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1.
Extraction of the comminuted seeds has yielded an oil from which have been isolated: C33-C25, C18 and C17 paraffinic hydrocarbons, C18:1, C18:2, C18:3, C17:1, C17:2 and C17:3 olefinic hydrocarbons, ethyl esters of C32:0, C31:0, C30:0, C29:0, and C28:0 fatty acids, sterols with molecular weights of 414, 412, and 400, and the alcohols -amyrin and lupeol with their natural acetates. Extraction of the uncomminuted seeds has shown that the paraffinic hydrocarbons, ethyl esters, and alcohol acetates pass into the oil from the husks of the seeds. This is the first time that the C31:0 and C29:0 fatty acids have been detected as natural compounds, and it is the first time that the ethyl esters of C34, C33, C32, C31, and C30 fatty acids have been isolated from seed oils of higher plants.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 612–615, September–October, 1979.  相似文献   

2.
A headspace solid-phase microextraction (HS-SPME) method in combination with gas chromatography–mass spectrometry (GC–MS) has been used for extraction and identification of components of the volatile fraction of Provola dei Nebrodi, a typical semi-hard Sicilian cheese. Cheese samples from different producers and at different ripening stages have been examined. The effects of various conditions (e.g. sample volume, sample headspace volume, sample heating temperature, extraction time, etc.) on extraction efficiency were studied in order to optimise the technique. The technique used made it possible to identify 61 components: fatty acids from C2 to C14 and their esters, aldehydes, alcohols, methyl ketones, -lactones, aromatic compounds, hydrocarbons and terpenes. The main components were butanoic, hexanoic and octanoic acids. The linear free fatty acids (FFA) from C2 to C10 were quantified by using the standard addition method. Calibration curves constructed for the FFA spiked into cheese were highly linear with a correlation coefficient R2>0.998. Significant statistical differences (P0.05) were evident for the even-carbon-number fatty acids during ripening.  相似文献   

3.
Summary The esterification of C1–C8 fatty acid in aqueous solutions and in the presence of sulfuric or hydrochloric acid and with n-butanol is described. It has been established that the esterification can be used for the quantitative determination of these fatty acids in the concentration ratio range of [H2O]/[n-BuOH]=0.01–5.3. In the concentration ratio range of 0.01–0.8 the water present does not interfere. In the concentration range of above 0.8 anhydrous sodium sulfate is used for binding the water, in the amount of [Na2SO4.anh.]/[H2O]0.2.  相似文献   

4.
The epigeal part of the plantLagochilus hirsutissimus has yielded a new diterpenoid lactone — lagohirsidin, C22H34O5, mp 144–145°C, [] D 22 – 17.5° (c 1; ethanol). Reduction with LiAlH4 has yielded a diol C22H38O5, mp 165–166°C [] D 20 –1.2 (c 0.6; ethanol). Acid hydrolysis of the diol has led to the formation of lagochilin, C20H36O5, mp 167–168°C, [] D 20 –3.9° (c 1; ethanol). The synthesis of lagohirsidin from lagochilin has been effected.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 788–792, November–December, 1979.  相似文献   

5.
This work evaluates the influence of the - and -cyclodextrin (CD) cavity size on the association constant (KCDA) with decanoate (C10) and octanoate (C8) anions. The spectral displacement technique with phenolphthalein was used to obtain the 1:1 association constant (KCDA) in NaHCO3/NaOH buffer pH 10.5 at 25 °C. The KCDA value obtained were 2.6 (±0.2) × 103, 2.5 (±0.5) × 102, for beta;CD–C10 and CD–C10 inclusion complexes, and 5.1 (±0.2) × 102 and 4.7 (±0.2) × 101 for CD–C8 and CD–C8 inclusion complexes, respectively. The KCDA values of either acid with CD is approximately 10 times higher than for the same acid with CD, where as for the same cyclodextrin, the KCDA value is 5 times higher for the C10 association than for the C8. The data demonstrate that the cyclodextrin cavity size exerts a greater influence on the association constant than the chain length of the acid for these compounds. 1H NMR studies show that fatty acid protonation has a distinct effect on the chemical shift of CD protons.  相似文献   

