共查询到20条相似文献,搜索用时 31 毫秒
1.
Genome size has been estimated by flow cytometry in 14 populations belonging to eight taxa (seven species, one of them with two varieties) of the genus Tripleurospermum. 2C nuclear DNA amounts range from 4.87 to 9.22 pg, and nuclear DNA amounts per basic chromosome set from 1.99 to 2.75 pg. Statistically significant differences depending on ploidy level, life cycle or environmental factors such as altitude have been found. Also, genome size is positively correlated with total karyotype length. The presence of rhizome is related to nuclear DNA content in these species.This work was supported by project BOS2001-3041-C02-01 of the Spanish government, and one of the authors (S.G.) received a predoctoral grant from the Spanish government. 相似文献
2.
James S. Craigie Shawna L. MacKinnon John A. Walter 《Journal of applied phycology》2008,20(5):665-671
Aqueous extracts of Ascophyllum nodosum and several other brown seaweeds are manufactured commercially and widely distributed for use on agricultural crops. The
increasingly regulated international trade in such products requires that they be standardized and defined to a degree not
previously required. We examined commercially available extracts using quantitative 1H NMR and principal components analysis (PCA) techniques. Extracts manufactured over a 4-year period using the same process
exhibited characteristic profiles that, on PCA, clustered as a discrete group distinct from the other commercial products
examined. In addition to recognizing extracts made from different seaweeds, analysis of the 1H spectra in the 0.35–4.70 ppm region allowed us to distinguish amongst extracts produced from the same algal species by different
manufacturers. This result established that the process used to make an extract is an important variable in defining its composition.
A comparison of the 1H NMR integrals for the regions 1.0–3.0 ppm and 3.0–4.38 ppm revealed small but significant changes in the A. nodosum spectra that we attribute to seasonal variation in gross composition of the harvested seaweed. Such changes are reflected
in the PCA scores plots and contribute to the scatter observed within the data point cluster observed for Acadian soluble
extracts when all data are pooled. Quantitative analysis using 1H NMR (qNMR) with a certified external standard (caffeine) showed a linear relationship with extract concentration over at
least an order of magnitude (2.5–33 mg/mL; R
2 > 0.97) for both spectral regions integrated. We conclude that qNMR can be used to profile (or “fingerprint”) commercial
seaweed extracts and to quantify the amount of extract present relative to a suitably chosen standard.
Issued as NRCC no. 42,652. 相似文献
3.
One solution to the global crisis of antibiotic resistance is the discovery of novel antimicrobial compounds for clinical
application. Marine organisms are an attractive and, as yet, relatively untapped resource of new natural products. Cell extracts
from the marine diatom, Phaeodactylum tricornutum, have antibacterial activity and the fatty acid, eicosapentaenoic acid (EPA), has been identified as one compound responsible
for this activity. During the isolation of EPA, it became apparent that the extracts contained further antibacterial compounds.
The present study was undertaken to isolate these additional antibacterial factors using silica column chromatography and
reverse-phase high-performance liquid chromatography. Two antibacterial fractions, each containing a pure compound, were isolated
and their chemical structures were investigated by mass spectrometry and nuclear magnetic resonance spectroscopy. The antibacterial
compounds were identified as the monounsaturated fatty acid (9Z)-hexadecenoic acid (palmitoleic acid; C16:1 n-7) and the relatively unusual polyunsaturated fatty acid (6Z, 9Z, 12Z)-hexadecatrienoic acid (HTA; C16:3 n-4). Both are active against Gram-positive bacteria with HTA further inhibitory to the
growth of the Gram-negative marine pathogen, Listonella anguillarum. Palmitoleic acid is active at micro-molar concentrations, kills bacteria rapidly, and is highly active against multidrug-resistant
Staphylococcus aureus. These free fatty acids warrant further investigation as a new potential therapy for drug-resistant infections. 相似文献
4.
