Showing papers on "Bark published in 2004"

Composition and antioxidant activity of the essential oils of Xylopia aethiopica (Dun) A. Rich. (Annonaceae) leaves, stem bark, root bark, and fresh and dried fruits, growing in Ghana.

Abstract: The chemical composition of the essential oils obtained from the leaves, the barks of the stem and the root, as well as from the fresh and dried fruits of Xylopia aethiopica, growing in Ghana, was investigated by gas chromatography/mass spectrometry analyses. Kovats indices, mass spectra, and standard compounds were used to identify a total of 93 individual compounds. The monoterpene hydrocarbons formed the main portion in all studied samples. β-Pinene was predominant in all cases, while trans-m-mentha-1(7),8-diene was the main compound in the essential oils of the leaves and the barks of roots and stems. Their potential antioxidant activity was also investigated and found to be significant in scavenging superoxide anion radical. Keywords: Xylopia aethiopica; Ghana; volatile constituents; leaves; fruits; stem bark; root bark

Anti-fungal effects of phenolic amides isolated from the root bark of Lycium chinense.

Abstract: Four phenolic amides, dihydro-N-caffeoyltyramine (1), trans-N-feruloyloctopamine (2), trans-N-caffeoyltyramine (3), and cis-N-caffeoyltyramine (4), were isolated from an ethyl acetate extract of the root bark of Lycium chinense Miller. All had an anti-fungal effect; compounds 1-3 were potent at 5–10 μg ml−1 and were without hemolytic activity against human erythrocyte cells. Compound 4 was active at 40 μg ml−1. All four compounds impeded the dimorphic transition of pathogen, Candida albicans.

Phenolic Extractives from the Bark of Pinus sylvestris L. and Their Effects on Inflammatory Mediators Nitric Oxide and Prostaglandin E2

Abstract: The anti-inflammatory properties of phenolic pine (Pinus sylvestris L.) bark extract were studied. The pine bark extract was fractionated by liquid−liquid extractions and semipreparative high-performance liquid chromatography to reveal the most potent constituents. The phenolic compositions of three pine bark samples obtained, a crude extract, a chloroform fraction, and a semipreparative fraction, were analyzed using high-performance liquid chromatography with UV diode array detection and/or electrospray ionization mass spectrometry. In addition, eight compounds were isolated and identified by NMR and MS techniques. In total 28 phenolic compounds were identified. The effects of the three pine bark samples on the synthesis of two proinflammatory mediators, nitric oxide and prostaglandin E2, were measured. It was shown that pine bark contains compounds that inhibit the production of these proinflammatory mediators. Keywords: Bark; HPLC−DAD; HPLC−ESI-MS; inflammation; macrophages; nitric oxide; nitric oxide ...

New camptothecin and ellagic acid analogues from the root bark of Camptotheca acuminata.

Abstract: As part of a study on chemical constituents of Camptotheca species, one new natural camptothecin analogue (2), two new alkaloids (3, 4), one new ellagic acid analogue (5), and 19 known compounds (1, 6-23) have been isolated from the root bark, stem bark, fruits, and leaves of Camptotheca acuminata Decaisne. The structures of 2-5 were determined from spectral data to be 10-methoxy-20-O-acetylcamptothecin (2), 20-O-beta-glucopyranosyl 18-hydroxycamptothecin (3), 20-formylbenz indolizino [1,2-b]quino-line-11(13H)-one (4), and 3,4-methylenedioxy-3'-O-methyl-5'-hydroxyellagic acid (5).

Repellency of aromatic medicinal plant extracts and a steam distillate to Aedes aegypti.

Abstract: The repellent activity of methanol extracts from 23 aromatic medicinal plant species and a steam distillate against female blood-starved Aedes aegypti was examined in the laboratory by skin test and compared with that of N,N-diethyl-m-toluamide (deet). Responses varied according to plant species. At a dose of 0.1 mg/cm2, the repellency of extracts of Cinnamomum cassia bark (91%), Nardostachys chinensis rhizome (81%), Paeonia suffruticosa root bark (80%), and Cinnamomum camphora steam distillate (94%) was comparable to deet (82%). The duration of the effectiveness for extracts from C. cassia bark and N. chinensis rhizome was comparable to deet and lasted for approximately 1 h. Relatively short duration of repellency was observed in P. suffruticosa root bark extract and C. camphora steam distillate. The plants described merit further study as potential mosquito repellent agents.

