Showing papers on "Bark published in 1996"
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TL;DR: This study represents only a precursory examination of several proteins reported to be stress related in herbaceous plants, but the results indicate that these proteins are also common to woody plants and that further research to characterize their regulation and function in relation to stress adaptation and the perennial life cycle of woody Plants is warranted.
Abstract: Although considerable effort has been directed at identifying and understanding the function and regulation of stress-induced proteins in herbaceous plants, reports concerning woody plants are limited. Studies with herbaceous crops have revealed similarities in the types of proteins that accumulate in response to a wide array of abiotic stresses and hormonal cues such as the accumulation of abscisic acid. Many of the identified proteins appear to be related to dehydrins (the D-11 subgroup of late-embryogenesis-abundant proteins). The objective of the present study was to determine if seasonal induction of dehydrins is a common feature in woody plants and to see if seasonal patterns existed for other stress-induced proteins. Bark tissues from eight species of woody plants were collected monthly for a period of 1.5 years. The species included: peach (Prunus persica) cv. Loring ; apple (Malus domestica) cv. Golden Delicious; thornless blackberry (Rubus sp.) cv. Chester ; hybrid poplar (Populus nigra) ; weeping willow (Salix babylonica) ; flowering dogwood (Cornus florida) ; sassafras (Sassafras albidum) ; and black locust (Robinia pseudo-acacia). Immunoblots of bark proteins were probed with a polyclonal antibody recognizing a conserved region of dehydrin proteins, and monoclonal antibodies directed against members of the HS70 family of heat-shock proteins. Some proteins, immunologically related to dehydrins, appeared to be constitutive ; however, distinct seasonal patterns associated with winter acclimation were also observed in all species. The molecular masses of these proteins varied widely, although similarities were observed in related species (willow and poplar). Identification of proteins using the monoclonal antibodies (HSP70, HSC70, BiP) was more definitive because of their inherent specificity, but seasonal patterns were more variable among the eight species examined. This study represents only a precursory examination of several proteins reported to be stress related in herbaceous plants, but the results indicate that these proteins are also common to woody plants and that further research to characterize their regulation and function in relation to stress adaptation and the perennial life cycle of woody plants is warranted.
118 citations
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TL;DR: The hypothesis that aggressive bark beetle species carry more pathogenic blue-stain fungi than other bark beetles is supported and pathogenic fungi are important for aggressive bark beetles to kill trees are indicated.
Abstract: Fungi associated with five bark beetle species colonizing Norway spruce (Piceaabies (L.) Karst.) were isolated from beetle-inoculated logs. Ipstypographus L., an aggressive tree-killing bark beetle, was associated with a different range of blue-stain fungi than the nonaggressive Pityogeneschalcographus L., Polygraphuspoligraphus L., and Hylurgopspalliatus Gyll. The flora of the nonaggressive Ipsduplicatus Sahib. was similar to that of I. typographus. The pathogenic fungus Ceratocystispolonica (Siem.) C. Moreau, and other blue-stain fungi, were isolated in high frequency from inoculations with both Ips species. Pathogenic blue-stain fungi were absent, or isolated in low frequencies, from inoculations with the other nonaggressive beetle species. With the exception of I. duplicatus, these results support the hypothesis that aggressive bark beetles carry more pathogenic blue-stain fungi than other bark beetles and indicate that pathogenic fungi are important for aggressive bark beetles to kill trees.
117 citations
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TL;DR: In this article, two new caryophyllene sesquiterpenes have been isolated from Pestalotiopsis sp., an endophytic fungus associated with the bark and leaves of Taxus brevifolia.
Abstract: Two new caryophyllene sesquiterpenes have been isolated from Pestalotiopsis sp., an endophytic fungus associated with the bark and leaves of Taxus brevifolia. Pestalotiopsin A (1) has a novel oxatricyclic ring system while pestalotiopsin B (3) exists as two slowly equilibrating atropisomers (6:5 ratio of ββ:βα) in chloroform solution at room temperature. Structures of 1 and 3 were determined by spectroscopic analyses and single-crystal X-ray diffraction.
