Kazuo Ina

Chlorophyllone-a, a new pheophorbide-a related compound isolated from ruditapes philippinarum as an antioxidative compound

A new pheophorbide a related compound named as chlorophyllone a (1), C33H32N4O3, was isolated as an antioxidative compound from the extract of the short-necked clam, Ruditapes philippinarum. It suggests a new degradative pathway of chlorophylls.

Geranyl 6-O-β-d-xylopyranosyl-β-d-glucopyranoside isolated as an aroma precursor from tea leaves for oolong tea

Abstract A new geranyl glycoside, geranyl 6-O-β- d -xylopyranosyl-β- d -glucopyranoside was isolated as an aroma precursor from tea leaves (Camellia sinensis var. sinensis cv Shuixian) for oolong tea. The isolation was guided by a two-phase acid hydrolysis and/or an enzymatic hydrolysis followed by GC and GC-MS analyses.

Formation of Flower Fragrance Compounds from Their Precursors by Enzymic Action during Flower Opening

Flower fragrance compounds were found to be produced from the precursor solution obtained from flower buds by crude enzyme prepared from the flowers at the opening stage. GC and GC-MS analyses showed the formation of volatile aroma constituents from the precursor solution of Jasminum polyanthum F, Jasminum sambac Ait, and Gardenia jasminoides E, but none in the case of Osmanthus fragrans L. The aroma-producing enzyme activity of G. jasminoides rapidly increased to reach the maximum at flower opening stage (stage 4) and decreased within 24 h after flower opening (stage 5). Fragrance precursors of G. jasminoides were suggested not to be mainly β-glucosides of linalool, eugenol, borneol, and isoeugenol based on the results after β-glucosidase and naringinase treatment of the precursor solution. The activity of hydrolytic enzyme(s) such as glycosidase was found to elevate during flower opening to result in the aroma formation.

Linalyl β-d-glucopyranoside and its 6′-O-malonate as aroma precursors from Jasminum sambac

Abstract Linalyl β- d -glucopyranoside 1 and its 6′- O -malonate 2 were isolated as aroma precursors of linalool from flower buds of Jasminum sambac guided by enzymatic hydrolysis followed by GC and GC-MS analyses.

LINALYL AND BORNYL DISACCHARIDE GLYCOSIDES FROM GARDENIA JASMINOIDES FLOWERS

(R)-Linalyl 6-O-alpha-L-arabinopyranosyl-beta-D-glucopyranoside and bornyl 6-O-beta-D-xylopyranosyl-beta-D-glucopyranoside were isolated as aroma precursors of linalool and borneol from flower buds of Gardenia jasminoides, guided by enzymatic hydrolysis followed by GC and GC-MS analyses.

Feeding-stimulant activity of algal glycerolipids for marine herbivorous gastropods.

Phagostimulant activity of glycerolipids such as digalactosyldiacylglycerol (DGDG), 6-sulfoquinovosyldiacylglycerol (SQDG), phosphatidylcholine (PC), phosphatidylethanolamine (PE), etc., have been examined using the Avicel plate method for three kinds of marine herbivorous gastropods, the abaloneHaliotis discus, the turban shellTurbo cornutus, and the topshellOmphalius pfeifferi. DGDG showed strong activity for all the test animals. SQDG was much less active than the other glycerolipids for abalone. The turban shell and the top shell responded more or less sensitively to all tested glycerolipids at doses of 10–20μg/sample zone.

A simple bioassay for feeding-stimulants for the young seahare Aplysia juliana

Water extracts of a green alga (Ulva sp.) are known to elicit phagostimulatory responses against a seahare Aplysia sp. In 1984 we happened, however, to find that a seahare shows its feeding preference for filter paper on which an ether extract of Ulva sp. had been absorbed. We succeeded in establishing a simple and reliable bioassay procedure for the feeding-stimulants for the seahare A. juliana, which is applicable to isolation of the active principles.

4(S)-(6-O-Caffeoyl-β-d-glucopyranosyl)-2-pentanone from young leaves of Photinia glabra

Abstract 13 C NMR analysis of hot water extracts from young leaves of Photinia glabra gave prominent signals unassignable to any known components. Guided by the characteristic 13 C NMR signals, a new glucoside ester was isolated. The structure of this compound was determined to be 4( S )- O -(6- O -caffeoyl-β- d -glucopyranosyl)-2-pentanone by 1 H and 13 C NMR analyses and other chemical evidence.

2-O-(β-L-Arabinopyranosyl)-myo-inositol as a Main Constituent of Tea (Camellia sinensis)

A new main tea constituent, 2-O-(β-l-arabinopyranosyl)-myo-inositol (1, ca. 0.8 % of a Japanese green tea) was characterized by 13C-NMR spectroscopy. The inositol glycoside (1) has been found not only in all the tea extracts so far examined but also in the homogenate of Camellia sinensis var. sinensis (“Yabukita cultivar”), suggesting its physiological importance in carbohydrate metabolism in the tea plant.

Oxidative dimerization of .ALPHA.-pyran.

Oxidative coupling of α-pyran (1) was examined. Oxidation of α-pyran (1) with manganic tris-(acetylacetonate) resulted in cleavage of the pyran skeleton to three diene dimers (5a, 5b and 6). On the other hand, treatment of α-pyran (1) with vanadium tetrachloride and anodic oxidation gave pyran dimers (7a_??_c and 8a, 8b), respectively.