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Biomedical subjects

H Takayanagi

Publications and source records attributed to H Takayanagi.

At least 55 records · Page 3Linked to original sources
PubMed1995

Pyripyropenes, Novel ACAT inhibitors produced by Aspergillus fumigatus. III. Structure elucidation of pyripyropenes E to L.

Eight new pyripyropenes, E to L, were isolated from the culture broth of Aspergillus fumigatus FO-1289-2501 selected as a higher producer by NTG mutation. Structural elucidation indicated that all the pyripyropenes have the same pyridino-alpha-pyrone sesquiterpene core as pyripyropenes A to D. Among them, pyripyropene L showed the most potent inhibition against acyl-CoA: cholesterol acyltransferase (ACAT) activity with an IC50 value of 0.27 microM in rat liver microsomes.

Animals↗
PubMed1995

Terpendoles, novel ACAT inhibitors produced by Albophoma yamanashiensis. II. Structure elucidation of terpendoles A, B, C and D.

Structures of terpendoles A, B, C and D, novel acyl-CoA: cholesterol acyltransferase (ACAT) inhibitors, were determined by spectroscopic studies. All terpendoles consist of diterpene and indole moieties in common. Terpendoles A, C and D possess an additional isoprenyl unit via oxygen atom(s) of their diterpene moieties. The relative stereochemistries of terpendoles C and D were confirmed by NOE experiments and X-ray crystallographic analysis.

Anti-Bacterial Agents↗
PubMed1995

Terpendoles, novel ACAT inhibitors produced by Albophoma yamanashiensis. III. Production, isolation and structure elucidation of new components.

Eight new components of terpendoles E to L were isolated and characterized from the culture broth of Albophoma yamanashiensis using a different production medium. All the structures were elucidated by spectroscopic analyses including various NMR experiments, indicating that all the terpendoles have the same indoloditerpene core as terpendoles A to D. Terpendoles J, K and L showed the moderate inhibition against acyl-CoA: cholesterol acyltransferase (ACAT) activity with IC50 values of 38.8, 38.0 and 32.4 microM in rat liver microsomes, respectively. But terpendoles E-I showed weak activities (IC50 145-388 microM).

Animals↗
PubMed1990

Synthesis of aminosterols and their derivatives.

Reactions of steroidal epoxides such as 5,6 alpha-epoxy-5 alpha-cholestane (I) and its 3 beta-chloro (II) and 3 beta-acetoxy (III) analogs with urea in dimethylformamide afforded 6 beta-amino-5 alpha-cholestan-5-ol (IV-VI), 6 beta-amino-N-formyl-5 alpha-cholestan-5-ol (VII-IX), and 6 beta-amino-N-amido-5 alpha-cholestan-5-ol (X-XII), along with the 5 alpha-cholestane-5,6 beta-diol (XIII-XV). In addition to these compounds, the 3 beta-acetoxy analog also afforded the N-carboxyl derivative (XVI).

Chemical Phenomena↗
PubMed1989

[Chemical studies of flower buds of Tussilago farfara L].

We have studied the flower buds of Tussilago farfara L. collected from Yulin county Shaanxi Province and have isolated a new terpenoid compound I with the composition C23H34O5, M+ 390.2416, mp 100-101 degrees C. On basis of physical and chemical properties and spectroscopic analysis (UV, IR, 1HNMR, 13CNMR, 1H-1H-COSY, 13C-1H-COSY DEPT, EI-MS, FAB-MS, HR-MS) and X-ray, the structure of I has been elucidated as a novel sesquiterpenoid compound, which is named farfaratin.

Chemical Phenomena↗
PubMed1988

Dynamics of FMRFamide immunoreactivity in response to physiologically active substances in the central nervous system of the snail, Achatina fulica.

1. The changes in FMRFamide (Phe-Met-Arg-Phe-NH2) immunoreactivity in response to incubation in dopamine, serotonin, met-enkephalin, oxytocin, arg-vasopressin and FMRFamide were examined in the central nervous system of the snail, Achatina fulica. 2. When the central nervous system was cultured in medium which contained dopamine and in medium which contained serotonin, the number of immunoreactive neurons increased in the anterior part of the cerebral ganglion and decreased in the sub-esophageal ganglion. 3. When arg-vasopressin was added to the culture medium, the number of immunoreactive neurons increased in the pedal ganglion and decreased in the other sub-esophageal ganglion. 4. By contrast, when the central nervous system was cultured in medium which contained oxytocin, the number of immunoreactive neurons did not increase, but rather decreased, in each ganglion. 5. No changes in immunoreactivity were detected in the central nervous system when it was cultured in medium which contained FMRFamide. 6. It appears, from these results, that the production and release of FMRFamide from different neurons are differentially affected by the physiologically active substances tested.

Animals↗
PubMed1988

Coexistence of FMRFamide, met-enkephalin and serotonin in molluscan neurons.

1. Coexistence of FMRFamide, met-enkephalin and serotonin immunoreactivities was examined in Achatina fulica and Aplysia kurodai. 2. Coexistence of FMRFamide and serotonin was found in some neurons of the visceral, right parietal and pedal ganglia of Achatina fulica, and in the pedal ganglion of Aplysia kurodai. 3. In Achatina fulica, coexistence of FMRFamide and met-enkephalin was found in a neuron of the left parietal ganglion and that of met-enkephalin and serotonin was found in a giant neuron of the right parietal ganglion. 4. Based on these results, the biological significance of coexistence was discussed.

Animals↗