Essential oils and fragrances from natural sources

Abstract: The study of a perfume includes extraction of scented ingredients from botanicals, behavior of chemical components, and careful blending of scents to achieve the desired composition. Essential oils may be found in roots, flowers, leaves, fruit, seeds or bark of the plant. Growing and harvesting conditions are optimized for the production of the best fragrances.

Variation in birch bark secondary chemistry between and within clones: implications for herbivory by hares

Abstract: We studied the variation in bark chemistry between and within 19 European white birch (Betula pendula) clones and its implications to resistance to the mountain hare (Lepus timidus). We used one-year-old clonal plantlets originating from randomly selected naturally regenerated parental trees. The same clones were used in both chemical analyses and in feeding experiments. The condensed tannins were analysed by an acid butanol assay, other phenolic components by HPLC-DAD, and triterpenoid components by HPLC-MS. The resistance to hare was tested in open-field feeding experiment. The main phenolic compounds in birch bark were catechin derivatives, rhododendrin, platyphylloside, and condensed tannins, and the main triterpenoids were papyriferic acid and pendulic acid. Most of the variation in the concentrations of the studied compounds was found between clones for the studied phenolics and large variation for triterpenoid components were found both between clones and among plantlets within the same clone. Hares clearly selected among the studied clones. Our results suggest that birch bark chemistry play an important role in resistance to herbivory by hare. The total triterpenoids and total flavonoid-aglycones showed significant negative correlation with hare feeding. It seems that a genetic basis for bark chemistry and birch resistance is strong. Such a high variation in secondary chemistry both between clones and within individual clones indicates that European white birch populations have a good resistance towards variable environmental conditions and varying pressures from herbivory.

Semiochemicals from Fungal Associates of Bark Beetles May Mediate Host Location Behavior of Parasitoids

Abstract: In laboratory olfactometer bioassays, females of two hymenopteran parasitoid species, Roptrocerus xylophagorum(Ratzeburg) (Hymenoptera: Pteromalidae) and Spathius pallidus(Ashmead) (Hymenoptera: Braconidae), were attracted to odors from bark or bolts of loblolly pine, Pinus taeda L., colonized by bluestain fungi (genus Ophiostoma) associated with the parasitoids' bark beetle hosts. Mock-inoculated bolts and bark were less attractive or unattractive in these bioassays. Bark infested with host larvae that lacked their fungal and other normal microbial associates was attractive to R. xylophagorum females, but was less so than bark infested with larvae possessing their normal complement of associated microbes. In contrast, in oviposition bioassays, R. xylophagorum females spent approximately equal time searching, made similar numbers of oviposition attempts, parasitized similar percentages of hosts, and laid similar numbers of eggs in bark fragments infested with either associate-free or associate-bearing host larvae. Furthermore, in field bioassays using bluestain-inoculated or mock-inoculated loblolly pine bolts as sources of attractants, the numbers of parasitoids attracted by the two treatments did not differ significantly and the two treatments were less attractive than bolts naturally infested with bark beetle larvae. Whereas our laboratory olfactometer data suggest that bark beetle fungal associates may enhance attraction of some parasitoids, our bioassays with associate-free hosts indicate that associate-produced are not required for short-range host location and parasitization. In addition, our field trials indicated that long-range attraction of parasitoids to the host-fungi-tree complex is not caused simply by an interaction between bluestain fungi and tree tissues.

