Showing papers on "Flavanone published in 1993"
TL;DR: The results of a systematic study of the reactivity of 13 selected flavonoids (from the flavonol, flavone, flavanone and flavane families) with singlet oxygen (1O2(1 delta g)) in order to establish a structure-activity relationship were reported in this paper.
Abstract: Flavonoids, polyphenolic pigments widely present in plants, have been reported to act as scavengers of various oxidizing species. However, most often an overall antioxidant effect was measured. In this paper we report the results of a systematic study of the reactivity of 13 selected flavonoids (from the flavonol, flavone, flavanone and flavane families) with singlet oxygen (1O2(1 delta g)) in order to establish a structure-activity relationship. The rate constants of the chemical reaction of these flavonoids with 1O2(k r) and their rate constants of 1O2 physical quenching (kq) have been determined by kinetic measurements and near-IR singlet oxygen luminescence. The efficiency of the physical quenching is mainly controlled by the presence of a catechol moiety on ring B, whereas the structure of ring C (particularly the presence of a hydroxyl group activating the double bond) is the main factor determining the efficiency of the chemical reactivity of these compounds with 1O2. The total reactivity factor determining the efficiency of the chemical reactivity of these compounds with 1O2. The total reactivity scale is dominated by kq, which is in general higher than kr. (+)-Catechin is the most efficient quencher of the series.
228 citations
TL;DR: The inhibition mechanisms of flavone, kaempferol, morin, flavanone, and 2'-hydroxyflavanone were concentration dependent, being competitive at low concentrations and mixed or non-competitive at concentrations about the ID50 value.
Abstract: Sixty-four flavonoids were tested for their antimutagenic potencies with respect to IQ in Salmonella typhimurium TA98 and in part also towards MeIQ, MeIQx, Trp-P-2, and Glu-P-1 and in S. typhimurium TA100. Antimutagenic potencies were quantified by the inhibitory dose for 50% reduction of mutagenic activity (ID 50 ). A carbonyl function at C-4 of the flavane nucleus seems to be essential for antimutagenicity: two flavanols and four anthocyanidines were inactive. Again, five isoflavons, except biochanin A, were inactive. Within the other groups of 21 flavones, 16 flavonols and 16 flavanones the parent compounds flavone, flavonol, and flavonone possessed the highest antimutagenic potencies (ID 50 : 4.1, 2.5, 5.5 nmoles). Increasing polarity by introduction of hydroxyl functions reduced antimutagenic potency. Reducing polarity of hydroxy flavonoids by methyl etherification, however, increased antimugenic potency again. 6-Hydroxy- and 2′-hydroxy substituted flavonoids were considerably less potent antimutagens. Of 11 flavonoid glycosides tested all compounds except apigenin- and luteolin-7-glucoside (ID 50 :74, 115 nmoles) were inactvie or only weakly antimutagenic. Rings C and A of the nucleus were not essential for antimutagenicity: chalcone and three derivatives were nearly as active as comparable flavones while antimutagenicity of benzylidenacetone was considerably redcued (ID 50 : 95 nmoles). Cinnamylaldehyde and cinnamoates, however, were inactive. A planar structure in the vacinity of the carbonyl group may also be important for antimutagenicity. Flavanones were less potent antimutagens than the corresponding flavones, but dihydrochalcones and 14 structurally related saturated aromatic carbonyl compounds were inactive. Fisetin and 6-hydroxyflavone were competitive inhibitors, but luteolin was a mixed type inhibitor. The inhibition mechanisms of flavone, kaempferol, morin, flavanone, and 2′-hydroxyflavanone were concentration dependent, being competitive at low concentrations and mixed or non-competitive (2′-hydroxyflavanone) at concentrations about the ID 50 value. No fundamental differences between the two tester strains and no clear influence of mutagen structure on antimutagenic potency could be detected.
173 citations
TL;DR: The analysis of the flavonoids present in orange nectar revealed that the flavanone hesperidin (hesperetin-7-rutinoside) was the major flavonoid detected and, therefore, this should be the main source of the hesperetin found in citrus honey.
