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1.
Specimens of dinoflagellate collected in tide pools along the Pacific coast of central and southern Japan are described as
a new species,Scrippsiella hexapraecingula Horiguchi et Chihara, of the Peridiniaceae (Class Dinophyceae). The plate formula is pp, x, 4′, 3a, 6″, 6c, 5‴, 2″" and,
5s, the same as that of other species ofScrippsiella, except in lacking one precingular plate. The genus must be emended, therefore, as having either six or seven precingular
plates.
This dinoflagellate migrates diurnally. In the morning motile cells are released from non-motile cells attached to the substrate
and in the evening the motile cells swim down to settle on the bottom of the tide pool. Attached non-motile cells form either
motile mono- or bispores. Sexual reproduction was not observed. 相似文献
2.
Toxic coplanar polychlorinated biphenyls (Co-PCBs) were used as substrates for a degradation experiment with white-rot fungus, Phlebia brevispora TMIC33929, which is capable of degrading polychlorinated dibenzo-p-dioxins. Eleven PCB congener mixtures (7 mono-ortho- and 4 non-ortho-PCBs) were added to the cultures of P. brevispora and monitored by high resolution gas chromatography and mass spectrometry (HRGC/HRMS). Five PCB congeners, 3,3′,4,4′-tetrachlorobiphenyl, 2,3,3′,4,4′-pentachlorobiphenyl, 2,3′,4,4′,5-pentachlorobiphenyl, 3,3′,4,4′,5-pentachlorobiphenyl, and 2,3′,4,4′,5,5′-hexachlorobiphenyl were degraded by P. brevispora. To investigate the fungal metabolism of PCB, each Co-PCB was treated separately by P. brevispora and the metabolites were analyzed by gas chromatography and mass spectrometry (GC/MS) and identified on the basis of the GC/MS comparison with the authentic compound. Meta-methoxylated metabolite was detected from the culture containing each compound. Additionally, para-dechlorinated and -methoxylated metabolite was also detected from the culture with 2,3,3′,4,4′-pentachlorobiphenyl, 2,3′,4,4′,5-pentachlorobiphenyl, and 2,3′,4,4′,5,5′-hexachlorobiphenyl, which are mono-ortho-PCBs. In this paper, we identified the congener specific degradation of coplanar PCBs by P. brevispora, and clearly proved for the first time by identifying the metabolites that the white-rot fungus, P. brevispora, transformed recalcitrant coplanar PCBs. 相似文献
3.
The occurrence of reductive dechlorination processes towards pre-existing PCBs and five exogenous coplanar PCBs were investigated
in a contaminated sediment of Porto Marghera (Venice Lagoon, Italy) suspended, under strictly anaerobic conditions, in water
collected from the same site. PCB dechlorination started after five months of incubation, when sulfate initially occurring
in the microcosms was completely depleted and methanogenesis was in progress. It was ascribed to sulfate-reducing bacteria.
Several pre-existing hexa-, penta- and tetra-chlorinated biphenyls were slowly bioconverted into tri- and di-, ortho-substituted PCBs from the 5th to the 16th month of experiment. Spiked coplanar PCBs, i.e., 3,3′,4,4′-tetrachlorobiphenyl,
3,3′,4,4′,5- and 2,3′,4,4′,5-pentachlorobiphenyls, 3,3′,4,4′,5,5′- and 2,3,3′,4,4′,5-hexachlorobiphenyls, were extensively
transformed (by about 90%) into lower chlorinated congeners, such as 3,3′,5,5′-/2,3′,4,4′-tetrachlorobiphenyl, 3,3′,5-, 2,4,4′-,
2,3′,4- and 2,3′,5-trichlorobiphenyl, 3,4-/3,4′- and 3,3′-dichlorobiphenyl and 2-chlorobiphenyl. The reductive dechlorination
of spiked PCBs did not influence significantly the biotransformation rate and extent of pre-existing PCBs. 相似文献
4.