111 citations
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TL;DR: In this article, the authors used as substrate cork oak bark (Quercus suber L), which contains phytotoxic phenolic compounds which can be washed out with hot water.
91 citations
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TL;DR: In this paper, the inner bark of Pinus sylvestris has been identified on the basis of chemical and spectroscopic evidence and 24 known phenolic compounds, including 3.2-O-[4′-(α- Hydroxypropyl )-2′- methoxyphenyl ]-1-O-β-d - xylopyranosyl glycerol and 3.
77 citations
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TL;DR: Three new sesquiterpene ortho-naphthoquinones, davidianones A, B and C, together with four known compounds, mansonones E, F, H and I, were isolated from the root bark of Ulmus davidiana on the basis of spectral data including pulse field gradient two-dimensional NMR spectroscopy.
72 citations
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TL;DR: The constituents of Betula platyphylla var. japonica were identified as follows as discussed by the authors : Fresh leaves : 12-O-acetyl-3-Omalonylbetulafolienetriol.
Abstract: The constituents of Betula platyphylla var. japonica were identified as follows : Fresh leaves : 12-O-acetyl-3-O-malonylbetulafolienetriol, 12-O-acetyl-3-O-malonylbetulafolienetriol oxide I (=papyriferic acid), 12-O-acetyl-betulafolienediolone, hydroxyhopanone, caryophyllene oxide, kaempferol 3-O-(4-O-acetyl)-α-L-rhamnopyran-oside, quercetin 3-O-(4-O-acetyl)-α-L-rhamnopyranoside. Outer bark : betulin, lupeol, betulinic acid, betulone, betulin 3-O-caffeate, oleanolic acid, oleanolic acid 3-O-acetate. Inner bark : (-)-catechin, (-)-catechin 7-O-β-D-xylopyranoside, rhododendrin (=betuloside), aceroside VII, aceroside VIII, 1, 7-bis[4-hydroxyphenyl]-3-hepten-5-one, 2-hydroxy-1, 7-bis[4-hydroxyphenyl]-3-hepten-5-one, acerogenin E, (3R)-3, 5'-dihydroxy-4'-methoxy-3', 4"-oxo-1, 7-diphenyl-1-heptene, 7α-hydroxy-β-sitosterol, 7β-hydroxy-β-sitosterol. Root bark : dammarenediol II 3-O-p-coumarate, dammarenediol II 3-O-caffeate, ocotillol II 3-O-caffeate, stigmast-4-ene-3-one. Spikes : caryo-phyllene oxide, (-)-rhododendrol (=betuligenol), 12-O-acetylbetulafolienetriol. The compounds with an asterisk are new.
71 citations
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TL;DR: 2'-Hydroxycinnamaldehyde, which inhibits farnesyl-protein transferase (FPTase), has been isolated from the stem bark of Cinnamomum cassia Blume and the structure was elucidated on the basis of 500 MHz NMR experiments.
Abstract: 2'-Hydroxycinnamaldehyde, which inhibits farnesyl-protein transferase (FPTase), has been isolated from the stem bark of Cinnamomum cassia Blume. The biologically active agent in the extract has been purified by silica column chromatography and HPLC. The structure of the isolated compound was elucidated on the basis of 500 MHz NMR experiments.
71 citations
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TL;DR: Two new berbine alkaloids, pessoine and spinosine, have been isolated from the bark of Annona spinescens and their structures were elucidated by spectroscopic methods.
Abstract: The trunk bark and roots of Annona spinescens have been investigated for their alkaloid content. Two new berbine alkaloids, pessoine (1) and spinosine (2), have been isolated from the bark, and their structures were elucidated by spectroscopic methods. Eight known isoquinoline alkaloids were also obtained. The trypanocidal and antileishmanial activities of these isolated compounds have been investigated.
65 citations
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TL;DR: A total of 210 Norway spruce trees with stem wounds resulting from bark peeling by moose were examined in three 45–50-year-old stands that contained 20-30% of damaged trees, and a positive correlation was found between tree d.b.h. and the age of the injury.
