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51.
The anthocyanin (GAA) in the epidermis and hair of the leaf ofGynura aurantiaca cv. ‘Purple Passion’ was isolated and identified as cyanidin tetra-glucoside acylated by three molecules of caffeic acid and one molecule of malonic acid. GAA was also isolated from the lower epidermis of the leaf ofG. bicolor DC. GAA showed a very stable reddish purple color from weakly acid to neutral pH region, but the color of the deacylated compound disappeared rapidly in the same region. This indicated that the attached organic acids must play an essential role in the stabilization of the color. Comparison of the profiles of the visible absorption spectra of the intact epidermal peels and cells ofG. aurantiaca andG. bicolor with those of GAA dissolved in various pH solutions suggested that the pH of the epidermal vacuole containing GAA was nearly 4.3. GAA was indistinguishable from the anthocyanin (rubrocinerarin) which we had previously isolated from the purplish red flowers ofSenecio cruentus DC. by means of UV-Vis, NMR and Mass spectra. Deceased  相似文献   
52.
Nucleotide sequence of threonine tRNA from Bacillus subtilis.   总被引:6,自引:3,他引:3       下载免费PDF全文
A threonine tRNA was purified from Bacillus subtilis W168 by a combined use of column chromatographic systems. The nucleotide sequence was determined to be pG-C-C-G-G-U-G-U-A-G-C-U-C-A-A-U-D-G-G-D(U)-A-G-A-G-C-A-A-C-U-G-A-C-U-mo5U-G-U-t6A-A-psi-C-A-G-U-A-G-m7G-U-U-G-G-G-G-G-T-psi-C-A-A-G-U-C-C-U-C-U-U-G-C-C-G-G-C-A-C-C-AOH, where about 40 % of D20 remained unmodified as U20. It consists of 76 nucleotides including a new minor nucleoside, 5-methoxyuridine (mo5U), which occupies the wobble position of anticodon.  相似文献   
53.
54.
The structure of a modified uridine derivative which was detected at the first letter position of the anticodon of Bacillus subtilis tRNA1Lys was determined to be 5-(carboxymethylaminomethyl)-2-thiouridine. The determination was mainly based in this ultraviolet absorption spectra and mass spectrometric analysis of the trimethylsilyl derivative.  相似文献   
55.
Seventy-eight poliovirus strains isolated from river water and sewage in Toyama Prefecture, Japan, during 1993 to 1995 were characterized by the PCR-restriction fragment length polymorphism (RFLP) method and by partially sequencing the VP3 and VP1 regions of the viral genome. Of these isolates, 36 were identified as Sabin vaccine strains, and 42 were identified as vaccine variant strains that had less than 1.4% nucleotide divergence from the Sabin strains, including 7 isolates with patterns different from those of Sabin strains as determined by PCR-RFLP analysis. These findings suggest that wild-type poliovirus was not circulating in Toyama Prefecture.  相似文献   
56.
Replacement of Tyr52 with Val or Ala in Lactobacillus pentosus d-lactate dehydrogenase induced high activity and preference for large aliphatic 2-ketoacids and phenylpyruvate. On the other hand, replacements with Arg, Thr or Asp severely reduced the enzyme activity, and the Tyr52Arg enzyme, the only one that exhibited significant enzyme activity, showed a similar substrate preference to the Tyr52Val and Tyr52Ala enzymes. Replacement of Phe299 with Gly or Ser greatly reduced the enzyme activity with less marked change in the substrate preference. Except for the Phe299Ser enzyme, these mutant enzymes with low catalytic activity consistently stimulated NADH oxidation in the absence of 2-ketoacid substrates. However, the double mutant enzymes, Tyr52Arg/Phe299Gly and Tyr52Thr/Phe299Ser, did not exhibit synergically decreased enzyme activity or the substrate-independent NADH oxidation, but rather increased activities toward certain 2-ketoacid substrates. These results indicate that the coordinative combination of amino acid residues at two positions is pivotal in both the functional recognition of the 2-ketoacid side chain and the protection of the bound NADH molecule from the solvent. Multiplicity in such combinations appears to provide d-LDH-related 2-hydroxyacid dehydrogenases with a great variety of catalytic and physiological functions.  相似文献   
57.
Eight spotted fever group (SFG) rickettsiae isolated from ticks in Japan were classified by phylogenetic analysis based on the nucleotide sequences of both the citrate synthase-encoding gene (gltA) and 190-kDa antigen-encoding gene (rOmpA). In the phylogenetic tree of gltA, strains DT-1 and FLA-1 isolated from the Dermacentor taiwanensis and Haemaphysalis frava ticks, respectively, were placed as Rickettsia japonica, and strains IO-1, IO-2, IO-25, IM-1 and IP-2 from genus Ixodes ticks were placed as Rickettsia helvetica. Strain AT-1 isolated from the Amblyomma testudinarium belonged to the cluster including Rickettsia akari, Rickettsia australis and Rickettsia felis. In the phylogenetic tree of the rOmpA, strains DT-1 and FLA-1 were placed as R. japonica, and strain AT-1 belonged to the cluster including Rickettsia cooleyi and the symbiont of Ixodes scapularis. The rOmpA fragments of 5 Ixodes isolates could not be amplified by PCR. The present study showed that strains DT-1 and FLA-1 were genotypically identical to R. japonica, and 5 Ixodes isolates were associated with the R. helvetica. Based on previous genotypic and antigenic data, and the phylogenetic analysis presented here, strain AT-1 should be considered as a new species among SFG rickettsiae.  相似文献   
58.
Seventy-eight poliovirus strains isolated from river water and sewage in Toyama Prefecture, Japan, during 1993 to 1995 were characterized by the PCR-restriction fragment length polymorphism (RFLP) method and by partially sequencing the VP3 and VP1 regions of the viral genome. Of these isolates, 36 were identified as Sabin vaccine strains, and 42 were identified as vaccine variant strains that had less than 1.4% nucleotide divergence from the Sabin strains, including 7 isolates with patterns different from those of Sabin strains as determined by PCR-RFLP analysis. These findings suggest that wild-type poliovirus was not circulating in Toyama Prefecture.  相似文献   
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60.
Three different anthocyanins were shown to be contained in the dull purple flowers ofMucuna sempervirens Hemsl. (Japanese nameAira-tobikazura). They were identified as the 3-monoglucosides of delphinidin, petunidin and malvidin, respectively, by means of paper chromatographic and spectral analyses, and present in the ratio about 1:5:4 in the petals.  相似文献   
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