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Biomedical subjects

Y Terui

Publications and source records attributed to Y Terui.

At least 55 records · Page 3Linked to original sources
PubMed1994

Plasma secretin fluctuates in phase with periodic pancreatic secretion and the duodenal migrating myoelectric complex in calves.

Plasma secretin and cholecystokinin (CCK) levels and the periodic secretions of the exocrine pancreas were studied simultaneously with the duodenal migrating myoelectric complexes (MMC) in six milk-fed calves which had been starved overnight. The experiments were performed first when the calves were 10 to 16 days old and subsequently when they were 36 to 45 days old. Plasma secretin and the secretion of pancreatic juice fluctuated periodically in phase with the duodenal MMC: plasma secretin, and the pancreatic secretion of water and protein were significantly higher during the phase of irregular spiking activity than during the phase of no spiking activity in both investigations. Plasma CCK did not change throughout the MMC. The intravenous infusion of secretin at 120 pmol kg-1 bodyweight for one hour markedly stimulated pancreatic secretion and prolonged the duodenal MMC cycle, but it did not abolish pancreatic and duodenal periodic activity.

Aging↗
PubMed1994

Biotransformation of a new synthetic retinoid, 4-[(5,6,7, 8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)carbamoyl] benzoic acid (Am-80), in the rat. Structure elucidation of the metabolites by mass and nmr spectrometry.

1. The major metabolites of Am-80 in rat bile were examined by tlc-radiochromatography and hplc-radiochromatography after the intravenous administration of 14C-Am-80, and > 15 metabolites were detected. 2. Intact and Glusulase-treated bile were analysed by both tlc-radiochromatography and hplc-radiochromatography. As both samples gave similar patterns in both chromatography systems, we have concluded that neither glucuronide nor sulphate conjugates were present. 3. 2H3-Am-80 and 2H6-Am-80 were administered to rats, and the major metabolites in bile were detected and their structures elucidated by GC-MS. 4. The chemical structures of seven major biliary metabolites, including unchanged Am-80, were identified by mass and two-dimensional nmr spectrometry, and included 6-hydroxy-Am-80 (M-3), 7-hydroxy-Am-80 (M-4), 6-oxo-Am-80 (M-5), unchanged Am-80 (M-0) and the taurine conjugates of M-3 (M-1), M-4 (M-2) and M-0 (M-6).

Animals↗
PubMed1992

Cinatrins, a novel family of phospholipase A2 inhibitors. I. Taxonomy and fermentation of the producing culture; isolation and structures of cinatrins.

Cinatrins A, B, C1, C2 and C3, a family of phospholipase A2 inhibitors were isolated from the fermentation broth of Circinotrichum falcatisporum RF-641. They were found to be novel spiro-gamma-dilactones and gamma-lactones derived from 1,2,3,5-tetra or 1,2,3(or 1,2,4)-trihydroxypentadecane-1,2,3-tricarboxylic acids. Structures were elucidated by MS and NMR studies and chemical transformations. The structure of cinatrin C3 was confirmed by X-ray crystallographic analysis, and its absolute configuration was determined by comparison of the CD spectra with related compounds.

Chromatography↗
PubMed1992

Depudecin: a novel compound inducing the flat phenotype of NIH3T3 cells doubly transformed by ras- and src-oncogene, produced by Alternaria brassicicola.

A novel compound depudecin inducing the flat phenotype of ras- and src- transformed NIH3T3 cells at a concentration of 1 microgram/ml was isolated from the culture broth of Alternaria brassicicola. Based on its spectroscopic characteristics and X-ray crystallographic analysis of its bis-(1S)-(-)-camphanate, the structure of depudecin was determined to be (2R,3S,4S,5E,7S,8S,9R)-2,9- dihydroxy-3,4;7,8-diepoxy-undeca-5,10-diene.

3T3 Cells↗
PubMed1990

Structures of agglomerins.

Structures of a series of new antibiotics, agglomerins A, B, C and D, which are active against a variety of anaerobic bacteria, were determined to be 1-acyl-2,3-dihydroxy-1,3-butadiene-1-carboxylic acid, (1----3)-gamma-lactones, i.e., 2-acyl-4-ylidenetetronic acids with different hydrocarbon chains in the acyl group. Their common chromophore exhibited tautomerism in solution. The relationship of their structure to the activity against anaerobes is discussed.

4-Butyrolactone↗
PubMed1990

The structure of PA48009: the revised structure of duramycin.

PA48009, a lanthionine-containing peptide antibiotic was isolated from the culture broth of Streptoverticillium griseoverticillatum PA-48009, and identified as duramycin. Determination of the structure using both Edman degradations and 2D NMR spectroscopy showed the need to revise the structure of duramycin given in literature. Duramycin (PA48009) was different from lanthiopeptin (Ro 09-0198, cinnamycin) only by a Lys/Arg exchange at position 2.

Amino Acid Sequence↗
PubMed1990

Isolation, characterization and structures of PA-46101 A and B.

