor of 4.5 and this yield was 1.8 times higher than the yield from untreated birch. Enzymatic glucose yields and methane yields were generally correlated. The results indicate that steam-exploded birch can be effectively converted to either glucose or methane.

Reactions of airway epithelial cells to birch pollen grains previously exposed to in situ atmospheric Pb concentrations: a preliminary assay of allergenicity

A growing body of evidence suggests that interactions between pollen grains and environmental pollutants, especially air pollutants, could be of critical importance with regard to the increase in allergic responses observed in the past decades. Using birch pollen grains (BPG), a major allergy source in European countries, and lead (Pb), a highly toxic metal trace element (MTE) present in urban areas, the immune response of human epithelial cells exposed to BPG or to Pb-associated BPG was compared. The cellular response after exposure either to BPG, BPG exposed to 30 mg/L of Pb (BPG-30), or BPG exposed to 60 mg/L of Pb (BPG-60) was evaluated after two time lapses (2 and 6 h) by measuring mRNA levels of four mediators, including two inflammatory (interleukin-8 and interleukin-6) and two allergic (interleukin-5 [IL-5] and interleukin-13) cytokines. After 2 h of exposure, significant upregulation of the IL-5 gene was observed after exposure to BPG-60 in comparison with exposure to BPG and BPG-30 (N (IL-5) = 1.9, Mann-Whitney test, p = 0.003). After 6 h of exposure, significant upregulation of the IL-5 gene was observed after exposure to BPG-30 with N (IL-5) = 1.8 and to BPG-60 with N (IL-5) = 2.3 (Mann-Whitney test, p = 0.0029) in comparison with exposure to BPG. This first attempt to investigate the influence of pollution by MTE on pollen grain showed a dose-time-dependent increase in IL-5 gene expression after exposure to BPG combined to Pb.

Cognition-enhancing and neuroprotective activities of the standardized extract of Betula platyphylla bark and its major diarylheptanoids

Diarylheptanoids have been the center of the intensive research efforts for Alzheimer's disease and other neurodegenerative diseases. The present study aimed to determine the effect of the standardized extract of B. platyphylla bark and its major diarylheptanoids in scopolamine-induced amnesic mice through cyclic AMP response element-binding protein (CREB) activation. Oral administration of the standardized extract of B. platyphylla bark (100mg/kg body weight), aceroside VIII (1mg/kg body weight) and platyphylloside (1 or 2mg/kg body weight) significantly ameliorated scopolamine-induced amnesia in passive avoidance test. CREB phosphorylation and brain-derived neurotrophic factor (BDNF) expression in the cortex and hippocampus of the scopolamine-treated mice were markedly increased by the treatment of the standardized extract of B. platyphylla bark and platyphylloside. The standardized extract of B. platyphylla bark and its major diarylheptanoids also significantly protected HT22 cells against neurotoxicity induced by glutamate insult. The standardized extract of B. platyphylla bark and platyphylloside may ameliorate memory deficits by activating the CREB-BDNF pathway and prevent a neurodegeneration by inhibiting neuronal cell death.

Xylans inhibit enzymatic hydrolysis of lignocellulosic materials by cellulases

Hemicelluloses have been found to be physical barriers in the hydrolysis of cellulose, and prevent the access of enzymes to cellulose surface. In addition, soluble hemicelluloses may strongly inhibit the cellulase activity. In this work, birchwood xylan clearly inhibited the enzymatic hydrolysis of wheat straw, Avicel and nanocellulose by cellulases. Hydrolysis efficiencies of cellobiohydrolase I (CBHI, from Thermoascus aurantiacus), cellobiohydrolase II (CBHII, from Trichoderma reesei) and endoglucanase II (from T. aurantiacus) were clearly inhibited by birchwood xylan, respectively. The strongest inhibitory effect of birchwood xylan was observed on the hydrolysis of Avicel by CBHI and CBHII, as a dramatically decreased formation of the main product, cellobiose. After additions of soluble and insoluble oat spelt xylan, cleaved cellobiose units by CBHI from cellulose chain decreased from 8 to 4 and 6, respectively. The results in this work demonstrated that xylans clearly inhibited the hydrolysis efficiencies of both endoglucanase and cellobiohydrolase.

