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Biomedical subjects

T Takei

Publications and source records attributed to T Takei.

At least 127 records · Page 7Linked to original sources
PubMed1979

Controlled biosynthesis of neoviridogriseins, new homologues of viridogrisein. III. Production, structures and biological properties of neoviridogriseins I and III.

The high response of our isolate of Streptomyces griseoviridus was exploited to provoke the synthesis of new viridogrisein homologues by adding various amino acids to the culture medium in an attempt to replace the alanine, sarcosine, leucine and phenylsarcosine moieties of virdogrisein. Among the amino acids added, L- and DL-alpha-amino-n-butyric acid and L-methionine gave new TLC spots which we named neoviridogriseins I and III and neoviridogrisein VII, respectively. The structures of neoviridogriseins I and III were elucidated: In both compounds, the alanine moiety of viridogrisein is replaced by a L-alpha-amino-n-butyric acid residue; furthermore, in neoviridogrisein I, the allo-hydroxy-D-proline is replaced by D-proline.

Amino Acids↗
PubMed1979

Controlled biosynthesis of neoviridogriseins, new homologues of viridogrisein. IV. In vitro synergism between neoviridogrisein II and the antibiotics of the mikamycin A group.

Neoviridogrisein II is a homologue of viridogrisein in which the hydroxyproline residue is replaced by proline. Neoviridogrisein II proved to be more active than the parent antibiotic against Gram-positive bacteria and Mycoplasma species. When neoviridogrisein II or viridogrisein was combined with griseoviridin, a non-peptidyl macrocyclic lactone, synergism was observed: maximum synergistic effect was observed for a combination ratio that depended on the test bacterium used. Neoviridogrisein II also exerted synergism when combined with mikamycin A and A-2315A.

Anti-Bacterial Agents↗
PubMed1979

Controlled biosynthesis of neoviridogriseins, new homologues of viridogrisein II. Production, biological properties and structure of neoviridogrisein II.

Our isolate of Streptomyces griseoviridus, which produced three minor factors in addition to viridogrisein and griseoviridus, which produced three minor factors in addition to viridogrisein and griseoviridin, was more sensitive to the addition of L-proline than the type culture of Streptomyces griseoviridus (NRRL2427). Yield improvement of these minor factors was attempted by the so-called controlled biosynthesis with L-proline. Addition of L-proline increased the production of neoviridogrisein II in which allo-hydroxy-D-proline in viridogrisein was replaced by D-proline.

Anti-Bacterial Agents↗
PubMed1979

Deformation of the articular cartilage and joint space of the human knee joint under static load.

In order to define the deformation of articular cartilage and the joint space under statically loaded knee joints, we studied serial sections in the frontal plane of knee joints which were frozen under the application of a load. Normal articular cartilage surfaces did not make contact even under loads of 100kg or more, leaving always a space between. The compressive deformation of articular cartilage mainly occurred at the central area near to the intercondylar notch or prominence, but the deformation of cartilage in the area covered by menisci was negligible.

Adult↗