首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Veronica davisii M. A.Fischer, sp. n., limited to the mountains of Kurdistan (S. E. Turkey and N. Iraq), is related to the Turkish-CaucasianV. gentianoidesVahl.V. montbretii M. A.Fischer, sp. n., a local endemic of Erzincan prov. (E. Anatolia), shows affinities to the CaucasianV. liwanensisC. Koch and to the Turkish endemicV. oltensisWoron. & Schelk. from Erzurum province.  相似文献   

2.
3.
12 species ofPertusaria DC. were collected from various areas in Japan. Their phycobionts were isolated and studied taxonomically. The phycobionts of these species were indentified asTrebouxia potteriAhmadjian exGärtner.Dedicated to Prof. DrLothar Geitler on the occasion of the 90th anniversary of his birthday.  相似文献   

4.
5.
Two new cycloartane derivatives, macrostachyosides A (1) and B (2), and seventeen known compounds were isolated from the methanol extract of Mallotus macrostachyus leaves. Their structures were elucidated by NMR and MS data. Macrostachyosides A (1) and B (2) showed significant cytotoxic activities on KB (epidermoid carcinoma) and LU-1 (lung adenocarcinoma) human cancer cell lines with IC50 values ranging from 4.31 ± 0.09 to 7.12 ± 0.07 μg/mL.  相似文献   

6.
In a flavonoid survey of direct and hydrolysed leaf extracts of sixteenAttalea, sevenScheelea and fourOrbignya species free tricin, tricin 7-glycosides, tricin 5-glucoside and flavone C-glycosides were the most frequent constituents; present in 100, 89, 70, and 81% of species, respectively. Luteolin, quercetin and isorhamnetin were each found in only 15% of the sample. The present results confirm the findings of a previous survey thatAttalea, Scheelea andOrbignya are chemically heterogeneous with as much variation between species as between genera. Furthermore, threeAttalea species,A. allenii, A. guaranitica andA. victoriana showed some infraspecific variation. On the other hand all three accessions ofA. ferruginea and six ofA. geraensis examined gave identical flavonoid profiles. The results support the view thatA. geraensis andA. guaranitica are closely related but do not support the suggested close relationship based on morphology betweenA. oleifera, A. burretiana andA. piassabossu.  相似文献   

7.
Hypericin in Hypericum lydium Boiss. growing in Turkey   总被引:1,自引:1,他引:0  
  相似文献   

8.
The composition of the essential oils of ten Centaurea species from Turkey, Centaurea aladaghensis, C. antiochia var. prealta, C. antitauri, C. babylonica, C. balsamita, C. cheirolepidoides, C. deflexa, C. iconiensis, C. lanigera, C. ptosimopappoides have been studied. Multivariate statistical analyses (Principal Component Analysis, Multidimensional Scaling, Hierarchical Cluster Analysis) applied to GC-MS data, seem to be very useful to investigate and establish the natural taxonomic delimitation of this very difficult genus. The groupings resulted independent from the ecological similarities (i.e. plants that live in the same habitats or share similar morphological characteristics), so it seems that the environment has no influence on the biosynthesis of the volatiles of these plants.  相似文献   

9.
The crude methanolic extracts of six species of Hypericum [H. caprifoliatum Cham. & Schlecht., H. carinatum Griseb., H. connatum Lam., H. ternum A. St. Hil., H. myrianthum Cham. & Schlecht. and H. polyanthemum Klotzsch ex Reichardt] growing in southern Brazil were analyzed for antimicrobial activity against several microorganisms (bacteria and fungi). The most active plant was H. caprifoliatum, which showed activity against Staphylococcus aureus. Only H. polyanthemum and H. ternum extracts were active against Bacillus subtilis. None of the crude methanolic extracts showed activity against S. epidermidis, Escherichia coli or Saccharomyces cerevisiae. Extracts from these species were evaluated chemically and tannin, flavonoid and phenolic acids were the prominent compounds. The plants contained quercitrin, hyperoside (except H. connatum) and, less frequently, isoquercitrin and chlorogenic acid. In contrast to H. perforatum, which has high concentrations of rutin, these species do not produce this flavonoid or it appears as traces. The tannin concentration varied between 5.1 and 16.7% in H. myrianthum and H. ternum, respectively.  相似文献   

