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1.
The new natural compound lavandoside with the structure ferulic acid 4-O-β-D-glucopyranoside was isolated by column chromatography over silica gel and polyamide from the extract of Lavandula spica flowers. The chemical structure of lavandoside was established using UV, NMR, and mass spectra and chemical transformations.
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Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 133–134, March–April, 2008. 相似文献
2.
Jian-Rong Luo Hong-En Jiang You-Xing Zhao Jun Zhou Jin-Fu Qian 《Chemistry of Natural Compounds》2008,44(1):6-9
To probe the organic constituents of over 2000-year-preserved Populus euphratica found in an ancient tomb, a chemical investigation was undertaken, which led to the isolation of a new compound, 2-(4′-hydroxy-3′-methoxyphenyl)-2-oxoacetamide
(1), together with 12 known compounds (2–13) by column chromatography. Their structures were elucidated on the basis of spectroscopic evidence. It is the first time
that compounds 2–13 were isolated from this plant.
Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 7–9, January–February, 2008. 相似文献
3.
Long L Song Y Wu J Lei L Huang K Long B 《Analytical and bioanalytical chemistry》2006,386(7-8):2169-2174
In our research into chlorophylls of marine dinoflagellates, chlorophyll a was separated rapidly from the hexane extract of Amphidinium carterae in three steps. The first step was silica gel column chromatography, where elution was performed with 0–50% ethyl acetate
in n-hexane. The second was high-speed counter-current chromatography using a two-phase solvent system consisting of n-hexane–ethyl acetate–methanol–water (5:5:5:1, v/v), and the third step was preparative reversed-phase high-performance liquid
chromatography using a solvent system of acetone–water (89:11, v/v). HPLC analysis showed that the purity of chlorophyll a from the second step was over 83%, and after the third it was over 99%. Thirty milligrams of chlorophyll a was isolated from a crude sample of 250 mg of chlorophylls, and its structure was identified by analyzing its MS, 1H NMR and 13C NMR spectra. 相似文献
4.
Fungicidal lipid-transfer peptide from <Emphasis Type="Italic">Daucus carota sativa</Emphasis> seeds
A. Yili H. A. Aisa X. Imamu R. H. Zhen Q. Zhang V. V. Maksimov O. N. Veshkurova Sh. I. Salikhov 《Chemistry of Natural Compounds》2007,43(4):450-453
A non-specific lipid-transfer peptide (nsLTP) with fungicidal activity was isolated from Daucus carota sativa carrot seeds. Peptides were purified by a method including aqueous extraction, anion-exchange chromatography over CM-TSK-650M,
and HPLC over a column of 250/8/4 Protein@Peptide C18 using an acetonitrile gradient. The molecular weight of the peptide was determined as 9624 Da by mass spectrometry. The peptide
was found to have fungicidal activity against the pathogenic fungus Verticillium dahliae. The partial N-terminal sequence, which was highly homologous to the N-terminal sequences of lipid-transfer peptides from seeds of rice, tobacco, and maize, was determined using Edman automated
sequencing.
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Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 371–373, July–August, 2007. 相似文献
5.
Thereza Christina Vessoni Penna Marina Ishii Adalberto Pessoa Junior Olivia Cholewa 《Applied biochemistry and biotechnology》2004,114(1-3):469-483
The thermal stability of the recombinant green fluorescent protein (GFPuv) expressed by Escherichia coli cells and isolated by three-phase partitioning extraction with hydrophobic interaction chromatography was studied. The GFPuv
(3.5–9.0 μg of GFPuv/mL) was exposed to various pH conditions (4.91–9.03) and temperatures (75–95°C) in the 10 mM buffers: acetate (pH 5.0–7.0), phosphate (pH 5.5–8.0), and Tris-HCl (pH 7.0–9.0). The extent of protein denaturation (loss
of fluorescence intensity) was expressed in decimal reduction time (D-value), the time exposure required to reduce 90% of the initial fluorescence intensity of GFPuv. For pH 7.0 to 8.0, the thermostability
of GFPuv was slightly greater in phosphate buffer than in Tris-HCl. At 85°C, the D-values (pH 7.1–7.5) ranged from 7.24 (Tris-HCl) to 13.88 min (phosphate) The stability of GFPuv in Tris-HCl (pH>8.0) was
constant at 90 and 95°C, and the D-values were 7.93 (pH 8.38–8.92) and 6.0 min (pH 8.05–8.97), respectively. The thermostability of GFPuv provides the basis
for its potential utility as a fluorescent biologic indicator to assay the efficacy of moist-heat treatments at temperatures
lower than 100°C. 相似文献
6.