Abstract: Seventeen flavonoid aglycones were identified in various experimental and commercial citrus honey samples by HPLC analysis The flavanone hesperetin was detected in all samples This flavanone was not detected in any of the honey samples, from diverse floral origin (including rosemary, lavender, sunflower, almond, sweet chestnut, white clover, Erisarum, Robinia, Rhododendron, Tilia, Prosopis, Eucalyptus and Calluna honeys) previously investigated The analysis of the flavonoids present in orange nectar revealed that the flavanone hesperidin (hesperetin-7-rutinoside) was the major flavonoid detected and, therefore, this should be the main source of the hesperetin found in citrus honey Hesperetin should be produced by hydrolysis of hesperidin by the bee enzymes present in honey These results suggest that hesperetin could be used as a marker for the botanical origin of citrus honey
161 citations
TL;DR: In this paper, the authors reported that the ethyl ether layer was the most effective in stabilizing lard against oxidation, with activity equal to butylated hydroxytoluene.
Abstract: Oregano (Origanum vulgare L.) leaves were successively extracted with hexane, ethyl ether, ethyl acetate and ethanol. The ethanol extract was reextracted in a separatory funnel with petroleum ether, ethyl ether, ethyl acetate and butanol. The ethyl ether layer was the most effective in stabilizing lard against oxidation, with activity equal to butylated hydroxytoluene. It also showed antioxidant activity when tested on vegetable oils under storage or frying conditions. The main antioxidant factors isolated from the ethyl ether layer consisted of flavonoids. Chromatographic and spectrophotometric analysis demonstrated the presence of the flavone apigenin, the flavanone, eriodictyol and the dihydroflavonols, dihydrokaempferol and dihydroquercetin.
145 citations
TL;DR: The putative role of histidines as chelators of ferrous ions in the active site of flavanone 3 beta-hydroxylases was corroborated by diethyl-pyrocarbonate modification of the partially purified recombinant Petunia enzyme.
Abstract: A heterologous cDNA probe from Petunia hybrida was used to isolate flavanone-3 beta-hydroxylase-encoding cDNA clones from carnation (Dianthus caryophyllus), china aster (Callistephus chinensis) and stock (Matthiola incana). The deduced protein sequences together with the known sequences of the enzyme from P. hybrida, barley (Hordeum vulgare) and snapdragon (Antirrhinum majus) enabled the determination of a consensus sequence which revealed an overall 84% similarity (53% identity) of flavanone 3 beta-hydroxylases from the different sources. Alignment with the sequences of other known enzymes of the same class and to related non-heme iron-(II) enzymes demonstrated the strict genetic conservation of 14 amino acids, in particular, of three histidines and an aspartic acid. The conservation of the histidine motifs provides strong support for the possible conservation of structurally similar iron-binding sites in these enzymes. The putative role of histidines as chelators of ferrous ions in the active site of flavanone 3 beta-hydroxylases was corroborated by diethyl-pyrocarbonate modification of the partially purified recombinant Petunia enzyme.
103 citations
TL;DR: In this article, the antioxidant activities against fish oil oxidation of six commercially available flavonoids and of five flavonoid purified from two Chilean native plants were compared to those ofdl-α-tocopherol and of two synthetic antioxidants, butylated hydroxytoluene andbutylated hydroxyanisole.
Abstract: The antioxidant activities against fish oil oxidation of six commercially available flavonoids and of five flavonoids purified from two Chilean native plants were compared to those ofdl-α-tocopherol and of two synthetic antioxidants, butylated hydroxytoluene and butylated hydroxyanisole. Among the commercial flavonoids, catechin, morin and quercetin showed a higher activity when fish oil oxidation (either spontaneous or Fe2+-induced) was assessed from the formation of peroxides or thiobarbituric acid-reactive substances. Among the native flavonoids, the 5,3′,4′-trihydroxy-7-methoxy flavanone (designated as Pt-2) showed the highest antioxidant activity. Mixtures of quercetin or of Pt-2 withdl-α-tocopherol produced better inhibitory effects when compared to that of each substance assayed by itself. Also, when Pt-2 and quercetin were assayed in combination (0.3 g/kg oil and 0.7 g/kg oil, respectively), a synergistic antioxidant effect was observed. Results indicate that several flavonoids could be used as natural antioxidants as a means to replace those synthetic antioxidants, the use of which has been questioned.
