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1.
The polyfunctional compounds of the oleoresins of three species of larch have been studied. Larixol diacetate, 3-hydroxyepimanool, and 15-oxopimara-4(14)-enoic 13-hydroxy-7-oxoabicta-8(14)-enoic, 3-hydroxysandaracopimaric, and 8,15-dihydroxyabietic acids have been isolated for the first time. The investigation performed has shown that the oleoresins of the larch contain polyfunctional compounds of various structural types. Depending on the species, their composition changes, and this fact can be used in the chemotaxonomy of larches.Novosibirsk Institute of Organic Chemistry of the Siberian Branch of the USSR Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 571–576, September–October, 1986.  相似文献   

2.
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.  相似文献   

3.
    
Conclusions 1. The hydrobromide of N-tosyl-L-lysyl-L-phenylalanyl-L-leucyl-L-glutamyl-L-glutamyl-Nim-benzyl-L-histidyl-L-orolylglycylglycine, corresponding to sequence 26–34 of cytochrome B5, has been synthesized by the solid-phase method.2. The lability of the bond between proline and the amino acids adjacent to it under the conditions of the splitting off of the peptide from the resin has been shown.Lomonosov Moscow Institute of Fine Chemical Technology. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 599–602, September–October, 1970.  相似文献   

4.
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.  相似文献   

5.
Using the method of analytical GLC in a glass capillary column, the compositions have been studied of the volatile fractions of the oleoresins of five species of conifers:Larix decidua,Pinus strobus,Pinus mugo,Picea excelsa, andPinus abies. In the oleoresins 21 monoterpene and 22 sesquiterpene compounds were identified from their relative retention times and with the aid of additives. The main components of the volatile fractions of the oleoresins were - and -pinenes and 3-carene among the monoterpenes, and longifolene caryophyllene, - and -cadinenes and -murolene among the sesquiterpene compounds. The quantitative analysis of the fractions was carried out by the method of internal normalization from averaged correlation coefficients.Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, Novosibirsk. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 629–632, September–October, 1990.  相似文献   

6.
Lowering of the interfacial tension of heptane–water, benzene–water, and nitrobenzene–water interfaces due to addition of 20 different amino acids to the aqueous phase has been measured. From the plot of surface pressure against molar concentration of amino acids, the initial slope and the surface excess 2 1 for different amino acids have been calculated using the Gibbs adsorption equation. 2 1 for most amino acids at benzene–water and heptane–water interfaces was found to be positive, with only a few being negative. At the nitrobenzene–water interface, both positive and negative 2 1 values were observed. The area per adsorbed molecule at surface saturation A m was found to vary widely, indicating different orientations of amino acid molecules at the interfaces. Using the integrated form of the Gibbs adsorption equation, the standard Gibbs energy change G o in kJ-m2 of the adsorbed surface have been calculated for various interfaces. G o was found to vary linearly with the 2 1 of different amino acids and the slope of the line, designated as –G B 0 was found to be 22 kJ-mol–1 for heptane–water, 23.2 kJ-mol–1 for benzene–water, and 19.3 kJ-mol–1 for nitrobenzene–water interfaces, irrespective of the nature of the amino acid. The origin of the linear scale of the Gibbs energy for heptane–water, benzene–water and nitrobenzene–water interfaces has been discussed in terms of hydrophobic and other interactions.  相似文献   

7.
The formation of nucleic acids/8-hydroxyquinoline/yttrium(III) ternary complexes and their fluorescent properties have been studied. The nucleic acids studied include native and thermally denatured calf thymus DNA, fish sperm DNA and yeast RNA. In the range of pH 7.6–8.5, controlled by NH3-NH4C1 buffer, ternary complexes are formed that fluoresce at different wavelengths with different nucleic acids. Based on the fluorescence reactions, sensitive spectrofluorimetric methods for nucleic acids are proposed. In optimal conditions, the calibration curves were linear in the range 0.5–4.0 gml–1 for calf thymus DNA, 0.5–2.5 g ml–1 for fish sperm DNA and 0.5–4.0 g ml–1 for yeast RNA. The limits of determination (3 ) were 0.030 g ml–1 for calf thymus DNA, 0.020 g ml–1 for fish sperm DNA and 0.090 g ml–1 for yeast RNA. Corresponding to the interferences of coexisting substances, six synthetic samples were constructed and the results of determination were satisfactory.  相似文献   

8.
Chelex-100, in the anionic form has been studied for its ability to perform selective separation and concentration of some metal ions of nuclear importance from mineral acid solutions. The sorption behavior of Zr(IV)–Nb(V), Mo(VI), Tc(VII), Te(IV) and U(VI) from solutions of hydrochloric and sulphuric acids on Chelex-100 has been studied under static and dynamic conditions. Mo(VI) and Tc(VII) have been concentrated on the resin from hydrochloric or sulphuric acid solutions at low acidities probably, as the anions MoO 4 2– and TcO 4 , respectively. Te(IV) has been isolated from hydrochloric acid solutions of normalities 6 in the form of the anionic chloro complex TeCl 6 2– . Optimum conditions for elution and separation of Mo(VI), Tc(VII), Te(IV) and U(VI) were recommended.  相似文献   