6.
Summary The concentrations of lipids were determined in atmospheric particle samples, collected seasonally, in an urban coastal area of the Island of Crete. Lipid compound classes, such as n-alkanes, hopanes and steranes, PAH, fatty alcohols, fatty acids and fatty acids selts, were determined by GC-FID and GC-MS analysis. The concentrations ranged between 56–215 ng/m3 for n-alkanes, 10–52 ng/m3 for PAH, 2–31 ng/m3 for fatty alcohols, 13–279 ng/m3 for fatty acids and 24–220 ng/m3 for fatty acid salts. -Oxocarboxylic acids were also determined as salts, indicating the atmospheric oxidation of unsaturated fatty acids.  相似文献   

7.
From the roots with rhizomes of the plantRhaponticum carthamoides Willd) Iljin Compositae), in addition to integristerone A, ecdysterone, polypodin B, 2-deoxyecdysterone, and 24(28)-dehydromakisterone A, we have isolated the new compounds ecdysteron3–2,3-monoacetonide (I), ecdysterone 20,22-monoacetonide (II)) and rhapisterone (III): I — C30H48O7, mp 232–233° (ethyl acetate-methanol) [] D 20 +56.4±2° (c 0.0; methanol); II — C30H48O7, mp 227–229° (ethyl acetate-methanol), [] D 20 +60.1±2° (c 1.3; methanol); III — C29H48O7, mp, 241–242° (ethyl acetate-methanol), [] D 20 +30±2° (c 0.1; dioxane). The structure of (III) was established on the basis of spectral characteristics as 2, 3, 14, 20R, 22R, 23-5-stigmast-7-en-6-one. Details of the PMR, mass, and IR spectra of all the compounds and of the CD of rhapisterone are given.Institute of the Chemistry of Plant Substances of the Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 681–684, September–October, 1987.  相似文献   

8.
The composition of the fatty mono- and dihydroxy acids of the fruit ofRumex paulsenianus Rech. fil. (familyPolygonaceae) has been determined by a combination of IRS, UVS, GLC, and mass-spectrometric methods. (22) Monohydroxy acids of the C14–C20 series, including isomers and isologues, and four dihydroxy acids from C18 to C20, including a new isomeric 9-OH-10, 12–17:2 acid have been detected.Institute of the Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 762–765, November–December, 1991.  相似文献   

9.
The precision and accuracy of two closely similar radioanalytical methods are compared using the statistical approach (5 parallel experiments for each distribution): sub- and superequivalence isotope dilution analysis and concentration dependent distribution. The solvent extraction system used for both procedures involves the distribution of radiobarium between aqueous phase and nitrobenzene solution of the acid of cobalt dicarbolide H+ {–(3)–1,2–B9C2H11]2 Co and mono-p-nonyl phenyl ether polyethylene glycol HO(CH2 CH3 O)20–(C6H4)C9H13. The influence was tested of the choice of a concrete person to evaluated the results of the analysis by graphic methods upon the precision and accuracy. The advantages and drawbacks of different graphical evaluation procedures are compared.  相似文献   

10.
Zusammenfassung Der Aufbau des Dreistoffes: Hf–Ta–C wird für 1850°C mittels druckgesinterter und vakuum-geglühter Proben bestimmt. Die lückenlose Mischbarkeit der Monocarbide wird erneut bestätigt. Ta2C löst etwas mehr als 10 Mol% Hafniumcarbid. Die -Phase (Ta3C2) wird bereits bei geringen Hf-Konzentrationen unterdrückt. Das Dreiphasenfeld: (Hf, Ta)-Mischkristall+(Hf, Ta)C1-x+(Ta, Hf)2C charakterisiert den Schnitt. Hafnium reichert sich in der Carbidphase an. Die Gleichgewichte werden unter vereinfachenden Annahmen thermodynamisch ausgewertet und folgende Differenzen für freie Bildungsenergien (1850°C) errechnet: G HfCG TaC=–8500 cal/Mol, G(Hf2C)—G Ta 2C=–5000 cal/Mol. Ein zu Ta2C analoges Hafniumcarbid (Hf2C) ist jedoch um 10 000 cal/Mol weniger stabil als ein Gemenge: HfC1–x+Hafnium. Es besteht gute Übereinstimmung zwischen den gerechneten und den experimentell ermittelten Konoden. Aussagen über das verwandte System: Hf–Nb–C werden gemacht.Mit 5 Abbildungen  相似文献   

