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1.
The Escherichia coil JC1 58(pCIA12/pG FK5) strain carrying a cyclic digene system with a negative feedback on the pCIA12 plasmid reacting to the DNA damage by changing the synthesis level of reporter genes-GFP and beta-galactosidase-was tested. The acquired phenotype was inherited by the next generations after the removal of the genotoxic action when the concentration of the DNA-damaging compounds was above the threshold level. A potential has been shown for the application of bacterial biosensors to monitor the presence of genotoxicants in the environment and to test the consequences of short-term exposures to toxic compounds. 相似文献
2.
We have identified a new class of microtubule-binding compounds—noscapinoids—that alter microtubule dynamics at stoichiometric
concentrations without affecting tubulin polymer mass. Noscapinoids show great promise as chemotherapeutic agents for the
treatment of human cancers. To investigate the structural determinants of noscapinoids responsible for anti-cancer activity,
we tested 36 structurally diverse noscapinoids in human acute lymphoblastic leukemia cells (CEM). The IC50 values of these noscapinoids vary from 1.2 to 56.0 μM. Pharmacophore models of anti-cancer activity were generated that identify
two hydrogen bond acceptors, two aromatic rings, two hydrophobic groups, and one positively charged group as essential structural
features. Additionally, an atom-based quantitative structure–activity relationship (QSAR) model was developed that gave a
statistically satisfying result (R
2 = 0.912, Q
2 = 0.908, Pearson R = 0.951) and effectively predicts the anti-cancer activity of training and test set compounds. The pharmacophore model presented
here is well supported by electronic property analysis using density functional theory at B3LYP/3-21*G level. Molecular electrostatic
potential, particularly localization of negative potential near oxygen atoms of the dimethoxy isobenzofuranone ring of active
compounds, matched the hydrogen bond acceptor feature of the generated pharmacophore. Our results further reveal that all
active compounds have smaller lowest unoccupied molecular orbital (LUMO) energies concentrated over the dimethoxy isobenzofuranone
ring, azido group, and nitro group, which is indicative of the electron acceptor capacity of the compounds. Results obtained
from this study will be useful in the efficient design and development of more active noscapinoids. 相似文献
3.
Natali Rianika Mustafa Hye Kyong Kim Young Hae Choi Robert Verpoorte 《Biotechnology letters》2009,31(12):1967-1974
The effect of salicylic acid (SA) on the metabolic profile of Catharanthus roseus suspension cells throughout a time course (0, 6, 12, 24, 48 and 72 h after treatment) was investigated using NMR spectroscopy
and multivariate data analysis. When compared to control cell lines, SA-treated cells showed a high level of sugars (glucose
and sucrose) up to 48 h after treatment, followed by a dynamic change in amino acids, phenylpropanoids, and tryptamine. Additionally,
one compound—2,5-dihydroxybenzoic-5-O-glucoside—was detected solely in SA-treated cells. 相似文献
4.
Ettinger-Epstein P Tapiolas DM Motti CA Wright AD Battershill CN de Nys R 《Marine biotechnology (New York, N.Y.)》2008,10(1):64-74
The Great Barrier Reef sponge Luffariella variabilis (Poléjaeff 1884) produces a range of potent anti-inflammatory compounds as its major metabolites. These major metabolites—manoalide
monoacetate, manoalide, luffariellin A and seco-manoalide—were monitored temporally and spatially to quantify the potential
yield from wild harvest or aquaculture. Production of the major metabolites was hardwired at the population level with little
variation in space and time over meters to tens of kilometers in the Palm Islands, Queensland, Australia. Manoalide monoacetate
(35 to 70 mg g−1 dry weight of sponge) was consistently the most abundant compound followed by manoalide (15 to 20 mg g−1 dry weight). Luffariellin A and seco-manoalide were 10 to 70 times less abundant and varied between 0 and 3 mg g−1 dry weight. On a larger spatial scale, L. variabilis from Davies Reef and Magnetic Island contained the same rank order and yields of compounds as the Palm Islands, indicating
a generality of pattern over at least 100 km. The “hardwiring” of metabolite production at the population level by L. variabilis was also reflected in the lack of any inductive effect on metabolite production. In addition, individually monitored sponges
produced fixed ratios of the major metabolites over time (years). However, these ratios varied between individuals, with some
individuals consistently producing high levels of manoalide and manoalide monoacetate, providing the potential for selection
of high-yielding stocks. 相似文献
5.