Extraction of betulin, trimyristin, eugenol and carnosic acid using water-organic solvent mixtures

A solvent system consisting of ethyl acetate, ethyl alcohol and water, in the volume ratio of 4.5:4.5:1, was developed and used to extract, at room temperature, betulin from white birch bark and antioxidants from spices (rosemary, thyme, sage, and oregano) and white oak chips. In addition, under reflux conditions, trimyristin was extracted from nutmeg using the same solvent system, and eugenol from olives was extracted using a mixture of salt water and ethyl acetate. The protocol demonstrates the use of water in organic solvents to extract natural products from plants. Measurement of the free-radical scavenging activity using by 2,2-diphenyl-1-picrylhydrazyl (DPPH) indicated that the extraction of plant material using ethyl acetate, ethyl alcohol and water (4.5:4.5:1, v/v/v) was exhaustive when carried out at room temperature for 96 h.

Effects of a catalytic converter on PCDD/F, chlorophenol and PAH emissions in residential wood combustion

Catalytic converters can be used to decrease carbon monoxide, organic compounds and soot from small-scale wood-fired appliances. The reduction is based on the oxidation of gaseous and particulate pollutants promoted by catalytic transition metal surfaces. However, many transition metals have also strong catalytic effect on PCDD/F formation. In this study birch logs were burned in a wood-fired stove (18 kW) with and without a catalytic converter with palladium and platinum as catalysts. PCDD/F, chlorophenol and PAH concentrations were analyzed from three phases of combustion (ignition, pyrolysis and burnout) and from the whole combustion cycle. PCDD/F emissions without the catalytic converter were at a level previously measured for wood combustion (0.15-0.74 ng N m(-3)). PAH emissions without the catalytic converter were high (47-85 mg N m(-3)) which is typical for batch combustion of wood logs. Total PAH concentrations were lower (on average 0.8-fold), and chlorophenol and PCDD/F levels were substantially higher (4.3-fold and 8.7-fold, respectively) when the catalytic converter was used. Increase in the chlorophenol and PCDD/F concentrations was most likely due to the catalytic effect of the platinum and palladium. Platinum and palladium may catalyze chlorination of PCDD/Fs via the Deacon reaction or an oxidation process. The influence of emissions from wood combustion to human health and the environment is a sum of effects caused by different compounds formed in the combustion. Therefore, the usage of platinum and palladium based catalytic converters to reduce emissions from residential wood combustion should be critically evaluated before wide-range utilization of the technology.

Hemicelluloses prior to aspen chemithermomechanical pulping: pre-extraction, separation, and characterization

A portion of hemicelluloses and acetic acid can be pre-extracted with dilute sulfuric acid prior to the aspen chemithermomechanical pulp process. The streams collected from the second press-impregnation stage after acid pre-extraction contain a significant amount of acid pre-extracted hemicelluloses. Most of the total sugars obtained from the pressate were xylan, in which xylan was further hydrolyzed to sugar monomers under the acid pre-extraction condition. To fully understand the characteristics of hemicelluloses yielded prior to pulping, the pre-extracted hemicelluloses were separated and characterized by FT-IR, (1)H NMR, and thermogravimetric analysis in this study. Most of the FT-IR bonds from the hemicelluloses agreed well with the other two spectra of birch xylan and CA0050 xylan, except a new absorption at 1734 cm(-1) contributed to acetyl groups. The hemicelluloses obtained from acid pre-extraction began to decompose significantly at about 225 °C, slightly lower in comparison with organosolv and alkaline hemicelluloses reported in the literature.