Four new dinoflagellates 总被引:1,自引:0,他引:1
Enrique Balech 《Helgoland Marine Research》1990,44(3-4):387-396
Fragilidium fissile is a new species of this rare genus. It somewhat resemblesF. subglobosum. It differs from the latter in having a slot and a pore in the first apical plate 1′ (the nomenclature of dinoflagellate
plate designation follows the Kofoid system). Both species are also distinguishable by noticeable differences in Po, 1″″ and
1‴.Peridinium tyrrhenicum is a small species differing from all the other known species ofPeridinium in its shape, apical channel and several plates, especially some of the sulcal components.Alexandrium foedum somewhat resemblesA. balechii, but it differs from the latter in that its width is greater than its length, and in the characters of all the main sulcal
plates. The above listed species were found in a sample from the Tyrrhenian Sea. The fourth species,Alexandrium andersoni, is a small dinoflagellate obtained in coastal waters off Cape Cod. It differs from all the other species of the minutum
group in the very typical shapes of both the 6″ and the S. s.Pentapharsodinium daleii Indelicato and Loeblich is transferred toPeridinium. 相似文献
5.
The fungus Cunninghamella elegans is a useful model of human catabolism of xenobiotics. In this paper, the biotransformation of fluorinated biphenyls by C. elegans was investigated by analysis of the culture supernatants with a variety of analytical techniques. 4-Fluorobiphenyl was principally
transformed to 4-fluoro-4′-hydroxybiphenyl, but other mono- and dihydroxylated compounds were detected in organic extracts
by gas chromatography–mass spectrometry. Additionally, fluorinated water-soluble products were detected by 19F NMR and were identified as sulphate and β-glucuronide conjugates. Other fluorobiphenyls (2-fluoro-, 4,4′-difluoro- and 2,3,4,5,6-pentafluoro-biphenyl)
were catabolised by C. elegans, yielding mono- and dihydroxylated products, but phase II metabolites were detected from 4,4′-difluorobiphenyl only. 相似文献
6.
Degradation experiment of model polychlorinated biphenyl (PCB) compound 4,4′-dichlorobiphenyl (4,4′-DCB) and its metabolites by the white-rot fungus Phanerochaete chrysosporium and newly isolated 4,4′-DCB-degrading white-rot fungus strain MZ142 was carried out. Although P. chrysosporium showed higher degradation of 4,4′-DCB in low-nitrogen (LN) medium than that in potato dextrose broth (PDB) medium, Phanerochaete sp. MZ142 showed higher degradation of 4,4′-DCB under PDB medium condition than that in LN medium. The metabolic pathway of 4,4′-DCB was elucidated by the identification of metabolites upon addition of 4,4′-DCB and its metabolic intermediates. 4,4′-DCB was initially metabolized to 2-hydroxy-4,4′-DCB and 3-hydroxy-4,4′-DCB by Phanerochaete sp. MZ142. On the other hand, P. chrysosporium transformed 4,4′-DCB to 3-hydroxy-4,4′-DCB and 4-hydroxy-3,4′-DCB produced via a National Institutes of Health shift of 4-chlorine. 3-Hydroxy-4,4′-DCB was transformed to 3-methoxy-4,4′-DCB; 4-chlorobenzoic acid; 4-chlorobenzaldehyde; and 4-chlorobenzyl alcohol in the culture with Phanerochaete sp. MZ142 or P. chrysosporium. LN medium condition was needed to form 4-chlorobenzoic acid, 4-chlorobenzaldehyde, and 4-chlorobenzyl alcohol from 3-hydroxy-4,4′-DCB, indicating the involvement of secondary metabolism. 2-Hydroxy-4,4′-DCB was not methylated. In this paper, we proved for the first time by characterization of intermediate that hydroxylation of PCB was a key step in the PCB degradation process by white-rot fungi. 相似文献
7.