The oxidative deamination of methylated putrescine by a diamine oxidase activity (DAO) is an important step in the biosynthesis of nicotine in tobacco and tropane alkaloids in several Solanaceous plants. A polyclonal rabbit antiserum was previously developed to a purported purified DAO enzyme from Nicotiana tabacum. The antiserum bound to a single 53 kDa protein and immunoprecipitated 80 of DAO activity from tobacco root extracts. In an effort to obtain DAO cDNAs, this antiserum was used to screen a tobacco cDNA expression library and three distinct immunoreactive cDNA clones were isolated. These cDNAs encoded predicted proteins that were either identical or nearly identical to predicted S-adenosylhomocysteine hydrolase (SAHH) from two Nicotiana species. Thus, the rabbit antiserum was not specific to DAO, even though it immunodepleted the majority of DAO activity from root extracts. Alternative hypotheses to explain the DAO immunodepletion results (such as poisoning of DAO activity or that SAHH is a bifunctional enzyme) were tested and ruled out. Therefore, we hypothesize that SAHH associates with DAO as part of a larger multienzyme complex that may function in planta as a nicotine metabolic channel. 相似文献
5.
Adjei MD Deck J Heinze TM Freeman JP Williams AJ Sutherland JB 《Journal of industrial microbiology & biotechnology》2007,34(3):219-224
Mycobacterium sp. 7E1B1W and seven other mycobacterial strains known to degrade hydrocarbons were investigated to determine their ability
to metabolize the piperazine ring, a substructure found in many drugs. Cultures were grown at 30°C in tryptic soy broth and
dosed with 3.1 mM N-phenylpiperazine hydrochloride; samples were removed at intervals and extracted with ethyl acetate. Two metabolites were
purified from each of the extracts by high-performance liquid chromatography; they were identified by mass spectrometry and
1H nuclear magnetic resonance spectroscopy as N-(2-anilinoethyl)acetamide and N-acetyl-N′-phenylpiperazine. The results show that mycobacteria have the ability to acetylate piperazine rings and cleave carbon-nitrogen
bonds. 相似文献
6.
Sara Agnolet Jerzy W. Jaroszewski Robert Verpoorte Dan Staerk 《Metabolomics : Official journal of the Metabolomic Society》2010,6(2):292-302
Commercial preparations of Ginkgo biloba are very complex mixtures prepared from raw leaf extracts by a series of extraction and prepurification steps. The pharmacological
activity is attributed to a number of flavonoid glycosides and unique terpene trilactones (TTLs), with largely uncharacterized
pharmacological profiles on targets involved in neurological disorders. It is therefore important to complement existing targeted
analytical methods for analysis of Ginkgo biloba preparations with alternative technology platforms for their comprehensive and global characterization. In this work, 1H NMR-based metabolomics and hyphenation of high-performance liquid chromatography, photo-diode array detection, mass spectrometry,
solid-phase extraction, and nuclear magnetic resonance spectroscopy (HPLC-PDA-MS-SPE-NMR) were used for investigation of 16
commercially available preparations of Ginkgo biloba. The standardized extracts originated from Denmark, Italy, Sweden, and United Kingdom, and the results show that 1H NMR spectra allow simultaneous assessment of the content as well as identity of flavonoid glycosides and TTLs based on a
very simple sample-preparation procedure consisting of extraction, evaporation and reconstitution in acetone-d
6. Unexpected or unwanted extract constituents were also easily identified in the 1H NMR spectra, which contrasts traditional methods that depend on UV absorption or MS ionizability and usually require availability
of reference standards. Automated integration of 1H NMR spectral segments (buckets or bins of 0.02 ppm width) provides relative distribution plots of TTLs based on their H-12
resonances. The present study shows that 1H NMR-based metabolomics is an attractive method for non-selective and comprehensive analysis of Ginkgo extracts. 相似文献
7.
