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1.
Summary Intervarietal hybrids formed between coliphages P2 and 186 have been isolated and their preliminary genetic characterization described. Three insertion mutants of 186 have also been isolated.  相似文献   

2.
Two new bibenzyls have been isolated from Radula complanata and their structures have been elucidated by chemical and spectral evidence. In addition to the above two bibenzyls and four known bibenzyls, two new acidic bibenzyls have been isolated as their methyl esters.  相似文献   

3.
 This review summarises information on hydroxyproline-rich glycoproteins (HRGPs) and clones encoding these molecules isolated from male and female tissues of flowering plants. HRGPs are abundant in sexual tissues and a number of different HRGPs have been isolated. The protein and carbohydrate components of these HRGPs have been characterised and cDNAs encoding the protein backbones of several have been isolated and sequenced. Further work is directed at detailed structural analysis of the carbohydrate side chains of these molecules and their points of linkage to the protein backbones. The biological functions of most of these molecules have not yet been established unequivocally. Received: 5 March 1997 / Accepted: 16 May 1997  相似文献   

4.
Biochemical and serological properties of mycoplasmas isolated from the blood, feces and parenchymatous organs of monkeys have been studied to determine their species. It was established that the isolated strains belong to the family Acholeplasmatoceae. The study of their biochemical properties in different tests has revealed the presence of 5 biochemically heterogeneous groups. Their serological properties suggest that 13 out of 45 strains are identical to the reference strain of A. laidlawii A, and all other strains have been classified as new Acholeplasma species which have never been isolated from monkeys before.  相似文献   

5.
Summary Salmonella typhimurium mutants affecting the plaque morphology of P22 and other phages have been isolated. Using one such bacterial mutant phage mutants making turbid plaques have been isolated.  相似文献   

6.
Three alkaloids have been isolated from leaves of Crioceras dipladeniiflorus. Two of them, 12-methoxy-voaphylline and criophylline are new and their structures have been determined. The third has been identified as andrangine an alkaloid isolated recently from another Apocynaceae Craspidospermum verticillatum.  相似文献   

7.
Two new compounds, isolated from the rhizomes of Cryptocoryne spiralis, have been characterized as ethyl 14-oxotetracosanoate and 15-oxoeicosanyl 14-oxoheptadecanoate by spectral data and chemical studies. Hentriacontane and sitosterol have also been isolated and identified.  相似文献   

8.
Carbohydrate-containing biopolymers have been isolated from Erwinia carotovora subsp. atroseptica 549 by two methods--the aqueous-phenol and with using physiological solution--with addition and without addition of ethylenediaminetetraacetate (EDTA). The biopolymers yield from the cells of bacteria are shown to depend on the extraction method. Lipopolysaccharide-protein complex have been isolated by the sparing method. The purest lipopolysaccharide have been isolated by the aqueousphenol method. The preliminary treatment of cells by EDTA increased the biopolymers output. Carbohydrate containing biopolymers isolated from the cells of bacteria by different methods possess the similar qualitative composition of monosaccharides but they differ in the quantitative content of monosaccharides, spectrum of fatty acids of lipid components as well as in the protein content.  相似文献   

9.
Six new bibenzyls have been isolated from the liverwort, Radula variabilis and their structures have been established by chemical and spectral evidence. In addition, a new dihydrochalcone and a new bibenzy] have been isolated as their methyl ethers. Except for two of the bibenzyls, the present compounds have a unique seven-membered heterocyclic ring and they are the first members of a new group of natural product.  相似文献   

10.
The peptides which result from treatment of the S-[14C]carboxymethyl derivative of dogfish M4 lactate dehydrogenase (EC 1.1.1.27) with trypsin have been isolated and their sequences have been elucidated. Each identical subunit has a molecular weight of 36,000 and on the basis of the amino acid composition 40 unique tryptic peptides are anticipated. Thirty-seven of these peptides have been isolated and have been completely characterized. The amino acid sequences of these peptides are presented.  相似文献   

11.
Ten novel neo-clerodane diterpenoids, named cornutins C-L, have been isolated from the leaves of Cornutia grandifolia var. intermedia. Their structures have been elucidated by detailed spectroscopic analysis. In addition, the in vitro antiplasmodial activity of four isolated compounds (cornutin C-F) has been evaluated, revealing only a marginal activity.  相似文献   

