Search results for "Bark"
showing 10 items of 137 documents
The use of bark of Scots Pine in environmental impact assessment of cement and lime dust
2016
Analizie poddano korę sosny zwyczajnej znajdującej się pod presją zanieczyszczeń alkalicznych cementowni Chełm. Na podstawie wodnych wyciągów z kory określono zasięg oddziaływania pyłów cementowo-wapienniczych na środowisko. Zależności pomiędzy pHH2O kory a odległością od źródła emisji pyłów badano metodą analizy regresji i korelacji liniowej. Wyniki badań odnoszono do wyników uzyskanych na leśnej powierzchni kontrolnej - wolnej od zanieczyszczeń alkalicznych. W miarę oddalania od źródła zanieczyszczeń opad pyłów cementowo-wapienniczych obniża się, co jest zrozumiałe, i znajduje potwierdzenie w zmiennych wartościach pHH2O kory sosny. Najsilniej odnotowano presję w kierunku NE, ES i SW, gdzi…
Characterisation of Diarylheptanoid- and Flavonoid-type Phenolics in Corylus avellana L. Leaves and Bark by HPLC/DAD-ESI/MS
2013
Introduction The leaves of Corylus avellana L. (common hazel, Betulaceae), a plant with a wide distribution in Europe, have been used in folk medicine for various diseases, but phytochemical exploration of C. avellana is still incomplete. To the best of our knowledge there is no previous report concerning diarylheptanoids in C. avellana, although these compounds show a frequent occurrence among Betulaceae plants. Objective To improve existing online chromatographic methods for the investigation of the phenolic compounds in C. avellana leaves and bark, focusing on diarylheptanoid-type molecules. Methods Dried and powdered leaves and bark of C. avellana were extracted with increasing polarity…
Combretastatin Analogs via Hydration of Stilbene Derivatives
1993
Hydration of the double bond of some stilbene congeners of Picea abies bark by TiCl4·NaBH4 reagent is described. Five racemic 1,2-diphenylethanol derivatives (9–13), structurally related to (R)-(·)-combretastatin [(R)-1], have been obtained and characterized mainly by 13C- and 1H-NMR as well as mass spectrometry. The antileukemic activity of each compound has preliminarily been tested by the mouse leukemia L1210 system. Compound 10 has been synthesized by Friedel-Crafts acylation.
UJI AKTIVITAS ANTIBAKTERI DARI ESTRAK TUMBUHAN AKWAY (Drimys beccariana. Gibbs)
2010
<p><em>The plant Akway (Drimys beccariana.</em>Gibbs<em>) is endemic to Papua and is frequently used traditionally by the Arfak tribe as a medicinal plant. We extract the plant by maceration with ethanol. The antibacterial test is done by Agar diffusion method. As microba test we used Escheresia coli and Bacillus subtilis. Result obtained from fitochemistry skrinning of the leaf and bark contained alkaloid, flavonoid, steroid, tannin, glikosida, saponin, triterpenoid, steroid and fenolik. Concentration of active substances from the leaf are flavonoid (0,3680%) and tanin (10.33 %); while from the bark flavonoid 18.35% and tanin (27.65%). Antibacterial test showed…
30-Norfriedelane triterpenes from the stem bark ofCaloncoba glauca
1992
Abstract The stem bark of Caloncoba glauca has yielded three friedelane triterpenes of which two are characterized by the loss of C-30 and the presence of a C-27, C-15 lactone. They were identified, with considerable use of long-range C H coupling studies, as the known compound trichadonic acid (3-oxofriedelan-27-oic acid) and two new 30-norfriedelane derivatives, 3,27-dioxo-30-norfriedelan-20(29)-en-27,15α-lactone (caloncobalactone) and 3,27-dioxo-21β-hydroxy-30-norfriedelan-20(29)-en-17,15α-lactone (21β-hydroxycaloncoba lactone).
Friedelane triterpenes from the stem bark of Caloncoba glauca
1993
Further investigation of the stem bark of Caloncoba glauca has yielded three minor (D:A)-friedo-oleanane derivatives. These have been identified, on the basis of NMR studies, as the known compound kokoonol [3-oxo-(D:A)-friedo-olean-27-ol] and the novel natural products kokoonal [3-oxo-(D:A)-friedo-olean-27- al] and 3β,21β-dihydroxy-30-nor-(D:A)-friedo-olean-27-oic acid.
Polyacanthoside A, a new oleanane-type triterpenoid saponin with cytotoxic effects from the leaves of Acacia polyacantha (Fabaceae)
2018
The chemical investigation of the leaves and stem bark of Acacia polyacantha (Fabaceae) led to the isolation of a new oleanane-type triterpenoid saponin named polyacanthoside A 1 together with fifteen known compounds. Their structures were established from spectral , mainly HRESIMS, 1D NMR and 2D NMR and by comparison with literature data. The cytotoxicity of compound 1 and the analogues 8 as well as doxorubicin was determined in a panel of 9 cancer cell lines including sensitive and drug resistant phenotypes. Unlike the analogue 8, compound 1 as well as doxorubicin displayed cytotoxic effects in all the 9 tested cancer cell lines with IC50 values ranged from 8.90 μM (towards CCRF-CEM leuke…
Isomotiol, a new triterpene from strychnos potatorum
1978
Isomotiol (fern-8-en-3β-ol) was isolated from the leaves of Strychnos potatorum; it was not known previously as a natural product, but it has been obtained by acidic isomerization of compounds with a fern-7-ene or a fern-9(11)-ene skeleton. From the leaves and the bark mixtures of sitosterol, stigmasterol and campesterol were also isolated.
Pat Barker’s Regeneration: Subverting the Masculinity of World War I Official Discourse
2014
Pat Barker’s Regeneration (1991) offers an imaginative deconstruction of the myth of the Great War as produced within British official patriotic rhetoric and in some of the best-known lyrics by Wilfred Owen (1893- 1918), who, together with Siegfried Sassoon (1886-1967), has always been celebrated as one of the leading War poets. If Owen’s poetry partly entails the apolitical sublimation of the devastating facts of war through the ambiguous sentiment of pity, in Barker’s novel any suppression of emotions is posited as artificial and counterbalanced by a thorough exploration of those contradictory aspects of the Great War which official discourses have tended to obscure: the homoerotic experi…
Idiosyncratic responses to simulated herbivory by root fungal symbionts in a subarctic meadow
2021
Plant-associated fungi have elementary roles in ecosystem productivity. There is little information on the interactions between arbuscular mycorrhizal (AM) fungal symbiosis, fine endophytic (FE) and dark septate endophytic (DSE) fungi, and their host plants in cold climate systems. In particular, the environmental filters potentially driving the relative abundance of these root symbionts remain unknown. We investigated the interlinkage of plant and belowground fungal responses to simulated herbivory (clipping, fertilization, and trampling) in a subarctic meadow system. AM and FE frequency in the two target plant roots, Potentilla crantzii and Saussurea alpina, was unaffected by simulated he…