Showing papers by "Nobuo Shimma published in 1993"
TL;DR: Tetronothiodin inhibited the binding of CCK8 to rat cerebral cortex membranes (CCK type-B receptors) and inhibited Ca2+ mobilization in GH3 cells, a rat anterior pituitary cell line, but was without effect on the basal cytosolic Ca2- concentration.
Abstract: A novel cholecystokinin type-B receptor antagonist named tetronothiodin has been isolated by column chromatography and preparative HPLC from the fermentation broth of Streptomyces sp. NR0489. Tetronothiodin inhibited the binding of CCK8 (C-terminal octapeptide of cholecystokinin) to rat cerebral cortex membranes (CCK type-B receptors) with an IC50 of 3.6 nM, whereas it did not inhibit CCK8 binding to rat pancreatic membranes (CCK type-A receptors). It also inhibited CCK8 induced Ca2+ mobilization in GH3 cells, a rat anterior pituitary cell line, but was without effect on the basal cytosolic Ca2+ concentration. This finding indicated tetronothiodin was an antagonist of CCK type-B receptors.
33 citations
TL;DR: Tetronothiodin is a potent and selective cholecystokinin type B (CCK-B) receptor antagonist produced by Streptomyces sp.
Abstract: Tetronothiodin (1) is a potent and selective cholecystokinin type B (CCK-B) receptor antagonist produced by Streptomyces sp. NR0489. Its structure was elucidated to be a macrocyclic compound comprising cyclohexene, alpha-acyltetronic acid and tetrahydrothiophene moieties based on various 2D NMR experiments on 1 and its dihydro derivative. The stereochemistries for the cyclohexene and tetrahydrothiophene rings were elucidated based on the analysis of NOEs obtained by NOESY experiments and NOE difference spectroscopy. The relative configuration of the cyclohexene moiety in 1 was revealed to be the same as that of the corresponding part in kijanimicin and chlorothricin, which can be structurally related to 1 in terms of their containing a cyclohexene ring with a spirotetronic acid in the molecule.
17 citations
TL;DR: Restrictinol 2 and 9, 10, 11, 12-tetrahydro-7desmethylrestricticin (Ro 09-1571) have been synthesized from L-glucose.
Abstract: Restrictinol 2 and 9, 10, 11, 12-tetrahydro-7-desmethylrestricticin (Ro 09-1571) have been synthesized from L-glucose. Ro 09-1571 showed improved in vitro antifungal activity and chemical stability as compared with Restricticin 1.
11 citations
Journal Article•
TL;DR: Tetronothiodin (1) is a potent and selective cholecystokinin type B (CCK-B) receptor antagonist produced by Streptomyces sp. NR0489 as mentioned in this paper.
Abstract: Tetronothiodin (1) is a potent and selective cholecystokinin type B (CCK-B) receptor antagonist produced by Streptomyces sp. NR0489. Its structure was elucidated to be a macrocyclic compound comprising cyclohexene, alpha-acyltetronic acid and tetrahydrothiophene moieties based on various 2D NMR experiments on 1 and its dihydro derivative. The stereochemistries for the cyclohexene and tetrahydrothiophene rings were elucidated based on the analysis of NOEs obtained by NOESY experiments and NOE difference spectroscopy. The relative configuration of the cyclohexene moiety in 1 was revealed to be the same as that of the corresponding part in kijanimicin and chlorothricin, which can be structurally related to 1 in terms of their containing a cyclohexene ring with a spirotetronic acid in the molecule.