10.
The forest under-storey herbs Anemone nemorosa, Lamiastrum galeobdolon and Veronica montana are generally considered indicator species of old, broadleaved woodland sites where the soil fertility is often low. In a glasshouse bioassay, however, all three species not only showed large positive growth responses to supplied P concentrations (0–10mgL –1) solutions, but also tolerated high P concentrations (20–40mgL –1), well above those normally found in their natural habitat. Plants responded by raising the concentrations of P in their shoot and root tissues and increasing their biomass, resulting in an increased P uptake. A shade-tolerant competitor species, Urtica dioica, also grew vigorously across the full range of P concentrations, restricting the growth of the woodland species. This emphasises the difficulty of establishing semi-natural woodland vegetation in the presence of competitor species, for example in situations where new woodlands are planted on fertile ex-agricultural soils containing large residual concentrations of P. The influence of soil pH on the growth and nutrient relations of A. nemorosa, L. galeobdolon, V. montana, Poa trivialisandU. dioicawas determined in a separate experiment using an ex-arable soil as the growing medium with pH levels adjusted from 7.4 to 5.8 and 4.3 respectively. Acidifying the soil enhanced growth, but reduced the concentrations of N, P and K in the leaves of all three woodland species, probably due to dilution of these minerals in the increased dry matter production. The competitor species (P. trivialis and U. dioica) responded in similar manner to the woodland indicator species. These results suggest that manipulating soil pH as a means of facilitating the establishment of woodland indicator species in new farm woods is unlikely, in the short term, to be effective where competitor species are present.  相似文献   

11.
The genus Verbascum L. (mulleins) comprises of about 360 species of flowering plants in the Scrophulariaceae family. Mulleins have been used in the traditional folk medicine for centuries, for treatment of a wide range of human ailments, inter alia bronchitis, tuberculosis, asthma, and different inflammations. Despite all applications the knowledge of the metabolites, accumulated in different mullein species, is still limited and based mainly on determination of the major compounds. Here we report the application of 1H NMR metabolic fingerprinting in combination with principal component analyses (PCA) in five different Verbascum species. Based on the obtained results mulleins were divided in two groups: group A (Verbascum phlomoides and Verbascum densiflorum) and group B (Verbascum xanthophoeniceum, Verbascum nigrum and Verbascum phoeniceum). Further it was found that the plants in group B accumulate higher amounts of bioactive iridoid and phenylethanoid glycosides. V. xanthophoeniceum and V. nigrum accumulate higher amounts of the pharmaceutically-important harpagoside (∼0.5% on dry weight basis) and verbascoside, forsythoside B and leucosceptoside B (in total 5.6–5.8% on dry weight basis), which underlines the possibility for their application in pharmaceutical industry. To the best of our knowledge this is the first report on the analyses of Verbascum sp. leaf metabolome.  相似文献   

12.
13.
An explorative trip was made to southwesternTurkey in April 1995 in search of pear thrips,Taeniothrips inconsequens (Uzel)(Thysanoptera: Thripidae), and its naturalenemies. Forty-three females and 13 males of apreviously undescribed species of the genusCeranisus Walker (Hymenoptera:Eulophidae) were found, mainly in floweringArbutus andrachne L. Although theparasitoid was found in association withseveral thrips species, but especially T.inconsequens adults and larvae, its host orhosts were not determined. The parasitoid isdescribed and given the name Ceranisusantalyacus S. Triapitsyn.  相似文献   

14.
Summary The nitrification rate in the rhizosphere of Suaeda and Arthrocnemum plants growing in saline soils, as affected by microbial populations, temperature, pH, and organic matter, was examined in the field throughout the year. The genera Nitrosomonas and Nitrobacter were most common in the rhizosphere soil. The bacterial counts in the rhizosphere of both plants fluctuated during the study period, reaching peak values during February–March and in August. The nitrate concentration in the rhizosphere soil could be related with the observed increase in the numbers of ammonium-oxidizers and nitrite-oxidizers in the latter part of the study period. The pH of the rhizosphere soils did not have any influence on the nitrification rate at the values measured. The rhizosphere organic content varied between 1.8 and 4% (w/w), showing the continuous availability of organic matter in the soil. The seasonal changes in bacterial populations in the rhizospheres of both plants was described as the result of the combination of several factors.  相似文献   

15.
The occurrence of vascular tracheids inBetula, Alnus, Carpinus andCorylus is reported. It is established that the cells are a consistent feature in early and late wood where they are associated with vessel elements in radial multiples. The possible function and taxonomic importance of these cells are briefly considered.  相似文献   