96 citations
TL;DR: In this paper, a catechin mixture extracted from the tea plant Camellia sinensis was used for the analysis of plant flavonoids including their glycosides, and three types of ring cleavages in the pyran ring of the flavonoid were made.
72 citations
TL;DR: In this article, various aglycones were evaluated for their inhibitory activities against croton-oil or arachidonic acid induced mouse ear edema by oral or topical administration.
Abstract: In this investigation, the various flavonoid aglycones were evaluated for their inhibitory activities against croton-oil or arachidonic acid induced mouse ear edema by oral or topical administration. The compounds tested were thirteen derivatives of flavan-3-ol (catechin and epicatechin), flavanone (flavanone and naringenin), flavone (flavone, chrysin and apigenin), flavonol (flavonol, galangin, quercetin and morin) and isoflavone (biochanin A and 2-carbethoxy5,7-dihydroxy-4′-methoxyisoflavone), along with hydrocortisone, indomethacin, 4-bromophenacyl bromide, nordihydroguaiaretic acid and phenidone as positive controls. As a general, 5,7-dihydroxy-flavonols having hydroxyl group(s) in B-ring and biochanin A (isoflavone) were found to show broad inhibitory activities (14–52%) against croton-oil or arachidonic acid induced ear edema by oral or topical application at the dose of 2 mg/mouse, although they showed less activity than hydrocortisone (26–88%) or indomethacin (36–80%). Flavonoid aglycones tested showed higher activity when applied topically than by the oral administration. It was also found that they inhibited arachidonic acid induced edema more profoundly than croton-oil induced edema by topical application. In arachidonic acid induced edema when applied topically, flavone derivatives such as flavone, chrysin and apigenin were revealed to be the good inhibitory agents in addition to flavonols and isoflavones. When quercetin and biochanin A were selected for evaluating in carrageenan induced rat pleurisy model (5 hr and 24 hr), both flavonoids showed antiinflammatory activity at the dose of 70 mg/kg by the oral administration. All of these results revealed that flavonoid aglycones, especially 5,7-dihydroxy-flavonols having hydroxyl group(s) in B-ring and biochanin A (isoflavone) possessedin vivo antiinflammatory activity.
69 citations
TL;DR: In this article, a continual study of various flavonoid glycosides have been evaluated in mouse ear edema assay using archidonic acid or crotonoil as a inflammagen.
Abstract: Our previous report demonstrated that certain flavonoid aglycones such as apigenin (flavone), quercetin, morin (flavonols), and biochanin A (isoflavone) showedin vivo antiinflammatory activityvia topical and oral routes of administration. As a continual study, the various flavonoid glycosides have been evaluated in mouse ear edema assay using archidonic acid or crotonoil as a inflammagen. Flavonoids were orally administered (2 mg/mouse) and ear edema inhibition was measured. Significant antiinflammatory activities were found especially in flavone and flavonol glycosides (15–19% inhibition) although the flavonoid derivatives tested showed less antiinflammatory activity than hydrocortisone or indomethacin. Chalcone and flavanone derivatives were not significantly active. And in general, flavonol glycosides of kaempferol-type were found to have a higher oral antiinflammatory activity than that of flavonol glycosides of quercetin-type in mice.
69 citations
TL;DR: In this article, the first study concerned with the isolation of hesperetin 7-O-glucoside from Citrus tissues and with the quantitative distribution of both flavanone glucosides during the development of C. aurantium fruits.