New antibiotics, PA-46101 A and B, were isolated from the culture broth of a Streptomycete. The molecular formulae of A and B were determined to be C52H70O18 and C61H86O22, respectively, by elemental analyses, NMR and mass spectrometry. Their structures were elucidated by X-ray crystallography and NMR spectroscopy. These antibiotics are active in vitro against anaerobic Gram-positive and Gram-negative bacteria and also against a limited number of aerobic Gram-positive bacteria.

Aminoglycosides↗
PubMed1990

Isolation of cepafungins I, II and III from Pseudomonas species.

New acylpeptide antibiotics named cepafungins I, II and III were isolated from the culture broth of a strain identified as Pseudomonas sp. These antibiotics are neutral substances, soluble in aqueous alcohols and dimethyl sulfoxide, and show UV maxima at 260.5 nm. The IR spectra indicated these to be peptides. Molecular formulas C28H46N4O6, C27H44N4O6 and C26H42N4O6 for cepafungins I, II and III were indicated by elemental analysis and SI-MS. Cepafungins exhibited inhibitory activity against yeast and fungi, and antitumor activity against P388 leukemia in mice.

Animals↗
PubMed1990

Structures of cepafungins I, II and III.

Structures of interesting acylpeptide antibiotics cepafungins I, II and III were elucidated by NMR spectroscopic studies and some degradation experiments. The antibiotics contain a common peptide part that consists of threonine and two unusual amino acid residues, gamma-hydroxylysine and 4-amino-2-pentenoic acid. The unusual amino acid residues compose an interesting 12-membered ring with an exocyclic N-terminus to which the threonine is connected. Different fatty acyl groups connected to the N-terminus of the threonine distinguish the three cepafungins. The major component I and minor component III are new substance, but the minor component II has a structure identical with that of the recently reported antibiotic glidobactin A.

Amino Acids↗
PubMed1989

Quaternary ammonium glucuronide of croconazole in rabbits.

1. A water-soluble croconazole glucuronide was isolated from the urine of rabbits dosed intravenously with croconazole, using XAD-2 column chromatography, reversed-phase RP-8 column chromatography and h.p.l.c. 2. beta-Glucuronidase hydrolysis liberated unchanged croconazole from the glucuronide. 3. Secondary ion mass spectra, i.r. and n.m.r. spectroscopic studies, including two-dimensional n.m.r. techniques (ROESY and HETCOR), showed the metabolite to be a quaternary ammonium glucuronide of croconazole: i.e. a chemical bond exists between a nitrogen, having sp2 type orbital, in the imidazole ring of croconazole and the anomeric carbon of glucuronic acid. 4. The urinary excretion of the glucuronide amounted to 2.8 +/- 0.7% of dose (mean +/- SD, n = 4) in rabbits.

Animals↗
PubMed1989

Isolation of CB-25-I, an antifungal antibiotic, from Serratia plymuthica.

A new antifungal antibiotic, CB-25-I, was isolated from the culture broth of a strain of Serratia plymuthica. The antibiotic, a water-soluble dipeptide, is structurally related to Sch 37137 and A 19009, both produced by strains of Actinomycetales. The antibiotic exhibits inhibitory activity against Candida albicans in YNB medium (a synthetic medium), but the activity is significantly reduced in Sabouroud dextrose medium.

Amino Acids↗
PubMed1988

NMR studies of chromomycins, olivomycins, and their derivatives.

Detailed studies on the 13C and 1H NMR spectra of chromomycins A2 and A3, olivomycins A and B, and their derivatives clarified the assignment of many signals which had been unassigned or erroneously reported in the literatures. The revised assignments for chromomycin A3 and olivomycin A include the assignment of a key 13C signal used to discuss the saccharide linkage in question. Structure analyses based on the revised assignments support the alpha,1----3-bond between components of the disaccharide moiety in the molecules. Some general information useful for structure analysis of saccharides is also reported.

Chromomycins↗
PubMed1988

Isolation of a new phenazine antibiotic, DOB-41, from Pseudomonas species.

A new phenazine antibiotic, DOB-41, was isolated from the culture broth of a Pseudomonas strain. The antibiotic obtained as yellow crystals showed UV maxima at 255 nm and 370 nm. A molecular formula, C19H18N2O6, was indicated by elemental analysis and mass spectrometry. The structure was elucidated by X-ray diffraction analysis. The antibiotic exhibited inhibitory activity against Gram-positive bacteria, and antitumor effect against leukemia P388 in mice.

Animals↗
PubMed1988

The structures of katanosins A and B.

1H and 13C NMR studies on katanosin A confirmed the presence of eight usual amino acid residues which were previously deduced by amino acid analysis and suggested the presence of beta-hydroxyaspartic acid, beta-hydroxyleucine and beta-phenylserine residues. These amino acids were isolated and confirmed, including their stereochemistries, by comparison with the respective authentic specimens. Stereochemistries of the usual amino acids were determined by comparing the L-leucylated amino acids with reference compounds by HPLC. Lithium borohydride reduction and chromic acid oxidation of katanosin A and alkali-treated katanosin A elucidated a lactone linkage between the C-terminal Ser and phenylserine residues. Edman degradation on alkali-treated katanosin A clarified the total amino acid sequence. The difference in katanosins A and B was determined to be replacement of Val in A by Ile in B. Thus, the structures of katanosins A and B were elucidated.

Amino Acid Sequence↗