Isolation and Identification of New Polymethoxyflavonoids from Dancy Tangerine Leaves

Abstract

Ten highly oxygenated flavonoids, including four new compounds, were isolated from the leaves of Dancy tangerine. Six were identified as 5,6,7,3‘,4‘-pentamethoxyflavone (sinensetin) (1), 5,6,7,8,4‘-pentamethoxyflavone (tangeretin) (2), 5,6,7,8,3‘,4‘-hexamethoxyflavone (nobiletin) (3), 5-hydroxy-6,7,3‘,4‘-tetramethoxyflavone (4), 5,7-dihydroxy-6,8,3‘,4‘-tetramethoxyflavone (5), and 5-hydroxy-6,7,8,3‘,4‘-pentamethoxyflavone (5-O-desmethylnobiletin) (6) by direct comparison with authentic samples, comparing their spectroscopic data with those reported in the literature or by simply interpreting their spectral data. The new compounds were elucidated as 5,7,8,3‘,4‘- pentamethoxyflavanone (7), 5,6,7,8,3‘,4‘-hexamethoxyflavanone (8), 7-chloro-3,5,6,8,3‘,4‘-hexamethoxyflavone (9), and 7-chloro-3,5,6,8,4‘-pentamethoxyflavone (10) on the basis of chemical and spectroscopic studies. Keywords: Citrus; Dancy tangerine leaves; polymethoxyflavone; chloride polymethoxyflavone; polymethoxyflavanone

Tetramethyl-O-scutellarin isolated from peels of immature Shiranuhi fruit exhibits anti-inflammatory effects on LPSinduced RAW264.7 cells

“…Among those isolated PMF derivatives, nobiletin and tangeretin have been intensively explored owing to their availability and interesting pharmacological activities. Numerous studies suggest that PMF compounds isolated from citrus display a broad spectrum of biological activity [21].…”

Surface‐enhanced Raman scattering characterization of monohydroxylated polymethoxyflavones

“…capillary electrochromatography, [8] flashing chromatography, [9,10] thin-layer chromatography, [11,12] supercritical fluid chromatography, [13,14] gas chromatography, [15] and high-performance liquid chromatography (HPLC). [7,[16][17][18][19][20][21][22][23][24][25] Mass spectrometry and nuclear magnetic resonance were usually conducted after chromatographic system for structural identification and elucidation. [12,15,17,18,22] There are growing interests on using an innovative analytical method, surface-enhanced Raman spectroscopy (SERS), to characterize PMFs and other flavones.…”

“…[7,[16][17][18][19][20][21][22][23][24][25] Mass spectrometry and nuclear magnetic resonance were usually conducted after chromatographic system for structural identification and elucidation. [12,15,17,18,22] There are growing interests on using an innovative analytical method, surface-enhanced Raman spectroscopy (SERS), to characterize PMFs and other flavones. [26][27][28][29][30][31][32][33] SERS is a novel analytical method that combines Raman spectroscopy and nanotechnology.…”

“…Many analytical methods have been reported to separate and characterize those PMFs from citrus fruits, e.g. capillary electrochromatography, flashing chromatography, thin‐layer chromatography, supercritical fluid chromatography, gas chromatography, and high‐performance liquid chromatography (HPLC) . Mass spectrometry and nuclear magnetic resonance were usually conducted after chromatographic system for structural identification and elucidation …”

Isolation and Identification of Two New Flavanones and a Chalcone from Citrus kinokuni.

“…The known compounds were fully characterized as scoparone (4), scopoletin (5), nobiletin (6), 8) sinensetin (7), 8) tangeretin (8), 8) 5-hydroxy-6,7,8,4Ј-tetramethoxyflavone (9), 9) 5-hydroxy-6,7,3Ј,4Ј-tetramethoxyflavone (10), 10,11) 5-demethylnobiletin (11), 9,12) 6-demethoxynobiletin (12), 8) 6-demethoxytangeretin (13), 8) 5,6,7,4Ј-tetramethoxyflavone (14), 13,14) 3,5,6,7,3Ј,4Ј-hexamethoxyflavone (15), 15,16) 3Ј-hydroxy-5,6,7,8,4Ј-pentamethoxyflavone (16), 17) 3,5,6,7,8,3Ј,4Ј-heptamethoxyflavone (17), 8) 7-hydroxy-5,6,3Ј,4Ј-tetramethoxyflavone (18), 17) 7-hydroxy-5,6,8,3Ј,4Ј-pentamethoxyflavone (19), 18) 5,7,8,3Ј,4Ј-pentamethoxyflavanone (20), 19) 5-Odemethylcitromitin (21), 20) 3,4,3Ј,4Ј,5Ј,6Ј-hexamethoxy-2Ј-hydroxychalcone (22), 21) 2Ј-hydroxy-4,4Ј,5Ј,6Ј-tetramethoxychalcone (23) 22,23) and b-sitosterol (24) by direct comparison with authentic samples and/or spectral data reported in the literature.…”