Abstract: The flavanone glucosides prunin (naringenin 7-O-glucoside) and hesperetin 7-O-glucoside were isolated and identified in the immature fruits of Citrus aurantium. Only prunin was identified in Citrus paradisi This is the first study concerned with the isolation of hesperetin 7-O-glucoside from Citrus tissues and with the quantitative distribution of both flavanone glucosides during the development of C. aurantium fruits. Both reach minimum concentration during the first stages of growth, gradually decreasing until the fruits reach minimum development. The total content per fruit of both glucosides is at its greatest at the end of the logarithmic phase of fruit development
56 citations
TL;DR: In this paper, six flavone glycosides were separated by HPLC using RP-18 with a quaternary mobile phase mixture [water-acetonitrile-tetrahydrofuran-acetic acid (80:16:3:1, v/v)].
TL;DR: The antifungal activity of three flavones and one flavanone and of different mixtures of these flavonoids was investigated on malt extract agar against four fungi usually occurring on grain.
Abstract: The antifungal activity of three flavones and one flavanone and of different mixtures of these flavonoids was investigated on malt extract agar against four fungi usually occurring on grain. As pure substances the unsubstituted flavone and flavanone showed higher activity than the hydroxylated flavones. Mixtures containing flavone and 7-hydroxyflavon or flavone, flavanone and flavonol caused higher inhibition of fungal growth than the remaining ones.
TL;DR: Four triterpenes and five flavonoids were isolated from the leaves of Bosistoa brasii and identified wing spectroscopic methods and characterized as baurenol and multiflorenol, friedelan-3 β-ol, and D-friedoolean-14-ene-3β,7α-diol.
Abstract: Four triterpenes and five flavonoids were isolated from the leaves of Bosistoa brasii (Rutaceae) and identified wing spectroscopic methods. The triterpenes were characterized as baurenol and multiflorenol (isolated as a mixture), friedelan-3β-ol, and D-friedoolean-14-ene-3β,7α-diol [1]. Four of the flavonoids were identified as kumatakenin (5,4'-dihydroxy-3,7-dimethoxyflavone) [2], 5,7-dihydroxy-3-methoxy-4'-(3-methylbut-2-enyloxy)flavone [3], 5,7-dihydroxy-4'-methoxy-8-(3-methylbut-2-enyl)flavanone [4], and 5,7-dihydroxy-4'-methoxy-8-(2-hydroxy-3-methylbut-3-enyl)flavanone [5]
TL;DR: In this paper, a spectral analysis of the phenolic compound in the roots and stems of Echinosophora koreensis led to the isolation of three new isoflavanones from the root and 14 compounds, including two new flavanones, from the stems.
TL;DR: One of the compounds isolated from CHCl3 extract, 2'-hydroxymatteucinol (3), showed dose-dependent hypoglycemic activity, and a blood sugar lowering effect was observed even at the dose of 10 mg/kg (p.o.) in STZ-induced diabetic rats.
Abstract: The CHCl3 extract of Matteccia orientalis showed very strong hypoglycemic activity in streptozotocin (STZ)-induced diabetic rats. A new C-methyl flavanone derivative, 2'-hydroxymatteucinol (3) was isolated from the hypoglycemic activity bearing fraction, along with two known compounds, demethoxymatteucinol (1) and matteucinol (2). The structures of these isolated compounds were elucidated by spectroscopic methods. One of the compounds isolated from CHCl3 extract, 2'-hydroxymatteucinol (3), showed dose-dependent hypoglycemic activity, and a blood sugar lowering effect was observed even at the dose of 10 mg/kg (p.o.) in STZ-induced diabetic rats.
TL;DR: Flavone, its methoxy derivatives and flavanone were synthesized by standard methods and were tested for analgesic activity in mice by employing acetic acid writhing and tail flick methods.
Abstract: SUMMARY
1. Flavone, its methoxy derivatives and flavanone were synthesized by standard methods and were tested for analgesic activity in mice by employing acetic acid writhing and tail flick methods.