DNA amounts have been determined in the micronuclei and macronuclei of 8 strains ofParamecium aurelia and 6 strains ofTetrahymena pyriformis. In the case ofTetrahymena a distribution of values for the amount of DNA in the macronuclei of all the strains was observed but the lowest values were
approximately the same, viz. 1.17×10−11
g. There are two groups of strains in relation to micronuclear DNA values ofTetrahymena, one giving an average of 0.36×10−12 g and the other 0.815×10−12 g. The ratio of MIC/MAC DNA varies in the two groups.Paramecium again has a range of macronuclear values within each stock—lowest value 2.51×10−10 g—and the micronuclear values are similar in all stocks—approximately 0.613×10−12 g. The ratio of MIC/MAC DNA is similar in each stock.—The haploid genome values calculated from these data show excellent
agreement with the values obtained by DNA renaturation studies.
Supported by a Research Grant B/SR/8276 from the Science Research Council. The Vickers densitometer was purchased with a grant
from the Medical Research Council. 相似文献
6.
The fermentative behavior of two hybrid wine yeast strains (first-generation hybrid-strain 12 233×6167—obtained by hybridization
of the cryotolerant strainS. bayanus 12 233 with the mesophilic strainsS. cerevisiae 6167, and TT254×6392 arising by hybridization of the thermotolerant strainS. cerevisiae TT254 with the mesophilic strainS. cerevisiae 6392) was compared with that of a commercial wine yeast strainS. cerevisiae K1 in must from black grapes of the Calabrian variety Gaglioppo. The goal was to obtain wines with a high content of ‘polyphenols’
from a grape must with a limited phenolic content such as the Gaglioppo must. The progress of the winemaking was estimated
according to residual sugars; at the end of fermentation, the wines were decanted, bottled and principal physico-chemical
characteristics determined. Our results point to the possibility to select wine yeasts (significantly differing in the above
parameters) by their ability to interact with phenolic compounds. 相似文献
7.
Maaike Bruinsma Sarah van Broekhoven Erik H. Poelman Maarten A. Posthumus Martin J. Müller Joop J. A. van Loon Marcel Dicke 《Oecologia》2010,162(2):393-404
Herbivore-induced plant defences influence the behaviour of insects associated with the plant. For biting–chewing herbivores
the octadecanoid signal-transduction pathway has been suggested to play a key role in induced plant defence. To test this
hypothesis in our plant—herbivore—parasitoid tritrophic system, we used phenidone, an inhibitor of the enzyme lipoxygenase
(LOX), that catalyses the initial step in the octadecanoid pathway. Phenidone treatment of Brussels sprouts plants reduced
the accumulation of internal signalling compounds in the octadecanoid pathway downstream of the step catalysed by LOX, i.e.
12-oxo-phytodienoic acid (OPDA) and jasmonic acid. The attraction of Cotesia glomerata parasitoids to host-infested plants was significantly reduced by phenidone treatment. The three herbivores investigated,
i.e. the specialists Plutella xylostella, Pieris brassicae and Pieris rapae, showed different oviposition preferences for intact and infested plants, and for two species their preference for either
intact or infested plants was shown to be LOX dependent. Our results show that phenidone inhibits the LOX-dependent defence
response of the plant and that this inhibition can influence the behaviour of members of the associated insect community. 相似文献
8.
