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Yonago, Japan

Kimura H.,Kotobuki Seika Co. | Tokuyama S.,Kotobuki Seika Co. | Ishihara T.,Kotobuki Seika Co. | Ogawa S.,Kotobuki Seika Co. | And 2 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2015

Indigo plant (Polygonum tinctorium Lour) has been utilized as a medicinal plant with a variety of biological activities. We have recently detected higher levels of flavonoids in indigo leaves. This study was undertaken to conduct the simultaneous analysis of those flavonoids using total extracts from indigo leaves by ultra-performance liquid chromatography-electrospray ionization-time-of-flight/mass spectrometryE (UPLC-ESI-TOF/MSE). The analysis by UPLC-ESI-TOF/MSE allowed us to determine 11 peaks of flavonoid species. The chemical structures of these compounds were identified as flavonol O-glycosides with different types of aglycones by the combination of spectroscopic and chemical methods. The predominant compounds were flavonol O-glycosides with 3,5,4'-trihydroxy-6,7-methylenedioxyflavone as an aglycone. Of these, three compounds were elucidated as new compounds. All the isolated flavonol O-glycosides exhibited the inhibitory activity against 3-hydroxy-3-methylglutaryl-CoA reductase in a dose-dependent manner with different potencies. Taken together, our results suggest the potential usefulness of the major flavonol O-glycosides from indigo leaves in controlling cholesterol biosynthesis. © 2015 Elsevier B.V.


Ogawa S.,Kotobuki Seika Co. | Michida M.,Kotobuki Seika Co. | Kimura H.,Kotobuki Seika Co. | Nakamura Y.,Food Research Institute | And 3 more authors.
Nippon Shokuhin Kagaku Kogaku Kaishi | Year: 2013

The present study was conducted in order to determine the interactive effects of L-ascorbic acid 2-glucoside (AA-2G) and trehalose on their anti-oxidant actions. Linoleic acid was readily peroxidized in the presence of Fe3+ and L-ascorbic acid (AsA). In contrast, the combination of AA-2G and Fe3+ had no effect on chemical peroxidation. On the other hand, the peroxidation of linoleic acid induced by the coexistence of Fe3+ and AsA was inhibited by trehalose in a dose-dependent manner. Further analysis of the action of trehalose as a novel anti-oxidant by the oxygen radical absorbance capacity (ORAC) method revealed that trehalose synergistically stimulated the ORAC values of AA-2G, but had no synergistic effect on those of AsA. These findings indicate that a mixture of AA-2G and trehalose is advantageous as an anti-oxidant food additive.


Kimura H.,Kotobuki Seika Co. | Ogawa S.,Kotobuki Seika Co. | Akihiro T.,The University of Shimane | Yokota K.,The University of Shimane | Yokota K.,Tottori University
Journal of Chromatography A | Year: 2011

Compared with oligomeric proanthocyanidins, highly polymeric proanthocyanidins have more difficulty to analyze the molecular sizes and the mode of interflavan linkages of flavan-3-ol units through doubly linked A-type bonds and single B-type bonds. Recently, we have shown that seed shells of the Japanese horse chestnut contain highly polymeric proanthocyanidins as dominant polyphenolics that can be separated into two fractions according to the difference in the molecular sizes. Here, we tried to perform the structural characterization of them in terms of the molecular sizes and the proportions of A-type linkages relative to B-type linkages. The results were compared with those of the corresponding preparations with variations in the sizes from fruits of blueberry and cranberry. Gel permeation chromatography revealed that the molecular sizes of them were higher in the order of blueberry > cranberry > seed shells of the Japanese horse chestnut when they are compared between the respective fractions. For the analysis of terminal and extension units of those proanthocyanidins, the isolated fractions were subjected to the thiolytic cleavage of the B-type linkages using 1-dodecanethiol, and the resulting degradation products were identified by ultra-performance liquid chromatography electrospray-ionization mass spectrometry (UPLC-ESI/MS). These analyses provided fast and good resolution of the degradation products and revealed higher proportions of A-type linkages compared with B-type linkages in the both isolated fractions in the order of the seed shells > cranberry > blueberry. Moreover, the isolated fractions with higher molecular sizes and those more abundant in the proportions of A-type linkages were found to be more effective in the inhibition of pancreatic lipase activity. The results suggest that higher molecular sizes and more abundance of A-type bonds in polymeric proanthocyanidins are promising key factors for the attenuation of lipid digestion as dietary supplements. © 2011 Elsevier B.V.


Kimura H.,Kotobuki Seika Co. | Ishihara T.,Kotobuki Seika Co. | Michida M.,Kotobuki Seika Co. | Ogawa S.,Kotobuki Seika Co. | And 3 more authors.
Natural Product Research | Year: 2014

The indigo plant (Polygonum tinctorium Lour) has been used traditionally as a medicinal plant with a variety of biological effects. Of these, polyphenolic ingredients are postulated to contribute to these activities. However, the identification and quantification of polyphenolic compounds in indigo plants have not been conducted comprehensively until now. This study was undertaken to identify the related ingredients by combined instrumental analyses using ultra-performance liquid chromatography electrospray-ionisation mass spectrometry and gas chromatography-mass spectrometry after the extracts of plant tissues were fractionated by absorption column chromatography. These analyses allowed the identification of kaempferol, quercetin-3-O-glucuronide, quercetin, kaempferol-3-O-glucopyranoside, caffeic acid, chlorogenic acid and tentative 3,5,4′-trihydroxy-6,7-methylenedioxyflavone. Furthermore, predominant polyphenolic compounds were quantified by reverse-phase high-performance liquid chromatography and capillary gas chromatography, revealing the higher proportions of kaempferol, quercetin-3-O-glucuronide and quercetin among them. The results indicate that the indigo plant is a promising source for flavonoids and the related compounds with beneficial medicinal effects. © 2014 Taylor & Francis.


Kimura H.,Kotobuki Seika Co. | Ogawa S.,Kotobuki Seika Co. | Sugiyama A.,Tottori University | Jisaka M.,Tottori University | And 4 more authors.
Food Research International | Year: 2011

Recently, we have shown that seed shells contain a large amount of highly polymeric proanthocyanidins having a series of heteropolyflavan-3-ols with doubly linked A-type linkages as well as single B-type bonds without gallic acid esterified to them. Here, we attempted to evaluate in vivo anti-obesity effects of the polymerized proanthocyanidins in mice. An oral starch or glucose tolerance test in mice revealed that the isolated two fractions of highly polymerized proanthocyanidins with the different degree of polymerization suppressed effectively the elevation of blood glucose from oral starch, but not from oral glucose, suggesting the preferential inhibition of the digestive enzymes of carbohydrates. Moreover, in vivo anti-obesity effects of the total fraction containing the proanthocyanidins as a drink were investigated in mice fed a high-fat diet. Their anti-obesity effects became more evident after 9. weeks as determined by the attenuation of the elevation in body weight, the mass of peritoneal adipose tissues, and the plasma levels of total cholesterol and leptin. Furthermore, the increased size of hepatocytes and the generation of steatosis with micro- and macrovesicles in liver were normalized by the dietary supplementation of the total proanthocyanidin fraction. The findings suggest the usefulness of highly polymeric proanthocyanidins from seed shells in the application to food as a dietary supplement with anti-obesity effects in vivo through the inhibition of digestive enzymes of carbohydrates and fats. © 2010 Elsevier Ltd.

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