Procyanidin xylosides from the bark of Betula pendula

A procyanidin dimer xyloside, catechin-(4α→8)-7-O-β-xylopyranosyl-catechin, was isolated from the inner bark of Betula pendula and its structure was determined using 1D and 2D NMR, CD and high-resolution ESIMS. Interestingly, the 7-O-β-xylopyranose unit was found to be present in the lower terminal unit of the dimer. In addition to this procyanidin dimer xyloside, an entire series of oligomeric and polymeric procyanidin xylosides was detected. Their structures were investigated by hydrophilic interaction HPLC-HRESIMS. Procyanidin glycosides are still rarely found in nature.

Detection and analysis of unusual features in the structural model and structure-factor data of a birch pollen allergen

Physically improbable features in the model of the birch pollen structure Bet v 1d (PDB entry 3k78) are faithfully reproduced in electron density generated with the deposited structure factors, but these structure factors themselves exhibit properties that are characteristic of data calculated from a simple model and are inconsistent with the data and error model obtained through experimental measurements. The refinement of the 3k78 model against these structure factors leads to an isomorphous structure different from the deposited model with an implausibly small R value (0.019). The abnormal refinement is compared with normal refinement of an isomorphous variant structure of Bet v 1l (PDB entry 1fm4). A variety of analytical tools, including the application of Diederichs plots, Rσ plots and bulk-solvent analysis are discussed as promising aids in validation. The examination of the Bet v 1d structure also cautions against the practice of indicating poorly defined protein chain residues through zero occupancies. The recommendation to preserve diffraction images is amplified.

Test of tree core sampling for screening of toxic elements in soils from a Norwegian site

Tree core samples have been used to delineate organic subsurface plumes. In 2009 and 2010, samples were taken at trees growing on a former dump site in Norway and analyzed for arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and zinc (Zn). Concentrations in wood were in averages (dw) 30 mg/kg for Zn, 2 mg/kg for Cu, and < 1 mg/kg for Cd, Cr, As and Ni. The concentrations in wood samples from the polluted test site were compared to those derived from a reference site. For all except one case, mean concentrations from the test site were higher than those from the reference site, but the difference was small and not always significant. Differences between tree species were usually higher than differences between reference and test site. Furthermore, all these elements occur naturally, and Cu, Ni, and Zn are essential minerals. Thus, all trees will have a natural background of these elements, and the occurrence alone does not indicate soil pollution. For the interpretation of the results, a comparison to wood samples from an unpolluted reference site with same species and similar soil conditions is required. This makes the tree core screening method less reliable for heavy metals than, e.g., for chlorinated solvents.

Sesquiterpenes from the inner bark of the silver birch and the paper birch

The compositions of the mixtures of sesquiterpenoids, largely hydrocarbons that were found in the inner bark of the silver birch, Betula pendula Roth and the paper birch, Betulapapyrifera Marshall, grown in New Zealand were analyzed by SPME-GCMS. The major components of the volatile oil from the inner bark of B. pendula were trans alpha-bergamotene (31%) and alpha-santalene (19%). This composition was quite different from that of the oil from the branches, buds and leaves of the same species from Turkey, but was very similar to that of the oil from the bark of B. pubescens from Russia. The major components of the oil from the inner bark of B. papyrifera were trans alpha-bergamotene (18%), ar-curcumene (12%), E-beta-farnesene (12%), Z-beta-farnesene (10%) and cis-alpha-bergamotene (8%).

