866737-00-0Relevant articles and documents
Quantitation of chafurosides A and B in tea leaves and isolation of prechafurosides A and B from oolong tea leaves
Ishida, Hitoshi,Wakimoto, Toshiyuki,Kitao, Yukiko,Tanaka, Shimako,Mlyase, Toshio,Nukaya, Haruo
, p. 6779 - 6786 (2009)
A procedure was developed for the quantitative determination of chafuroside A, a flavone C-glycoside with potent anti-inflammatory activity, and its regioisomer chafuroside B, as well as isovitexin and vitexin, by selected reaction monitoring liquid chromatography-tandem mass spectrometry (SRM LC-MS/MS) analysis. This method was successfully applied to commercial leaves of green tea, houji tea, oolong tea, and black tea. High levels of chafurosides A and B were found in oolong tea leaves that had been heated at >140°C. Next, their precursors, prechafurosides A and B, were isolated from methanol extract of oolong tea leaves prepared from Shizu 7132, Camellia sinensis (L.) O. Kuntze, by partition with n-butanol and H2O and chromatography on Diaion SP-825, Sephadex LH-20, and ODS C-18, guided by assay of chafuroside formation. Prechafurosides A and B gave chafurosides A and B, respectively, in good yields when heated at 160°C for 0.5 h. Solvolysis of prechafurosides A and B with pyridine and dioxane quantitatively afforded isovitexin and vitexin, respectively. On the basis of these results and physicochemical data (MS, UV, and NMR), prechafurosides A and B were concluded to be new flavone C-glycoside sulfates, isovitexin2"-sulfate and vitexin-2″-sulfate, respectively.
Concise synthesis of chafurosides A and B
Furuta, Takumi,Nakayama, Miho,Suzuki, Hirotaka,Tajimi, Hiroko,Inai, Makoto,Nukaya, Haruo,Wakimoto, Toshiyuki,Kan, Toshiyuki
supporting information; experimental part, p. 2233 - 2236 (2009/10/02)
The regioselective synthesis of chafurosides A (1) and B (2) from the same methyl ketone 5 was accomplished using a novel protecting group strategy. Both flavone rings were constructed from β-diketone intermediate 4, which was readily obtained by condensation of an acyl donor and ketone 5. Construction of the dihydrofuran ring was achieved via an intramolecular Mitsunobu reaction.
NOVEL DERIVATIVE OF FLAVONE C-GLYCOSIDE AND COMPOSITION CONTAINING THE SAME
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Page/Page column 7, (2008/06/13)
The present invention relates to novel flavone C-glycoside derivatives or salts thereof, especially those showing an anti-allergic effect, and compositions containing them. Recently, cases of allergic diseases, especially pollenosis and atopic dermatitis