LC-NMR: a new tool to expedite the dereplication and identification of natural products 总被引:1,自引:0,他引:1
The rapid identification of known or undesirable compounds from natural products extracts — “dereplication” — is an important
step in an efficiently run natural products discovery program. Dereplication strategies use analytical techniques and database
searching to determine the identity of an active compound at the earliest possible stage in the discovery process. In the
past few years, advances in technology have allowed the development of tandem analytical techniques such as liquid chromatography
mass spectrometry (LC-MS), LC-MS-MS, liquid chromatography nuclear magnetic resonance (LC-NMR), and LC-NMR-MS. LC-NMR, despite
its lower sensitivity as compared to LC-MS, provides a powerful tool for rapid identification of known compounds and identification
of structure classes of novel compounds. LC-NMR is especially useful in instances where the data from LC-MS are incomplete
or do not allow confident identification of the active component of a sample. LC-NMR has been used to identify the marine
alkaloid aaptamine as the active component in an extract of the sponge Aaptos sp. This extract had been identified as an enzyme inhibitor by a high throughput screening (HTS) effort. Isolated aaptamine
exhibited an IC50=120 μM against this enzyme. Strategies for the identification of aaptamine and for the use of LC-NMR in a natural products
HTS program are discussed. Journal of Industrial Microbiology & Biotechnology (2000) 25, 342–345.
Received 30 March 2000/ Accepted in revised form 03 July 2000 相似文献
9.
D. V. Klochkov P. A. Eryuchenkov 《Journal of Evolutionary Biochemistry and Physiology》2000,36(2):170-177
The responsess of the mink reproductive systems in October to a single intramuscular injection of chorionic gonadotropin (CG,
Profasi R, Italy) at doses of 10, 20, 50, and 100 IU was studied. The estrous cycle state, folliculogenesis, and reproductive
parameters of the female minks were estimated. To evaluate functional polymorphism in the reproductive system of the females
in response to the CG injection, a dose of 20 IU was chosen. On the sixth day after administration of this dose of CG, the
females (n = 185) were distributed according to the stages of the estrous cycle as follows: anestrus—71 animals (38.4%), anestrus-proestrus—37
(20.0%), proestrus—30 (16.2%), proestrus-estrus—14 (7.6%), estrus—33 (17.8%). In the females of the “anestrus-proestrus” and
“proestrus” groups as compared with the other groups as well as with control, a statistically significantly higher fertility
was revealed. The study of folliculogenesis in the females with different parameters of the estrous cycle in November demonstrated
the high level of fertility to be due to ability of these females to produce, under influence of the CG injection, the maximal
number of mature follicles. A high heritable responsiveness of the reproductive system of the females to the CG injection
(coefficient of realized heritabilityh = 0.64; the calculation made on the data for the sisters) indicates that this method may be an additional criterion in the
selection of females for fertility. 相似文献
10.
Hengeveld R 《Acta biotheoretica》2007,55(2):97-131
This paper compares two approaches that attempt to explain the origin of life, or biogenesis. The more established approach
is one based on chemical principles, whereas a new, yet not widely known approach begins from a physical perspective. According
to the first approach, life would have begun with—often organic—compounds. After having developed to a certain level of complexity
and mutual dependence within a non-compartmentalised organic soup, they would have assembled into a functioning cell. In contrast,
the second, physical type of approach has life developing within tiny compartments from the beginning. It emphasises the importance
of redox reactions between inorganic elements and compounds found on two sides of a compartmental boundary. Without this boundary,
“life” would not have begun, nor have been maintained; this boundary—and the complex cell membrane that evolved from it—forms
the essence of life. 相似文献
11.
Eugeniusz Kuźniewski 《Plant Ecology》1975,30(1):55-60
Zusammenfassung Es wird berichtet über eine vegetationskundliche Untersuchung der Ackerunkrautgesellschaften des Südwestlichen Polen, Fünf
Regionen werden unterschieden: Flachland-, Hochland-, Flu?tal-, Gebirgs- und Gebirgskessel-Region. Auf 100 nach der ‘Methode
der Goldene Punkte’ bestimmten Punkten im Gebiet wurden ca 1500 pflanzensoziologische Aufnahmen gemacht. Drei Assoziationen:Euphorbio-Melandrietum, Aphano-Matricarietum undTeesdaleo-Arnoseridetum mit verschiedenen Untereinheiten werden beschrieben.
