Showing papers by "Mitsuo Miyazawa published in 2006"

Inhibition of Helicobacter pylori Motility by (+)-Syringaresinol from Unripe Japanese Apricot

Abstract: A methanol extract from unripe Japanese apricot showed inhibitory activity of Helicobacter pylori motility. Inhibitory compound 1 was isolated and identified as (+)-syringaresinol (1) by spectoroscopic means. (+)-Syringaresinol (1) inhibited >90% of the H. pylori motility at a concentration of 500 microg/ml and the IC50 value was 50 microg/ml.

Identification of the main aroma compounds in dried seeds of Brassica hirta

Abstract: The composition of the volatile oil from Sinapis Semen, dried seeds of Brassica hirta (Cruciferae), have been investigated using capillary GC and GC/MS. The important odor-active compounds in the oil were also detected by means of GC-olfactometry (GC-O) and aroma extract dilution analysis (AEDA). The oil was found to contain 68 components, representing 95.36% of the total oil. The main constituents were 4-hydroxy-benzeneacetonitrile (29.63%), palmitic acid (14.55%), linoleic acid and oleic acid (9.67%). The AEDA and GC-O analyses showed that heptanal, phenylethylalcohol, (2E)-octenal and (2E, 4E)-dodecadienal are to a large extent responsible for the characteristic flavor of Sinapis Semen.

Identification of the Key Aroma Compounds in Dried Roots of Rubia cordifolia

Abstract: The compositions of the essential oil from Rubiae Radix (roots of Rubia cordifolia, Rubiaceae) have been investigated by capillary GC and GC/MS. The important odor-active compounds were also detected in the oil using GC-Olfactometry (GC-O) and aroma extract dilution analysis (AEDA). As a result, 43 components, accounting for 91.5 % of the total oil, were detected. The main components in the essential oil were mollugin (19.6%), furomollugin (17.4%), eugenol (12.7%) and (E)-anethole (10.6%). AEDA and GC-O showed that geraniol, eugenol and geranyl acetate were the most aroma-compounds.

Biotransformation of (-)-menthone by human liver microsomes.

Abstract: The aim of the current study was to investigate the metabolism of (-)-menthone by liver microsomes of humans. (-)-Menthone (1) was metabolized to (+)-neomenthol (2) (3-reduction) and 7-hydroxymenthone (3) by human liver microsomes. The metabolites formed were analyzed on GC and GC-MS. Kinetic analysis showed that K(m) and V(max) values for the metabolized (-)-menthone to respective (+)-neomenthol and 7-hydroxymenthone by liver microsomes of human sample HG70 were 0.37 mM and 4.91 nmol/min/mg protein and 0.07 mM and 0.71 nmol/min/mg protein.

Biotransformation of Geraniol by the Larvae of Common Cutworm (Spodoptera litura)

Abstract: Biotransformation of geraniol by the common cutworm (Spodoptera litura) larvae was investigated. Geraniol was mixed in an artificial diet, and the diet was fed to the larvae (fourth-fifth instar) of S. litura. Geraniol was transformed to 8-hydroxygeraniol, 9-hydroxygeraniol, (2E,6E)-8-hydroxy-3,7-dimethyl-2,6-octadienoic acid, (2E,6E)-3,7-dimethyl-2,6-octadiene-1,8-dioic acid and (2E,6Z)-3,7-dimethyl-2,6-octadiene-1,9-dioic acid. Geraniol was preferentially oxidized at the allylic methyl group and primary alcohol by S. litura larvae.

Biotransformation of isoflavones by Aspergillus niger as biocatalyst

Abstract: Biotransformation of the isoflavones, 6,7,4′-trimethoxyisoflavone (1) and 5,7,4′-trimethoxyisoflavone (2) by Aspergillus niger was investigated. Compound 1 was transformed to 4′-hydroxy-6,7-dimethoxyisoflavone (3) and 2 to 4′-hydroxy-5,7-dimethoxyisoflavone (4). This suggested that 1 and 2 were demethylated at the C-4′ position with regioselectivity by Aspergillus niger. Copyright © 2006 Society of Chemical Industry

Microbial O‐demethylation of sinesetin and antimutagenic activity of the metabolite