D. Natarajan N. Nagamurugan A. Ramachandran C. Mohanasundari K. Srinivasan 《World journal of microbiology & biotechnology》2007,23(5):719-721
The present work demonstrates the screening of extracts of the rare medicinal herb Euphorbia fusiformis for antifungal activity. The main aim was to investigate its antifungal properties against Candida albicans and Cryptococcus neoformans, the causative agents of human candidiasis and cryptococcosis, respectively. Aqueous and organic solvent extracts from the
leaves and rootstock of the plant were tested against the fungi by the well-in-agar method. Almost all the organic solvent
extracts exhibited an inhibitory effect against C. albicans and to some extent on C. neoformans, except for the aqueous extracts, which had no effect. The combined formulations of the extracts also had better activity
against C. albicans than C. neoformans. This study thus concludes by demonstrating the antifungal properties of E. fusiformis and also the potential research in identifying the active principles, which may have future therapeutic value. 相似文献
8.
Bacteria with the ability to grow on nitrogen-free media and with nitrogenase activity under aerobic or microaerobic conditions were isolated from sugarcane roots collected from four different agricultural locations in Granada (Spain). Isolates were Gram negative rods and were identified as Azotobacter chroococcum and Azospirillum brasilense. Our results suggest that Azotobacter isolates do not have a particular affinity for sugarcane rhizospheres and that, on the contrary, Azospirillum isolates show specific association and perhaps endophytic colonization of sugarcane. However, obligate endophytes (Gluconacetobacter diazotrophicus) were not found in the apoplastic fluid of the stems and macerates extracts of sugarcane tissues with the procedure applied. Population of this microorganism might be in low number in the Spanish sugarcane varieties studied which is also discussed. 相似文献
9.
10.
Lavandula genus is an important member of Labiatae (Lamiaceae) family. People use commonly Lavandula stoechas as a medicinal plant for various diseases around the world and also in Turkey. The aim of this study was to investigate cytotoxic
and genotoxic effects of aqueous extracts (40, 80 and 120 g/L) from L. stoechas flowers on Allium cepa root tip meristem cells. For this purpose, A. cepa onion bulbs were treated with the above-mentioned L. stoechas flower extracts for 72 h. Spring water (pH 7.3) was used as a control. The result of this study sowed that aqueous extracts
reduced mitotic index, but induced chromosome aberrations and mitotic aberrations in comparison with control, significantly
(p < 0.05). Aqueous extracts induced breaks, stickiness, pole deviations and micronuclei. Furthermore, these effects were related
to extract concentrations. These results showed that L. stoechas aqueous extracts have cytotoxic and genotoxic effects. 相似文献
11.
Culture medium extracts obtained from 115 culture media of 35 different microalgae species were screened for the presence of algicidal compounds, in particular for compounds which are cytotoxic to Arthrospira (Spirulina) laxissima. In agar plate diffusion tests and in a test system combining thin layer chromatography (TLC) with the use of an aqueous suspension of living A. laxissima cells as spray reagent, 14 microalgae species were found with cytotoxic activity of different intensity to A. laxissima. In a so-called TLC plate diffusion test, using A. laxissima and other microalgae as test organisms, the culture medium extracts of Nodularia harveyana and Nostoc insulare possessed the highest strength and range of algicidal activity. The algicidal compound in the culture medium extracts of Nodularia harveyana was shown to be norharmane (9H-pyrido(3,4-b)indole), a known indole alkaloid. The main algicidal compound in culture medium extracts of Nostoc insulare was identified as 4,4′-dihydroxybiphenyl. The possible applicability of both compounds as therapeutics or as useful agents for removing cyanobacterial water blooms or for developing new antifouling systems is discussed. 相似文献
12.
13.
