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1.
Free and bound lipids from Helianthus tuberosus tubers were investigated. Neutral, glyco-and phospholipid classes and their fatty-acid compositions were determined. The
composition of unsaponified substances was established.
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Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 3–4, January–February, 2008. 相似文献
2.
Qing LS Xue Y Deng WL Liao X Xu XM Li BG Liu YM 《Analytical and bioanalytical chemistry》2011,399(3):1223-1231
The chemical composition of herbal medicines is very complex, and their therapeutic effects are determined by multi-components
with sophisticated synergistic and/or suppressive actions. Therefore, quality control of herbal medicines has been a formidable
challenge. In this work, we describe a fast analytical method that can be used for quality assessment of herbal medicines.
The method is based on ligand fishing using human-serum-albumin-functionalized magnetic nanoparticles (HSA-MNPs) and mass
spectrometry. To demonstrate the applicability of the proposed method, eight samples of Dioscorea panthaica were analyzed. The sampled plants were of both wild and cultivated origins. They grew at different geographical locations
and were harvested at different times. The ligands bound to HSA-MNPs were isolated from the plant extracts and detected by
using direct infusion electrospray ionization mass spectrometry (DI–ESI–MS). Chemical identity has been confirmed for five
of the ligands isolated. From more than 15 peaks in the ESI–MS spectrum, 11 common peaks were selected for calculating the
correlation coefficient and cosine ratio. The values of correlation coefficient and cosine ratio were >0.9824 and >0.9988,
respectively, for all the samples tested. The results indicated a high level of similarity among the eight D. panthaica samples. Compared with chromatographic fingerprint analysis, the proposed HSA-MNP-based DI–ESI–MS/MS approach was not only
fast and easy to carry out but also biological-activity-oriented, promising a more effective data interpretation and thus
reliable assessment conclusions. 相似文献
3.
Nilgün Yener Müşerref Önal Gökçe Üstünışık Y. Sarıkaya 《Journal of Thermal Analysis and Calorimetry》2007,88(3):813-817
An industrial raw material taken from Beypazarı (Ankara, Turkey) region was heated at different temperatures in the 100–1100°C
interval for 2 h. The volumetric percentage of particles having diameter below 2 μm in an aqueous suspension of the material
held 24 h were determined as 85% by the particle size distribution analysis. The mineralogical composition of the material
was obtained as mass% of 81% sepiolite, 15% dolomite, and 4% interparticle water by using the X-ray diffraction (XRD) and
thermal analysis (TG, DTA) data. The temperature ranges were determined for the dehydrations of the interparticle water and
the zeolitic water as 25–340°C, for the dehydration of the bound water as 340–580°C, and for the dehydroxylation of the hydroxyls
as 800–833°C in the sepiolite. The zig-zag changes in the specific surface area (S/m2 g−1) and specific micro-and mesopore volume (V/cm3 g−1) with the temperature increases were discussed according to the dehydrations and dehydroxylation of the sepiolite. 相似文献
4.
L. A. Yakovishin V. I. Grishkovets N. N. Arnautov V. Ya. Chirva 《Chemistry of Natural Compounds》1999,35(5):587-588
Triterpene glycosides from leaves of canary ivyHedera canariensis Willd. were previously isolated and characterized [1–4]. The glycosidic composition of the plant stems is reported in the
present article.
Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 676–678, September–October, 1999. 相似文献
5.
H. Bayram M. Önal G. Üstünışık Y. Sarıkaya 《Journal of Thermal Analysis and Calorimetry》2007,89(1):169-174
An industrial raw material taken from Sivrihisar (Eskişehir, Turkey) region was heat-treated at different temperatures in
the range of 100–1000°C for 2 h. The volumetric percentage of the particles having a diameter below 2 μm after staying in
an aqueous suspension of the material was determined as 67% by the particle size distribution analysis. The mineralogical
composition of the material was obtained as mass% of 32% palygorskite, 10% metahalloysite, 35% magnesite, 20% dolomite and
3% interparticle water by using the acid treatment, X-ray diffraction and thermal analysis (TG, DTA) data.