2. All the tested compounds except flavanone exhibited significant dose-dependent analgesic activity in both the assay models. Some of the compounds were found to involve opioid mechanisms in their analgesic effect.
3. A definite structure-activity relationship was observed in the analgesic activity of flavone derivatives as well as in their mechanism of action.
TL;DR: Four complex flavanones, kurziflavolactones A, B, C, C and D and a complex chalcone 6 with an unprecedented carbon side chain on the flavanone or chal cone A ring have been isolated from a Malaysian plant, Cryptocarya kurZii.
Abstract: Four complex flavanones, kurziflavolactones A [2], B [3], C [4], and D [5] and a complex chalcone 6 with an unprecedented carbon side chain on the flavanone or chalcone A ring have been isolated from a Malaysian plant, Cryptocarya kurzii (Lauraceae). Their structures were determined by extensive spectroscopic analysis, especially 2D nmr experiments. Compounds 3 and 6 showed slight cytotoxicity against KB cells, with IC50 values of 4 and 15 micrograms/ml, respectively. A biosynthetic pathway for the formation of these compounds is suggested.
TL;DR: The isolation for the first time from the genus Artemisia (Compositae) of the known flavanone, 7-O-methyleriodictyol (7-methoxy-5,3',4'-trihydroxy-flavanone), its identification, and its biological effects on rat isolated smooth muscles are described.
Abstract: The isolation for the first time from the genus Artemisia (Compositae) of the known flavanone, 7-O-methyleriodictyol (7-methoxy-5,3',4'-trihydroxy-flavanone), its identification, and its biological effects on rat isolated smooth muscles are described 7-O-Methyleriodictyol (10(-7) M to 3 x 10(-4) M) caused concentration-dependent inhibition of the amplitude of the phasic contractions and reduced the tone of the ileum, the uterus, and the urinary bladder It also caused relaxation of the phenylephrine-precontracted pulmonary artery and the acetylcholine-precontracted trachea The flavanone also shifted to the right the acetylcholine concentration-effect curve on the ileum and the oxytocin concentration-effect curve on the uterus The maximum contractions induced by acetylcholine or oxytocin were also inhibited by 7-O-methyleriodictyol These antispasmodic effects are partly consistent with the use of A monosperma in folk medicine for certain gastrointestinal disorders
TL;DR: A novel flavanone glycoside has been isolated from the Chinese crude drug “mu tong” which is used in Hunan province, China as discussed by the authors, and the structure of this new natural product is identified as 5,4′-dihydroxy-3′-methoxyflavanone-7-(6″- o -β- l -rhamnopyranosyl)-β- d -glucopyrano-ideal.
TL;DR: A new dihydroflavonol, eriotrinol, and a new prenylated flavanone, sigmoidin G, have been isolated from the stem bark of Erythrina eriotricha and E. sigmoidea, respectively as discussed by the authors.
TL;DR: Phytochemical analysis of the leaves from Chromolaena subscandens afforded β-sitosterol, umbelliferone, p-methoxybenzoic acid, and several known flavonoids, as well as a new one, 5,7-dihydroxy-8,4'-dimethoxyflavanone, which is named subscandenin.
Abstract: Phytochemical analysis of the leaves from Chromolaena subscandens afforded β-sitosterol, umbelliferone, p-methoxybenzoic acid, and several known flavonoids, as well as a new one, 5,7-dihydroxy-8,4'-dimethoxyflavanone, which we have named subscandenin [1]. The strucrure of this new flavanone was established by spectral methods
TL;DR: Comparison in vivo studies of flavonoid biosynthesis in Rhododendron simsii petals and supplementary in vitro experiments with enzyme preparations show that p -coumaroyl-CoA is a much better substrate for chalcone synthase than caffeoyl -CoA, suggesting that in RhodODendron the 3′-hydroxylation of the B-ring occurs at the stage of a C 15 intermediate.