Water-extractable magnesium, manganese and copper in leaves and herbs of medicinal plants

Since herbal teas, infusions and decoctions prepared from medicinal plants are popular remedies, it remains a topical question whether these herbal drugs can be treated as sources of essential elements for humans, who often use them in their everyday diet. Therefore, total and water-extractable contents of Mg, Mn and Cu were determined in 41 leaves originating from four botanical species of Plantago lanceolata, Arctostaphyllos uva-ursi, Rubus fruticosus and Betula sp., as well as in 33 samples of herbs represented by three species of Urtica dioica, Hypericum perforatum and Achillea millefolium. The highest level was determined in the case of Mg (in a range from 2.0 to 7.0 mg/g of dry mass [d.m.]), followed by Mn (from 50.0 to 1300.0 mg/kg d.m.), and lowest of all, Cu (from 3.5 to 19.5 mg/kg d.m.). Student's t-test showed that a statistically significant difference exists between samples originating from different plant species regarding the total content and water-extractable forms of Mg, Mn and Cu. By analysis of the relations between elements, it was observed that total level of Cu correlated with total levels of Mg and Mn, which indicates a synergistic interaction between the essential elements under study. With regard to Dietary Reference Intakes (DRIs), the leaves of Rubus fruticosus contained the highest amounts of a water-extractable bioavailable form of Mn, which guarantees from 160 to 200% of the daily requirement of Mn for women and men, respectively. On the other hand, the extract obtained from Urticae folium gave water-extractable Mg in the amount of 76 mg/500 mL, which constitutes about 20% of daily requirement. The plant material richest in water-extractable Cu was Hyperici herba, containing 154.5 microg/500 mL, or 17% of DRI for both sexes.

[A multicenter comparative observation on the effectiveness and the rapidness of the effect of Cystostop Rapid versus antibiotic therapy in patients with uncomplicated cystitis]

The currently available treatment for uncomplicated urinary tract infections includes only antibiotics and chemotherapeutic agents. Experience in the management of acute uncomplicated infections using non-antibiotic products is very limited. The aim of this observation was to study to what extent the response to Cystostop Rapid would be more rapid and more effective compared to antibiotic therapy in patients with acute uncomplicated urinary bladder infections. The secondary objective was to determine the time to improvement of cystitis symptoms following the start of treatment, as well as the duration of patients' disablement. A total of 158 female subjects were included, assessed microbiologically, and evaluated for incidence and severity of symptoms, before the start of treatment and after completion of treatment. A visual analogue scale was used for patient self-assessment of the severity of symptoms, the improvement of symptoms, as well as the time to improvement of symptoms.

RESULTS

158 females, eligible according to the inclusion criteria of the study, were allocated to one of the two groups according to time of enrollment: Group A included 86 subjects: assigned to Cystostop Rapid for 3 days and administered according to the manufacturer's recommended regimen; and Group B included 72 women: assigned to ciprofloxacin 500 mg twice daily for 3 days according to the Product Registration File with the BDA. The clinical and microbiological effectiveness of Cystostop Rapid was comparable to that of ciprofloxacin, providing a two-fold more rapid improvement of cystitis symptoms, at a mean time to improvement of 24 hours (p < 0.02) versus 46 hours for ciprofloxacin. Clinical improvement within 48 hours of Cystostop Rapid regimen occurred in 97% (p < 0.02) of patients, vs. 65.3% of patients on ciprofloxacin. Improvement of symptoms within 12 hours was reported in 36% of patients on Cystostop Rapid vs. 5.5% of patients in the ciprofloxacin group (p < 0.02). No adverse events or intolerability to the therapy were reported throughout the course of the study.

[Interspecific allelopathic effect of different organs' aqueous extracts of Betula platyphylla and Larix olgensis on their seed germination and seedling growth]