9.
On-line ion-exchange preconcentration of iron(III) on a conventional cation exchange resin with spectrophotometric detection based on thiocyanate complexation is described. The calibration graph is linear over the range 0.01–0.2 g ml–1 and the detection limit (3 ) is 6 ng ml–1 for a 6-ml sample. No interference effects were detected. The recovery of iron from the resin is 95%. 12 samples h–1 can be analysed.  相似文献   

10.
Ion-exchanger phase Spectrophotometry withp-nitrochlorophosphonazo (CPApN) has been developed for the determination of scandium. The linear range is 1–8 g of scandium in 50 ml of solution, using 0.8 g of resin, with an apparent molar absorptivity of 2.76 × 105 1 mol–1 cm–1. Aluminum and rare earth elements in reasonable amounts do not interfere. The method has been applied successfully to the determination of scandium in alloys, with relative standard deviations of 2–4%.  相似文献   

11.
The apparent molar volumes, V,2, of glycine, L-alanine, DL--amino-n-butyric acid, L-valine, and L-leucine have been determined in aqueous 0.25, 0.75, 1.0, and 1.5 mol-dm–3 tetraethylammonium bromide (TEAB) solutions by density measurements at 298.15 K. These data have been used to calculate the infinite dilution apparent molar volumes, V2,m, for the amino acids in aqueous tetraethylammonium bromide and the standard partial molar volumes of transfer (tr V2,m) of the amino acids from water to the aqueous salt solutions. The linear correlation of V2,m for a homologous series of amino acids has been utilized to calculate the contribution of the charged end groups (NH3+, COO), CH2 group, and other alkyl chains of the amino acids to V2,m. The results of the standard partial molar volumes of transfer from water to aqueous tetraethylammonium bromide have been interpreted in terms of ion–ion, ion–polar, and hydrophobic–hydrophobic group interactions. The volume of transfer data suggest that ion–ion or ion–hydrophilic interactions are predominant in the case of glycine and alanine, and hydrophobic–hydrophobic group interactions are predominant in the case of DL--amino butyric acid, L-valine, and L-leucine.  相似文献   

12.
The apparent molar volumes, V,2, of glycine, alanine, -amino-n-butyric acid, valine, leucine, and lysine monohydrochloride have been determined in aqueous solutions of 0.05, 0.1, and 0.4 mol-kg–1 Triton X-100 (TX-100), and the partial specific volume, v0, of hen-egg-white lysozyme in 0.4 mol-kg–1 TX-100 by density measurements at 298.15 K. These data have been used to calculate the infinite dilution apparent molar volumes, V2,m0, for the amino acids in aqueous TX-100 solutions and the standard partial molar volumes of transfer, tr V2,m0, of the amino acids from water to the aqueous surfactant solutions. The linear correlation of V2,m0 for a homologous series of amino acids has been utilized to calculate the contribution of the charged end groups (NH3+, COO), CH2 group and other alkyl chains of the amino acids to V2,m0. The results on tr V2,m0, of amino acids from water to aqueous TX-100 solutions have been interpreted in terms of ion–ion, ion–polar, hydrophilic–hydrophilic and hydrophobic–hydrophobic group interactions. For all the six amino acids studied, the values of tr V2,m0 from water to all the studied concentrations of aqueous TX-100 are small in spite of their different hydrophobic content, indicating an overall balance in interactions of zwitterionic/hydrophilic groups of amino acids with the hydrophilic groups of TX-100, and of hydrophobic and ionic/hydrophilic groups of the amino acids with hydrophobic groups of TX-100. Comparison of the interactions of the amino acids with nonionic, anionic and cationic surfactants has also been made and discussed. The partial specific volume of transfer of lysozyme from water to aqueous TX-100 solutions also indicates a balance of the hydrophobic and hydrophilic interactions in the protein–nonionic surfactant system.  相似文献   

13.
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   

14.
A possibility of photochemical reduction of Re(VII) to Re(VI) in mixture of concentrated sulfuric and hydrochloric acids has been demonstrated. The reaction mechanisms of Re(VII) photoreduction and ReVIOCl5 complex decay have been considered from view point of acids and water content. The optimal conditions of ReVIOCl5 stability have been found.Spectrophotometric and ESR methods of rhenium determination based on photochemical production of ReVIOCl5 complex with the detection limit of 1g/ml have been proposed. Rhenium concentration in industrial sulfuric acid has been determined.  相似文献   