The structure of the sulfated analogue of cauloside C, a biologically active triterpenoid glycoside, was elucidated to be
3-O-[β-D-glucopyranosyl-(1→2)-α-L-arabinopyranosyl]-hederagenin 23,4′,4″,6″-tetrasulfate pentasodium salt by the comparison of its13C NMR spectrum with that of cauloside C potassium salt. 相似文献
8.
Yoshio Ino 《Ecological Research》1990,5(2):195-205
Net photosynthesis and dark respiration (CO2 flux) of Antarctic mosses were measured at Langhovde, East Antarctica, from 9 to 17 January 1988. Moss blocks were taken
from communities in the Yukidori Valley (69°14′30″S, 39°46′00″E) at Langhovde. Each block was composed ofCeratodon purpureus andBryum pseudotriquetrum, orB. pseudotriquetrum. The upper part of the block was used to measure net photosynthesis and dark respiration. The net photosynthesis of each
sample was measured in the field for one or three days with two infrared CO2 gas analyzers and an assimilation chamber. The relationships of net photosynthetic rate and dark respiration rate, to the
water content of the sample, the intensity of solar radiation and the moss temperature were estimated from the field data.
The maximum rate of net photosynthesis was about 4 μmol CO2 m−2s−1 at saturating radiation intensity and at optimum temperature, about 10°C. Environmental features of moss habitats in the
Yukidori Valley are discussed in relation to these results. 相似文献
9.
S. Aime Monica Chiaussa Giuseppe Digilio Eliana Gianolio Enzo Terreno 《Journal of biological inorganic chemistry》1999,4(6):766-774
N,N′,N″,N‴ -pentaacetic acid) bearing different substituents for binding to human serum albumin (HSA) are compared. In spite of the structural
differences of the recognition synthon and of the residual electric charge, the two chelates display an analogous binding
affinity for the serum protein. Upon formation of the adducts with HSA, the exchange rates of the coordinated water appear
slowed down by an amount corresponding to ca. 50% of the rates found for the free complexes. The relaxivity of [Gd(BOM)3DTPA (H2O)]2 − is significantly higher than that of MS-325 either in the free complex or in the macromolecular adduct. Finally, the effect
of pH on the stability of the HSA adducts and on the values of their relaxivities has been investigated.
Received: 11 June 1999 / Accepted: 15 September 1999 相似文献
10.
Jagroop S. Dahiya 《Plant and Soil》1991,134(2):297-304
A broad-host-range plasmid (pEA2-21) containing a Bradyrhizobium sp (F-4) nod DABC-lacZ translation fusion was constructed and used to monitor nod gene expression in response to pigeonpea root exudate. Two nod-inducing compounds were isolated and identified. Spectral analysis using ultraviolet absorption, infrared spectra, proton nuclear magnetic resonance, and mass spectrometry showed that the two inducers were 5,4-dihydroxy-6-(3-methyl-2-butenyl)-2, 2-dimethyl pyrano-[5, 6:7, 8]-flavanone (cajaflavanone) and 2,4,5-trihydroxy-5-isopentenyl-6, 7-dimethylchromene iso-flavanone (cajanone). When pEA2-21 was introduced into Rhizobium trifolii and R. meliloti cajanone and cajaflavanone did not induce nod gene indicating that specificity of induction appears to be influenced by the host-strain genome. 相似文献
11.
Inhibitor studies and mutant analysis revealed a C30 pathway via 4,4′-diapophytoene and 4,4′-diaponeurosporene to 4,4′-diaponeursoporene-4-oic acid esters related to staphyloxanthin
in Halobacillus halophilus. Six genes may be involved in this biosynthetic pathway and could be found in two adjacent gene clusters. Two genes of this
pathway could be functionally assigned by functional pathway complementation as a 4,4′-diapophytoene synthase and a 4,4′-diapophytoene
desaturase gene. These genes were organized in two operons together with two putative oxidase genes, a glycosylase and an
acyl transferase ortholog. Pigment mutants were obtained by chemical mutagenesis. Carotenoid analysis showed that a white
mutant accumulated 4,4′-diapophytoene due to a block in desaturation. In a yellow mutant carotenogenesis was blocked at the
stage of 4,4′-diaponeurosporene and in an orange mutant at the stage of 4,4′-diaponeurosporene-4-oic acid. The protective
function of these pigments could be demonstrated for H. halophilus after inhibition of carotenoid synthesis by initiation of oxidative stress. A degree of oxidative stress which still allowed
50% growth of carotenogenic cells resulted in the death of the cells devoid of colored carotenoids. 相似文献
12.