Propagation by softwood canes and cuttings is preferred as a practical system for vegetative reproduction of many ornamental
plant species, despite the advances in tissue culture techniques. Dracaena purplecompacta L. is a species that has a high demand for exports. Conversely, coconut water (CW) is a rich supplement that naturally contains
plant growth regulators such as indole acetic acid (IAA). The objective of this work was to evaluate the potential of CW extracts
containing natural IAA, on adventitious root development in vegetative propagation of ornamental plant canes of D. purplecompacta L. Five different concentrations (28, 57, 143, 286, 571 μM of natural IAA) of CW extracts were tested. Another set of treatment
was carried out with the same concentrations of authentic IAA hormone for comparison purpose. The 143-μM IAA CW extract recorded
the best root induction and development. It was found that the root expression was faster (5 weeks) with the use of the novel
method. In the conventional method, the canes are propagated by quick dip application of commercial product containing artificial
hormone IAA and placing them on coir fiber dust beds. It takes up to 6 weeks for the canes to develop adventitious roots to
the desired level. Steeping canes in 143-μM IAA CW extract improved rooting in D. purplecompacta L., and it was comparable to the application of 143-μM authentic IAA. The study indicates that adventitious root development,
shoot development, and leaf emergence of D. purplecompacta L. is promoted by IAA CW extracts. 相似文献
14.
Guo X. Xie Yan Ni Ming M. Su Yuan Y. Zhang Ai H. Zhao Xian F. Gao Zhong Liu Pei G. Xiao Wei Jia 《Metabolomics : Official journal of the Metabolomic Society》2008,4(3):248-260
The morphological appearance and some ingredients of Panax ginseng, Panax notoginseng and Panax
japonicus of the Panax genus are similar. However, their pharmacological activities are obviously different due to the significant differences in
the types and quantity of saponins in each herb. In the present study, ultra-performance liquid chromatography-quadrupole
time-of-flight mass spectrometry (UPLC-QTOFMS) was used to profile the abundances of metabolites in the three medicinal Panax herbs. Multivariate statistical analysis technique, that is, principle component analysis (PCA) and partial least squares-discriminant
analysis (PLS-DA) were used to discriminate between the Panax samples. PCA of the analytical data showed a clear separation of compositions among the three medicinal herbs. The critical markers such as chikusetsusaponin IVa, ginsenoside R0, ginsenoside Rc, ginsenoside Rb1, ginsenoside Rb2 and
ginsenoside Rg2 accountable for such variations were identified through the corresponding loading weights, and the tentative
identification of biomarkers is completed by the accurate mass of TOFMS and high resolution and high retention time reproducibility
performed by UPLC. The proposed analytical method coupled with multivariate statistical analysis is reliable to analyze a
group of metabolites present in the herbal extracts and other natural products. This method can be further utilized to evaluate
chemical components obtained from different plants and/or the plants of different geographical locations, thereby classifying
the medicinal plant resources and potentially elucidating the mechanism of inherent phytochemical diversity. 相似文献
15.
The work was conducted with the purpose to evaluate antioxidant activity of Parmelia saxatilis (PS) by different analytical methods. Water and methanol were used as solvents and antioxidative effects were measured by
a ferric thiocyanate method (FTC) and thiobarbituric acid test (TBA). The antioxidant activity increased with the increasing
amount of extracts (from 50 to 250 μg) added to linoleic acid emulsion. The methanol extract of PS exhibited high antioxidative
activity that was not significantly (P < 0.05) different from α-tocopherol, while aqueous extracts of PS showed low antioxidative activity. Similar trends of antioxidant activity were observed
using either the FTC or TBA methods. Antioxidant activity, reducing power, free radical scavenging (DPPH·), superoxide anion radical scavenging, metal chelating and hydrogen peroxide scavenging activities of PS extracts showed
dose dependence and increased with concentration of PS extract. The results obtained in the present study indicate that the
PS might be a potential source of natural antioxidant. 相似文献
16.
17.
18.
The antimicrobial properties of acetone, methanol, and aqueous extracts of the lichens Lasallia pustulata, Parmelia sulcata, Umbilicaria crustulosa, and Umbilicaria cylindrica were studied comparatively in vitro. Antimicrobial activities of the extracts of different lichens were estimated by the
disk diffusion test for Gram-positive bacteria, Gram-negative bacteria, and fungal organisms, as well as by determining the
MIC (minimal inhibitory concentration). The obtained results showed that the acetone and methanol extracts of Lasallia pustulata, Parmelia sulcata, and Umbilicaria crustulosa manifest antibacterial activity against the majority of species of bacteria tested, in addition to selective antifungal activity.