TL;DR: In addition to known compounds, investigation of the aerial parts of Lychnophora diamantinana afforded two new sesquiterpene lactones of the heliangolide type.
TL;DR: A new isoprenylated flavanone has been isolated from the exudate of the resin glands present in shoot apices and young leaves of Azadirachta indica and characterized as 8-prenyl-5,7-dihydroxy-3′-(3,3-dimethylbutyl)-4′-methoxyflavanone on the basis of physical and spectroscopic data.
TL;DR: A new flavanone glycoside, onychin, was isolated as cytotoxic principles from the aerial parts of Onychium japonicum and the structure was established as 5-hydroxy-7-rhamnosylglucosyloxyflavanone by spectroscopic methods.
TL;DR: An isolate of diphysin from the bark of the decay-resistant Costa Rican tree Dyphysa robinioides was shown to be a dimer (at C-3) of 3,4-dihydro-4-(4′-hydroxyphenyl)-5,7-diphydroxycoumarin this paper.
TL;DR: The aerial parts of Lophopappus tarapacanus gave a new flavanone and pinocembrin; Pachylaena atriplicifolia gave α- and β-amyrin, lupeyl acetate and sitosterol.
TL;DR: With the described method it is possible to distinguish the three mistletoe subspecies abietis, album and austriacum.
Abstract: Hydrolyzed alcoholic extracts of Viscum album L. were analyzed by HPLC for their flavonoid content. Besides the known flavonoid aglyca 4′,5,7-trihydroxy-3′- methoxyflavanone (homoeriodictyol), 5,7-dimethoxy-4′- hydroxyflavanone, 3′-methylquercetin (isorhamnetin) and 3′,7-dimethylquercetin (rhamnazin) another flavanone derivate, 4′,5-dihydroxy-7-methoxyflavanone (sakuranetin) was detected in mistletoe extracts for the first time. With the described method it is possible to distinguish the three mistletoe subspecies abietis, album and austriacum.
TL;DR: Naringenin 7-O-(6″-O-p-coumaroly-β-D-glucopyranoside) and the new flavanone naringENin 7 -O-(2″)-O-moumaroyl-β-, D-glocopyranoide) have been isolated from the seeds of Ricinus communis L. as mentioned in this paper.
Abstract: Naringenin 7-O-(6″-O-p-coumaroly-β-D-glucopyranoside) and the new flavanone naringenin 7-O-(2″-O-p-coumaroyl-β-D-glucopyranoside) have been isolated from the seeds of Ricinus communis L. The structures of the compounds isolated were established on the basis of the results of chemical transformations and spectral characteristics.
Patent•
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06 Apr 1993
TL;DR: An anti-trypsin agent comprising a flavonoid compound, preferably hydroxy and/or alkoxy derivatives of flavone or hydroxy derivative of flavanone such as quercetin, baicalein, luteolin, kaempferol, apigenin, oroxylin, scrucaflavone-II, wogonin or compounds of formula I and formula II (R is H: R =R =OH; R is H or OH) as an active ingredient is obtained as mentioned in this paper.
Abstract: PURPOSE:To obtain an anti-trypsin agent useful for preventing and treating acute and chronic pancreatitis and thrombotic diseases and preventing transition to diabetes by pancreatitis because of strong inhibition of trypsin activity and no influence on thrombin CONSTITUTION:An anti-trypsin agent comprising a flavonoid compound, preferably hydroxy and/or alkoxy derivatives of flavone or hydroxy derivative of flavanone such as quercetin, baicalein, luteolin, kaempferol, apigenin, oroxylin, scrucaflavone-II, wogonin or compounds of formula I and formula II (R is H: R =R =OH; R is H or OH) as an active ingredient is obtained The compound is obtained from a crude drug such as flower of Sophora japonica, root of Scutellaria baicalensis, flower of crysanthemum or cranesbill by extraction A dose as the medicine is preferably about 60-600mg daily in the case of ordinary adult and is orally administered dividedly at least three times after a meal