Adaucto B. Pereira-Netto Carmem L. O. Petkowicz Claudia T. A. Cruz-Silva Mariana T. Gazzoni Arianne F. P. Mello Joana L. M. Silveira 《In vitro cellular & developmental biology. Plant》2007,43(4):356-363
Shoots of the marubakaido apple rootstock grown in culture medium containing BBL agar presented significantly lower multiplication
rate (MR) compared to MRs found for shoots grown in medium containing A-7002, A-7921, Select, and Phytagar as gelling agents.
In addition, significant hyperhydricity was found for shoots grown in Phytagar and A-7921 agar-containing media. Analysis
of elastic (G′) and viscous (G″) modulus showed that for all of the five agar brands used in this study, G′ was always much
higher, i.e., typically one order of magnitude higher than G″, which characterizes a strong gel. G′ changed randomly with
time for all of the agar brands studied, except for BBL, which presented progressive decline in G′ throughout the culture
cycle. Examination of G′, within the same week, showed that Select agar always had the smallest G′, while Phytagar always
had the highest G′. Analysis of the loss tangent (tan δ = G″/G′), a better indicator for gel behavior compared to G′ isolated, showed that tan δ for Select and Phytagar were always
between tan δ values found for A-7002 and BBL. In addition, analysis of tan δ also indicated that BBL and Select agars showed a significantly weaker gel network, compared to Phytagar, A-7002 and A-7921
agars after the third week of culture. When seen together, these results indicate that shoot performance for the marubakaido
rootstock is not related to agar gel strength. In addition, the high hyperhydricity rate found for shoots grown on agars A-7921
and Phytagar could not be related to agar gel strength, as well. Analysis of HPSEC profiles indicated that the best performance,
i.e., multiplication rate, of marubakaido shoots in agars A-7002 and A-7921 is likely to be related to their lower polydispersity
and/or smaller amount of high molecular weight fractions, compared to BBL, Phytagar, and Select agars. 相似文献
13.
Gerhäuser C. Alt A.P. Klimo K. Knauft J. Frank N. Becker H. 《Phytochemistry Reviews》2002,1(3):369-377
Beer contains a variety of phenolic compounds. During the brewing process, some of these compounds are removed by polyvinylpolypyrrolidone
(PVPP) to prevent haze formation. We have analyzed the phytochemical composition of a PVPP residue as well as of unstabilized
beer and isolated a total of 51 compounds. Eight structures were identified as novel, i.e., 2-(4′-hydroxyphenyl)-3,5-dihydroxybenzoic
acid (6), 2′-(4″-hydroxyphenyl)isoferulic acid ester (12), 1,2,5,7-tetrahydroxyanthraquinone (23) and 4,7-dihydroxy-5-(2′,4′,6′-trihydroxyphenyl)-indan-1,2-dione (24) from the PVPP residue, and catechin-7-O-β-(6″-O-nicotinoyl)-β-D-glucopyranoside (41), ent-epigallo-catechin-(4αto8, 2αtoOto7)catechin (44), ent-epigallocatechin (4αto6, 2αtoOto7)catechin (45) and 2,3-cis-3,4-trans-2-[2,3-trans-3,3′,4′,5,7-pentahydroxyflavan-8-yl]-4-(3,4-dihydroxyphenyl)3,5,7-trihydroxybenzopyran (46) from the unstabilized beer. Most of the compounds were tested for potential cancer chemopreventive activities in in vitro test systems detecting a modulation of carcinogen metabolism (inhibition of phase 1 cytochrome P450 1A (Cyp1A) activity,
induction of NAD(P)H:quinone oxidoreductase (QR) activity) and anti-inflammatory mechanisms (inhibition of lipopolysaccharide
(LPS)-mediated induction of inducible nitric oxide synthase (iNOS), inhibition of cyclooxygenase 1 (Cox-1) activity). 1,2,5,7-Tetrahydroxyanthraquinone
(23) and xanthohumol (25), a prenylated chalcone derived from hop, were identified as the most potent compounds and were additionally tested for inhibition
of chemically-induced preneoplastic lesions in an ex vivo mouse mammary gland organ culture model (MMOC). Importantly, both agents inhibited lesion formation with halfmaximal inhibitory
concentrations (IC50) of 0.1 and 0.02 μM, respectively. Our results demonstrate that beer is an interesting source of potential cancer chemopreventive
agents and should be further investigated with this respect.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
14.