The temperature ranges were determined for the endothermic dehydrations for the interparticle water as 25–140°C, for the zeolitic
water as 140–320°C, and for the bound water as 320–480°C, in the palygorskite. The temperature range for the endothermic dehydroxylation
and exothermic recrystalization of the palygorskite is 780–840°C. The temperature range for the endothermic dehydroxylation
of the metahalloysite and calcinations of magnesite are coincided at 480–600°C. Dolomite calcined in the temperature range
of 600–1000°C by two steps. The zig-zag changes in the specific surface area (S/m2 g−1) and specific micro and mesopore volume (V/cm3 g−1) as the temperature increases were discussed according to the dehydrations in the palygorkskite, dehydroxylation of palygorskite
and metahalloysite, and calcinations in magnesite and dolomite. 相似文献
6.
The applicability of ATR-FTIR for the determination of the HDO content in heavy water (D2O) was investigated. Two groups of calibration standard solutions, of low contents (0–1 n% H2O in heavy water) and of higher contents (0–10 n% H2O in heavy water) were prepared by adding properly calculated amount of H2O to D2O by weight. The absorbances at 3400 cm−1 (ν, O–H) against the calibration standards were measured five times using two kinds of interchangeable IREs (1 bound and
9 bound reflections). And four calibration curves were obtained by linear least square fit of the measured absorbances for
the four different measurement conditions, which are (1) for low contents group using 1 bound reflection, (2) for low contents
group using 9 bound reflections, (3) for higher contents group using 1 bound reflection, (4) for higher contents group using
9 bound reflections. Determined contents (c
0) of each calibration standards for the four measurement conditions were obtained by the calibration curves and compared to
the calculated contents (c
cal). The uncertainty sources were considered when the HDO in heavy water is determined according to the procedure of this work.
The uncertainties u(c
0) of the determined contents (c
0) for the four different measurement conditions were calculated. 相似文献
7.
Ying Hui Shao Xiao Ning Ren Zi Ru Liu Xiang Zhang 《Journal of Thermal Analysis and Calorimetry》2011,103(2):617-623
The eutectic ternary phase diagrams of some typical volatilizable energetic materials have been investigated by high pressure
differential scanning calorimeter (PDSC). The ternary H–X phase diagrams for TNT/TNAZ/DNTF (TTD) and TNAZ/DNTF/RDX (TDR) systems were constructed by the correlation of the apparent
fusion heat with the composition (H–X method). And, the ternary T–X phase diagrams (the temperature dependence on composition) for the two ternary systems were constructed by calculating from
the data of the five T–X binary phase diagrams. The eutectic compositions (mol%) of TTD and TDR ternary systems were obtained to be 52.3/27.3/20.4
(H–X method), 53.2/25.8/21.0 (T–X method) and 54.9/39.6/5.5 (H–X method), 55.1/42.2/2.7 (T–X method), respectively. The eutectic temperatures of the ternary systems were obtained by PDSC determination and T–X method calculation to be 76.5 and 76.7 °C, 47.5 and 50.2 °C, respectively. It is shown that the results obtained by two methods
are in agreement and the error in measuring or calculating eutectic compositions and temperatures for the two ternary systems
are within allowable ranges of ±3 mol% and ±3 °C, respectively. Moreover, by means of constructing two ternary H–X phase diagrams with different fixed composition of a component and comparing the apparent fusion heat of eutectics with calculated
one, the results obtained from H–X method for TTD system were proved. The results showed that the gasification or volatilization of easy volatile materials
could be efficiently restrained by high pressure atmosphere, and the perfectly and ideally H–X ternary phase diagrams can be constructed. In comparison with T–X method, H–X method has as a virtue of being quick and simple, especially on constructing ternary phase diagram. 相似文献
8.
