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1.
We have studied the uptake of237Np in marine plants and animals belonging to several phyla, and collected samples from the end of January 1986 to March 1986, in a sampling station situated near the outlet of the irradiated fuel reprocessing plant at La Hague.We determined the237Np by neutron activation analysis. This method is very sensitive, with a limit of detection of 5×10–10 mg, 1.3×10–2 mBq. The method consists of the following steps:Reduction of the neptunium to the tetravalent state by treatment with a mixture of hydrazine sulfate and ferrous iron-chromatographic separations on Dowex 1×10 resin in a nitric medium, then in a hydrochloric medium-neutron irradiation in a nuclear reactor-purification of the neptunium by chromatography on Dowex 1×10 resin in a nitric then hydrochloric medium-measurement of the isotope238Np by gamma ray spectrometry using a Ge(Li) detector. The species were collected at Goury, at the northwest extremity of the Cotentin Peninsula, 5 km from the outlet of the reprocessing plant at La Hague. The levels of237Np were as follows: red algaeCorallina officinalis 64 mBq kg–1 wet weight; andChondrus crispus 18 mBq kg–1 wet weight; the spongeHalichondria panicea 14 mBq kg–1 wet weight; the ascidianDendrodoa grossularia 12 mBq kg–1 wet weight. The bivaive molluscsPatella vulgata andGibbula umbilicalis (the flesh ofP. vulgata andG. umbilicalis: 4 and 7 mBq kg–1 wet weight respectively) also prove to be interesting biological indicatorsThe transfer modes of237Np to the various species as a function of their trophic levels are discussed as well as the distribution among the organs in the species consumed and the radiological impact of human consumption.  相似文献   

2.
The uptake and release kinetics of137Cs from water by the tropical fishBrachydanio rerio has been studied under controlled laboratory condition. The accumulation of this radionuclide from food was avoided by feeding the fishes separately in an inactive environment. A steep inverse dependence of bioconcentration factor (BCF) with potassium concentration has been observed. This can formally be described by the equation BCF=5.2 · [K+]–0.44. The elimination rate constant K in fresh water conditions has been found to have a magnitude of 0.014±0.03 d–1 which corresponds to a biological half-life of 51±10 days. The uptake and release kinetics ofBrachydanio rerio has been compared with earlier studies of fresh water fishes.  相似文献   

3.
Summary The question of the hybridization of the atomic orbitals of Mo in the Mo(CN)8 4– ion is examined, and it is shown that the dodecahedral structure can exist without the participation off electrons.  相似文献   

4.
Summary 1. The polarographic behavior of haploperine, haplopine, haplophyllidine, and perforine in Britton-Robinson buffer solutions and in (C2H5)4NOH solutions has been studied. Optimum conditions for their quantitative determination in solutions within the range of concentrations from 5×10–4 to 1×10–2 M have been found.2. A method for the separate quantitative determination of the alkaloids in the seeds ofH. perforatum has been developed.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 5, pp. 333–337, 1966  相似文献   

5.
The influence of a number of bivalent metals on the activity ofStreptomyces atratus glucose isomerase has been studied. Mg2+ ions are activators and Co2+ ions are stabilizers of the glucose isomerase activity. The effective kinetic parameters for the action of the enzyme have been determined.Institute of Microbiology, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 838–842, November–December, 1991.  相似文献   

6.
Three new diterpene lactones have been isolated from a chloroform extract of the roots ofEuphorbia pallasii: pseudojolkinolide A psuedojolkinolide B, and 16-hydroxypseudojolkinolide B. Structures have been proposed for them on the basis of chemical transformations and IR, UV,13C and1H NMR, and mass spectra.Irkutsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 337–345, May–June, 1985.  相似文献   

7.
Summary The leaves ofFraxinus mandschurica Rupr. and the bark ofF. potamophila Herd. have yielded esculetin, fraxinol, and a new coumarin C10H8O5, mp 228–230°C which we have called isofraxetin. On the basis of NMR and UV spectroscopy it has been established that isofraxetin is 5,7-dihydroxy-7-methoxycoumarin.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Institute of Chemistry, Academy of Sciences of the Turkmen SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 493–497, July–August, 1973.  相似文献   

8.
The new phytoecdysteroid ecdysterone 22,25-di-O-benzoate (IV) has been isolated from the epigeal organs ofSilene scabrifolia Kom. The alkaline hydrolysis of (IV) gave ecdysterone 25-O-benzoate and ecdysterone (I). Details of the IR, UV, mass, PMR, and13C NMR spectra of compound (IV) are given.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 363–366, May–June, 1990.  相似文献   

9.
    
