- LUTEOLIN 7,4'-DIMETHYL ETHER 3'-GLUCOSIDE FROM GELONIUM MULTIFLORUM
-
A new flavone glycoside has been isolated from the leaves of Gelonium multiflorum and characterized as luteolin 7,4'-dimethyl ether 3'-glucoside. - Key Word Index: Gelonium multiflorum; Euphorbiaceae; luteolin 7,4'-dimethyl ether 3'-glucoside.
- Parveen, Nazneen,Khan, Nizam U.
-
-
Read Online
- Structure–activity relationships of flavanones, flavanone glycosides, and flavones in anti-degranulation activity in rat basophilic leukemia RBL-2H3 cells
-
The incidence of type I allergies, which are associated with mast cell degranulation and local inflammation, is increasing, and new treatments are needed. To date, structure–activity relationships of flavonoids in their degranulation-inhibiting activity have not been systematically characterized. In the current study, the degranulation-inhibiting activity of a series of flavonoids was evaluated. The following three observations were made: (1) the activity disappears when a sugar moiety is introduced into the A ring of the flavanone; (2) the activity depends on the number of hydroxyl groups on the B ring; (3) the activity is markedly enhanced when a double bond is introduced into the C ring. The information obtained in the current study may guide the development of a therapy for type I allergies.
- Noshita, Toshiro,Miura, Kaori,Ikeda, Kaoru,Ouchi, Hidekazu,Matsumoto, Takuya,Tai, Akihiro
-
-
Read Online
- Flavonoid compound as well as synthesis method and application thereof
-
The invention relates to a semi-synthetic flavonoid compound and an anti-inflammatory application thereof. The invention belongs to the technical field of medicines, particularly relates to synthesis of derivatives of natural products and an application of the derivatives in the anti-inflammatory aspect, and more particularly relates to a synthesis method of flavonoid compounds and an application of the flavonoid compounds in the anti-inflammatory aspect. According to the method, hesperetin is taken as a raw material, flavonol aglycone is synthesized, and finally flavonoid glycoside is synthesized through debenzylation and acetyl reaction. According to the invention, 32 flavonoid compounds, including 14 flavonoid aglycones and 18 flavonoid glycosides, including 15 known compounds and 17 unreported compounds, are synthesized in total. The part of the compounds show good in-vitro anti-inflammatory activity and can become anti-inflammatory drugs or lead compounds.
- -
-
-
- Extracellular melanogenesis inhibitory activity and the structure-activity relationships of ugonins from Helminthostachys zeylanica roots
-
Ugonin J, K, and L, which are luteolin derivatives, were isolated from Helminthostachys zeylanica roots by a series of chromatographic separations of a 50% ethanol/water extract. They were identified using nuclear magnetic resonance (NMR), ultraviolet (UV) spectra, and ultra-performance liquid chromatography coupled to time-of-flight mass spectrometry (UPLC-TOF-MS). In this study, the intra and extracellular melanogenic activity of the ugonins were determined using B16 melanoma cells. The results showed that ugonin J at 12.5, 25, and 50 μM reduced extracellular melanin contents to 75, 16, and 14%, respectively, compared to the control. This indicates that ugonin J showed a stronger activity than arbutin, used as the positive control. Moreover, ugonin K showed a more potent inhibition with 19, 8, and 9% extracellular melanin reduction at the same concentrations, than that shown by ugonin J. In contrast, ugonin L did not inhibit intra- or extracellular melanogenic activity. Furthermore, in order to investigate the structure-activity relationships of the ugonins, the intra- and extracellular melanogenic activity of luteolin, methylluteolin, quercetin, eriodictyol, apigenin, and chrysin were determined. Consequently, it was suggested that the catechol and flavone skeleton of ugonin K is essential for the extracellular melanogenic inhibitory activity, and the low polarity substituent groups on the A ring of ugonin K may increase the activity.
- Yamauchi, Kosei,Mitsunaga, Tohru,Itakura, Yuki,Batubara, Irmanida
-
-
- Pilloin 5-O-β-D-glucopyranoside from the stems of diplomorpha ganpi
-
The new flavonoid, pilloin 5-O-β-D-glucopyranoside (1), was isolated from the stems of Diplomorpha ganpi (Family: Thymelaeaceae) together with 19 known compounds. The structures of these compounds were determined on the basis of spectroscopic data.
- Devkota, Hari Prasad,Yoshizaki, Kouichi,Yahara, Shoji
-
p. 1555 - 1557
(2012/10/29)
-
- Structural requirements of flavonoids and related compounds for aldose reductase inhibitory activity
-
The methanolic extracts of several natural medicines and medicinal foodstuffs were found to show an inhibitory effect on rat lens aldose reductase. In most cases, flavonoids were isolated as the active constituents by bioassay-guided separation, and among them, quercitrin (IC50=0.15 μM), guaijaverin (0.18 μM), and desmanthin-1 (0.082 μM) exhibited potent inhibitory activity. Desmanthin-1 showed the most potent activity, which was equivalent to that of a commercial synthetic aldose reductase inhibitor, epalrestat (0.072 μM). In order to clarify the structural requirements of flavonoids for aldose reductase inhibitory activity, various flavonoids and related compounds were examined. The results suggested the following structural requirements of flavonoid: 1) the flavones and flavonols having the 7-hydroxyl and/or catechol moiety at the B ring (the 3′,4′-dihydroxyl moiety) exhibit the strong activity; 2) the 5-hydroxyl moiety does not affect the activity; 3) the 3-hydroxyl and 7-O-glucosyl moieties reduce the activity; 4) the 2-3 double bond enhances the activity; 5) the flavones and flavonols having the catechol moiety at the B ring exhibit stronger activity than those having the pyrogallol moiety (the 3′,4′,5′-trihydroxyl moiety).
- Matsuda, Hisashi,Morikawa, Toshio,Toguchida, Iwao,Yoshikawa, Masayuki
-
p. 788 - 795
(2007/10/03)
-
- On a Thermal Transmethylation Reaction with Flavon-5-methylethers
-
Upon heating to 300 deg C partial luteolinemethylethers undergo transmethylation.A reaction mechanism is put foreward. - Key words: Flavonemethylethers, Thermal Transmethylation, TLC, HPLC, Reaction Mechanism
- Geiger, Hans,Casteele, Karel Vande,Sumere, Christiaan F. Van
-
p. 393 - 396
(2007/10/02)
-
- O-methylation of flavonoids by cell-free extracts of calamondin orange
-
Cell-free extracts of calamondin orange (Citrus mitis) catalysed the O-methylation of almost all hydroxyls of a number of flavonoids, indicating the existence in citrus tissues of ortho, meta, para and 3-O-methyltransferases. The latter, hitherto unreported enzyme, catalysed the formation of 3-O-methyl ethers of galangin and quercetin. The stepwise O-methylation of a number of compounds, especially quercetin and quercetagetin, tends to suggest a coordinated sequence of O-methylations on the surface of a multienzyme complex. The methyl acceptor abilities of the flavonoid substrates used are discussed in relation to their hydroxyl substitution patterns and their negative electron density distribution.
- Brunet, Gunter,Ibrahim, Ragai K.
-
p. 741 - 746
(2007/10/02)
-