11.
The geometrical structure and conformation of dimethyloxalate, CH3OC(O)–C(O)OCH3, have been studied by gas electron diffraction (GED) and quantum-chemical calculations (MP2 and B3LYP methods with 6-31G* and cc-pVTZ basis sets). The GED analysis with a dynamic model (T = 323 K) results in a mixture of two planar conformers, anti (C2h symmetry) and syn (C2v symmetry) orientation of the two C=O bonds. The energy difference between these conformers is 0.02(0.18) kcal/mol and barrier to internal rotation around the C–C bond is 0.44(0.41) kcal/mol. The CH3 groups occupy synperiplanar positions with respect to the C=O bonds. The following main geometrical parameters for the anti conformer (Å and degrees) have been derived: rg(C–C) = 1.532(3), rg(C=O) = 1.203(2), rg(Csp3–O) = 1.436(3), rg(Csp2–O) = 1.333(3), (Csp2–Csp2–O) = 111.9(1.9), (Csp2–O–Csp3) = 116.3(1.6), (O–C= O) = 127.0(1.8).This paper is devoted to the 75th anniversary of gas electron diffraction method.  相似文献   

12.
Summary The retention indices (I) and their structural increments (l/°C, H, l) of C6–C14 n-alkenes on polyphenyl ether (PFE) and C12–C14 n-alkenes on polyethylene glycol 4000 (PEG) at 20–160 °C have been determined and correlated with the molecular structure of the isomers. A number of common regularities in gas chromatographic behaviour on these liquid phases and squalane (SQ) [1–3] have been found. On PFE the elution order of isomeric n-alkenes is similar to that on SQ (except C8–C10 1-alkenes and cis-4-tetradecene), for pairs with cis- and trans-configuration it depends on the column temperature, position of double bond and the number of carbon atoms (n) in the molecule. On PEG the cis- are always retained longer than the corresponding trans-alkenes. The linear relationships between 1 and n on PFE and PEG are given in equation form.  相似文献   

13.
A Taylor dispersion tube has been used to measure mutual diffusion in aqueous solutions of glycine hydrochloride at 25°C and concentrations from 0.0005 to 0.5 M. Analysis of the dispersion profiles shows that the diffusion of glycine hydrochloride (GlyHCl) produces a subtantial additional flow of hydrochloric acid that is liberated by the dissociation: GlyH+ + Cl- Gly + H+ + Cl-. Diffusion in this system is, therefore, a ternary process described by the equations J 1(GlyHCl) = – D 11C 1D 12C 2 and J 2(HCl) = –D 21C 1D 22C 2 for the coupled fluxes of total glycine hydrochloride (1) and hydrochloric acid (2) components. The ratio D 21/D 11 of measured diffusion coefficients indicates that up to two moles of HCl are cotransported per mole of GlyHCl. Although protonated glycine diffuses with relatively mobile Cl counterions, the main diffusion coefficient of glycine hydrochloride, D 11, is lower than or nearly identical to the diffusion coefficient of aqueous glycine. A model for the diffusion of protonated solutes is developed to interpret this result and the large coupled flows of HCl. Diffusion coefficients are also reported for the aqueous hydrochlorides of 3- and 4-aminobenzoic acids.  相似文献   

14.
Summary The roots ofAconitum monticola have yielded songorine, songaramine, norsongorine, an amorphous base with the composition C22H35NO6, a base C22H33NO6 with mp 166–167°C, a base C22H33NO5 with mp 161–164°C, and the new alkaloid acomonine. The structure of acomonine has been established on the basis of chemical transformations and spectral properties: It consists of a lycoctonine nucleus with an -hydroxy group at C3, an -methoxy group at C10,-methoxy groups at C6 and C15, an -glycol system at C7 and C8, and a methoxy group at C19.Institute of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 389–395, May–June, 1975.  相似文献   

15.
By column chromatography on polyamide sorbent, the inflorescences of pot marigold calendula have yielded eight substances of flavonoid nature: two aglycons — quercetin (C15H10O7, mp 309–311°C) and isorhamnetin (C16H12O7, mp 314–316°C); six glycosides, of which three have been identified as isoquercetin (C21H20O12, [] D 20 –36° in methanol, mp 218–220°C), isorhamnetin 3-O--D-glucoside (C22H22O12, [] D 20 –59° in dimethylformamide, mp 193–195°C), narcissin (C28H32O16, [] D 21 –28° in dimethylformamide, mp 180–182°C), and three substances that have proved to be new and have been called calendoflaside (C28H32O15, [] D 21 –85° in methanol, mp 192–195°C; calendoflavoside (C28H32O16, [] D 20 –106° in methanol, mp 189–192°C), and calendoflavobioside (c27H30O16, [] D 20 –105° in methanol, mp 194–197°C).All-Union Scientific-Research Institute of Drug Chemistry, Khar'kov. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 795–801, November–December, 1988.  相似文献   

