Flavonoids from the Flowers of Citrus ‘Hebesu’

Abstract

2(S)-3',4'-dimethoxy-5,7-dihydroxyflavanone 7-O-neohesperidoside (1), hesperidin (2), astragalin (3), trifolin (4), nicotiflorin (5), narirutin (6), rutin (7), kaempferol 7-O-rutinoside (8), tangeretin (9) and nobiletin (10) were isolated from the MeOH extract of flowers of Citrus 'Hebesu'. Structures of these compounds were elucidated on the basis of physical and spectral data. Absolute configuration and complete NMR spectral data for compound 1 are reported for the first time in this paper.

Anti‐neuroinflammatory activities of extract and polymethoxyflavonoids from immature fruit peels of Citrus ‘Hebesu’

“…Among these compounds, five were flavonoids ( 1 – 5 ) including one flavanone glycoside, hesperidin ( 1 ), and four polymethoxyflavonoids, i.e., tangeretin ( 2 ), 5‐hydroxy‐6,7,8,3′,4′‐pentamethoxyflavone ( 3 ), 3,5,6,7,8,3′,4′‐heptamethoxyflavone ( 4 ), and nobiletin ( 5 ); and one phenylpropanol derivative, 3,4,5‐trimethoxy‐ trans ‐cinnamic alcohol ( 6 ) and one coumarin derivative, meranzin hydrate ( 7 ). Our previous study on flowers of this plant had revealed the presence of tangeretin ( 2 ), nobiletin ( 5 ), and other flavonoid glycosides (Miyashita et al, ). To the best of our knowledge, compounds 3 , 4 , 6, and 7 are reported for the first time from this plant.…”

“…In Japan, many varieties and cultivars of Citrus fruits are cultivated and consumed for their health beneficial effects. Citrus 'Hebesu' is a local cultivar in Hyuga City, Miyazaki prefecture, Japan ( Figure 1) and immature fruits are consumed with many food recipes (Miyashita et al, 2018). As antiinflammatory activity of extracts and compounds from other Citrus fruits have been carried out extensively (Chen, Tait, & Kitts, 2017;Cui et al, 2010); however, no such studies are reported on the peels of Citrus "Hebesu."…”

“…In Japan, many varieties and cultivars of Citrus fruits are cultivated and consumed for their health beneficial effects. Citrus ‘Hebesu’ is a local cultivar in Hyuga City, Miyazaki prefecture, Japan (Figure ) and immature fruits are consumed with many food recipes (Miyashita et al, ). As antiinflammatory activity of extracts and compounds from other Citrus fruits have been carried out extensively (Chen, Tait, & Kitts, ; Cui et al, ); however, no such studies are reported on the peels of Citrus “Hebesu.” Thus, in search of potent anti‐neuroinflammatory compounds from underutilized natural sources, in present research, we evaluated the potential inhibitory effects of extract, fractions, and isolated compounds from Citrus ‘Hebesu’ on lipopolysaccharide (LPS)‐induced inflammatory responses on BV‐2 murine microglial cells.…”

Advances in extraction and purification of citrus flavonoids

“…In previous studies on citrus flavonoids, 45 and 5 of them were identified, respectively (Tables 3 and 4). However, these two flavonoids are uncommon and low in citrus cultivars, and quite a few are only found in citrus leaves or flowers (Miyashita et al., 2018, Wang et al., 2019a). Unless used for special purposes, citrus was rarely used as a raw material for the extraction of these two flavonoids.…”

Anti-oxidant and anti-inflammatory compounds from Magnolia liliifera (L.) Baill. flower and dendrobium signatum Rchb.f.

“…The HMBC correlations (Figure 3.21) of the methoxy proton of 3'-OCH 3 to C-3' and 4'-OCH 3 to C-4' allowed the presence of methoxy substituted at C-3' and C-4' position, respectively. From the above data and through comparison with previously elucidated report, compound 14 wasdetermined as (2S)-homohesperetin115,116 .…”