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21.
Ya. Popova Ch. Popov M. Ilieva 《Plant foods for human nutrition (Dordrecht, Netherlands)》1968,16(1-4):237-243
Summary The separation of vitamin B12 from its analogues is difficult because they are chemically closely related to cyanocobalamin.On the grounds of our experiments we suggested a new method for the separation of corphyrins on dry alumina (basic, second degree of activity according toBrockmann). As solvent system the mixture of isobutanol, isopropanol and water (1 : 1 : 1) was used. The separation with good compact spots was obtained of the following corphyrins: cyanocobalamin (vitamin B12), factor B12 III, pseudovitamin B12, factor A, factor B and factor V (nB).A new simple and rapid method for separation of hydroxocobalamin and cyanocobalamin on thin layer of dry alumina (neutral, second degree of activity according toBrockmann) was reported by us. Advantage was taken of the property of hydroxocobalamin to form with NH4 OH a compound of the cobalichrome type. Under these conditions cyanocobalamin does not change so that both compounds can be easily separated.The best separation was obtained by mixture of isobutanol, isopropanol and water (1.5 : 1 : 1.25) as solvent system (with addition of NH4 OH until the ph was 8.5).On the grounds of the results from attempts on the separation of cyanocobalamin from its analogues we reported a method for quantitative determination of vitamin B12 in microbial fermentations, commercial preparations, and concentrates. The method involved the precipitation of vitamin B12 and other analogues (accompanying it) as coper-cyanide complexes, the decomposition of complexes with addition of NaCN-solution to obtain the dicyanocomplexes, the separation of cyanocobalamin on thin layer of dry alumina and its colorimetric determination to 361 nm.
Zusammenfassung Die Trennung des Vitamin B12 und seiner Abkömmlinge ist wegen der großen Ähnlichkeit mit dem Cyanocobalamin schwierig. Basierend auf unsere Experimente schlagen wir eine neue Methode zur Trennung der Corphyrine auf Tonerde (basisches Aluminiumoxid, 2. Aktivitätsgrad nachBrockmann) vor. Als Lösungsmittel wird eine Mischung Isobutanol, Isopropanol und Wasser 1 : 1 : 1 benutzt. Eine Trennung mit scharf begrenzten Flecken der folgenden Corphyrine wurde erhalten: Cyanocobalamin, Faktor B12 III, Pseudovitamin B12, Faktor A, Faktor B und Faktor V (nB).Eine neue, einfache und rasche Methode zur Trennung der Hydroxocobalamine und der Cyanocobalamine auf Dünnschicht mit trockener Tonerde (neutrales Aluminiumoxid, 2. Aktivitätsgrad nachBrockmann) ist von uns beschrieben worden. Man benutzte die Eigenschaft der Hydroxocobalamine, mit NH4OH eine Verbindung der Gruppe der Cobalichrome zu bilden. In diesem Fall verändert sich das Cyanocobalamin nicht, so daß die zwei Verbindungen leicht getrennt werden können. Die beste Trennung wurde mit der Mischung Isobutanol, Isopropanol und Wasser (1,5 : 1 : 1,25) als Lösungsmittel erhalten (mit Zusatz von NH4OH, bis pH = 8,5).Auf Grund der Trennungsergebnisse der Cyanocobalamine von verwandten Stoffen wird eine Methode quantitativer Bestimmung des Vitamin B12 in mikrobiellen Gärungen, in Handelspräparaten und in Konzentraten beschrieben. Diese Methode schließt die Fällung des Vitamin B12 und anderer Abkömmlinge als Kupfer-Cyan Komplexe, die Zersetzung der Komplexe durch Zusatz einer Lösung NaCN, um Dicyan-Komplexe zu bekommen, die Trennung der Cyanocobalamine auf Dünnschicht mit trockener Tonerde und deren kolorimetrische Bestimmung bei 361 nm ein.
Résumé La séparation de la vitamine B12 d'avec ses analogues est difficile du fait de leur grande similitude avec la cyanocobalamine.En nous basant sur nos expériences nous avons suggéré une nouvelle méthode de séparation des corphyrines sur de l'alumine anhydre (alumine basique, du 2ème degré d'activité selonBrockmann). Comme système solvant un mélange isobutanol, isopropanol, eau, (1 : 1 : 1) a été employé. Une séparation avec des tâches bien délimitées des corphyrines suivantes fut obtenue: cyanocobalamine (vitamine B12), facteur B12 III, pseudovitamine B12, facteur A, facteur B et facteur V (nB).Une nouvelle méthode, simple et rapide, de séparation d'hydroxocobalamine et de cyanocobalamine sur couche mince d'alumine anhydre (alumine neutre, du 2e degré d'activité selonBrockmann) fut décrite par nous. On a utilisé la propriété de l'hydroxocobalamine de former avec le NH4 OH un composé appartenant au type des cobalichrome. Dans ces conidtions la cyanocobalamine ne subit pas de modifications, de sorte que les deux composés peuvent être facilement séparés. La meilleure séparation fut obtenue à l'aide du mélange isobutanol, isopropanol, et eau (1,5 : 1 : 1,25) comme système solvant (avec addition de NH4 OH jusqu'à pH 8,5).Sur la base des résultats des essais de séparation de la cyanocobalamine d'avec ses analogues on décrit une méthode pour la détermination quantitative de la vitamine B12 dans les fermentations microbiennes, les préparations commerciales, et les concentrés. La méthode implique la précipitation de la vitamine B12 et d'autres analogues l'accompagnant, sous forme de complexes cuivre-cyanure, la décomposition des complexes par l'addition d'une solution de Na CN afin d'obtenir des di-cyano-complexes, la séparation de la cyanocobalamine sur couche mince d'alumine anhydre et sa détermination colorimétrique à 361 nm.相似文献
22.
