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1.
Summary The dependence of specific refractive index increments (dñ/dc) of aromatic-aliphatic copolyamides on weight-average molecular weight, temperature and refractive indices of the solvents has been investigated at a wavelength of 546 run. Values of (dñ/dc) increase with increasing molecular weight and temperature. The temperature coefficient of (dñ/dc) in N,N-dimethylacetamide, dichloroacetic acid, trifluoroacetic acid and H2SO4 was found to be 7.85 · 10–4, 5.42 · 10–4, 6.00 · 10–4 and 6.83 · 10–4 cc · g–1 °C respectively which agrees closely with the values calculated on the basis ofGladstone andDale equation. (dñ/dc) was found to be a linear function of the refractive indices of the solvents.With 3 figures  相似文献   

2.
The lipids of the leaves, stems, and roots ofHibiscus sp. have been studied. Their fatty acid compositions have been determined. The greatest amount of unsaturated fatty acids was present in the glycolipids of the leaves and the stems. More than 25% of low-molecular-mass C10-C12 fatty acids have been found in the neutral lipids of the roots.Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 705–708, September–October, 1996. Original article submitted March 11, 1996.  相似文献   

3.
Two monosaccharides have been found by paper chromatography in an aqueous extract of the herbage of red clover (Trifolium pratense). One of them has been identified as glucose. After hydrolysis of a dry water-soluble extract by paper chromatography in the presence of markers, galactose, arabinose, xylose, and mannose were detected. By paper chromatography in the presence of markers the amino acids phenylalanine, leucine (isoleucine), methionine, aspartic acid, proline, alanine, and histidine have been identified. Phytin with decomp. p 276°C has been isolated and identified, giving, after hydrolysis, inositol with mp 225–226°C, and Ca2+, Mg2+, and PO 4 3– have been detected. The amount of ash in the herbage of clover is 8.4% and the amount insoluble in HC1 1.5%. The amounts of macroelements were determined by the flame photometry of a solution of the ash (mg–%): K+ 1620; Na+ 310; Ca2+ 1240; Mg2+ 1090.Pyatigorsk Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 483–485, July–August, 1980.  相似文献   

4.
Water-soluble polysaccharides have been isolated from two species ofEremurus — E. lactiflorus andE. luteus — with yields of 13.5% and 20.5%, respectively. They contained mainly glucose and mannose in ratios of 1:5 and 1:3.1. The polysaccharides ofE. lactiflorus were separated from a column of DEAE-cellulose. The yield of neutral fraction was 10.3%. Gel filtration of the polysaccharides on Sephadex G-200 showed their polydispersity. Homogeneous fractions were obtained by fractional precipitation with ethanol. They have been characterized with respect to monosaccharide composition, molecular weight, and IR spectra.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 604–608, September–October, 1979.  相似文献   

5.
The potential energy profile of an isolated CF2ClCOOH molecule with a CF2Cl group rotating around the C–C bond was determined by the Hartree–Fock method using the 6-31G(d) basis set. Barriers to internal rotation were estimated for this molecule; its geometrical parameters were found for the equilibrium and transition states that are due to the torsion potential with unequal wells. Crystal effect on CF2Cl reorientations in solid chlorodifluoroacetic acid has been evaluated.  相似文献   

6.
A study of the dioxane lignins of Althaea nudiflora and A. rosea   总被引:1,自引:0,他引:1  
Summary 1. The lignin has been isolated from the stems of the cotton plant of a late period of vegetation by the hydrochloric acid method. The elementary composition and functional groups have been determined. The mean composition for a C6-C3 structural unit has been determined.2. By the oxidation of a powder of the stems of the cotton plant with nitrobenzene in the presence of alkali it has been established that the hydrochloric acid lignin is more condensed than the DLA.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 648–650, September–October, 1975.  相似文献   

7.
An acid form of ricin — ricin T — with a molecular weight of 58 kDa, an isoelectric point, pI, of 7.0–7.1, and a sedimentation coefficient of 4.60 S has been isolated from the seeds of the Central Asian castor-oil plantRicinus communis by gel filtration on Sephadex G-75 followed by ion exchange chromatography on DEAE- and CM-celluloses. The amino acid composition and the N-terminal amino acid residues of ricin T have been determined.Institute of the Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 883–887, November–December, 1987.  相似文献   