Marek Doskocz Agnieszka Strupińska Szczepan Roszak Monika Prokopowicz Leo H. Koole Paweł Kafarski 《Journal of molecular modeling》2009,15(6):651-658
The study of spin-spin coupling constants across hydrogen bond provides useful information about configuration of complexes.
The interesting case of such interactions was observed as a coupling across an intramolecular hydrogen bond in 8-bromo-2′,3′-O-isopropylideneadenosine between the -CH2OH (at 5″ proton) group and the nitrogen atom of adenine. In this paper we report theoretical investigations on the 4h
J
NH coupling across the H″-C-O-H···N hydrogen bond in adenosine derivatives in various solvent models.
Figure Coupling constants in 8-bromo-2′,3′-O-isopropylideneadenosine
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
15.
Olivati CA Riul A Balogh DT Oliveira ON Ferreira M 《Bioprocess and biosystems engineering》2009,32(1):41-46
Langmuir-Blodgett (LB) and layer-by-layer films (LbL) of a PPV (p-phenylenevinylene) derivative, an azo compound and tetrasulfonated phthalocyanines were successfully employed as transducers
in an “electronic tongue” system for detecting trace levels of phenolic compounds in water. The choice of the materials was
based on their distinct electrical natures, which enabled the array to establish a fingerprint of very similar liquids. Impedance
spectroscopy measurements were taken in the frequency range from 10 Hz to 1 MHz, with the data analysed with principal component
analysis (PCA). The sensing units were obtained from five-layer LB films of (poly[(2-methoxy-5-n-hexyloxy)-p-phenylenevinylene]), OC1OC18-PPV (poly(2-methoxy,5-(n-octadecyl)-p-phenylenevinylene)), DR (HEMA-co-DR13MA (poly-(hydroxyethylmethacrylate-co-[4′-[[2-(methacryloyloxy)-ethyl]ethylamino]-2-chloro-4-nitroazobenzene])))
and five-bilayer LbL films of tetrasulfonated metallic phthalocyanines deposited onto gold interdigitated electrodes. The
sensors were immersed into phenol, 2-chloro-4-methoxyphenol, 2-chlorophenol and 3-chlorophenol (isomers) solutions at 1 × 10−9 mol L−1, with control experiments carried out in ultra pure water. Samples could be distinguished if the principal component analysis
(PCA) plots were made with capacitance values taken at 103 Hz, which is promising for detection of trace amounts of phenolic pollutants in natural water. 相似文献
16.