16.
Summary A method for the determination of low relative molecular mass carboxylic acids (C1–C4) in water is reported. The acids are converted to p-bromophenacyl esters prior to a glass-capillary gas chromatographic separation. By utilizing electron-caputre detection the detectability is substantially improved compared to flame-ionization detection. A comparison of three different ways to treat the water samples and to produce the derivatives is made. It is shown that the , p-dibromoacetophenone reagent decomposes to a small extent which limits the utility of the reagent. Nevertheless a detection limit for formic acid of approximately 2.5 mgl–1 is obtained. The method is applied to the determination of formic and acetic acids in a paper kraft water sample.  相似文献   

17.
Various sorbents recommended for solid phase extraction (SPE) in sample preparation procedures were studied for use in combination with capillary isotachophoresis (ITP). They were very efficient in achieving trace concentration levels (low ppb, i.e., low parts per 109) for different types of ITP analytes present in environmental and biological matrices. A macroporous carbon sorbent was convenient for sample preparation in ITP analysis of short chain fatty acids (C4–C9) in drinking water. Chelating sorbents based on hydroxyalkyl methacrylate matrix with salicylate, thioglycolate and 8-hydroxyquinolinate functionalities were found to be very suitable for preconcentration of heavy metals with an inherent sample clean-up. An octadecyl-bonded silica sorbent enabled in ITP a photometric detection of -aminobutyrate (labeled with a 2,4,6-trinitrophenyl group) at concentrations considerably lower than required for the determination of this amino acid in cerebrospinal fluid (5·10–8 mol/l).  相似文献   

18.
The viscoelasticity has been measured for aqueous solutions of tetradecyl-and hexadecyltrimethylammonium salicylates (C14TASal, C16TASal). The aqueous solutions of C14TASal without salt displayed the gel-like behavior at 10.0×10–2 g cm–3, but those more dilute than 3.2×10–2 g cm–3 presented the viscoelasticity similar to that of a Maxwell liquid. The Maxwell-like behavior was converted to the polymer-like one on the addition of (0.1–0.2) M NaBr or (0.02–0.2) M NaSal. The gel-like viscoelasticity can be connected with the spinnability of cohesive fracture failure, and the Maxwell-like and polymer-like viscoelasticities are concerned with the spinnability of ductile failure. The gel-like and Maxwell-like viscoelasticities originate in the pseudo-network formed by the pseudo-linkages between rodlike micelles, while the polymer-like viscoelasticity is caused by the entanglement of long rodlike micelles in semidilute and concentrated solutions. The aqueous solutions of C16TASal behaved very similar to those of C14TASal.  相似文献   

19.
The main class — the free fatty acids — of the lipids of the seeds of the second vegetation phase ofHelleborus abchasicus A. Br. has been studied. The analysis of the composition and structure of the fatty acids in the lipids of the seeds showed the presence of a set of known but rarely encountered acids: 20:0; 11-20:1; 11,14-20:2; and 11,14,17-20:3.I. G. Kutateladze Institute of Pharmacochemistry, Academy of Sciences of the Georgian SSR, Tbilisi. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 565–568, September–October, 1983.  相似文献   

20.
The compositions of the fatty acids and prostaglandins of extracts from thermophilic cyanobacteria of the taxaOscillatoria andMicrocystidaceae have been investigated. The fatty acids include not only saturated but also polyunsaturated species, including 20:3, 20:4, and 22:4 acids with a known pharmaceutical effect. It has been shown for the first time that the lipid fraction of thermophilic cyanobacteria includes a set of prostaglandins of groups A, E, and F, both in the free form and in the form of esters — MeA1, AcA1, AcMeA1, MeA2, AcA2, AcMeA2, MeA3, AcA3, AcMeA3, 6-ketoE1, MeE1, AcE1, AcMeE1, MeE2, AcE2, AcMeE2, MeE3, AcE3, AcMeE3, 6-ketoF1, MeF1, AcF1, AcMeF1, 6-ketoF2, MeF2, AcF2, and AcMeF2, The latter, together with other previously known compounds, undoubtedly make a contribution to the healing properties of thermal springs.Pacific Ocean Institute of Organic Chemistry, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 869–874, November-December, 1996. Original article submitted August 14, 1995; revision submitted August 12, 1996.  相似文献   

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