Abstract: Biotransformation of sinesetin by Aspergillus niger afforded 4′-hydroxy-5,6,7,3′-tetramethoxyflavone on the basis of its spectroscopic data including IR, heteronuclear multiple quantum coherence (HMQC) and heteronuclear multiple bond connectivity (HMBC) analysis. Sinesetin and the metabolite showed antimutagenic activity against chemical mutagens 4-dimethyl-3H-imidazo[4,5-f]quinolin-2-amine (MeIQ) and 3-amino-14-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) in the umu test using Salmonella typhimurium TA1535/pSK1002. Copyright © 2005 Society of Chemical Industry

Antimutagenic Compound from Yellow batai (Peltophorum dasyrachis)

Abstract: A ethanol extract from Yellow batai (Peltophorum dasyrachis) showed a suppressive effect on umu gene expression of SOS response in Salmonella typhimurium OY1001/1A2 against the mutagen 2-amino-3,4-dimethylimidazo[4,5-f ]quinoline (MeIQ). The ethanol exract was re-extracted with chloroform, ethylacetate, butanol, and water. A chloroform fraction showed a suppressive effect. Suppressive compound against MeIQ in the chloroform fraction was isolated by SiO2 column chromatography and identified as surangin C (1) by FABMS, EIMS, and 1 D and 2 D NMR spectroscopy. Surangin C exhibited an inhibition of the SOS-inducing activity of MeIQ in the umu test. Gene expression was suppressed 59.5% at a concentration of 100 μM. The ID50 value (50% inhibition dose) of compound 1 was 67.9 μM. On the other hand, compound 1 showed weak suppressive effects of the SOS-inducing activity on activated MeIQ.

Comparison of Larvicidal, Adulticidal and Acaricidal Activity of Two Geometrical Butylidenephthalide Isomers

Abstract: Insecticidal and acaricidal activities of two geometrical isomers, (E)- and (Z)-butylidenephthalide isolated from Angelica acutiloba, against larvae and adults of fruit fly (Drosophila melanogaster), cat fleas (Ctenocephalides felis) and house dust mites (Dermatophagoides farinae and Tyrophagus putrescentiae) were investigated and compared with that of positive controls. (E)- and (Z)-Butylidenephthalide exhibited 50% lethal concentration (LC50) values of 2.07 and 0.94 micromol/ml of diet concentration against larvae of D. melanogaster, respectively. This indicated that two isomers of butylidenephthalide have geometrical stereoselectivity for larvicidal effect. Even though both (E)- and (Z)-butylidenephthalide also showed potent adulticidal and acaricidal activity against adults of D. melanogaster and two mites, there was no significant difference between two isomers. Insecticidal activity of both (E)- and (Z)-butylidenephthalide toward adults of C. felis was not detected even at the maximum concentration of 200 microg/cm2.

Identification of the Key Aroma Compounds in Dried Roots of Isatis tinctoria

Abstract: The compositions of the essential oil from Baphicacanthis Rhizome, dried roots of Isatis tinctoria (Cruciferae), have been investigated by capillary GC and GC/MS. The important odor-active compounds were also detected in the oil using GC-O and AEDA. As a result, the oil was revealed to contain 70 components, representing 97.4% of the total oil. The oil was composed of many nitrogen-containing components, such as 4-pentenonitrile (67.4%), benzenepropanenitrile (3.6%), 5-methyl hexanenitrile (3.5%) and 4-isothiocynato-1-butene (2.9%). AEDA and GC-O showed that 5-methyl hexanenitrile, skatole, benzenepropanenitrile, (E)-2-hexenal and menthol were the most aroma characteristic compounds of the oil.

Biotransformation of isoflavones by the larvae of the common cutworm (Spodoptera litura).

Abstract: Biotransformation of the 5,7,4′-trimethoxyisoflavone (1), 6,7,4′-trimethoxyisoflavone (2), and 7,4′-dimethoxyisoflavone (3) by insects, Spodoptera litura was investigated. Compound 1 was transformed to 5-hydroxy-7,4′-dimethoxyisoflavone (4), 7-hydroxy-5,4′-dimethoxyisoflavone (5) and 4′-hydroxy-5,7-dimethoxyisoflavone (6) by S. litura. Compounds 2 and 3 were hardly metabolized by S. litura. This suggested that compound 1 was converted to compounds 4, 5 and 6 by demethylation at the C-5, C-7 and C-4′ position, respectively.