In this paper, the Betula platyphylla root-, branch-, and foliage aqueous extracts and Larix olgensis root-, branch-, foliage-, and bark aqueous extracts over a range of concentrations 5.0, 12.5, 25.0, 50.0, and 100.0 mg x mL(-1) were used to study their interspecific allelopathic effect on the seed germination and seedling growth of the two tree species. All the L. olgensis organs' extracts, except its root extracts at concentration 5.0 mg x mL(-1), had inhibition effect on B. platyphylla seed germination rate, which was 54%, 58%, 59%, and 66% under the effects of L. olgensis foliage-, branch-, bark-, and root extracts, respectively, as compared with the control. With increasing concentration, the inhibition effect of L. olgensis root- and branch extracts increased while that of L. olgensis foliage- and bark extracts decreased. The L. olgensis organs' extracts, especially the foliage extracts at concentration 100.0 mg x mL(-1), had strong inhibition effect on B. platyphylla seed radicle- and hypocotyl length growth, with a decrement of 38% and 55% (P < 0.05), respectively. L. olgensis branch- and foliage extracts promoted, but root- and bark extracts inhibited B. platyphylla seedling growth and biomass production. B. platyphylla organs' extracts promoted L. olgensis seed germination, root- and branch extracts promoted hypocotyl length growth, but foliage extracts at 50.0 and 100.0 mg x mL(-1) decreased the hypocotyl length growth by 27% and 28% (P < 0.05), respectively. B. platyphylla organs' extracts mainly promoted L. olgensis seedling growth, with the height- and collar diameter growth and biomass accumulation at B. platyphylla foliage extracts concentration 5.0 mg x mL(-1) increased by 54%, 60%, and 100% (P < 0.05), respectively. Our results suggested that there existed obvious allelopathic effect between B. platyphylla and L. olgensis, and thus, mixed planting B. platyphylla and L. olgensis could have promotion effects on the growth of the two tree species.

Effect of radial directional dependences and rainwater influence on CVOC concentrations in tree core and birch sap samples taken for phytoscreening using HS-SPME-GC/MS

Phytoscreening for chlorinated volatile organic compounds (CVOC) in tree core samples is influenced by many factors. For instance, greater fluctuations are observed for CVOC concentrations in samples taken around the trunk at a fixed height compared to samples taken directly next to each other. To avoid false negatives and inaccurate interpretation of the results, we investigated this radial directional dependence as well as the influence of rainwater on measured concentrations. CVOC analysis was performed by gas chromatography/mass spectrometry (GC/MS) following Solid-Phase-Microextraction (SPME). Phytoscreening was successfully carried out at three sites using this method. In addition, sap samples were taken from white birches during their budding period as a novel phytoscreening approach. Birch sap sampling is shown to be a suitable means of characterizing contaminant distribution within the soil subsurface. Radial directional dependence of CVOC concentrations varies by almost 80% for tree core samples and 50% for birch sap samples. Variations in concentrations measured around the trunk do not, however, provide information on the inflow direction of contaminated groundwater. The weather conditions were shown to have a greater influence so that CVOC concentrations measured from samples taken during colder, rainier weather were, on average, a factor of 100 lower than those taken during a warm and dry period. Nevertheless phytoscreening is adequate for CVOC characterization in the soil subsurface if the campaign is carried out during a dry weather period, the results then can be taken as being semiquantitative.

Degradation kinetics of the main carbohydrates in birch wood during hot water extraction in a batch reactor at elevated temperatures

Hot water extraction of wood at elevated temperatures may be a suitable method to produce hemicellulose-lean pulps and to recover xylan-derived products from the water extract. In this study, water extractions of birch wood were conducted at temperatures between 180 and 240 °C in a batch reactor. Xylan was extensively removed, whereas cellulose was partly degraded only at temperatures above 180 °C. Under severe extraction conditions, acetic acid content in the water extract was higher than the corresponding amount of acetyl groups in wood. In addition to oligo- and monosaccharides, considerable amounts of furfural and 5-hydroxymethylfurfural (HMF) were recovered from the extracts. After reaching a maximum, the furfural yield remained constant with increasing extraction time. This maximum slightly decreased with increasing extraction temperature, suggesting the preferential formation of secondary degradation products from xylose. Kinetic models fitting experimental data are proposed to explain degradation and conversion reactions of xylan and glucan.