Es werden zwei Beispiele der Kartierung dieser Gesellschaften gezeigt. Es wird einiges über die Auswertung dieser Untersuchungen
in der Landwirtschaft mitgeteilt. Die Verteilung der Arten der verschiedenen für das Gebiet aufgestellte soziologischen Gruppen
über 12 Ackerbenützungskomplexe wird dargestellt: 1 — sehr guter Weizenkomplex, 2 — guter Weizenkomplex, 3 — schwacher Weizenkomplex,
4 — sehr guter Roggenkomplex, 5 — guter Roggenkomplex, 6 — schwacher Roggenkomplex, 7 — Roggen-Lupinekomplex, 8 — Starker
Korn-Futterkomplex, 9 — Schwacher Korn-Futterkomplex, 10 — Gebirgs-Weizenkomplex, 11 — Gebirgs-Kornkomplex, 12 — Gebirgs-Hafer-Kartoffelkomplex.
Für die Nomenklatur: s. Tabelle 1. 相似文献
12.
The development of Gryllus argentinus Sauss. was studied under stable laboratory conditions: the temperature of 26°C, the air humidity of 60%, and the photoperiod
of 12h light: 12 h dark. The life cycle of Gryllus argentinus includes four stages: egg, pronymph, nymph, and adult. The duration of embryonic development is 18 days. The depth of egg
bedding in the peat is 9.63 ± 0.12 mm (n =145), the clutch containing 2–4 eggs. A female can lay over 1100 viable eggs during the entire oviposition period. Nymphal
development includes 9 instars and lasts 97 days. The duration of nymphal instars (days) is: I—5; II—6; III—6; IV—6; V—8;
VI—10; VII—13; VIII—14; IX—29. The duration of the adult life is 51 days in males and 69 days, in females. In the imaginal
ontogenesis of males and females, three periods can be distinguished: pre-reproductive, reproductive, and postreproductive.
Males start to emit the aggressive signal on the 6th (5–8th) day (the pre-reproductive period). They enter the reproductive
period (start to emit the calling song) on the 9th (8–13th) day. Females enter the reproductive period (become capable of
responding to the calling song and of copulation) on the 9th (8–10th) day. Oviposition starts on the day after the first copulation.
The reproductive period lasts about 40 (15–59) days in males and 58 (21–70) days in females. The post-reproductive period
starts in females at the moment of finishing the egg laying period and in males, with disappearance of reproductive behavior.
The period ends in the animal’s death. 相似文献
13.
Rafael Flores-Peredo Lázaro Rafael Sánchez-Velásquez Jorge Galindo-González Jorge E. Morales-Mávil 《Plant Ecology》2011,212(6):1037-1046
In order to assess the impact of seed removal and seedling establishment for four species of pines, we designed experiments
with and without the exclusion of seed removers in three vegetation types (pine forest, oak-alder forest, and subalpine grassland).
Seed removal was significantly different between species of pines (P < 0.01), as was the interaction between the vegetation types and category of exclusion (remover) (P < 0.0001). The significant difference in terms of seed removal was between P. patula and P. montezumae (33.0 and 17.9%, respectively). Seed removal was significant between pine forest—without exclusion (20.0%) versus oak-alder
forest—without exclusion (7.0%). There was significant interaction between seedling establishment of the pine species and
vegetation type (P < 0.0001). Highlighting differences between the pine forest—P. teocote (84.1%) versus oak-alder forest—P. patula (19.0%), oak-alder forest—P. pseudostrobus (45.0%), pine forest—P. patula (20.2%), pine forest—P. pseudostrobus (45.6%), subalpine grassland—P. montezumae (24.3%), subalpine grassland—P. patula (27.9%), and subalpine grassland—P. pseudostrobus (17.5%). The impact of the food preferences of rodents and other granivores for P. patula and P. pseudostrobus seeds, as well as the poor survival of seedlings of these species in the pine and oak-alder forest are both factors which
may explain the dominance of P. teocote in the study region. 相似文献
14.