Sh. Ya. Mirzaakhmedov Zh. F. Ziyavitdinov Z. R. Akhmedova A. B. Saliev D. T. Ruzmetova Kh. B. Ashurov Dimitrios Fessas Stefania Iametti 《Chemistry of Natural Compounds》2007,43(5):594-597
The accumulation dynamics of cellulolytic enzymes in culture media of the basidiomycete fungi Panus tigrinus, Pleurotus ostreatus, Fomes fomentarus, and the micromycete Aspergillus terreus were studied during a long incubation period. It was found that A. terreus was the most active producer of cellulolytic enzymes among the studied fungi. Two protein fractions with cellulase activity
were isolated using gel filtration and ion-exchange chromatography. PAAG electrophoresis showed that fraction-I consisted
of four components; fraction-II, an electrophoretically homogeneous protein.
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Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 489–491, September–October, 2007. 相似文献
7.
L. Lugo M. J. P. Comuñas E. R. López J. Fernández 《Journal of Thermal Analysis and Calorimetry》2007,87(1):179-187
New densities are reported over the whole composition range for 1-iodoperfluorohexane+n-octane system at temperatures from 288.15 to 308.15
K at atmospheric pressure. These data have been used to compute the excess
molar volumes, V
m
E.
Large positive V
m
E
values have been obtained over the entire range of composition, which increases
when the temperature rises. The experimental data were used to calculate the
isobaric thermal expansivity, and the quantities (∂V
m
E/∂T)p and (∂H
m
E/∂p)T. Furthermore,
the results have been used to investigate the volumetric prediction ability
of the equations of state Soave–Redlich–Kwong, Peng–Robinson,
Patel–Teja and Soave–Redlich–Kwong with volume translation. 相似文献
8.
The chemical composition of the fruits of the north algerian ecotype Pistacia atlantica subsp. atlantica was determined and compared to other fruits of different species in the genus growing in south Algeria and other Mediterranean
regions. These fruits were analyzed for their dry matter, protein, crude oil, ash, fatty acids, and phytosterol content. The
main fatty acids identified by gas chromatography were oleic (54.15%), linoleic (28.84%), and palmitic (12.21%) acids. The
fruits of the north ecotype were found to be rich in protein, oil, fiber, and unsaturated fatty acids, suggesting that they
may be valuable for food uses. The sterols isolated were campesterol, stigmasterol, β-sitosterol, and Δ5-avenasterol with β-sitosterol as the major constituent (85%±0.85). The biochemical data indicated an elevated MUFA rate (∼56%)
in pistacia oil which may be important against certain pathologies for its nutritional and preventive virtues.
Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 103–105, March–April, 2007. 相似文献
9.
The new phenylethanoid glycoside calceolarioside A-2′-α-L-rhamnopyranoside and calceolarioside A and calceolarioside B were isolated from the bark of Fraxinus mandschurica Rupr. for the first time by column chromatography.
Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 283–284, May–June, 2009. 相似文献
10.
Manoj Kumar Santosh Kumar Tiwari Sheela Srivastava 《Applied biochemistry and biotechnology》2010,160(1):40-49
Enterocin LR/6, a bacteriocin obtained from the culture filtrate of Enterococcus faecium strain LR/6, has been purified to homogeneity using ammonium sulfate precipitation, cation-exchange chromatography, gel-filtration,
and checked on reverse-phase high-performance liquid chromatography. It is active at high temperatures (boiling as well as
autoclaving) and over a wide range of pH (2.0–8.0). Also, it is sensitive to a number of proteolytic enzymes but is stable
in the presence of surfactants and organic solvents. The protein could be stored at least up to 1 year at low temperatures
(4 °C and −20 °C) without any loss of activity. The N-terminal sequence of enterocin LR/6 showed no homology with known enterocins
or other bacteriocins present in the database, suggesting it to be a novel enterocin. Matrix-assisted laser desorption/ionization-time-of-flight
mass spectrometry and tricine sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed its mass to be ∼6.1 kDa.
It showed a bactericidal mode of action against indicator strain, Micrococcus luteus. 相似文献
11.
A new compound of formula C28H48O with mp 179-180°C (aqueous ethanol) that was called eucanbin was isolated pure by column chromatography of the ethanol extract
of the aerial part of Eupatorium cannabinum L. The structure 24α-methylcholest-20(21)-en-3β-ol was assigned based on chemical and spectral data.
Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 318–320, May–June, 2009. 相似文献
12.
X. P. Geng Y. N. Wu B. H. Wang H. F. Zhang X. D. Geng J. W. Xing 《Journal of Thermal Analysis and Calorimetry》2006,85(3):601-608
Both
microcalorimetric determination of displacement adsorption enthalpies ΔH and measurement of adsorbed amounts of guanidine
– denatured lysozyme (Lys) refolding on the surface of hydrophobic interaction
chromatography (HIC) packings at 308 K were carried out and compared with
that at 298 K. Study shows that both temperature and concentration of guanidine
hydrochloride (GuHCl) affect the molecular mechanism of hydrophobic interaction
of protein with adsorbent based on the analysis of dividing ΔH values into three kinds of enthalpy fractions.