The MIC of lichen extracts was lowest (0.78 mg/ml) for the acetone extract of Lasallia pustulata against Bacillus mycoides. Aqueous extracts of all of the tested lichens were inactive. Extracts of the lichen Umbilicaria cylindrica manifested the
weakest activity, inhibiting only three of the tested organisms. 相似文献
19.
Ilkay Orhan Berrin Özçelik Sinem Aslan Murat Kartal Taner Karaoglu Bilge Şener Salih Terzioglu M. Iqbal Choudhary 《Phytochemistry Reviews》2007,6(1):189-196
Purpose of the present study was to evaluate antioxidant, antibacterial, antifungal, and antiviral activities of the petroleum
ether, chloroform, ethyl acetate and methanol extracts as well as the alkaloid fraction of Lycopodium clavatum L. (LC) from Lycopodiaceae growing in Turkey. Antioxidant activity of the LC extracts was evaluated by 1,1-diphenyl-2-picrylhydrazyl
(DPPH) radical-scavenging method at 0.2 mg/ml using microplate-reader assay. Antiviral assessment of LC extracts was evaluated
towards the DNA virus Herpes simplex (HSV) and the RNA virus Parainfluenza (PI-3) using Madin-Darby Bovine Kidney (MDBK) and Vero cell lines. Antibacterial and antifungal activities of the extracts
were tested against standard and isolated strains of the following bacteria; Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Acinobacter baumannii, Klebsiella pneumoniae, Staphylococcus aureus, Bacillus subtilis as well as the fungi; Candida albicans and C. parapsilosis. All of the extracts possessed noteworthy activity against ATCC strain of S. aureus (4 μg/ml), while the LC extracts showed reasonable antifungal effect. On the other hand, we found that only the chloroform
extract was active against HSV (16–8 μg/ml), while petroleum ether and alkaloid extracts inhibited potently PI-3 (16–4 μg/ml
and 32–4 μg/ml, respectively). However, all of the extracts had insignificant antiradical effect on DPPH. In addition, we
also analyzed the content of the alkaloid fraction of the plant by capillary gas chromatography-mass spectrometry (GC-MS)
and identified lycopodine as the major alkaloid. 相似文献
20.
The adverse health effects of Stachybotrys chartarum have often been linked to exposure to the trichothecene mycotoxins. Recent studies have shown that in addition to mycotoxins
this fungus is capable of producing and secreting in vivo proteins such as hemolysins and proteinases. Spore extracts obtained
from a high trichothecene producing isolate JS 58-17 exhibited a significantly lower proteolytic activity compared to the
low trichothecene producer, JS 58-06. Growing isolates on rice or potato dextrose agar results in higher proteolytic activity
of the spores compared to those grown on drywall. Proteinases in the spore extracts can hydrolyze gelatin and collagen I and
IV. Analysis of zymograms shows the presence of several proteins with proteolytic activity in the spores of S. chartarum. Human tracheal epithelial cells exposed to spore extracts produced significantly higher levels of IL-6, IL-8, and TNF-α
than control cells. This stimulation of cytokine production was completely abolished by Pefabloc, a serine protease inhibitor.
Neutrophil numbers and proinflammatory cytokine (IL1-β and TNF-α) concentrations were highly elevated in the lungs of 7 day
old rat pups exposed intratracheally to 4 × 104 spores/gm body weight compared to control. No significant differences in those inflammatory indices in vivo were noted between
the treatments with the high trichothecene producer, isolate JS 58-17 and JS 58-06, which does not produce macrocyclic trichothecenes.
Immunohistochemistry revealed reduced collagen IV labeling in spore-induced lung granulomas in rat pups exposed to both isolates.
These results suggest that proteinases from S. chartarum spores significantly contribute to lung inflammation and injury. 相似文献