Flavanone

About: Flavanone is a research topic. Over the lifetime, 1965 publications have been published within this topic receiving 54729 citations. The topic is also known as: flavanones.

Effects of flavonoids on rat aortic smooth muscle contractility: structure-activity relationships.

Abstract: 1. Flavonoids produced a concentration-dependent relaxation of the contractile responses induced by noradrenaline, KCl, or phorbol 12-myristate-13-acetate in rat aortic rings. Only the flavonoid with three contiguous hydroxyls in B rings (myricetin), at low concentrations, potentiates the contractions evoked by these agonists. 2. The relaxant effects of flavanone on the noradrenaline-induced contractions were potentiated by isoprenaline and those of morin, chrysin, flavanone, and naringenin by sodium nitroprusside. 3. Several mechanisms are implicated in the vasodilatory effects of flavonoids: inhibition of protein kinase C; inhibition of cyclic nucleotide phosphodiesterases; and/or decreased Ca2+ uptake.

Tumor-specificity and apoptosis-inducing activity of stilbenes and flavonoids.

Abstract: We have previously reported the tumor-specific cytotoxicity of flavonoids and analogous phenols. Most pryranoflavones and their derivatives and prenylated or geranylated flavones were cytotoxic, but showed weak tumor-specificity (TS=0.32.3), suggesting that the presence of both hydrophobic and hydrophilic groups within the molecule are necessary for the cytotoxic activity (1-3). Licochalcone B, a chalcone derivative without the isoprenoid group, showed the highest tumorspecificity (TS=31.7). Isoprenoid-substituted chalcone showed higher cytotoxicity, and prenylation(s) on an isoflavone, genistein, also increased the cytotoxicity, but is not necessary for tumor-specificity (4). Among flavonoids and 2arylbenzofurans with isoprenoid substituents, sanggenol M, sanggenon C and sanggenon B showed some tumor-specific cytotoxicity (TS= 2.5, 2.7 and 2.3, respectively). These compounds are Diels-Alder-type adducts with a chalcone and a 6-dehydrogeranyl(prenyl)flavanone and its derivative. Seven other flavanones showed similar tumor-specificity (TS=1.63.0), whereas the more hydrophobic 2-arylbenzofurans showed much weaker cytotoxicity and tumor-specificity (TS=1.0-1.5) (5). Benzophenones, compounds with two isoprenoid groups, showed higher cytotoxicity than the monoprenylated compound, but they showed weak tumorspecific cytotoxicity (TS=1.2-1.3). Fourteen xanthones showed marginal tumor-specific cytotoxicity (TS=1.1->2.0) (6). Thirteen anthraquinones showed relatively higher tumorspecific cytotoxicity. Among them, emodin and aloe-emodin, without glycosylation, were the most potent (TS=8.5 and >18.6, respectively), whereas other anthraquinone glycosides (TS=1.0->3.4), phenylbutane glucosides (TS=1.5-3.3) and naphthalene glucosides (TS=1.1->1.4) were less active. These data suggest that the glycosyl moiety is not necessary for the tumor-specificity of anthraquinones (7). Studies with eleven isoflavones and isoflavanones from Sophora species suggest that: (i) compounds with two isoprenyl groups (one in the A-ring and the other in the B-ring) or the ·,·dimethylallyl group at C-5’ of the B-ring should have

Structure-activity relationships of the inhibitory effects of flavonoids on P-glycoprotein-mediated transport in KB-C2 cells.

Abstract: We studied the effects of flavonoids, naringenin (flavanone), baicalein (flavone), kaempferol, quercetin, myricetin, morin, and fisetin (flavonols) as well as two glycosides of quercetin on P-glycoprotein (P-gp) function in multidrug-resistant P-gp overexpressing KB-C2 cells. Flavonoids such as kaempferol and quercetin increased the accumulation of rhodamine-123 dependent on their chemical structure. Analysis by flow cytometry indicated that the increase in substrate accumulation was due to the inhibition of substrate efflux. Naringenin, which lacks the 2,3-double bond in the C ring, had no effect, although it was more hydrophobic than myricetin, fisetin and morin. Therefore, the planar structure of the flavonoids seemed to be important for their interaction with P-gp. The effects of other flavonoids on the accumulation of daunorubicin were in the order of kaempferol>quercetin, baicalein>myricetin>fisetin, morin. Quercetin-3-O-glucoside and rutin had no effect. The order of the effects corresponded with that of the partition coefficients. Difference in the number and position of hydroxyl groups in flavonoid molecules by themselves seemed to have little effect. These results suggested that hydrophobicity as well as planar structure is important for the inhibitory effects of flavonoids on P-gp-mediated transport.

Inhibition of quorum sensing (QS) in Yersinia enterocolitica by an orange extract rich in glycosylated flavanones.

Abstract: Flavanones, flavonoids abundant in Citrus, have been shown to interfere with quorum sensing (QS) and affect related physiological processes. We have investigated the QS-inhibitory effects of an orange extract enriched in O-glycosylated flavanones (mainly naringin, neohesperidin, and hesperidin). The QS-inhibitory capacity of this extract and its main flavanone components was first screened using the bacteriological monitoring system Chromobacterium violaceum. We next examined the ability of the orange extract and of some of the flavanones to (i) reduce the levels of the QS mediators produced by Y. enterocolitica using HPLC-MS/MS, (ii) inhibit biofilm formation, and (iii) inhibit swimming and swarming motility. Additionally, we evaluated changes in the expression of specific genes involved in the synthesis of the lactones (yenI, yenR) and in the flagellar regulon (flhDC, fleB, fliA) by RT-PCR. The results showed that the orange extract and its main flavanone components inhibited QS in C. violaceum, diminis...