著者

Yasuhide Hiraga Takeshi Ara Yoshiki Nagashima Norimoto Shimada Nozomu Sakurai Hideyuki Suzuki Kota Kera

出版者

Japanese Society for Plant Biotechnology

雑誌

Plant Biotechnology (ISSN:13424580)

巻号頁・発行日

vol.37, no.3, pp.377-381, 2020-09-25 (Released:2020-09-25)

参考文献数

26

被引用文献数

4

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The model land plant Physcomitrella patens synthesizes flavonoids which may act as protectant of ultraviolet-B radiation. We aimed to uncover its flavonoid profile, for which metabolome analysis using liquid chromatography coupled with Ion trap/Orbitrap mass spectrometry was performed. From the 80% methanol extracts, 661 valid peaks were detected. Prediction of the elemental compositions within a mass accuracy of 2 ppm indicated that 217 peaks had single elemental composition. A compound database search revealed 47 peaks to be annotated as secondary metabolites based on the compound database search. Comprehensive substituent search by ShiftedIonsFinder showed there were 13 peaks of potential flavonoid derivatives. Interestingly, a peak having m/z 287.0551, corresponding to that of luteolin, was detected, even though flavone synthase has never been identified in P. patens. Using P. patens labeled with stable isotopes (13C-, 15N-, 18O-, and 34S), we confirmed the elemental composition of the peak as C15H10O6. By a comparison of MS/MS spectra with that of authentic standard, the peak was identified as luteolin or related flavone isomers. This is the first report of luteolin or related flavones synthesis and the possibility of the existence of an unknown enzyme with flavone synthase activity in P. patens.

著者

Kota Kera Shohei Makino Risako Takeda Aoi Shimeno Masaya Hojo Sadahiro Hamasaki Akihito Endo Masumi Iijima Tsutomu Nakayama

出版者

Japanese Society for Food Science and Technology

雑誌

Food Science and Technology Research (ISSN:13446606)

巻号頁・発行日

pp.FSTR-D-23-00189, (Released:2023-12-27)

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The astringency of persimmon fruits is a significant factor for consumers and the nutritional industry. To date, astringents, such as polyphenols, specifically persimmon condensed tannins, have been assessed using polyphenol quantification assays, such as the Folin–Ciocalteu method, based on their reducing power. However, these methods are influenced by the presence of other reducing substances. In this study, we developed a cost-effective liposome turbidity analysis using a portable visible spectrophotometer based on the interaction between liposomes and astringents. Authentic astringents, such as catechins and theaflavin-3-O-gallate, were analyzed, and their half-maximal effective concentrations (EC50) were calculated. These results indicated that the affinity to the membrane was similar to that of astringency, as determined by sensory analysis. Additionally, the EC50 values of partially purified tannins from non-astringent and astringent persimmons were calculated. In conclusion, we determined the application methods to assess astringent persimmon fruits with and without the removal of astringency.

著者

Tsutomu Nakayama Hideharu Huriya Asuka Kamo Kenzi Kosako Takeyuki Kozima Maki Sugawara Taiki Suzuki Mie Nishizima Ai Yamashita Megumi Yano Shouhei Makino Kota Kera Masumi Iijima

出版者

Japanese Society for Food Science and Technology

雑誌

Food Science and Technology Research (ISSN:13446606)

巻号頁・発行日

pp.FSTR-D-22-00202, (Released:2023-01-20)

被引用文献数

2

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The molecular interaction of black tea components with phospholipid vesicles has been investigated to elucidate the various functions of black tea infusions, such as astringency, inhibition of cholesterol absorption, and inactivation of viruses. We have developed a simple method to analyze the turbidity of phospholipid vesicle solutions reacted with black tea infusions or components as an indicator of the molecular interaction. Using a portable visible spectrophotometer, the dose-dependency of catechins, theaflavins, thearubigins, and black tea infusions on turbidity was analyzed. The results indicate that authentic catechins and theaflavins independently caused aggregation of the phospholipid vesicles; however, their concentrations in the tea infusions were insufficient. Meanwhile, thearubigins prepared from black tea leaves caused aggregation at the concentration found in the tea infusions. It is concluded that thearubigins, instead of theaflavins, mainly contribute to the interaction with phospholipid vesicles.