16.
Nest-mounds of the harvester ant Messor capensis occur on and around nutrient-rich patches, along minor drainage lines in nutrient-rich soils, and on the plains, generally in nutrient-poor soils. Nest-site selection is related to the presence of suitable deep soils, the presence of stones and the distance from the nearest neighbouring nest. Two plant species, Galenia fruticosa and Pteronia pallens, were significantly associated with Messor capensis nest-mounds, both in numbers of mounds occupied and in numbers of individuals. A third species, Drosanthemum montaguense, was also more common in numbers of individuals, while a fourth species, Rhinephyllum macradenium was negatively associated with these mounds. The analysis of species guilds by soil type shows that significantly more species of nutrient-rich soils are present on M. capensis nest-mounds. Also, significantly more taller, woody species occurred on nest-mounds than in inter-mound spaces. Two species, Pteronia pallens and Osteospermum sinuatum, growing on ant nest-mounds had significantly longer inter-nodes than the same species growing off mounds. However, two other species, Pteronia cf. empetrifolia and Galenia fruticosa showed no difference in inter-node lengths between plants growing on and off mounds. Six of the nine species of plants sampled on ant nest-mounds had significantly higher seed production than plants of the same species growing in inter-mound spaces. The other three species showed a tendency towards more seeds per plant on ant nest-mounds. The proportions of live and dead plants on mounds differed between species. Only Ruschia spinosa showed a significant difference between the numbers of dead plants in the population on and off mounds, with more dead plants occurring on mounds. Significantly more seeds set on individuals of Pteronia pallens growing on ant nest-mounds than those growing off nest-mounds, but no such difference occurred in P. cf. empetrifolia. There was no significant difference in the proportion of seeds parasitized by the tephritid fly Desmella anceps for individuals of P. pallens and P. cf. empetrifolia growing on and off mounds.  相似文献   

17.
In vitro anthelmintic activity of crude extracts of the ripe fruits of Hedera helix was investigated on eggs and adult nematode parasites Haemonchus contortus. Aqueous extract of H. helix was also evaluated for in vivo anthelmintic activity at dose of 1.13 and 2.25 g/kg in sheep artificially infected with H. contortus. ED(50) for egg hatch inhibition was 0.12 and 0.17 mg/ml for aqueous and hydro-alcoholic extracts, respectively. There was no statistically significant difference in the activity of the two extract types (p>0.05). Hydro-alcoholic extract showed better in vitro activity against adult parasites compared to the aqueous extract. Significant faecal egg count reduction (FECR) was detected in groups treated with both doses of H. helix (p<0.05) on day 2 post-treatment. On day 7 post-treatment significant reduction was detected only for higher dose of H. helix (p<0.05) while on day 14 post-treatment there was no significant FECR in both groups treated with H. helix. The percentage of larvae recovered from culturing faeces obtained from groups of sheep treated with lower and higher doses of H. helix was 47.52% and 36.07%, respectively, which was significantly lower than (p<0.05) that recovered from the control group (60%). Significant (p<0.05), dose dependent total worm count reduction (WCR) was observed for groups of sheep treated with H. helix. Increasing the dose of H. helix improved the efficacy against the male than the female parasites. Treatment with both doses of H. helix helped the animals maintain their packed cell volume (PCV) unlike the untreated control group. The overall findings of the current study indicated that H. helix has a potential anthelmintic benefit and further in vitro and in vivo evaluation of the different parts and fractions is needed to make use of this plant for therapeutic purposes.  相似文献   

18.
Veronica fridericae spec. nova, described from the type locality in the S.E. Turkish province Van, is related toV. acrotheca andV. farinosa, both endemic to W. Iran. All 8 perennial species with pinnatifid leaves in S.W. Asia are presented in a key.  相似文献   

19.
Coastal dunes in western Europe have long been under grazing and recreational pressure, but the vegetative cover appears to be remarkably resilient. In a series of experiments on Ynyslas Dunes, Cardigan Bay (Wales, U.K.), trampling, protection, fertiliser, and herbicide treatments were monitored using non-destructive and destructive sampling methods. This paper discusses the behaviour of 12 important species after these treatments on three major dune habitats: Agrostis tenuis, Ammophila arenaria, Bellis perennis, Festuca rubra, Galium verum, Leontodon taraxacoides, Ononis repens, Plantago lanceolata, Poa subcaerulea, Thymus praecox, Homalothecium lutescens, Tortula ruraliformis.Although stability is usually thought of as a feature of the community, a reductionist approach suggests that grasses react quickly but temporarily, dicotyledonous forbs often show slower reaction times, each species reacting in its own way to changes in the environment. A tentative classification of our study species is possible.Nomenclature follows Smith (1978), for bryophytes and Clapam, Tutin & Warburg (1962), for angiosperms.  相似文献   

20.
The essential oils of six Eupatorium species were obtained by hydrodistillation and analysed by GC-MS. The oil of E. macrophyllum was rich in sabinene (46.7%) and limonene (23.3%). The oil of E. laevigatum was mainly constituted by a mixture of aristolone+laevigatin (23.6%), globulol (16.2%) and germacrene D (8.6%). The principal constituents of the oils of the chemotypes A and B of E. squalidum, E. amygdalinum and E. conyzoides were caryophyllene oxide (17.4–30.1%), globulol (25.1%), germacrene D (10.4–21.6%), spathulenol (14.2%) and β-caryophyllene (7.1–12.3%). The oils of the chemotypes A and B of E. marginatum were dominated by α-zingiberene (57.5%), α-gurjunene (19.5%), germacrene D (14.8%), (E)-8-bisabolene (9.7%) and α-selinene (9.0%).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号