Avoidance of nonhost plants by a bark beetle, Pityogenes bidentatus, in a forest of odors

Abstract: The bark beetle, Pityogenes bidentatus (Coleoptera: Scolytidae), searches in mixed conifer and deciduous forests of northern Europe for suitable branches of its host, Scots pine (Pinus sylvestris). We tested whether odors from several diverse nonhost trees and plants common in the habitat (e.g., mountain ash, Sorbus aucuparia; oak, Quercus robur; alder buckthorn, Frangula alnus; blueberry, Vaccinium myrtillus; raspberry, Rubus idaeus; and grass, Deschampsia flexuosa) would reduce the attraction of the bark beetle to traps releasing its aggregation pheromone components in the field. Volatiles from the leaves or bark of each of these plants significantly reduced the attraction of the beetles to their pheromone. Odors collected from these nonhosts and analyzed by GC/MS contained monoterpenes, sesquiterpenes, and “green-leaf” alcohols, several of which (e.g., 1-octene-3-ol and β-caryophyllene) reduced the attraction to pheromone in the field and elicited electroantennographic responses. In the laboratory, reproduction by the beetle was marginal in nonhost Norway spruce, Picea abies, and was absent in the other nonhost trees. Olfactory avoidance of unsuitable nonhosts may have evolved due to advantages in avoiding mistakes during host selection.

Antibacterial activity of naphthoquinones and triterpenoids from Euclea natalensis root bark.

Abstract: Phytochemical studies of an ethanolic extract of Euclea natalensis root bark afforded two new compounds, octahydroeuclein (1) and 20(29)-lupene-3 beta-isoferulate (2), in addition to three known compounds, shinanolone (3), lupeol, and betulin. The chemical structures of 1 and 2 were determined by spectroscopic means. Shinanolone (3) showed inhibitory activity against Gram-positive bacterial strains and a drug-sensitive strain of Mycobacterium tuberculosis at a concentration of 0.1 mg/mL.

Distribution and partial characterization of seasonally expressed proteins in different aged shoots and roots of 'Loring' peach (Prunus persica).

Abstract: During autumnal leaf senescence, leaf nitrogen in deciduous trees is translocated to storage sites, especially bark and xylem tissues. Proteins that accumulate in large amounts in bark and xylem in winter and are absent from these organs in summer are called storage proteins, and are believed to be vehicles for storing nitrogen reserves. These reserves are important for spring growth and help trees tolerate or recover from both abiotic and biotic stresses. Based on seasonal patterns of accumulation, we previously identified three storage proteins with molecular masses of 60, 19 and 16 kDa in bark tissues of 'Loring' peach (Prunus persica (L.) Batsch). To characterize the distribution of these proteins in different-aged tissues and to determine if they have any function other than nitrogen storage, we examined their seasonal distribution in bark tissues of current-year and 1-year-old shoots, scaffold branches, main trunks and 4-5-year-old roots of 'Loring' peach. Verification of protein identity was based on molecular mass and reactions with antibodies directed against each specific protein. Protein distribution was variable. For all three proteins, the greatest amount was present in mid-winter in current-year and 1-year-old shoots. These tissues also showed the greatest seasonal variation in the amount of protein present. The 16 kDa protein was present only in the youngest shoots, whereas the 19 kDa protein was present in all tissues examined. The 60 kDa protein was absent in root tissue. The amino acid composition and sequence of each protein were determined. The 60 kDa protein was identified as a dehydrin, and the 19 kDa protein appeared to be related to a family of allergen proteins in Rosaceous plants, some members of which are associated with pathogenesis-related proteins. The amino acid sequence of the 16 kDa protein appeared to have no homology with any proteins in the SwissProt database. Therefore, it is likely that the 16 kDa protein, in a strict sense, is a bark storage protein. Defining storage proteins solely by their pattern of accumulation and the extent to which they accumulate may not be a good functional definition. It is possible that storage proteins have functional roles in addition to nitrogen storage.

Maturation feeding and reproductive development in adult pine weevil, Hylobius abietis (Coleoptera: Curculionidae).

