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1.
Biologically active substances and antioxidant activity of extracts from leaves and inflorescences of nine representatives of the genus Spiraea L. growing on the territory of the Far East of Russia were investigated. Widespread species of the genus Spiraea (S. salicifolia, S. media var. media, S. betulifolia and S. ussuriensis subsp. ussuriensis) have the highest levels of biologically active substances. The inflorescences of spiraeas there contain more flavonols (up to 3.9%), oxycinnamic acids (up to 1.2%), catechins (up to 5.7%) and saponins (up to 5.1%) compared to their leaves, and there are more tannins (up to 11.6%) in the leaves. Among the Far Eastern representatives of the genus Spiraea, S. betulifolia and S. beauverdiana (section Calospira), S. humilis and S. salicifolia (section Spiraria), S. pubescens and S. media var. media (section Chamaedryon) are promising antioxidants. Plants of the genus Spiraea probably contain water-soluble antioxidant compounds of phenolic type, because the antioxidant activity of aqueous extracts in the leaves and inflorescences of spiraeas is higher (0.16–2.79 mg/g) than that of water-alcoholic compounds (0.06–2.54 mg/g). The antioxidant activity in the leaves of spiraeas is generally higher than that in the inflorescence. A reliable positive correlation is observed between the antioxidant activity of aqueous extracts from the organs of spiraeas and a content of oxycinnamic acids.  相似文献   

2.
The effect of A. rhizogenes-mediated genetic transformation on the antioxidant status of Artemisia tilesii, A. vulgaris, A. dracunculus, and A. annua transgenic roots has been studied. Antioxidant activity (AOA) of aqueous extracts was determined using methods based on the ability to reduce DPPH+ and ABTS+-radicals. The level of AOA (DPPH) in 50% of extracts obtained from transgenic roots was higher than the level of activity possessed by extracts from untransformed roots. An increased ability to reduce the ABTS+ radical was observed in 80% of the extracts. Extracts of A. annua and A. tilesii transgenic roots were the most active, while the lowest antioxidant activity was shown in A. dracunculus extracts. Thus, A. rhizogenes-mediated transformation has led to a change in the antioxidant status of the “hairy” roots of several Artemisia spp. plants (except A. vulgaris). It can be used as a method for the enhancement of the natural antiradical properties of plants belonging to the Artemisia genus.  相似文献   

3.
Artemisia arborescens L. is a perennial fast-growing Mediterranean shrub, which releases abundant leaf litter upon soil surface throughout the year. The paper aimed to both evaluate the phytotoxic potential and identify major compounds occurring in the plant leaf litter. Following methanolic maceration of the leaf litter, the crude extract was then sequentially extracted with hexane, chloroform and ethyl acetate through a bio-guided fractionation method. The phytotoxic potential of the methanolic extract and its solvent fractions was assessed in vitro on germination and root growth of two sensitive (Lactuca sativa L., Raphanus sativus L.) and native (Amaranthus retroflexus L., Cynodon dactylon (L.) Pers.) species. Moreover, the most active fractions were chemically characterized by GC–MS and HPTLC analysis. In all species, the physiological processes were highly inhibited by both the methanolic extract and its solvent fractions. Several classes of biologically active phytochemicals such as terpenoids, fatty acids, lignans and phenolic compounds were identified in all fractions. Artemisia arborescens leaf litter could be considered an important source of biologically active phytochemicals, which may have a significant allelopathic impact towards neighbouring species once released into the environment.  相似文献   

4.

Background

The genus Aloe is renowned for its medicinal and cosmetic properties and long history of use. Sixty-three Aloe species occur in Kenya, of which around 50 % are endemic. Several species of aloes are threatened with extinction and knowledge about their use is of major importance for sound conservation strategies. The main aims of this study were to assess the biocultural value of Aloe in Kenya by documenting local uses of aloes and evaluating how the vernacular names reflect the relative importance in different ethnic groups.

Methods

Ethnobotanical and ethnotaxonomical data were collected using field observations and semi-structured interviews. Information was collected by interviewing 63 respondents from nine different ethnic groups, representing different ages, gender and occupations. Statistical analyses were performed using R version 3.1.2.

Results

A total of 19 species of Aloe were found in the study area, of which 16 were used. On the generic level Aloe was easily distinguished. At species level, the local and scientific delimitation were almost identical for frequently used taxa. Aloe secundiflora, with 57 unique use records was the most important species. The two most frequently mentioned Aloe treatments, were malaria and poultry diseases. In our study area neither age nor gender had a significant influence on the level of knowledge of Aloe use. Finally, no correlation was found between extent of use and people’s perception of decrease in local aloe populations. The aloes are highly appreciated and are therefore propagated and transported over large areas when people relocate.