An efficient protocol for cryopreservation of somatic embryos of Coriandrum sativum, an important spice and medicinal herb, was developed. The successful cryopreservation procedure utilized embryo clumps (ECs) comprised of 3–4 somatic embryos at the globular or heart-shape stage. These ECs were precultured for 3 days on medium supplemented with 100 g/L sucrose, desiccated under the current of sterile air for 100 min, then sealed in cryovials and plunged directly into liquid nitrogen. Preliminary incubation on sucrose-enriched medium (100 g/L) improved both desiccation- and cryo-tolerance of ECs compared to medium with normal sucrose content (30 g/L) and enhanced embryo formation after cryopreservation. The regrowth after cryopreservation and average number of new embryos developed from cryopreserved ECs were retained at the level of the untreated control (98% and 13 embryos per clump, respectively). Both normal and abnormal plants were produced from control and cryopreserved cultures, indicating that appearance of abnormalities was not related to cryopreservation. The regenerants with normal phenotype showed the same peaks of relative DNA content regardless of cryopreservation. The results suggest that simple desiccation method is effective for cryopreservation of coriander somatic embryos with subsequent regeneration. 相似文献
23.
Assya Petrova Milena Popova Christina Kuzmanova Iva Tsvetkova Hristo Naydenski Eliud Muli Vassya Bankova 《Fitoterapia》2010
From propolis samples from Kenya, two new arylnaphtalene lignans were isolated, tetrahydrojusticidin B 1 and 6-methoxydiphyllin 2, along with four known phenolic compounds 5–8, found for the first time in propolis. The structures of the compounds were elucidated based on their spectral properties. The geranylstilbenes 7 and 8 demonstrated antibacterial activity against S. aureus, and the geranylflavon macarangin 6 possessed antiradical activity against DPPH radicals. 相似文献
24.
S. L. Tyuterev K. V. Novozhilov E. F. Panarin E. V. Popova I. S. Kochetkova V. V. Azanova N. I. Vorob’ev 《Russian Agricultural Sciences》2011,37(1):25-30
An antibacterial composition with multifunctional biological activity for protecting plants against pathogens of bacterial infections has been created on the basis of the polymeric membrane-active nanodisperse antimicrobial preparation Katapol and a fungicide for preplanting treatment of vegetable seeds and potato tubers. The high protective effect of the composition is shown. 相似文献
25.
P Orozova I Sirakov V Chikova R Popova A H Al‐Harbi M Crumlish B Austin 《Journal of fish diseases》2014,37(10):891-898
Hafnia alvei was isolated in Bulgaria from healthy noble crayfish, Astacus astacus (L.), and then from farmed diseased brown trout, Salmo trutta L., with signs of haemorrhagic septicaemia. The isolates were identified initially with conventional phenotyping and commercial Merlin Micronaut and API 20E rapid identification systems, followed by sequencing of the 16S rRNA gene. Hafnia alvei Bt1, Bt2 and Aa4 were of low virulence to rainbow trout and brown trout, although cytotoxicity was demonstrated by Bt1 and Bt2, but not by Aa4. 相似文献
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27.
T.?G.?FomenkoEmail author V.?P.?Popova E.?A.?Chernikov 《Russian Agricultural Sciences》2018,44(3):260-264
This paper presents the results of a study on the effects of long-term use of drip irrigation with mineralized or, in other words, saline waters on the physicochemical properties of black chernozem soils in a fruit nursery. Irrigation induced local accumulation of water-soluble salts in the main wetted zone, alkalinization of the soil, and saturation of the soil-absorbing complex with Na+ and Mg2+ cations and Ca2+ depletion. The introduction of phosphogypsum in a dose of 2 t/ha for chemical reclamation reduced high alkalinity of the soil and increased the content of exchangeable calcium in the soil-absorbing complex. The application of phosphogypsum seems to be an effective method to restore the fertility of chernozem soils under conditions of long-term use of drip irrigation with mineralized waters. 相似文献
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29.
A pectic polysaccharide named comaruman (CP) was extracted from the aerial part of Comarum palustre with 0.7% aqueous ammonium oxalate and subsequent precipitation with ethanol. Oral administration of comaruman (5-100 mg/kg) was found to reduce a paw edema observed 24 h after injection of 2% formalin in mice. A fraction of comaruman (CP-H9) exhibited a similar antiinflammatory activity. Comaruman, CP deprived of lipid, CP purified by proteins and CP fractions obtained with acidic hydrolysis inhibit spontaneous and phorbol-12-myristate-13-acetate-activated adhesion of peritoneal leukocytes in vitro. 相似文献
30.
Natalia V. Melnikova Ganka D. Ganeva Zapryanka G. Popova Svetlana P. Landjeva Alexander M. Kudryavtsev 《Genetic Resources and Crop Evolution》2010,57(4):587-595
The polymorphism of gliadins was studied in 98 Bulgarian durum wheat (Triticum durum Desf.) landraces and classified according to the existing catalogues of blocks of gliadin components. In total, 31 alleles,
including 12 new ones, were revealed for five gliadin-coding loci. Nine allele families, which included several alleles coding
similar blocks differed only by minor components, were found. The gliadin loci had a high genetic diversity (H = 0.70), and Gli-A2
d
was the most polymorphic locus. Significant differences in allele distribution were observed through the Bulgarian region
under study. The results made it possible to explain the distribution by historical factors. Presumably, the genetic material
flew into the country via two different ways and different durum wheat subgroups contributed to the formation of Bulgarian
landraces. The landraces were a result of long-term selection and, probably, had a close association with the history of the
human populations of the region. 相似文献