15.
Nalwaya  N.  Jain  A.  Hiran  B. L. 《Kinetics and Catalysis》2004,45(3):345-350
Oxidation of -amino acids by pyridinium bromochromate (PBC) was studied in acetic acid–water mixture containing perchloric acid. The reaction rate is first order in [PBC] and inverse first order in [H+] and has aldehyde as a product. The results are contrary to that of Karim and Mahanti, who observed first order with [H+] and cyanide as the product in the oxidation of amino acids by quinolinium dichromate. Michaelis–Menten type kinetics has been observed with respect to -amino acids. The rate of reaction increases with a decrease in the polarity of solvent indicating an ion–dipole interaction in the slow step. The reactions exhibit no primary kinetic isotope effect. The activation parameters have been evaluated. The reaction mechanism involving the formation of chromate-ester between unprotonated PBC and unprotonated amino acid followed by C–C bond fission in the slow step has been suggested. The value of the Michaelis constant (substrate–oxidant complex formation constant) increases as the number of carbon atoms increases in the amino acid.  相似文献   

16.
Novel fluorescent colloids as a DNA fluorescence probe   总被引:1,自引:0,他引:1  
Fluorescent perylene colloids in the 80–90 nm size range have been prepared by the reprecipitation method. These nanoparticles were modified by cetyltrimethylammonium bromide (CTAB) which inhibited their growth. The nanoparticles also readily interacted with DNA. The fluorescence emission was measured at ex/em=400/565 nm. The fluorescence decrease of colloid–CTAB in aqueous solution was measured in the presence of nucleic acids. Under the optimum conditions, the ratio of fluorescence intensity in the absence and presence of nucleic acids was proportional to the concentration of nucleic acids over the range 0.02–5.1 µg mL–1 for FS (fish sperm) DNA or CT (calf thymus) DNA. The detection limits were 0.01 µg mL–1 for FS DNA and 0.012 µg mL–1 for CT DNA, respectively. Based on this approach, a new quantitative method for DNA assay is presented in this paper.  相似文献   

17.
The interactions of the alumina-electrolyte in the presence of inorganic ions (copper, selenium) and/or organic acids (benzoic acid, glutamic acid, phenol) have been studied. The acid-based properties of-alumina have been determined in NaCl media (pzc=8.5±0.3). Three types of hydroxy groups with different acidity constants have been found. The adsorption of copper and selenium have been described by the formation of the surface complexes: (=Al1–OH, CuCl) and (=Al1, SeO3). The interaction of copper with the surface oxygen atoms is strong and so is the interaction of selenium with the surface aluminium atoms, which involves a shift of the iep of alumina. For the three organic acids studied (HX), the adsorption equilibrium is:=Ali–OH+HX(=Ali, X)+H2O. The interaction of the X group and the aluminium atoms is strong following the order: glutamic acid > benzoic acid > phenol. The uptake of selenium is uninfluenced by the presence of organic acids with carboxylic, amino-acidic and phenolic groups. The uptake of copper is highly increased by the presence of organic acids but it is not influenced by the presence of the phenolic groups. Both of these behaviours can be extrapolated to inorganic ions of the same chemical structure.  相似文献   

18.
On the basis of tracer experiments, a simple and rapid radiochemical separation method for simultaneous determination of I, Br and Cl in one aliquot of a water sample (only 2–4 ml) has been developed. The method is based on short irradiation of the water sample and separation of the halogens using sequential ion exchange columns filled with Dowex 1×8, 100–200 mesh anionic resin prepared in I/I2, Br/Br2 and Cl form. After washing the columns with an appropriate volume of 2% NaCl solution, the resins were transferred to vials and activities of the isolated radionuclides128I,82Br and38Cl measured together with standards in a well type or on a coaxial Ge detector connected to a Canberra 90 multichannel analyzer. Besides high chemical yields, from the -spectra of the isolated radionuclides, it is evident that high decontamination fac-The paper was presented at the MTAA-8, Vienna, September 1991.  相似文献   

19.
Summary The mass-spectrometric method for the analysis of inorganic solutions is not only a very sensitive technique but also one of broad applicability. The study of the behaviour of solutions of mineral acids chilled to –70°C under a r.f. voltage from 7 to 15 kV indicated that solutions of hydrochloric acids containing 20–32% of hydrogen chloride allow to obtain stable ion currents. The equipment for the analysis of solutions on the spark source mass-spectrometer is designed and the procedure of analysis is described. The detection limits of 47 elements are in the range from 10–7 to 10–11 g. The accuracy of the determinations was established by the added-found method. The reproducibility is 0.1–0.34 for content levels of 10–7–10–9 g. The analytical possibilities of different spark source mass-spectroscopic methods for the analysis of solutions are compared.  相似文献   

20.
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   

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