Abstract: Maturation feeding on conifer bark by newly emerged Hylobius abietis(Linnaeus) is essential for reproductive development. When feeding occurs on young conifer transplants, this weevil causes significant economic damage. Between emergence and oviposition however, weevils feed on bark from different sources but of unknown nutritional ‘quality’. The factors influencing the rate of feeding by males and females and female reproductive development were determined in laboratory bioassays using two contrasting food sources – the bark on different species of seedling conifer and on logs of mature trees. The nutritional ‘quality’ of bark was characterized by the concentration of nitrogen, total sugars, total polyphenols and resin. Regression models were used to show that overall, the rate of feeding on the bark of both seedlings and logs increased with weevil size and was negatively related to nitrogen concentration. The nitrogen concentration in seedling bark (mean 1.1%) was about three times higher than that of logs (mean 0.4%). The rate of reproductive development increased with nitrogen intake during feeding and the preoviposition period for weevils feeding on seedlings and logs was ~ 13 days and 46 days, respectively. Analysis of weevil mortality and of the weight gain of surviving weevils suggests that a nitrogen content of around 0.3% may be limiting for H. abietis. The possibility that nutritionally adequate food resources may be limiting for H. abietis is briefly discussed.

Hylobius pine weevils adult host selection and antifeedants: feeding behaviour on host and non-host woody scandinavian plants

Abstract: 1 We searched for antifeedant activity in predomonantly non-host woody plants to find new compounds for seedling protection of Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) against feeding by pine weevil Hylobius abietis. In total, 38 species from 25 families were compared in choice and no-choice tests. 2 In choice tests with Empetrum, Juniperus, Ledum, Populus, Betula, Evonymus, Sorbus, Salix, Myrica and Pinus, the weevils preferred Pinus to all others. In no-choice tests with the same species, the insects removed a similar or even greater area of the bark in three of 10 species than Pinus. The results were clearly different between the test modes. 3 In experiment 4, the areas of outer and inner bark (phloem) removed were quantified separately.The weevils removed significantly less of both outer and inner bark in Ilex, Evonymus, Populus, Syringa, Taxus, Tilia, Viburnum, Lonicera and Sorbus than Pinus. 4 Large areas of outer bark were removed in Juglans, Fraxinus, Sambucus, Aesculus, Quercus, Corylus, Fagus, Salix, Alnus and Acer. However, in the latter cases the insects stopped when reaching the inner bark. Thus, certain plant species have the outer bark removed by the insects but possessed an inner bark with antifeedant qualities.

The Use of Plants as Regular Food in Ancient Subarctic Economies: A Case Study Based on Sami Use of Scots Pine Innerbark

Abstract: This study combines ethnological, historical, and dendroecological data from areas north of the Arctic Circle to analyze cultural aspects of Sami use of Scots pine (Pinus sylvestris L.) inner bark as regular food. Bark was peeled in June when trees were at the peak of sapping, leaving a strip of undamaged cambium so the tree survived. As a result, it is possible to date bark-peeling episodes using dendrochronology. The paper argues that the use of Scots pine inner bark reflects Sami reli- gious beliefs, ethical concerns, and concepts of time, all expressed in the process of peeling the bark. A well-developed terminology and a set of specially designed tools reveal the technology involved in bark peeling. Consistent patterns with respect to the direction and size of peeling scars found across the region demonstrate common values and standards. Peeling direction patterns and cere- monial meals relating to bark probably reflect ritual practices connected to the sun deity, Biejvve.

Chemical composition and gross calorific value of the above-ground biomass components of young Picea abies

Abstract: Fertilization is used to increase the total yield of biomass on a site, as well as sustaining or improving the health, vigour and vitality of trees. How fertilization affects the chemical composition and the fuel characteristics is poorly known. Extractives, lignin, holocellulose, ash content and calorific heat value were measured in the stem wood at the root (0 m), 2 m and 4 m levels, in the branches, and in the bark of young Norway spruce [Picea abies (L.) Karst.] trees. Ten control trees and six fertilized trees were evaluated. Fertilization with a balanced nutrient mixture had only a minor effect on the detected chemical and fuel parameters. The main differences in chemical composition within the tree were found between stem, branches and bark. Thus, fertilization can be recommended as a silvicultural treatment to increase the net biomass production on a site intended for fuel production.