Veronika Buchtová Dragana ?ivkovi? Jan V?e?t’ál Dragan Manasijevi? Ale? Kroupa 《Monatshefte für Chemie / Chemical Monthly》2005,27(2):1939-1945
Binary thermodynamic data, successfully used for phase diagram calculations of binary systems Ag–In, Ag–Sb, and In–Sb, were
used for prediction of phase equilibria in ternary Ag–In–Sb system at 200°C. Symmetrical Redlich–Kister–Muggianu model for ternary thermodynamic function calculation was proved to be best valid in this ternary system. Predicted equilibria
were compared with experimentally (SEM, EDX) determined composition of phases in chosen alloys after long term annealing and
with the results of DTA measurements. 相似文献
9.
Summary. Binary thermodynamic data, successfully used for phase diagram calculations of binary systems Ag–In, Ag–Sb, and In–Sb, were
used for prediction of phase equilibria in ternary Ag–In–Sb system at 200°C. Symmetrical Redlich–Kister–Muggianu model for ternary thermodynamic function calculation was proved to be best valid in this ternary system. Predicted equilibria
were compared with experimentally (SEM, EDX) determined composition of phases in chosen alloys after long term annealing and
with the results of DTA measurements. 相似文献
10.
Foster A. Agblevor Sandra Batz Jessica Trumbo 《Applied biochemistry and biotechnology》2003,105(1-3):219-230
Cotton gin residue (CGR) collected from five cotton gins was fractionated and characterized for summative composition. The
major fractions of the CGR varied widely between cotton gins and consisted of clean lint (5–12%), hulls (16–48%), seeds (6–24%),
motes (16–24%), and leaves (14–30%). The summative composition varied within and between cotton gins and consisted of ash
(7.9–14.6%), acid-insoluble material (18–26%), xylan (4–15%), and cellulose (20–38%). Overlimed steam-exploded cotton gin
waste was readily fermented to ethanol by Escherichia coli KO11. Ethanol yields were feedstock and severity dependent and ranged from 58 to 92.5% of the theoretical yields. The highest
ethanol yield was 191 L (50 gal)/t, and the lowest was 120 L (32 gal)/t. 相似文献
11.
B. Tirillini A. Ricci G. Pintore M. Chessa L. Menghini R. Pagiotti 《Chemistry of Natural Compounds》2007,43(1):44-46
The essential oil composition of aerial parts of Santolina etrusca Marchi & D’Amato from Italy was analyzed by GC and GC/MS. Twenty-nine compounds of oil were identified representing 97.1%
of the oil. The most abundant compounds were viridiflorol (17.9%), terpinen-4-ol (14.4%), myrcene (11.8%), β-pinene (9.9%),
and cis-muurola-4(14),5-diene (9.9%). To the best of our knowledge, this is the first report on the GC/MS determination of the essential
oil composition of S. etrusca.
Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 38–39, January–February, 2007. 相似文献
12.
Physicochemical properties and fatty acid composition of Juglans regia cultivars grown in Serbia 总被引:1,自引:0,他引:1
Tree cultivars (Jupiter, Sejnov, and Elit) of walnut (Juglans regia L.) were collected during the 2004 harvest from Cacak, Central Serbia. The chemical composition, including moisture, total
oil content, crude protein, ash, and carbohydrates, was determined. Afterwards, two techniques of oil extraction were implemented:
cold pressing extraction and organic solvent extraction. Iodine value, saponification value, acid value, and peroxide value
of obtained walnut oils were analyzed. The fatty acid composition of the walnut oils was determined using gas chromatography
with flame ionization detector. The oleic acid content of the oils ranged from 15.9–23.7% of the total acids, while linoleic
acid content ranged from 57.2–65.1% and the linolenic acid from 9.1–13.6%. The process of oil extraction had no significant
effect on content and composition of fatty acids.
Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 118–120, March–April, 2008. 相似文献
13.
Typical
data of a new microporous material obtained from gels with titanium and silicon 总被引:1,自引:0,他引:1
M. Veltri D. Vuono P. De
Luca J. B. Nagy A. Nastro 《Journal of Thermal Analysis and Calorimetry》2006,84(1):247-252
The
aim of this work is the synthesis and the characterization of a microporous
material obtained from gels with titanium and silicon: NTS (titanosilicate).
The structure of NTS zeotype is similar to that of AM-1 and JDF-L1 (titanosilicates).