A UDP-glucose: anthocyanin 3′,5′-O-glucosyltransferase (UA3′5′GT) (EC 2.4.1.-) was purified from the petals of Clitoria ternatea L. (Phaseoleae), which accumulate polyacylated anthocyanins named ternatins. In the biosynthesis of ternatins, delphinidin
3-O-(6″-O-malonyl)-β-glucoside (1) is first converted to delphinidin 3-O-(6″-O-malonyl)-β-glucoside-3′-O-β-glucoside (2). Then 2 is converted to ternatin C5 (3), which is delphinidin 3-O-(6″-O-malonyl)-β-glucoside-3′,5′-di-O-β-glucoside. UA3′5′GT is responsible for these two steps by transferring two glucosyl groups in a stepwise manner. Its substrate
specificity revealed the regioselectivity to the anthocyanin′s 3′- or 5′-OH groups. Its kinetic properties showed comparable
k
cat values for 1 and 2, suggesting the subequality of these anthocyanins as substrates. However, the apparent K
m value for 1 (3.89 × 10−5 M), which is lower than that for 2 (1.38 × 10−4 M), renders the k
cat/K
m value for 1 smaller, making 1 catalytically more efficient than 2. Although the apparent K
m value for UDP-glucose (6.18 × 10−3 M) with saturated 2 is larger than that for UDP-glucose (1.49 × 10−3 M) with saturated 1, the k
cat values are almost the same, suggesting the UDP-glucose binding inhibition by 2 as a product. UA3′5′GT turns the product 2 into a substrate possibly by reversing the B-ring of 2 along the C2-C1′ single bond axis so that the 5′-OH group of 2 can point toward the catalytic center.
K. Kogawa, N. Kato, K. Kazuma, and N. Noda contributed equally to this work. 相似文献
17.
The toxicity of iron is believed to originate from the Fenton reaction which produces the hydroxyl radical and/or oxoiron(2+).
The effect of nitrogen monoxide on the kinetics of the reaction of iron(II) bound to citrate, ethylenediamine-N,N′-diacetate (edda), ethylenediamine-N,N,N′,N′-tetraacetate (edta), (N-hydroxyethyl)amine-N,N′,N′-triacetate (hedta), and nitrilotriacetate (nta) with hydrogen peroxide was studied by stopped-flow spectrophotometry. Nitrogen
monoxide inhibits the Fenton reaction to a large extent. For instance, hydrogen peroxide oxidizes iron(II) citrate with a
rate constant of 5.8×103 M−1 s−1, but in the presence of nitrogen monoxide, the rate constant is 2.9×102 M−1 s−1 . Similar to hydrogen peroxide, the reaction of tert-butyl hydroperoxide with iron(II) complexes is also efficiently inhibited by nitrogen monoxide. Generally, nitrogen monoxide
binds rapidly to a coordination site of iron(II) occupied by water. The rate of oxidation is influenced by the rate of dissociation
of the nitrogen monoxide from iron(II).
Electronic Supplementary Material Supplementary material is available for this article at 相似文献
18.
Arvind Misra Pratibha Dwivedi Mohammad Shahid 《Russian Journal of Bioorganic Chemistry》2009,35(1):62-67
A modified fluorescent probe UFAA AAT CTC CGC CGC was synthesized using the nucleoside analogue 3′-O-(N,N′-diisopropylamino-2-cyanoethoxyphosphinyl)-5′-O-(4,4′-dimethoxytrityl)-2′-O-(dansyl-1-sulfonamidohexylaminocarbonyl)uridine for hybridization studies with perfectly matched (U/A) complementary DNA
and with a DNA strand having similar G-rich telomeric units at their 3′-ends. Data on the thermal stability and decrease in
fluorescence intensity due to the presence of dG units clearly demonstrated the potential application of this approach in
DNA diagnostics in homogeneous hybridization assays.
The text was submitted by the authors in English. 相似文献
19.
20.
By the use of the Immobiline technique at pH ranges 7.0–7.6 and 6.9–7.9, 16 different hemoglobin (Hb) phenotypes were observed
in 61 English Saanen goats. They are explained in this breed by a genetic theory of five β-globin genes (A
4,A
6,A
8,E, andD) and two closely linked α-globin loci (′α and ″α) of which the ″α has a variant allele, provisionally called ″α
X
. Family data together with observed and expected Hb frequencies were in agreement with the genetic theory. Among six Barbary
sheep there were three Hb phenotypes explained by the occurrence of the β-chain allelesB andC
na. 相似文献