The adsorption in higher concentrations of GuHCl (>1.3 mol L–1)
at 308 K is an enthalpy-driving process, and the adsorption under other GuHCl
concentrations is an entropy-driving process. The fact that the Lys denatured
by 1.8 mol L–1 GuHCl forms a relatively stable
intermediate state under the studied conditions will not be changed by temperature. 相似文献
13.
Vijai Singh Pallavi Somvanshi Gaurav Rathore D. Kapoor B. N. Mishra 《Applied biochemistry and biotechnology》2010,160(7):1985-1991
Aerolysin is a significant virulent toxin protein secreted by Aeromonas hydrophila; it produces deep wound infections and hemorrhagic septicemia. The complete aerolysin gene (1,482 bp) was amplified from
A. hydrophila. Furthermore, it was cloned and expressed into Escherichia coli BL21(DE3) codon plus RP cells using 0.5 mM IPTG for induction. The protein size was 54 kDa as estimated by SDS-PAGE, and
it was purified by Ni–NTA affinity chromatography. Anti-His antibodies were used to characterize the expressed aerolysin by
Western blotting and showed hemolytic activity with fish red blood cells. Aerolysin may be used as immunoassays for earlier
control of A. hydrophila and is also compatible for vaccination. 相似文献
14.
Components of the ethylacetate extract of <Emphasis Type="Italic">Hedysarum theinum</Emphasis> roots
I. V. Nechepurenko N. P. Polovinka O. I. Sal’nikova L. M. Pokrovskii N. I. Komarova N. F. Salakhutdinov S. B. Nechepurenko 《Chemistry of Natural Compounds》2007,43(1):5-9
Isoflavonoids (-)-medicarpin, (-)-vestitol, and formononetin and butylphenols raspberry ketone and rhododendrol were isolated
for the first time from the ethylacetate extract of Hedysarum thienum roots by column chromatography. GC-MS showed that the ethylacetate extract contained fatty acids, the principal ones being
palmitic, linoleic, oleic, behenic, and lignocerinic.
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Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 6–9, January–February, 2007. 相似文献
15.
Sphingomonas xenophaga QYY, capable of growing significantly on more than ten kinds of aromatic compounds as sole carbon source, was used to study
characterization of catechol 1,2-dioxygenase (C12O) in cell extracts. Characterization of the crude C12O showed that the maximum
activity was obtained at 40–70°C and pH 7.8–8.8. Metal ions had different influences on the activity of crude C12O. It was
suggested that strain QYY possessed an inducible and ferric-dependent C12O. Kinetic studies showed that the value of V
max and K
m was 0.25 μmol catechol/L/mg protein/min and 52.85 μmol/L, respectively. In addition, the partial purification of C12O was
achieved by a HiTrap Q Sepharose column chromatography.
Supported by the National Natural Science Foundation of China (Grant No. 50608011) and the 39th Postdoctoral Funds of China
(Grant No. 20060390983) 相似文献
16.
Sh. Ya. Mirzaakhmedov Zh. F. Ziyavitdinov Z. R. Akhmedova A. B. Saliev D. T. Ruzmetova S. T. Azizov Dimitrios Fessas Stefania Iametti 《Chemistry of Natural Compounds》2007,43(6):682-684
The accumulation dynamics of lignolytic enzymes in culture media of the basidiomycetes Panus tigrinus, Pleurotus ostreatus, Fomes fomentarus, and the micromycete Aspergillus terreus were studied during the incubation period. It was found that Pleurotus ostreatus is the most active producer of lignoperoxidase enzymes among the studied fungi. Gel filtration and ion-exchange chromatography
were used to isolate a homogeneous enzyme with lignoperoxidase activity. The maximum activity was found at pH 2.7 and 29°C.
Gel electrophoresis determined the molecular weight (44 kDa).
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Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 564–566, November–December, 2007. 相似文献
17.
Qu Lingbo Chen Xiaolan Lu Jiansha Yuan Jingwei Zhao Yufen 《Chemistry of Natural Compounds》2005,41(5):565-568
Six substances were isolated from the branches and leaves of the Chinese herb Leptopus Chinensis (Bunge) Pojark. by column chromatography for the first time. Their structures were elucidated as 3α-hydroxyfriedelan-2-one,
saccharose, triacontanol, friedelane-2α,3β-diols, β-sitosterol-3-O-β-D-glucoside, and β -sitosterol on the basis of x-ray,
chemical, and spectroscopic methods.
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Published in Kimiya Prirodnikh Soedinenii, No. 5, pp. 462–464, September–October, 2005. 相似文献
18.