Conclusion

Biocultural value is reflected in the ethnotaxonomy of Aloe in Kenya. Different ethnic groups recognise their most-valued Aloe at the genus level as “the aloe” and add explanatory names for the other species, such as the “spotted aloe” and the “one-legged aloe”. Widespread species of Aloe have the highest number of uses. There is no obvious correlation with high use and decrease in abundance of aloes locally, and we found no compelling evidence for local uses causing devastating damage to populations of the 19 species in use, whereas habitat loss and commercial harvesting appear to be of urgent concern for these important plants.
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5.
Aconitum heterophyllum is the only non-toxic species of Aconitum genus having immense therapeutic potential. To date, only roots of this plant species are used for the preparation of various herbal formulations while leaves are discarded due to lack of information on the presence of any therapeutically active compounds. To the best of our knowledge, this is the first report on the detection and quantification of diterpene steviol in the leaves of A. heterophyllum. Interestingly, the level of steviol is equivalent to Stevia rebaudiana leaves which is the richest source reported so far. Thus, A. heterophyllum leaves will not only provide a novel source for extraction of steviol but also benefit the harvesters to get additional economic returns on leaf biomass for this high-value non-toxic plant species.  相似文献   

6.
Steroidal saponins are widely distributed among monocots, including the Amaryllidaceae family to which the Allium genus is currently classified. Apart from sulfur compounds, these are important biologically active molecules that are considered to be responsible for the observed activity of Allium species, including antifungal, cytotoxic, enzyme-inhibitory, and other. In this paper, literature data concerning chemistry and biological activity of steroidal saponins from the Allium genus has been reviewed.  相似文献   

7.
Species of Alternaria are serious plant pathogens, causing major losses on a wide range of crops. Leaf blight symptoms were observed on tomato leaves, and samples were collected from various regions. Isolation was done from symptomatic tomato leaves, and 15 representatives were selected from a collection of 65 isolates of Alternaria species. The virulence of Alternaria isolates was investigated on detached leaves (DL) and whole plants of tomato cv. Super strain B. A phylogenetic analysis was performed based on three partial gene regions, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH), the RNA polymerase second largest subunit (RPB2) and the Alternaria major allergen gene (Alt a 1). The potentiality of Alternaria isolates to produce toxins was also investigated on the basis of thin-layer chromatography (TLC). Our investigations revealed that Alternaria isolates showed different levels of virulence either on tomato plants or DL. Based on the phylogeny of three genes, Alternaria isolates encompassed two species of small-spored morphospecies: A. alternata (14 isolates) and A. arborescens (single isolate). The produced toxins varied among Alternaria isolates with tenuazonic acid (TeA) being the most abundant mycotoxin produced by most isolates. This study highlighted on other Alternaria species in Egypt that might represent a serious concern for tomato producers as causal agents of leaf blight over other species, i.e. A. solani.  相似文献   

8.
9.
We combined morphological and combined ITS, TUB and TEF sequence data to infer the phylogeny of the recently introduced genus Pseudopestalotiopsis. Two new species from China, Ps. camelliae from blighted leaves of Camellia sinensis and Ps. ignota from an undetermined host in China, are introduced with illustrated accounts and compared with similar taxa. Grey blight disease of tea appears to be caused by a group of fungi that constitutes a species complex. A new combination is proposed to emend the monophyly of Pseudopestalotiopsis and a species comparison is provided for taxa in the genus.  相似文献   

10.
11.
Two new species of Arachnothryx (Guettardeae, Rubiaceae) from the cloud forest of the Sierra Norte of Oaxaca, Mexico are described and illustrated. Arachnothryx axillaris together with A. heteranthera are the only two species in the genus with axillary inflorescences, but otherwise they are not similar. The new species is more similar to A. capitellata, but it differs in pubescence and inflorescence morphology. Arachnothryx flores-olverae can be confused with A. buddleioides mainly because they share discolorous leaves with densely tomentose pubescence, but they differ in stipule and inflorescence morphology. With these two new species the Sierra Norte of Oaxaca becomes more evidently the main hotspot of species diversity for the genus.  相似文献   

12.
Zostera asiatica is one of the five members of the genus Zostera that can be found in Korea. Studies have reported the phytochemical properties and bioactivities of Zostera species. Current study focused on the antioxidant effects of Z. asiatica as a part of ongoing research for bioactive substances from marine resources. Results indicated that a crude extract of Z. asiatica not only scavenged on peroxynitrite in vitro and on intracellular reactive oxygen species (ROS) but also inhibited production of nitric oxide (NO). The crude extract was subjected to solvent fractionation for bioactivity-based separation using aforementioned three bioassay systems. From the active n-butanol fraction, two flavonoids were isolated and characterized as luteolin (1) and luteolin-3’-sulfate (2). Both flavonoids showed significant antioxidant effects. In conclusion, Z. asiatica was demonstrated to possess antioxidant effect partly attributed to isolated flavonoids, the first such effect reported from Z. asiatica, to the best of our knowledge.  相似文献   