12.
The stems of Lonicera periclymenum have been investigated for secoiridoid glycosides. In addition to two well-known glucosides, secologanin and morroniside, two rare secoiridoids, secoxyloganin and secologanoside, have been isolated and characterized by chemical and spectroscopic means. Secologanoside has been isolated for the first time as a genuine, non-derivatized compound.  相似文献   

13.
Since 1976 strains of Neisseria gonorrhoeae producing beta-lactamase have been isolated in many countries. Strains with high level resistance to tetracycline have been also described. The appearance of resistant strains implies a constant surveillance of the isolated gonococcus and the study of their antibiotics sensitivity.  相似文献   

14.
Leaves of Holarrhena febrifuga from East Africa contain 1·5% of alkaloids, mostly of the amino-3α ceto-20 pregnane-5α type. Six alkaloids have been isolated: funtumine (I), holamine (II), dimethyl- and monomethyl-funtumine (Ia) and (Ib), dimethyl- and monomethylholamine (IIa) and (IIb); these methyl derivatives have been isolated for the first time from natural source. Pregnane-3,20-dione has been isolated from the same leaves.  相似文献   

15.
Immunogenic properties of influenza virus hemagglutinin, isolated by new detergents O-14 (desintegron-O) and B-14 (desintegron-B) have been studied. Hemagglutinin isolated by desintegron-O has been found to be more immunogenic than virions. It has been shown that hemagglutinin isolated by desintegron-B induces a lower humoral immune response than the influenza virus.  相似文献   

16.
Two new compounds, B and C, isolated from the roots of Costus speciosus have been characterized as 24-hydroxyhentriacontan-27-one and 24-hydroxytriacontan-26-one by spectral data and chemical studies. Methyl triacontanoate, diosgenin and sitosterol have also been isolated and identified.  相似文献   

17.
ISOLATION AND PROPERTIES OF LIVER CELL NUCLEOLI   总被引:5,自引:3,他引:2       下载免费PDF全文
1. The significance of the term nucleolus has been discussed. 2. A detailed method for the isolation of nucleoli from already isolated rat or cat liver nuclei has been presented. 3. The presence of DNA in isolated liver cell nucleoli has been indicated by histochemical methods. 4. The percentages of DNA and RNA in the isolated nucleoli have been determined by chemical analysis. 5. The specific activities of aldolase, arginase, and catalase have been determined for two subnuclear fractions and for the isolated nucleoli of rat and cat liver, and the relative amounts of these enzymes in the same subnuclear fractions and nucleoli of rat liver have been measured. 6. The significance of the above findings has been discussed and consideration has been given to what types of isolated nuclei might best serve as starting material for the isolation of nucleoli. 7. A new hypothesis has been presented that nucleoli of the liver cell type may function primarily in furnishing (directly or indirectly) templates for the synthesis of the particular enzymes that must govern the chemistry of mitosis.  相似文献   

18.
Antigenic analogues of all known epidemic human viruses (H1, H2 and H3) have been isolated from natural sources in the USSR. A 5 to 25-year persistence of genes coding haemagglutinins of these viruses in the genome structures of natural populations of viruses have been established. The viruses are more commonly isolated from water birds (ducks, gulls, terns, coots, shelducks, sandpipers), and the circulation of influenza viruses in nature among pigeons, crows, chickens and other birds have been identified. The viruses have been also isolated from bats, whales, squirrels, deer, fishes and lake water. The exchange between the genofond of natural populations of influenza A viruses and epidemic influenza viruses is discussed.  相似文献   

19.
Six alkaloids have been isolated from root bark of Araliopsis soyauxii. Five are known, maculine, flindersiamine, skimmianine, (?) ribalinine, (+) isoplatydesmine and the sixth, araliopsine is new; its structure has been established as hydroxyisopropyldihydrofuro-2-quinolone. From the trunk bark four alkaloids have been isolated: flindersiamine, kokusaginine (?) ribalinine, (+) isoplatydesmine.  相似文献   

20.
The virulence and toxigenicity of newly isolated P. aeruginosa strains have been studied in experiments on white mice. These biological properties have been shown to be most pronounced in P. aeruginosa strains isolated from proteins, sometimes greatly exceeding those in strains isolated from healthy persons and the environment. Virulence and the factors which determine it are definitely interrelated in microorganisms and can vary, depending on the conditions of their habitat.  相似文献   

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