Gutka HJ Rukseree K Wheeler PR Franzblau SG Movahedzadeh F 《Applied biochemistry and biotechnology》2011,164(8):1376-1389
The glpX gene (Rv1099c) of Mycobacterium tuberculosis (Mtb) encodes Fructose 1,6-bisphosphatase II (FBPase II; EC 3.1.3.11); a key gluconeogenic enzyme. Mtb possesses glpX homologue as the major known FBPase. This study explored the expression, purification and enzymatic characterization of functionally
active FBPase II from Mtb. The glpX gene was cloned, expressed and purified using a two step purification strategy including affinity and size exclusion chromatography.
The specific activity of Mtb FBPase II is 1.3 U/mg. The enzyme is oligomeric, followed Michaelis–Menten kinetics with an apparent km = 44 μM. Enzyme activity is dependent on bivalent metal ions and is inhibited by lithium and inorganic phosphate. The pH
optimum and thermostability of the enzyme have been determined. The robust expression, purification and assay protocols ensure
sufficient production of this protein for structural biology and screening of inhibitors against this enzyme. 相似文献
19.
Javed MR Rashid MH Nadeem H Riaz M Perveen R 《Applied biochemistry and biotechnology》2009,157(3):483-497
Monomeric extracellular endoglucanase (25 kDa) of transgenic koji (Aspergillus oryzae cmc-1) produced under submerged growth condition (7.5 U mg−1 protein) was purified to homogeneity level by ammonium sulfate precipitation and various column chromatography on fast protein
liquid chromatography system. Activation energy for carboxymethylcellulose (CMC) hydrolysis was 3.32 kJ mol−1 at optimum temperature (55 °C), and its temperature quotient (Q
10) was 1.0. The enzyme was stable over a pH range of 4.1–5.3 and gave maximum activity at pH 4.4. V
max for CMC hydrolysis was 854 U mg−1 protein and K
m was 20 mg CMC ml−1. The turnover (k
cat) was 356 s−1. The pK
a1 and pK
a2 of ionisable groups of active site controlling V
max were 3.9 and 6.25, respectively. Thermodynamic parameters for CMC hydrolysis were as follows: ΔH* = 0.59 kJ mol−1, ΔG* = 64.57 kJ mol−1 and ΔS* = −195.05 J mol−1 K−1, respectively. Activation energy for irreversible inactivation ‘E
a(d)’ of the endoglucanase was 378 kJ mol−1, whereas enthalpy (ΔH*), Gibbs free energy (ΔG*) and entropy (ΔS*) of activation at 44 °C were 375.36 kJ mol−1, 111.36 kJ mol−1 and 833.06 J mol−1 K−1, respectively. 相似文献
20.
Zhang C Rodriguez C Circu ML Aw TY Feng J 《Analytical and bioanalytical chemistry》2011,401(7):2165-2175
S-glutathionylation (Pr–SSG) is a specific post-translational modification of cysteine residues by the addition of glutathione.
S-Glutathionylated proteins induced by oxidative or nitrosative stress play an essential role in understanding the pathogenesis
of the aging and age-related disorder, such as Alzheimer’s disease (AD). The purpose of this research is to develop a novel
and ultrasensitive method to accurately and rapidly quantify the Pr–SSG by using capillary gel electrophoresis with laser-induced
fluorescence detection (CGE-LIF). The derivatization method is based on the specific reduction of protein-bound S-glutathionylation with glutaredoxin (Grx) and labeling with thiol-reactive fluorescent dye (Dylight 488 maleimide). The experiments
were performed by coupling the derivatization method with CGE-LIF to study electrophoretic profiling in in vitro oxidative
stress model–S-glutathionylated bovine serum albumin (BSA-SSG), oxidant-induced human colon adenocarcinoma (HT-29) cells, brain tissues,
and whole blood samples from an AD transgenic (Tg) mouse model. The results showed almost an eightfold increase in S-glutathionyl abundance when subjecting HT-29 cells in an oxidant environment, resulting in Pr–SSG at 232 ± 10.64 (average
±SD; n = 3) nmol/mg. In the AD–Tg mouse model, an initial quantitative measurement demonstrated the extent of protein S-glutathionylation in three brain regions (hippocampus, cerebellum, and cerebrum), ranging from 1 to 10 nmol/mg. Additionally,
we described our developed method to potentially serve as a highly desirable diagnostic tool for monitoring S-glutathionylated protein profile in minuscule amount of whole blood. The whole blood samples for S-glutathionyl expression of 5-month-old AD–Tg mice are quantified as 16.3 μmol/L (=7.2 nmol/mg protein). Altogether, this
is a fast, easy, and accurate method, reaching the lowest limit of Pr–SSG detection at 1.8 attomole (amol) level, reported
to date. 相似文献