Abstract: Summary
A total of 210 Norway spruce trees with stem wounds resulting from bark peeling by moose (Alces alces) were examined in three 45–50-year-old stands that contained 20-30% of damaged trees. Injured stems were between 8 and 40 cm diameter at breast height (d.b.h.) and showed 1 to 23-year-old wounds. Wounds varied in size from 2 to 4815 cm2. The size of injury correlated negatively with the age of the injury (r=-0.24; p=0.004), and positive correlation was established between the age of the injury and d.b.h. of the wounded tree (r=0.50; p=0.0001). Each wound was sampled once using an increment borer and fungi were isolated. Among basidiomycetes, Stereum sanguinolentum was the most common (isolated from 26.7% of the damaged stems). Other common species were Cylindrobasidium evolvens (23.8%), Amylostereum areolatum (5.2%), A. chailletii (0.5%), Heterobasidion annosum (5.2%), Peni-ophorapithya (1.4%), Sistotrema brinkmannii (1.0%). The ascomycete Nectria fuckeliana was the most common among all fungi (present in 35.7% of bark peeling wounds). The frequency of S. sanguinolentum infection correlated positively with the age of the injury (r=0.27; p=0.001) and the opposite relationship was revealed for C. evolvens (r=−0.30; p=0.0001). Furthermore, C. evolvens infection correlated positively with the wound size (r=0.30; p=0.0001) and negatively with the tree d.b.h. (r=−0.20; p=0.004). A positive correlation was found between tree d. b. h. and the occurrence in stems of H. annosum (r=0.23; p=0.001 and N. fuckeliana (r=0.23; p=0.0006). The spruce bark beetle Dendroctonus micans attacked 14.8% of wounded trees. Presence in stems of N. fuckeliana was associated significantly with the D. micans attack (r=0.190; p =0.006; χ2 test: p=0.01). Except for a negative correlation between infections of S. sanguinolentum and H. annosum (r=-0.140; p=0.04), no significant relationship between fungal species was found.
61 citations
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TL;DR: In this paper, a simple system was developed to investigate the deposition of lignin and synthesis occurring in response to mechanical wounding in the woody angiospermEucalyptus gunnii Hook.
Abstract: A simple system was developed to investigate the deposition of lignin and synthesis occurring in response to mechanical wounding in the woody angiospermEucalyptus gunnii Hook. The spatiotemporal deposition of these phenolic polymers was histochemically characterized in stem tissue through a combination of fluorescent microscopy and specific stains. Lignin and suberin deposition was detectable 24 h post wounding in the “xylem wound zone” and by 3 days post wounding in the “bark wound zone” where a welldeveloped necrophylactic (wound) periderm could be observed by 7 days post wounding. Close examination suggests that the spatial reinforcement of cell walls with lignin and/or suberin is carefully orchestrated so as to rapidly produce an effective protective barrier. Specific lignin colour reactions indicate that the lignin formed in response to wounding in both the bark and xylem wound zones is relatively poor in syringyl monomers as compared to that of “developmental” xylem lignin.
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TL;DR: The numbers of species and individuals of bark beetles did not differ between the countries, which indicates that extensive forest management has not increased the general level of bark beetle populations, and bark beetles were most abundant in old mesic forests.
Abstract: The population levels of bark beetles in non-epidemic conditions were compared between intensively managed forests in Finnish Karelia and extensively managed forests in Russian Karelia Thirty randomly chosen sample plots with five window flight traps in each were established in both countries The numbers of species and individuals of bark beetles did not differ between the countries This indicates that extensive forest management has not increased the general level of bark beetle populations Species assemblages were, however, different between the countries and between the forest site types Hylastes brunneus and Pityogenes bidentatus, which are common in stumps or in logging residue of Scots pine, were more abundant in Finland Crypturgus subcribrosus, Polygraphus punctifrons, and Hylurgops glabratus, which prefer dead spruce trees in shady conditions, and Trypodendron signatum, which live in dead deciduous trees, were more common in Russia Bark beetles were most abundant in old mesic forests The amount of decaying wood on the ground did not correlate with the numbers of bark beetles caught
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TL;DR: Changes in soluble phenol contents of Scots-pine phloem were studied after inoculation with Ophiostoma brunneo-ciliatum, a fungus associated with Ips sexdentatus to find concentrations of some phenolic compounds could be markers for trees' response efficiency.