Randolph R. J. Arroo Vasilis Androutsopoulos Asma Patel Somchaiya Surichan Nicola Wilsher Gerry A. Potter 《Phytochemistry Reviews》2008,7(3):431-443
It has been generally accepted that regular consumption of fresh fruits and vegetables is linked with a relatively low incidence
of cancers (e.g. breast, cervix, and colon). A number of plant-derived compounds have been identified that are considered
to play a role in cancer prevention. However, at present there is no satisfactory explanation for the cancer preventative
properties of the above-mentioned compound groups. The current review is an effort to develop a consistent and unambiguous
model that explains how some plant-derived compounds can prevent tumour development. The model is based on recent discoveries
in the fields of genomics and drug-metabolism; notably, the discovery that CYP1 genes are highly expressed in developing tumour cells but not in the surrounding tissue, and that a variety of plant-derived
compounds are substrates for the CYP1 enzymes. Our hypothesis is that some dietary compounds act as prodrugs, i.e. compounds
with little or no biological effect as such, but become pharmaceutically effective when activated. More specifically, we state
that the abovementioned prodrugs are only activated in CYP1-expressing cells—i.e. cells in the early stages of tumour development—to be converted into compounds which inhibit cell growth.
Thus, the prodrugs selectively kill precancerous cells early in tumour development. The review focuses on the identification
of naturally-occurring prodrugs that are activated by the tumour-specific CYP1 enzymes and aims to assess their role in cancer
prevention. 相似文献
15.
A. V. Muravyov A. A. Maimistova I. A. Tikhomirova S. V. Bulaeva P. V. Mikhailov A. A. Muravyov 《Human physiology》2012,38(2):200-205
The proteomic analysis has shown that the red cell membrane contains several kinases and phosphatases. Therefore the aim of
this study was to investigate the role of protein kinases of human red cell membrane in deformability and aggregation alterations.
The exposure of red blood cells (RBCs) to some chemical compounds has led to a change in the RBC microrheological properties.
When forskolin (10 μM), an adenylyl cyclase (AC) and a protein kinase A (PKA) stimulator were added to RBC suspension, the
RBC deformability (RBCD) was increased by 20% (p<0.05). Somewhat more significant deformability rise appeared after RBC incubation with dB-AMP (by 26%; p<0.01). The red cell aggregation (RBCA) was significantly decreased under these conditions (p<0.01). Markedly less changes of deformability were found after RBC incubation with protein kinase stimulator C (PKC)—phorbol
12-myristate 13-acetate (PMA). This drug reduced the red cell aggregation only slightly. The red cell tyrosine phosphotase
activity was changed by N-vanadat and a significant RBCD rise and RBCA lowering were obtained. The similar effect was found
when the cells were incubated with cisplatin as a tyrosine protein kinase (TPK) activator. It is important to note that a
selective TPK inhibitor—lavendustin eliminated the above mentioned effects. 相似文献
16.
K. Szende 《Plant and Soil》1971,35(1):81-84
Summary The genome structure of the temperateRhizobium meliloti phage and the attachment site of this phage on the host chromosome were examined by genetic means. The heat-sensitive mutants
used in 2 and 3 point crosses gave a linear chromosome map. There was no evidence for map circularity. The immunity region
has a distal position on the phage chromosome. The functional grouping of the used 23 phage mutants was made byin vivo andin vitro complementation tests and 20 cistrons were obtained. The cistrons, near to the immunity region, were identified as early
genes, the remaining ones as morphogenetic cistrons. The latter inin vitro complementation tests gave two complementing groups, presumably as head and tail donors. The attachment site of the prophage
on the host chromosome was localized by pulse mutagen treatments in synchronously replicating cultures. The sequence of markers
are O-str — hs — att
16−3 — T. 相似文献
17.
Epicatechin belongs to flavonoids protecting cells against oxidative/nitrative stress. Oxidative/nitrative stress observed
in schizophrenia may be caused partially by the treatment of patients with various antipsychotics. The aim of our study was
to establish the effects of epicatechin and antipsychotics action (the first generation antipsychotic (FGA)—haloperidol and
the second generation antipsychotic (SGA)—amisulpride) on peroxidation of plasma lipids in vitro. Lipid peroxidation in human
plasma was measured by the level of thiobarbituric acid reactive species (TBARS). The properties of epicatechin were also
compared with the action of a well characterized antioxidative commercial polyphenol—resveratrol (3,4′,5-trihydroxystilbene)
and quercetin (3,5,7,3′,4′-pentahydroxyflavone). Amisulpride, contrary to haloperidol (after 1 and 24 h) does not significantly
influence the increase of plasma TBARS level in comparison with control samples (P > 0.05). After incubation (1 and 24 h) of plasma with haloperidol in the presence of epicatechin we observed a significantly
decreases the level of TBARS (P < 0.001, P < 0.001, respectively). In our other experiments, we found that epicatechin also decreased the amount of TBARS in human plasma
treated with amisulpride. In conclusion, the presented results indicate that epicatechin—the major polyphenolic component
of green tea reduced significantly human plasma lipid peroxidation caused by haloperidol. Moreover, epicatechin was found
to be a more effective antioxidant, than the solution of pure resveratrol or quercetin. 相似文献
18.