13.
The genus Astragalus L., Fabaceae (Leguminosae) is presented in Bulgarian flora by 31 species including local endemics, nine of them listed in the Red Data Book. The main biologically active compounds found in the Bulgarian Astragalus plants are saponins and flavonoids with a variety of effects: immunomodulatory, hepatoprotective, cytotoxic, antioxidant, antihypoxic and others. In the recent years volatiles with cytotoxic activity have also been determined. Saponins and flavonoids are still preferably produced by plants due to their complex structures. Variable quantities and qualities of the wild plant material, plants that need to grow several years before they are ready for harvesting and over-collecting of endangered Astragalus species are just a few of the problems connected with the production of these natural products. Therefore, cultured cells are possible alternative for production of high-value secondary metabolites. This review is focused on phytochemical, pharmacological and biotechnological studies of Bulgarian Astragalus plants and includes also results from our investigations.  相似文献   

14.
Secondary metabolites of 22 fungal strains (genus Aspergillus, section Usti) isolated at diverse geographic regions, including the Arctic permafrost deposits, were studied. The studied strains were found to synthesize a variety of biologically active compounds, structurally identified as drimane sesqueterpenoids, isoquinoline alkaloids (TMC-120 A?C, derivative 1), meroterpenoids (austalides О and J), and anthraquinone pigments (averufin, versicolorin C). Desferritriacetylfusigen production by A. calidoustus isolates is reported for the first time. The individual spectra of secondary metabolites were used for reidentification of 17 strains, of which 15 were identified as A. calidoustus and two, as A. pseudodeflectus.  相似文献   

15.
Environmental sampling yielded two yeast species belonging to Microstromatales (Exobasidiomycetes, Ustilaginomycotina). The first species was collected from a leaf phylloplane infected by the rust fungus Coleosporium plumeriae, and represents a new species in the genus Jaminaea, for which the name Jaminaea rosea sp. nov. is proposed. The second species was isolated from air on 50% glucose media and is most similar to Microstroma phylloplanum. However, our phylogenetic analyses reveal that species currently placed in Microstroma are not monophyletic, and M. phylloplanum, M. juglandis and M. albiziae are not related to the type species of this genus, M. album. Thus, Pseudomicrostroma gen. nov. is proposed to accommodate the following species: P. glucosiphilum sp. nov., P. phylloplanum comb. nov. and P. juglandis comb. nov. We also propose Parajaminaea gen. nov. to accommodate P. albizii comb. nov. and P. phylloscopi sp. nov. based on phylogenetic analyses that show these are not congeneric with Jaminaea or Microstroma. In addition, we validate the genus Jaminaea, its respective species and two species of Sympodiomycopsis and provide a new combination, Microstroma bacarum comb. nov., for the anamorphic yeast Rhodotorula bacarum. Our results illustrate non-monophyly of Quambalariaceae and Microstromataceae as currently circumscribed. Taxonomy of Microstroma and the Microstromataceae is reviewed and discussed. Finally, analyses of all available small subunit rDNA sequences for Jaminaea species show that J. angkorensis is the only known species that possess a group I intron in this locus, once considered a potential feature indicating the basal placement of this genus in Microstromatales.  相似文献   

16.
The fur mite genus Dubininetta Fain & Lukoschus, 1978 (Acariformes: Listrophoridae) represented by ectoparasites of moles (Soricomorpha: Talpidae) is revised. An amended diagnosis of this genus is provided. Two new species are described from moles in Vietnam: Dubininetta euroscaptor n. sp. from Euroscaptor parvidens (Miller) and Dubininetta abramovi n. sp. from Euroscaptor subanura Kawada, Son & Can. The insufficiently described D. taiwanensis (Fain & Lukoschus, 1978) from Mogera insularis (Swinhoe) (type-host) is redescribed based on the type-specimens and numerous newly collected in the Russian Far East specimens from Mogera robusta Nehring. The host ranges are considered for all species of Dubininetta. A key to the five species presently known in this genus is provided.  相似文献   

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19.
The phylogenetic affinities of the fern genus Aenigmopteris have been the subject of considerable disagreement, but until now, no molecular data were available from the genus. Based on the analysis of three chloroplast DNA regions (rbcL, rps16-matK, and trnL-F) we demonstrate that Aenigmopteris dubia (the type species of the genus) and A. elegans are closely related and deeply imbedded in Tectaria. The other three species of genus are morphologically very similar; we therefore transfer all five known species into Tectaria. Detailed morphological comparison further shows that previously proposed diagnostic characters of Aenigmopteris fall within the range of variation of a broadly circumscribed Tectaria.  相似文献   

20.
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