Temporal variation in epidermal flavonoids due to altered solar UV radiation is moderated by the leaf position in Betula pendula

The physiological mechanisms controlling plant responses to dynamic changes in ambient solar ultraviolet (UV) radiation are not fully understood: this information is important to further comprehend plant adaptation to their natural habitats. We used the fluorimeter Dualex to estimate in vivo the epidermal flavonoid contents by measuring epidermal UV absorbance (A(375) ) in Betula pendula Roth (silver birch) leaves of different ages under altered UV. Seedlings were grown in a greenhouse for 15 days without UV and transferred outdoors under three UV treatments (UV-0, UV-A and UV-A+B) created by three types of plastic film. After 7 and 13 days, Dualex measurements were taken at adaxial and abaxial epidermis of the first three leaves (L1, L2 and L3) of the seedlings. After 14 days, some of the seedlings were reciprocally swapped amongst the treatments to study the accumulation of epidermal flavonoids in the youngest unfolded leaves (L3) during leaf expansion under changing solar UV environments. A(375) of the leaves responded differently to the UV treatment depending on their position. UV-B increased the A(375) in the leaves independently of leaf position. L3 quickly adjusted A(375) in their epidermis according to the UV they received and these adjustments were affected by previous UV exposure. The initial absence of UV-A+B or UV-A, followed by exposure to UV-A+B, particularly enhanced leaf A(375) . Silver birch leaves modulate their protective pigments in response to changes in the UV environment during their expansion, and their previous UV exposure history affects the epidermal-absorbance achieved during later UV exposure.

Inter- and intra-specific variation in stem phloem phenolics of paper birch (Betula papyrifera) and European white birch (Betula pendula)

Outbreaks of bronze birch borer (BBB) (Agrilus anxius), a wood-boring beetle endemic to North America, have been associated with widespread mortality of birch (Betula spp.). There is substantial inter- and intra-specific variation in birch resistance to BBB. Species endemic to North America, such as paper birch (B. papyrifera), have coevolved with BBB and are more resistant than European and Asian birch species, such as European white birch (B. pendula), which lack an evolutionary history with BBB. Borer larvae feed on stem phloem tissue. Therefore, in search of potential resistance mechanisms against BBB, we compared the constitutive phenolic profile of stem phloem tissue of paper birch with that of European white birch. We also analyzed intraspecific variation in phenolic composition among clones and/or half-siblings of both species. Three phenolics (coumaroylquinic acid, betuloside pentoside A, and a diarylheptanoid hexoside) were detected only in paper birch, and concentrations of six other phenolics were significantly higher in paper birch. These differences may contribute to the high resistance of paper birch to BBB relative to European white birch. There was significant intraspecific variation in four of 17 phenolics found in paper birch and in five of 14 found in European white birch, but clones and half-siblings within each species could not be distinguished by phenolic composition using multivariate analysis.

Black painted pottery, Kildehuse II, Odense County, Denmark

This work aimed at characterization of a black layer covering a Bronze Age (period VI) pot surface. To solve research problems plane polarized light microscopy (PLM), scanning microscopy with X-ray microanalyser (SEM/EDS), Raman and FTIR microspectroscopies were applied. Observation of the black layer under the PLM suggests that we deal with an opaque, isotropic layer, purposely put on leather-hard, burnished surface of a pot. No traces of organic substances that might have modified a pot surface before painting were detected. The black layer coats the pot with a continuous 0.2-0.4 μm thick layer. The black layer must have been applied while warm or hot. It is recognized that the black layer is a true painting layer. Spectroscopic analyses (Raman and FTIR) point that birch tar or a birch-pine tar had been applied. Carbon black should be definitely excluded. The analyzed organic substance is structurally ordered in various degrees, due to varying temperature influence. Some Raman spectra reveal, in second-order region of the spectrum (>2000 cm(-1)), the graphite presence. Scarce points reveal the presence of inorganic admixtures: clay minerals, feldspars and quartz. The next question is: Is it an organic paint or a carbon-based, "mixed" paint? Inorganic admixtures are only casual. Relatively high concentration of alumina is expected to have appeared due to aluminum mobility in acidic environment and this was provided by organic tar/pitch substances. Phosphorus (usually with calcium) mostly concentrates together with clay minerals. Thus, hypothesis on bone powder or ash addition to tar/pitch should be excluded. Some elements may originate not only from inorganic substances but also from wood ashes.