8.
Summary 1. Lignin has been isolated from the stems ofPhragmites communus Trin. by the hydrochloric acid and the copperammonia methods. Its elementary composition and functional groups have been determined. The mean composition of the C6-C3 structural unit has been determined.2. The oxidation of comminuted reed stems with nitrobenzene in the presence of alkali has given a mixture of aldehydes: syringaldehyde, vanillin, and p-hydroxybenzaldehyde. Their yield was 3–4 times less than from wood.Khimiya Prirodnykh Soedinenii, Vol. 1, No. 6, pp. 424–427, 1965  相似文献   

9.
The N-terminal amino acids and the amino acid compositions of four species-specific proteins of two species of the cotton plant —Gossypium hirsutum andG. barbadense — have been determined. Peptide maps of tryptic hydrolysates of these proteins have been obtained and compared. Individual tryptic peptides have been isolated and purified. The N-ends, amino acid compositions, and amino acid sequences of individual peptides have been determined. The N-terminal sections of the proteins ofG. hirsutum andG. barbadense as far as the 16th amino acid residue have been sequenced. A comparative analysis has been made of the peptides and proteins of these cottonplant species.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 858–864, November–December, 1997.  相似文献   

10.
Summary 1. The new sesquiterpene lactone tanachin (I) has been isolated from a chloroform extract ofTanacetum pseudoachillea C. Winkl.2. With the aid of double and triple resonances, the chemical shifts and coupling constants of the protons of (I) have been determined. On the basis of these results and by the application of a paramagnetic shift reagent —Eu (FOD)3 — the structure of 1,6-dihydroxygermacr-4,10(14),11(13)-trien-8,12-olide has been established for tanachin. The orientations of the hydroxy groups have been determined.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 462–467, July–August, 1976.  相似文献   

11.
A protein nerve growth factor has been isolated in the pure form from the muscles of the lake frogRana ridibunda. The individuality of the substance obtained has been shown, its molecular mass (106.0–110.0 kDa) and pI value (9.2–9.4) have been determined, and lysine and valine have been found as the N- and C-terminal amino acid residues of its polypeptide chain. In view of the detection of the presence of sugars (about 1%), the substance has been identified as a glycoprotein. Its absorption spectra in the UV region has been obtained and the amino acid composition of the isolated protein has been determined. Information on the amino acid composition of various proteins with nerve growth activity has been subjected to comparative analysis with the aid of computer programs, and on this base their phylogenetic tree has been constructed.Institute of Biochemistry, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 251–257, March–April, 1992.  相似文献   

12.
A new diterpenoid acid of the clerodane series, C20H32O4, [] D 20 –75.4° (c 0.26; methanol), which has been called salvicin, and the known flavonoid rutin have been isolated from a chloroform extract of the epigeal part ofPulicaria salviifolia. The structure of salvicin has been established on the basis of spectral characteristics and chemical transformations.Deceased.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 299–301, May–June, 1986.  相似文献   

13.
Ten oligosaccharides have been isolated from the products of the partial hydrolysis of a native acetylated glucomannan obtained fromEremurus lactiflorus O. Fedtsch. Their structures have been studied with the aid of acid hydrolysis before and after reduction with NaBH4, by the GLC method, and also by chromatography with markers. The compositions and sequence of the monomers in tetra- and heptaoligo-saccharides have been determined by the13C NMR method. The glucommannan ofE. lactiflorus differs from theEremurus glucomannans studied previously by the ratio of monosaccharides, the presence of 0-Ac groups, the degree of polymerization, and the presence of a cellobiose unit (Glcp-Glcp) in the polymer chain. The repeating unit consists of 14 hexose residues.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 680–684, November–December, 1982.  相似文献   

14.
Complexes of deoxycholic acid with polyethers, [–(CH2) m–1CHR–O–] n (R=H,m=2–4, 6 andR=CH3,m=2), were prepared. The crystals are orthorhombic and similar to those most commonly observed for complexes with low molecular weight molecules. Dimensiona in the poly(propylene oxide) complex is about 1 Å longer than those in other polyether complexes, whileb andc do not differ much in these DCA-polyether complexes.  相似文献   