Trees for food – a 3000 year record of subarctic plant use

Abstract: The authors present a unique long record of inner bark use by the Sami people of northern Scandinavia extending back to 2800 BP. Consistent patterns with respect to the direction and size of bark peeling scars shows that common values and standards were early applied. They further conclude that inner bark was important as a regular food and a vitamin C source at these northern latitudes. Bark-peeled trees as biological artefacts in forests also provide important data to understand subsistence strategies and spatial patterns of land use unique to areas with long winter seasons.

Historical records of airborne polycyclic aromatic hydrocarbons by analyzing dated corks of the bark pocket in a Longpetiole Beech tree.

Abstract: Historical monitoring of airborne polycyclic aromatic hydrocarbons (PAHs) pollution levels was novelly demonstrated by analyzing the dated corks of a bark pocket formed from 1873 to 2003 in a Longpetiole Beech (Fagus longipetiolata) tree trunk sampled from southeastern China. The fundamental studies indicated that the PAHs of log Koa 8.5 existing as particle-phase dependent on log Vp are accumulated through stochastic entrapment by the lenticels on the surface of the cork. The translocation of PAHs by xylem flow and phloem stream as well as radial diffusion from the cork to the inner tissues was not significant, and the cork is most effective for accumulating airborne PAHs. The total concentrations of 16 EPA PAHs (ΣPAHs) in the dated corks progressively increased from 43.5 ng/g recorded in the earliest available cork in 1873−1875 to the maximum 345.7 ng/g in 1956−1961, and ...

Influence of Tree Substrate on the Diversity of Epiphytic Lichens: Comparison Between Tilia platyphyllos and Quercus ilex (Central Italy)

Abstract: A comparison between lime (Tilia platyphyllos) and holly oak (Quercus ilex) as substrate trees for epiphytic lichens was carried out in Siena (central Italy). The purpose of this study was to investigate the influence of these phorophytes on the diversity of epiphytic lichens, at a similar climatic regime and at the same air pollution status. The diversity values measured on Tilia were on the average 1.5 times higher than those on Quercus. No difference between the two tree species appeared for bark pH and bark concentrations of NO3−, SO42−, NH4+, Cu, and Pb. Bark concentrations of Mn were higher for Quercus. The water-holding capacity of the bark of Tilia was higher than that of Quercus. The amount of incident light radiation was similar for the two trees in summer, when both species have leaves, but was higher on deciduous lime in winter, when only the evergreen Q. ilex has leaves. Influx light in winter is the most important factor for determining differences in the biodiversity of epiphytic l...

The application of bio-indicators for the assessment of air pollution

Abstract: Levels of metals were assessed in topsoil, dust, leaves, grass, lichen and bark from the Kruger National Park using electrothermal atomic absorption techniques. It was found that dust, lichen and bark reflected the levels of air pollution better than grasses or leaves of trees. It is suggested that the difference in levels of accumulated metals in the bark or lichens could be used as an indicator of air pollution in remote areas.

Effects of bark mulch and npk fertilizer on yield, leaf nutrient status and soil mineral nitrogen during three years of strawberry production

Abstract: The effects of bark mulch and NPK fertilizers on yield and leaf and soil nutrient status of ‘Korona’ strawberry plants (Fragaria×ananassa Duch.), were studied over a period of three years. A signif...

Phaeoacremonium rubrigenum - hyphomycete associated with bark beetles found in Czechia.

Abstract: Phaeoacremonium is a recently described genus (Crouset al. 1996) associated with decline diseases of woody hosts and with human infections. During a study of surface mycobiota of the oak bark beetles, the hyphomycetous microfungusPhaeoacremonium rubrigenum was isolated from larvae ofScolytus intricatus (Coleoptera: Scolytidae) and their galleries onQuercus robur and also from an adult ofLeperisinus fraxini found under the bark ofFraxinus excelsior. The species determination was confirmed by rDNA (ITS1-5.8S-ITS2) comparison.P. rubrigenum was recorded for the first time in Czechia. The records on oak are considered to be the first ones in the world. A description of morphological features and figures of the fungus are given. Representative strains are maintained in theCulture Collection of Fungi (CCF), Faculty of Science, Charles University (Prague, Czechia).