Tomáš Pavlíček Csaba Csuzdi Mete Mısırlıoğlu Boris Vilenkin 《Biodiversity and Conservation》2010,19(7):1989-2001
The analysis presents earthworm distribution in eight designated tectonic units (C—Cyprus, EP—East Pondites, ET—East Taurus
block, Sc—Sakarya continent, Kb—Kırşehir block, L—the Levant, TM—Taurus–Menderes block, WP—West Pondites) in the East Mediterranean
region (EM). It represents a full list of earthworm species (N = 81) of the region and reveals significant faunal similarities between Sc + WP, and between Kb + TM. The new Sc + WP unit
is characterized by the presence of archaic (Spermophorodrilus) as well as modern earthworm fauna. In contrast, the second newly established Kb + TM unit is characterized by poorly presented
earthworm autochthonous fauna and by a lack of endemic species. The analysis done on the species list (N = 73) representing the autochthonous family Lumbricidae showed statistically supported separation of L and EP between themselves
and from other designated units. The Levant, part of the Arabian tectonic plate, is characterized by a high level of endemism
in ancient (Healyella) and modern (Dendrobaena, Perelia) genera, and by the lack of archaic genera. The EP harbors unique species representing archaic (Eophila), ancient (Healyella), and modern (Allolobophora, Aporrectodea,
Dendrobaena and Eisenia) earthworm genera in the EM. The analysis also indicates origin of earthworm fauna in TM and faunistic relationships among
the designated units. Clearly, the present-day division of the EM earthworm fauna shows recognizable influences of tectonic
history. 相似文献
19.
M. Pavlíková-Mořická I. Lacko F. Devínsky L’. Masárová D. Mlynarčík 《Folia microbiologica》1994,39(3):176-180
New surface-active bisquaternary ammonium salts derived from bis-(2-dimethylaminoethyl) ester of glutaric acid are highly
effective against representatives of Gram-positive, Gram-negative bacteria and yeasts. Relationships between structure, lipophilicity
and antimicrobial effectiveness were demonstrated by quantitative structure-activity methodology. The nonlinear dependence
of biological activity on the structure as well as lipophilicity (expressed as critical micelle concentration—CMC) was shown
using Kubinyi’s bilinear model. The most effective compounds were those with the alkyl chain of 11–12 carbon atoms and with
the CMC values around 0.7−1.0 mmol/L. These derivatives possessed higher antimicrobial activity particularly to Gram-negative
bacteria.
Part 45 of the seriesQuaternary Ammonium Salts; part 44: Brádlerová A.et al., Pharmazie, in press. 相似文献
20.
O. B. Kazakova E. V. Tret’yakova O. S. Kukovinets G. A. Tolstikov T. I. Nazyrov I. V. Chudov A. F. Ismagilova 《Russian Journal of Bioorganic Chemistry》2010,36(6):762-770
The synthesis of a new group of maleopimaric acid amides containing fragments of methyl ethers of amino acids, aliphatic amines,
imidazole, and N-methylpiperazine was carried out. The ozonolysis of methylmaleopimarate occurs via the cleavage of the double bond C18(19)
and the opening of an anhydrous ring with the formation of secotriacid. As a result of the screening of the anti-inflammatory
and antiulcer activity of maleopimaric acid derivatives, new effective compounds such as maleopimaric acid and its methyl
ether, a product of ozonolysis—diterpenic secotriacid—and maleopimaric acid amide with L-leucine were found. An important advantage of the studied compounds is the low toxicity and the presence of bidirectional
activity in the absence of adverse effects on the animal. 相似文献