Birch bark extract as therapy for chronic hepatitis C--a pilot study

The hepatoprotective effect of birch bark extract (BBE) in patients with chronic hepatitis C (CHC) was studied. Forty-two patients with serologically confirmed chronic hepatitis C were treated for 12 weeks with 160 mg standardized BBE per day. The primary outcome parameter measured was the rate of alanine aminotransferase (ALT) normalization after 12 weeks. Secondary parameters included the course of ALT, aspartate aminotransferase (AST) levels, quantitative HCV RNA levels, subjective symptoms associated with CHC (fatigue, abdominal discomfort, depression, and dyspepsia), safety and compliance. The qualitative-quantitative analysis of BBE was made using high performance liquid chromatography to confirm the presence of 75% betulin and 3.5% betulinic acid. Significant differences in the mean ALT and HCV RNA levels were observed after 12 weeks of treatment. The level of ALT was decreased in 54.0% and normalized (p=0.046). HCV RNA was reduced in 43.2% (p=0.016). After 12 weeks of treatment, reports of fatigue and abdominal discomfort were reduced by 6-fold (p=0.028) and 3-fold (p=0.05), respectively. Dyspepsia was no longer reported (p=0.042) and the effect was significantly different from baseline. Because this study lacks a control group clinical relevance of the data can only be estimated in future by following controlled clinical trials.

An aqueous birch leaf extract of Betula pendula inhibits the growth and cell division of inflammatory lymphocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Leaf extracts of Betula pendula have been traditionally used for the treatment of patients with rheumatoid arthritis (RA) or osteoarthritis.

AIM OF THE STUDY

We investigated the anti-proliferative capacity of an aqueous leaf extract of Betula pendula (BPE) on human primary lymphocytes in vitro, because activated lymphocytes play a major role in the initiation and maintenance of RA.

MATERIALS AND METHODS

Lymphocyte proliferation and cell division was measured by the activity of mitochondrial dehydrogenases and by using the membrane-permeable dye carboxyfluorescein diacetate succinimidyl ester (CFSE), respectively. Apoptosis was analyzed by surface staining of phosphatidylserine and intracellular activation of effector caspases 3 and 7 in comparison to the drug methotrexate using flow cytometric and photometrical analysis. In addition, the impact of the extract on cell cycle distribution was investigated by propidium iodide staining of DNA. For the bioassays BPE concentrations of 10-160 μg/mL were investigated. A phytochemical analysis, using LC-MS and HPLC, was conducted to identify the polyphenolic constituents of the birch leaf extract.

RESULTS

Leaf extracts of Betula pendula inhibited the growth and cell division (CD8(+): 40 μg/mL: 45%; 80 μg/mL: 60%; 160 μg/mL: 87%) (CD4(+): 40 μg/mL: 33%; 80 μg/mL: 54%; 160 μg/mL: 79%) of activated, but not of resting T lymphocytes in a significant dose-dependent manner. The inhibition of lymphocyte proliferation due to apoptosis induction (compared to untreated control: 40 μg/mL: 163%; 80 μg/mL: 240%; 160 μg/mL: 348%) and cell cycle arrest was comparable to that of methotrexate. LC-MS analyses showed that the extract contains different quercetin-glycosides.

CONCLUSION

Our results give a rational basis for the use of Betula pendula leaf extract for the treatment of immune disorders, like rheumatoid arthritis, by diminishing proliferating inflammatory lymphocytes.