The synthesis were carried out with gels
of composition: 3.5Na2O–yTiO2–4.48HCl–xSiO2–110H2O
with 1.0≤x≤12.0 and 0.2≤y≤0.7. The temperature of reaction was 190±2°C. 相似文献
14.
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
15.
We studied thermal transitions and physical stability
of oil-in-water emulsions containing different milk fat compositions, arising
from anhydrous milk fat alone (AMF) or in mixture (2:1 mass ratio) with a
high melting temperature (AMF–HMT) or a low melting temperature (AMF–LMT)
fraction. Changes in thermal transitions in bulk fat and emulsion samples
were monitored by differential scanning calorimetry (DSC) under controlled
cooling and reheating cycles performed between 50 and –45°C (5°C
min–1). Comparison between bulk fat samples
and emulsions indicated similar values of melting completion temperature,
whereas initial temperature of fat crystallization (Tonset)
seemed to be differently affected by storage temperature depending on triacylglycerols
(TAG) composition. After storage at 4°C, Tonset
values were very similar for emulsified and non-emulsified AMF–HMT blend,
whereas they were lower (by approx. 6°C) for emulsions containing AMF
or mixture of AMF–LMT fraction. After storage at –30°C, Tonset values of re-crystallization
were higher in emulsion samples than in bulk fat blends, whatever the TAG
fat composition. Light scattering measurements and fluorescence microscopic
observations indicated differences in fat droplet aggregation-coalescence
under freeze-thaw procedure, depending on emulsion fat composition. It appeared
that under quiescent freezing, emulsion containing AMF–LMT fraction
was much less resistant to fat droplet aggregation-coalescence than emulsions
containing AMF or AMF–HMT fraction. Our results indicated the role of
fat droplet liquid-solid content on emulsion stability. 相似文献
16.
A (n, n + 1)-graph G is a connected simple graph with n vertices and n + 1 edges. In this paper, we determine the upper bound for the Merrifield–Simmons index in (n, n + 1)–graphs in terms of the order n, and characterize the (n, n + 1)–graph with the largest Merrifield–Simmons index. 相似文献
17.
The chemical composition of neutral lipids from seeds of Cercis siliquastrum, Sapium sebiferum, and Koelreuteria paniculata were studied. Characteristic features of their individual classes were established.
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Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 318–319, July–August, 2007 相似文献
18.
Tomáš Grygar Petr Bezdička Pawel Piszora Emilia Wolska 《Journal of Solid State Electrochemistry》2001,5(7-8):487-494
Electrochemical reductive dissolution of Li–Mn–O and Li–Fe–Mn–O spinels and Li+ extraction/insertion in these oxides were performed using voltammetry of microparticles. Both electrochemical reactions are
sensitive to the Fe/(Fe+Mn) ratio, specific surface area, Li content in tetrahedral positions, and Mn valence, and can be
used for electrochemical analysis of the homogeneity of the elemental and phase composition of synthetic samples. The peak
potential (E
P) of the reductive dissolution of the Li–Mn–O spinel is directly proportional to the logarithm of the specific surface area. E
P of Li–Fe–Mn–O spinels is mainly controlled by the Fe/(Fe+Mn) ratio. Li+ insertion/extraction can be performed with Mn-rich Li–Fe–Mn–O spinels in aqueous solution under an ambient atmosphere and
it is sensitive to the regularity of the spinel structure, in particularly to the amount of Li in tetrahedral positions and
the Mn valence.
Electronic Publication 相似文献
19.
20.
T. I. Emets M. V. Steblyuk N. A. Klyuev V. V. Petrenko 《Chemistry of Natural Compounds》1994,30(3):292-294
The lipid composition of the free fatty acids of the seed oil ofMalva sylvestris from the Ukrainian flora has been studied by chromato-mass spectrometry. The fatty acid composition was represented by 20
compounds, among which malvic and sterculic acids were detected. The presence of terpineols and retinol has been shown.
Zaporozh'e Medical Institute. Translated from Khimiya Prirodnykh Soedenii, No. 3, pp. 322–325, May–June, 1994. 相似文献