Abstract: Summary
Changes in soluble phenol contents of Scots-pine (Pinus sylvestris) phloem were studied after inoculation with Ophiostoma brunneo-ciliatum, a fungus associated with Ips sexdentatus. They were compared to the length of the fungus-induced reaction zone of the phloem, taken as an estimation for the trees' response efficiency against aggression.
Five clones consisting of 14 trees were studied, and eight soluble phenolic metabolites were analysed in detail in reaction zones and in unwounded phloem sampled 3 weeks after inoculation.
The stilbenes pinosylvin and pinosylvin monomethylether, and the flavonoid pinocembrin, were detected in reaction zones only. Concentrations of two p-coumaric-acid esters and an acetophenone glycoside decreased after inoculation. Variations of the flavonoids taxifolin and 3' taxifolin glucoside were inconsistent.
One tree had longer reaction zones and a phenolic content different from the others. In unwounded phloem, concentrations of some phenolic compounds and in particular the ratio between the two p-coumaric-acid esters could be markers for trees' response efficiency. In the reaction zone, markers could be the ratios between concentrations of certain preformed compounds and concentrations of newly synthesized pinosylvin and pinocembrin.
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TL;DR: In this paper, the antimalarial principles of Spathodea campanulata stem bark extract were isolated and characterized, and the authors reported the first report of the isolation of ursolic acid and its derivatives as Antimalarial compounds, and two of its derivatives; 3β-hydroxyurs-12,19-dien-28-oic acid (tomentosolic acid) and 3β,20β-dihydroxyurs -12-en-28 oic acid.
Abstract: Antimalarial principles of Spathodea campanulata stem bark extract were isolated and characterized. The antimalarial principles in the stem bark were 3β-hydroxyurs-12-en-28-oic acid (ursolic acid) and two of its derivatives; 3β-hydroxyurs-12,19-dien-28-oic acid (tomentosolic acid) and 3β,20β-dihydroxyurs-12-en-28 oic acid. This is the first report of the isolation of ursolic acid and its derivatives as antimalarial compounds
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TL;DR: The Quillaja saponaria Molina (Rosaceae) tree, first described in 17821, has remained of special interest ever since, because of its bark (soap bark, Panama wood), containing 9-10% saponins as discussed by the authors.
Abstract: The Quillaja saponaria Molina (Rosaceae) tree, first described in 17821, has remained of special interest ever since, because of its bark (soap bark, Panama wood), containing 9–10% saponins.
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TL;DR: In this paper, Clausena excavata root and stem bark was extracted and a binary carbazole-pyranocoumarin dimer, carbazomarin-A, was identified.
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TL;DR: Five new trichilin-type limonoids isolated from the extract of the root bark of Melia azedarach were elucidated by spectroscopic means and their cytotoxic activities against P388 cells in vitro were tested by means of MTT assay.
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TL;DR: It was found that all plant parts contained camptothecins following 1 year of growth in the field, and that field-grown C. acuminata has the observed characteristic of multiple current-year branching.
Abstract: Camptotheca acuminata plantations were established in southern Louisiana in an effort to provide raw plant materials for deriving camptothecins, compounds having antitumor activity. This study was conducted to evaluate the growth and camptothecin distribution within the trees. It was found that all plant parts contained camptothecins following 1 year of growth in the field. Branches, roots, and stems accumulated significantly higher concentrations of camptothecins than leaves. Bark was significantly higher in camptothecin concentration than wood. Younger and older tissues within a growing season were not significantly different in camptothecin concentrations. High correlation in camptothecin concentration was found between branch and stem, root and stem, and root and branch, whereas little correlation was observed between bark and wood, and leaf and any other plant component. Field-grown C. acuminata has the observed characteristic of multiple current-year branching. The proportion of bark in term of dry ...
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TL;DR: Rhododendron indicum and pittosporum tobira variegata Ait were produced in 10.2 liter containers in substrates consisting of 20, 40, 60, and 80% (v/v) composted yard waste mixed with pine bark and coarse sand as discussed by the authors.