Summary From the epigeal part ofInula britannica L. a new sesquiterpene lactone has been obtained — britannin, with the composition C19H26O7, mp 192–194°C (from ethanol). [] D 20 –26° (c 5.0; chloroform). Structure (I) has been proposed for it.All-Union Scientific-Research Institute for Medicinal Plants. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 276–280, May–June, 1971.  相似文献   

10.
Summary 1. The content of total alkaloids in the hypogeal parts ofAndrachne rotundifolia C. A. Mey. (family Euphorbicease) is 0.2–0.3% and in the epigeal parts 0.06–0.08%.The total alkaloids in both the hypogeal and the epigeal parts ofAndrachne rotundifolia consist of five or six non-phenolic bases.2. Three individual substances have been isolated: andrachnine C11H17NO2, which is a new alkaloid; base (II), giving a perchlorate with mp 139°–140° C; and base (III) with mp 135°–136° C.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 4, pp. 257–260, 1966  相似文献   

11.
Conclusions The cardenolide and coumarin composition ofC. varia L. and the closely related speciesC. hyrcana Pril.,C. cretica L., andC. orientalis Müll have been investigated. It has been shown that they all contain the cardiac glycoside hyrcanoside, with the exception ofC. orientalis, in which another, unidentified, glycoside, has also been found.A comparative study of some properties of hyrcanogenin (4-strophanthidin) and pachygenin (5-strophanthidin) connected with conformational features has been carried out.In the species studied, no less than five coumarins have been found of which umbelliferone, scopoletin, and daphnoretin have been isolated.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 3, pp. 141–144, 1969  相似文献   

12.
Reserpine, ajmaline, serpentine, ajmalicine, isoreserpiline, and other alkaloids have been isolated from the roots ofRauwolfia cambodiana Pierre ex Pitard,R. verticillata Baill. andR. serpentina Benth.R. vomitoria Afz. was the richest in alkaloids.Leningrad Institute of Pharmaceutical Chemistry. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 813–816, November–December, 1991.  相似文献   

13.
    
Berberine, palmatine, jatrorrhizine, oxyacanthine, berbamine, reticuline, obaberine, isocorydine, thalicmidine, and the new base berberal (I) have been isolated from leaves and young shoots ofBerberis heterobotrys Wolf. The structure of berberal has been established by a study of its1H and13C NMR spectra and measurement of intramolecular NOEs, and also by mass-spectrometric analysis.Institute of the Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Andizhan State Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 869–873, November–December, 1993.  相似文献   

14.
Summary The oil of the seeds ofRindera oblongifolia, family Boraginaceae, growing in Central Asia, has been studied for the first time. Among the acids of the triglycerides of the oil five types of monoenoic acid differing by the length of the carbon chain but having the same length of the terminal carbon chain — 18:19, 20:111, 22:113, 24:115, and 26:117 — have been detected for the first time. This is the first time that the last of these acids has been found in a seed oil of this family.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 26–29, January–February, 1976.  相似文献   

15.
    
The isomerization of 5-vinyl-2-norbornene (1) has been studied in the presence of Co (R1-COCHCOR2)x–Et6–yAl2Cly (x=2, 3; y=2–4) catalytic systems. Co(acac)2–AlEt3 and Co(acac)3–AlEt3 systems isomerize1 to 5-ethylidene-2-norbornene (2), whereas the Co(PhCOCHCOPh)2–AlEt3 system selectively forms 3-vinylnortricyclene (3).2 is always accompanied by formation of ethylidene norbornane (4). A possible mechanism for formation of products is proposed.  相似文献   

16.
Coumaris ofHaplophyllum obtusifolium Ledeb. — obtusinin, capensin, and fraxetin 7-O--D-glucopyranoside — have been investigated by13C NMR spectroscopy. Several distinctive features of their NMR spectra have been observed. A complete assignment of the13C NMR spectra of these coumarins has been made and their structures have been confirmed.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 796–799, November–December, 1987.  相似文献   

17.
    
Summary The roots ofPrangos ferulaceae (L.) Lindl. have yielded (–)-7-methoxy-8-(, -dihydroxyisopentyl)-coumarin, composition C15H18O5, with mp 128°. [] D 20 -53.03°, identical with a synthetic hydrate of meransin and found by us in nature for the first time. Various coumarin derivatives are present in the roots ofPrangos ferulaceae (L.): osthole, oxypeucedanin, oxypeucedanin hydrate, and isoimperatorin.Khimiya Prirodnykh Soedinenii, Vol. 1, No. 4, pp. 283–288, 1965  相似文献   

18.
Summary The biosynthesis of the alkaloids ofAmmodendron karelinii Fisch. et Mey has been studied by feeding the plant with labelled [1,5-14C]cadaverine. It has been shown that cadaverine is a precursor of anagyrine, pachycarpine, ammodendrine, N-methylcytisine, and cytisine. Possible routes of interconversions have been considered by feeding the plant with the tritium-labelled [3H]pachycarpine, [3H]lupanine, [3H]anagyrine, and [3H]ammodendrine.V. I. Lenin Tashkent State University. Institute of Plant Biochemistry, Academy of Sciences of the GDR, Halle. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 247–250, March–April, 1977.  相似文献   

19.
The roots ofFerula pallida Korov. have yielded pallinin, C25H38O5, mp 79–80°C, []D20 –148.5° (c 0.1; CHCl3) — an ester of the new carotane alcohol pallinol and angelic acid. A structure and absolute configuration have been proposed for it on the basis of chemical transformations and spectral characteristics.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 53–56, January–February, 1986.  相似文献   

20.
    
Summary From the roots ofFerula korshinskyi Eug. Kor. we have isolated a new ester with the composition C22H34O5, [] D 23 –29° (c 0.94; chloroform) n D 24 1.491, bp 42°C/8 mm Hg, which we have called fekorin. On the basis of a study of the products of hydrolysis and also spectral characteristics, it has been established that fekorin is 8-acetoxy-6-angeloyloxy-9,10-epoxygermacr-3-ene.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 152–155, March–April, 1975.  相似文献   

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