15.
The diaphorase activities of the proteins of different varieties of two species of cotton plant —Gossypium hirsutum L. andG. barbadense L. — have been studied. It has been shown that the proteins of the seeds of the cotton plantG. barbadense possess a low diaphorase activity in comparison with the proteins of the seeds of aG. hirsutum plant. On an electrophoretogram of the proteins, diaphorase activity was localized in two zones, with Rf 0.45 and 0.70. The diaphorase with Rf 0.45 has been isolated by electrophoresis in polyacrylamide gel (PAAG) and some of its properties have been studied. The diaphorase isolated oxidizes NADH and NADPH in the presence of various artificial electron Acceptors, and has two pH optima (at 7.20 and 8.70) and is characterized by relative thermal stability (at 80°C). In the case of the total extract, brief boiling does not lead to inactivation of the enzyme, which shows the presence in cotton seeds of a factor stabilizing this diaphorase. The molecular weight of the proteins isolated, according to gel filtration on Sephadex G-150, is 59,000, and from the results of SDS-PAAG electrophoresis it is 13,600, which shows a tetrameric structure of the enzyme.Institute of Experimental Plant Biology, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 416–421, May–June, 1987.  相似文献   

16.
The13C kinetic isotope effect (K.I.E.) in the decarbonylation of formic acid of natural isotopic composition in 85% orthophosphoric acid, in 100% H3PO4, and in pyrophosphoric acid has been measured in different temperature intervals ranging from 19 to 133 °C. In 85% H3PO4 the carbon-13 K.I.E. is determined by the fractionation of carbon isotopes expected for C–O bond rupture (k 12/k 13=1.0531 at 70°C). In 100% H3PO4 the13C K.I.E. indicates that C–H bond rupture is the major component of the reaction coordinate motion (thek 12/k 13 lay in the range of 1.026–1.017 over the range 30–70 °C). In pyrophosphoric acid the fractionation factor for13C equals 1.010 at 19 °C. Activation parameters for the decarbonylation of H12COOH in phosphoric acid media have been determined also and suggestions concerning the intimate mechanisms of decarbonylation of formic acid in dilute and concentrated phosphoric acids are made.  相似文献   

17.
The class composition and the total fatty acid composition of the readily- and difficulty-extractable lipids and the amino acid composition of a protein hydrolysate of the dry biomass from the golden-yellow microalgaMonochrysis lutheri have been determined for the first time. It has been established that the difficulty-extractable lipids differ sharply from the readily extractable lipids in the composition of the neutral and glycolipid components and also in that of the fatty acids; 27% of the weight of the fatty acids of the latter is composed of the 20:4 and 20:5 species. The protein hydrolysate ofM. lutheri contains almost the whole set of essential fatty acids.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbekistan Republic, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 507–511, July–August, 1993.  相似文献   

18.
The nuclear properties of99mTc radionuclide are ideal for organ imaging. Study of the technetium transport across supported liquid membranes has been performed to get data for its separation from other elements. Tri-n-octylamine diluted in xylene was used to constitute the liquid membranes, supported in polypropylene microporous films. Stripping on the product solution side was performed with dilute NaOH solutions. The effect of sulphuric acid, nitric acid and hydrochloric acid in the feed on transport of99mTc as TcO 4 ions has been studied. The permeability of the given ions determined from kinetic activity data has been found to be in the order of PH2SO4>PHCl>PHNO3. The flux values have been calculated based on this permeability data. The increase in carrier concentration has shown an increase in flux and permeability values to a given optimum concentration. The increase in temperature has been found to reduce the transport of Tc ions. The optimum conditions for transport of99mTc for the given acid concentration have been determined. Mechanism of Tc ion transport has also been provided based on chemical reactions involved at the membrane interfaces and uptake of Tc ions by the membrane. MoO 4 2– ions do not permeate through membrane under optimum conditions of transport for TcO 4 2– ions from H2SO4 solution.  相似文献   

19.
The molecular structure of 2-methyl-4,4-diphenyl-5-phenylazo-2-thia-3-aza-4-phosphahepta-2,4-diene-6-one-2-oxide has been determined by x-ray crystallography. The sulfur and phosphorus atoms exhibited distorted tetrahedral coordination. The P-N and P=C bond lengths are intnermediate between single and double bond lengths. Delocalization of -electron density was observed in the flattened molecular fragment Ph–N=N–C(=P)–C(=O)–CH3.Institute of Physiologically Active Substances, Russian Academy of Sciences, 142432 Chernogolovka. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 12, pp. 2737–2741, December, 1992.  相似文献   

20.
Summary A triacetinase has been isolated from cotton seeds by the methods of gel filtration and ion-exchange chromatography. The homogeneity of the enzyme was shown by rechromatography, electrophoresis, ultracentrifugation, and a determination of the terminal amino acid. The molecular weight of the triacetinase obtained by four different methods (column gel filtration, thin-layer chromatography, ultracentrifugation, and amino-acid composition) is 18,000±1200. The amino-acid composition and the N-terminal amino-acid residue — methionine — have determined.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 767–770, November–December, 1974.  相似文献   

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