Abstract: Rhododendron indicum (L.) Sweet ‘Due du Rohan’ and Pittosporum tobira variegata Ait. were produced in 10.2 liter (#3) containers in substrates consisting of 20, 40, 60, and 80% (v/v) composted yard waste mixed with pine bark and coarse sand. Plant growth, substrate physical properties, and N and P leachate were compared with a control substrate of pine bark fines:sledge peat:sand (3:1:1 by vol). Shoot growth of plants in compost substrates was similar or better than control plants and greater with daily irrigation compared to alternate day irrigation. Root growth and percent air porosity declined as compost composition and waterholding capacity increased. Total porosity was generally consistent throughout the study. Irrigation regime had no effect on root growth nor substrate physical properties. Ammonium, NO3-N, and P concentrations in leachates varied with substrate and time following topdressing with controlled release fertilizer. Both species grew best in the 40% compost, 50% pine bark, and 1...
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TL;DR: In this article, a comparison of tannins in the bark, sapwood and heatwood of Castanea crenata showed that the major tannin of the bark is hamamelitannin, whereas vescalagin and castalagin are dominant in the wood.
Abstract: HPLC comparison of tannins in the bark, sapwood and heatwood of Castanea crenata showed striking differences of composition. The major tannin of the bark is hamamelitannin, whereas vescalagin and castalagin are dominant in the wood. Inner heatwood contained three new C-glycosidic ellagitannin metabolites, castacrenins A, B and C. Outer heartwood contained dimeric, trimeric (castanenin A), tetrameric (castaneanins B and C) and pentameric (castaneanin D) C-glycosidic ellagitannins composed of vescalagin and castalagin units. Castacrenins and castaneanins are derived from vescalagin and castalagin by intramolecular and intermolecular dehydration, respectively.
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TL;DR: A MeOH extract of Nectandra salicifolia trunk bark, obtained during a diversity-based plant collection in a lower montane rainforest in Costa Rica, showed activity in an in vitro antiplasmodial assay measuring incorporation of [3H]-labeled hypoxanthie by Plasmodium falciparum.
Abstract: A MeOH extract of Nectandra salicifolia trunk bark, obtained during a diversity-based plant collection in a lower montane rainforest in Costa Rica, showed activity in an in vitro antiplasmodial assay measuring incorporation of [3H]-labeled hypoxanthie by Plasmodium falciparum. In addition to 15 known alkaloids isolated from samples of trunk bark, roots, and leaves/twigs of this species, a new bisbenzylisoquinoline alkaloid (+)-costaricine [(+)-12-O-methyllindoldhamine] (1) was isolated from bark (0.038% yield) and from roots (0.001%). (+)-Costaricine was active in the antiplasmodial assay, with IC50 values of 50 ng/mL vs. the chloroquine-sensitive D6 clone and 294 ng/mL vs. the chloroquine-resistant W2 clone of P. falciparum.
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TL;DR: Allelopathic effects of bark phytochemicals seem to be predominantly responsible for the absence of infestation of Alphitonia petriei by adventitious-root climbers.
Abstract: The abundance of adventitious-root-climbing vines, predominantly Freycinetia excelsa and Piper caninum, on potential host trees was investigated in a north Queensland tropical rain forest. All trees 10 cm DBH and greater were measured and assessed for adventitious-root-climber presence. Additional trees of the 17 most abundant species were examined giving a total of 833 trees. Some 1694 adventitious-root-climbing vines were recorded from the study area. Distribution over the rain forest trees was not homogeneous, but exhibited host associations. Interspecific differences between potential host trees were analyzed in terms of allelopathy, bark characteristics, and gross morphological features. Bark characteristics are proposed. as the main factor for the relative absence of adventitious-root-climbing vines on trees of Syzygium papyraceum and Austromyrtus shepherdii. Thin, peeling, sloughable bark characterize these members of the Myrtaceae. Trees heavily infested by adventitious-root climbers include Beilschmiedia collina with non-descript (though slightly rough) bark providing a good, stable climbing surface with little phytotoxicity, and Citronella smythii, with thick, corky, fissured bark, also lacking allelopathic materials. Allelopathic effects of bark phytochemicals seem to be predominantly responsible for the absence of infestation of Alphitonia petriei by adventitious-root climbers.
