著者

Fumio WATANABE Shigeo TAKENAKA Hiromi KITTAKA-KATSURA Shuhei EBARA Emi MIYAMOTO

出版者

Center for Academic Publications Japan

雑誌

Journal of Nutritional Science and Vitaminology (ISSN:03014800)

巻号頁・発行日

vol.48, no.5, pp.325-331, 2002 (Released:2009-04-28)

参考文献数

35

被引用文献数

43 90 76

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Substantial amounts of vitamin B12 were found in some edible algae (green and purple layers) and algal health food (chlorella and spirulina tablets) using the Lactobacillus delbrueckii subsp. lactis ATCC7830 microbiological assay method. Corrinoidcompounds were purified and characterized from these algae to clarify the chemical properties and bioavailability of the algal vitamin B12. True vitamin B12 is the predominate cobamide of green and purple layers and chlorella tablets. Feeding the purple layer to vitamin B12-deficient rats significantly improved the vitamin B12 status. The results suggest that algal vitamin B12 is a bioavailable source for mammals. Pseudovitamin B12 (an inactive corrinoid) predominated in the spirulina tablets, which are not suitable for use as a vitamin B12 source, especially for vegetarians.

著者

Fumio WATANABE Shigeo TAKENAKA Hiromi KATSURA Emi MIYAMOTO Katsuo ABE Yoshiyuki TAMURA Toshiyuki NAKATSUKA Yoshihisa NAKANO

出版者

(社)日本農芸化学会

雑誌

Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)

巻号頁・発行日

vol.64, no.12, pp.2712-2715, 2000 (Released:2005-01-28)

参考文献数

12

被引用文献数

34

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The edible purple laver, Porphyra yezoensis, contained 51.49±1.51 μg of vitamin B12 compounds per 100 g dry weight of the laver (mean±SEM, n=4). A vitamin B12 compound was purified from the lyophilized purple laver and partially characterized. The silica gel 60 TLC and reversed-phase HPLC patterns of the purified pink-colored compound were identical to those of authentic vitamin B12, but not to those of vitamin B12 analogues inactive for humans.

著者

Fumio WATANABE Joachi SCHWARZ Shigeo TAKENAKA Emi MIYAMOTO Noriharu OHISHI Esther NELLE Rahel HOCHSTRASSER Yukinori YABUTA

出版者

Center for Academic Publications Japan

雑誌

Journal of Nutritional Science and Vitaminology (ISSN:03014800)

巻号頁・発行日

vol.58, no.6, pp.438-441, 2012 (Released:2013-02-19)

参考文献数

9

被引用文献数

9 28

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This study determined the vitamin B12 content of six wild edible mushrooms which are consumed by European vegetarians. Zero or trace levels (0.01-0.09 μg/100 g dry weight) of vitamin B12 were determined in porcini mushrooms (Boletus spp.), parasol mushrooms (Macrolepiota procera), oyster mushrooms (Pleurotus ostreatus), and black morels (Morchella conica). By contrast, black trumpet (Craterellus cornucopioides) and golden chanterelle (Cantharellus cibarius) mushrooms contained considerable levels (1.09-2.65 μg/100 g dry weight) of vitamin B12. To determine whether C. cornucopioides or C. cibarius contained vitamin B12 or other corrinoid compounds that are inactive in humans, we purified a corrinoid compound using an immunoaffinity column and identified it as vitamin B12 based on LC/ESI-MS/MS chromatograms.

著者

Motoki MURATA Satomi KOMATSU Emi MIYAMOTO Chihiro OKA Ichian LIN Motofumi KUMAZOE Shuya YAMASHITA Yoshinori FUJIMURA Hirofumi TACHIBANA

出版者

BMFH Press

雑誌

Bioscience of Microbiota, Food and Health (ISSN:21863342)

巻号頁・発行日

vol.42, no.1, pp.87-93, 2023 (Released:2023-01-01)

参考文献数

48

被引用文献数

5

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Quercetin, a flavonol present in many vegetables and fruits, has been identified as a chemoprevention agent in several cancer models. However, the molecular mechanism of quercetin’s anticancer activity is not entirely understood. MicroRNAs (miRNAs), small noncoding RNAs, have been reported to play key roles in various biological processes by regulating their target genes. We hypothesized that quercetin can exert an anticancer effect through the regulation of miRNAs. To test this hypothesis, we investigated the effects of quercetin on the expression of tumor-suppressive miRNAs in cervical cancer. Quercetin up-regulated the in vivo and in vitro expression of tumor-suppressive miRNAs miR-26b, miR-126, and miR-320a. Quercetin suppressed the level of β-catenin, encoded by catenin beta 1 (CTNNB1), by up-regulating miR-320a in HeLa cells. Moreover, quercetin increased the expression of mir-26b, mir-126, and mir-320a precursors in HeLa cells. The results from this study show that quercetin has the potential to prevent cervical cancer by regulating the expression of tumor-suppressive miRNAs.

著者

Fumio WATANABE Yuri TANIOKA Emi MIYAMOTO Tomoyuki FUJITA Hiroyuki TAKENAKA Yoshihisa NAKANO

出版者

Center for Academic Publications Japan

雑誌

Journal of Nutritional Science and Vitaminology (ISSN:03014800)

巻号頁・発行日

vol.53, no.2, pp.183-186, 2007 (Released:2008-01-10)

参考文献数

19

被引用文献数

15 19

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Vitamin B12 content (98.8±5.6 μg/100 g dry weight) of an edible cyanobacterium, Nostoc commune (Ishikurage) was determined by the Lactobacillus delbrueckii ATCC 7830 microbiological method. Bioautography with vitamin B12-dependent Escherichia coli 215 indicated that N. commune contained two (main and minor) corrinoid-compounds. These corrinoid-compounds were purified to homogeneity from the dried algal cells and characterized. The main and minor purified corrinoid-compounds were identified as pseudovitamin B12 and vitamin B12, respectively, on the basis of silica gel 60 TLC, C18 reversed-phase HPLC, 1H NMR spectroscopy, and UV-visible spectroscopy. These results suggest that the bacterial cells are not suitable for use as a vitamin B12 source, especially in vegetarians.