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TL;DR: Structural and anatomical properties of the bark govern the basic conditions for the responses to invading bark beetles, and temporary changes in carbohydrate and water balance may affect the defences.
Abstract: The defence reactions of 105 Norway spruce trees in response to controlled attacks of Ips typographus were analysed and five groups with different defence reactions were recognized. Growth- and vigour-indices showed no significant correlation with the induced reactions, but parameters of bark anatomy were most important. Due to secondary radial growth, the formation of periderm was intensified. Thereby, the density and thickness of radial resin ducts in the phloem increased, the number of boring attempts decreased and the number of boring attempts, defended by primary resin exudation, increased. Seasonal changes in the defence reaction could partly be traced back to changes in starch reserves in the phloem. Temporary changes in carbohydrate and water balance may affect the defences, but structural and anatomical properties of the bark govern the basic conditions for the responses to invading bark beetles.
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TL;DR: The constituents of Betula maximowicziana REGAL in Japan were identified as follows as discussed by the authors : 12β-acetoxy-20(S), 24(R)-epoxy-3α, 17α, 25-trihydroxydammarane, 20(S) and naringenin.
Abstract: The constituents of Betula maximowicziana REGAL in Japan were identified as follows. Fresh leaves : 12β-acetoxy-20(S), 24(R)-epoxy-3α, 17α, 25-trihydroxydammarane, 20(S), 24(R)-epoxy-3α, 17α, 25-trihydroxydammarane, 3-epi-ocotillol II, 12β-acetoxy-20(S), 24(R)-epoxy-3α, 25-dihydroxydammarane, 12β-acetoxy-20(S), 24(R)-epxy-3α, 17α, 25-trihydroxydammarane 3-O-β-D-glucopyranoside (betulamaximoside A)*, 12β-acetoxy-20(S), 24(R)-epoxy-3α, 17α, 25-trihydroxydammarane 3-O-β-D-(6-O-acetyl)-glucopyranoside (betulamaximoside B)*, 12-O-acetyl-betulafolienetetraol, betulafolieneteraol, 6-methoxykaempferol, 6-methoxy-3-O-methylkaempferol and naringenin. Outer bark : betulin, betulin 3-O-caffeate, lupeol, lupane-3β, 20, 28-triol, lupane-3β, 20, 28-triol 3-O-caffeate, acetyl-oleanolic acid. Inner bark : acerogenin E, 16-hydroxy-17-O-methylacerogenin E*, alnusdiol β-D-glucopyranoside*, lyoniresinol 3α-O-α-L-rhamnopyranoside, 3, 4, 5-trimethoxyphenol β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside, benzyl alcohol β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside, (+)-catechin 7-O-β-D-xylopyranoside and monogynol A. Root bark : dammarenediol II 3-O-caffeate, dammar-24-ene-3β, 20(S), 26-triol 3-O-caffeate*, dammar-24-ene-3β, 20(S), 26-triol 3-O-coumarate*, oleanolic acid 3-O-caffeate. The six compounds with asterisks are new.
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TL;DR: Fungal growth in wood and lesion length in the inner bark were strongly correlated and variation in growth was explained by physiological stages and clone, both in terms of mean growth and mean growth ranking.
Abstract: Forty‐nine Picea abies (L.) Karst clones were inoculated under greenhouse conditions with a Heterobasidion annosum (Fr.) Bref. isolate of the S intersterility group. The cuttings were inoculated at the following vetetation stages; bud‐flushing stage, vegetative stage and after bud‐set. Fungal growth in sapwood and lesion length in the inner bark were measured after 34 days. The susceptibility of the various clones to H. annosum was strongly correlated among the three vegetation stages, both in terms of mean growth and mean growth ranking. Partitioning of variance components showed that variation in growth was explained by physiological stages and clone to 4% and 24%, respectively, and for interaction between clone and physiological stage to 9%. Corresponding values for lesion length in the inner bark were 3%. 14% and 5%, respectively. Fungal growth in wood and lesion length in the inner bark were strongly correlated (r 2 ranging between 0.23 and 0.36). When cuttings were inoculated during bud‐flushing, le...
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TL;DR: The bark of Juniperus procera yielded the diterpene 7β‐hydroxyabieta‐8,13‐dien‐11,12‐dione with strong activity against Mycobacterium species, and the hitherto unreported bisnorlabdane derivative 14,15‐bisnor‐13‐oxolabd‐8(17),11(E)‐ dien‐19‐oic acid (4).
Abstract: The bark of Juniperus procera yielded the diterpene 7β-hydroxyabieta-8,13-dien-11,12-dione (1) with strong activity against Mycobacterium species, and the hitherto unreported bisnorlabdane derivative 14,15-bisnor-13-oxolabd-8(17),11(E)-dien-19-oic acid (4). In addition, the bark yielded the known compounds crypotrienolic acid, isocupressic acid and sugiol. Structural assignments were largely based on the spectral data, including those derived from 2D NMR COSY and HETCOR experiments.
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TL;DR: The molecular weight distribution of tannins from the wood, bark and leaves of Eucalyptus camaldulensis, E. globulus and E. rudis from two different Spanish provenances has been studied by high performance gel permeation chromatography, using the compounds' acetylated derivatives.
Abstract: The molecular weight distribution of tannins from the wood, bark and leaves ofEucalyptus camaldulensis, E. globulus andE. rudis from two different Spanish provenances has been studied by high performance gel permeation chromatography, using the compounds' acetylated derivatives. The MW distribution profiles showed important variability depending on the type of vegetal tissue, the species and, in some cases, on the geographical provenance of the samples. Bark was the vegetal tissue that yielded tannins with the highest molecular weight, followed by wood and leaves. Tannins from wood and bark ofE. camaldulensis were of higher molecular size than those fromE. globulus andE. rudis; those in the leaves ofE. globulus andE. camaldulensis were similar in molecular size and larger than those in the leaves ofE. rudis.
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TL;DR: The occurrence of bark stripping by moose was significantly higher in April and May, coinciding with an increase in fibre, K, starch and total carbohydrate concentrations, and decreasing crude protein, P and Mg content.
Abstract: Bark stripping by moose (Alces alces L.) on young Scots pine (Pinus sylvestris L.) was studied at the Grimso Wildlife Research Area in south‐central Sweden. The investigation was launched to attempt to elucidate the underlying mechanism(s) for this behaviour. To document the seasonal pattern of bark stripping by moose, four young Scots pine plantations were observed between August 1988 and November 1989. In addition, pine bark samples were collected systematically throughout the study period, and the composition of various nutrients, minerals, and fibre fractions and their digestibility were determined. The occurrence of bark stripping was significantly higher in April and May, coinciding with an increase in fibre, K, starch and total carbohydrate concentrations, and decreasing crude protein, P and Mg content. Results are discussed with respect to the potential relationship between bark stripping and nutrient deficiencies in moose and the potential mechanisms inducing bark stripping.
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TL;DR: Variation in growth and defence between provenances appeared to reflect, independently, climatic limitations in the native habitat and this defensive trait was influenced by both genetic and environmental factors.
Abstract: 1. Lignified stone cell masses in Spruce bark are an important physical defence against insects and fungi and in Sitka Spruce and this defensive trait was influenced by both genetic and environmental factors. Single-tree, family and provenance mean heritability of the trait were 0.22, 0.68 and 0.79-0.95 respectively. 2. There was a distinct, clinal, increase in bark lignin with increasing latitude of provenance origin. Relative differences in bark lignin content between provenances were similar at four sites but absolute amounts were strongly site dependent. 3. Tree growth also varied systematically between provenances and differed between sites but we found no compelling evidence of a direct trade-off between growth and this quantitative defence. 4. Variation in growth and defence between provenances appeared to reflect, independently, climatic limitations in the native habitat.
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TL;DR: In this article, six new xanthones, caloxanthone F, G, H, 6-hydroxy-1,3,5-trimethoxy-, 3,6-dihydroxy- 1,5,dimethoxy- and 1,3.6-trihydroxyl-5,7-dimethoxidexanthone, were isolated from the stem wood of Calophyllum austroindicum, in addition to eight known xanthone.