Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FLAVONES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 433 records · Page 24Linked to original sources
PubMed2000

Flavones and flavonols at dietary levels inhibit a transformation of aryl hydrocarbon receptor induced by dioxin.

Dioxins invade the body mainly through the diet, and produce toxicity through the transformation of aryl hydrocarbon receptor (AhR). An inhibitor of the transformation should therefore protect against the toxicity and ideally be part of the diet. We examined flavonoids ubiquitously expressed in plant foods as one of the best candidates, and found that the subclasses flavones and flavonols suppressed antagonistically the transformation of AhR induced by 1 nM of 2,3,7,8-tetrachlorodibenzo-p-dioxin, without exhibiting agonistic effects that transform AhR. The antagonistic IC(50) values ranged from 0.14 to 10 microM, close to the physiological levels in human.

Animals↗
PubMed1998

Identification of a cytochrome P450 cDNA encoding (2S)-flavanone 2-hydroxylase of licorice (Glycyrrhiza echinata L.; Fabaceae) which represents licodione synthase and flavone synthase II.

The microsome of insect cells expressing CYP Ge-5 (CYP93B1), a cytochrome P450 cDNA of licorice (Glycyrrhiza echinata L.), catalyzed the formation of [14C]licodione and [14C]2-hydroxynaringenin from (2S)-[14C]liquiritigenin and (2S)-[14C]naringenin, respectively. On acid treatment, the products were converted to 14C-labeled 7,4'-dihydroxyflavone and apigenin. Eriodictyol was also converted to luteolin by the reaction with the microsome of yeast expressing CYP93B1 and subsequent acid treatment. CYP93B1 was thus shown to encode (2S)-flavanone 2-hydroxylase, which has previously been designated to licodione synthase and flavone synthase II depending on the substrates employed.

Animals↗
PubMed1999

Flavone and xanthone derivatives related to fluoroquinolones.

A number of flavone and xanthone derivatives bearing some characteristic features of fluoroquinolones such as the fluorine atom and an ortho piperazine ring are described. The new compounds have been tested for possible cytotoxic and antimicrobial activities. Cytotoxicity of both groups of compounds is rather poor, while the antibacterial activity is restricted to xanthones.

Anti-Infective Agents↗
PubMed1998

Simultaneous separation of flavanone glycosides and polymethoxylated flavones in citrus juices using liquid chromatography.

We present a simultaneous liquid chromatographic method for the separation of two flavonoid compound families, flavanone glycosides (FGs) and polymethoxylated flavones (PMFs), which are usually found in citrus fruits species and varieties. This technique permits the quantitation of six FGs (narirutin, naringin, hesperidin, neohesperidin, didymin, poncirin) and six PMFs (sinensetin, hexamethoxyflavone, nobiletin, scutellarein, heptamethoxyflavone and tangeretin). This technique, to be used to characterize a citrus juice by its polyphenolic profile, has been applied to the determination of flavonoid compounds in grapefruit- and orange juice. Differentiation of orange juice varieties and mixtures containing tangor juice using polyphenolic profiles and flavonoid content has been achieved.

Beverages↗
PubMed1992

Chemoimmunotherapy of metastatic murine renal cell carcinoma using flavone acetic acid and interleukin 2.

Metastatic renal cell carcinoma (RCC) remains largely incurable. We used a murine RCC (Renca) in BALB/c mice to investigate the treatment possibilities with chemoimmunotherapy using in vivo boosters of natural killer (NK) activity. Diffuse pulmonary metastases were induced by intravenous (i.v.) inoculation with 100,000 Renca cells. All untreated control animals died within one month from pulmonary metastases. Chemoimmunotherapy using the NK immunostimulator flavonic-8-acetic acid (FAA) at 200 mg./kg. i.v. was given on the third day post tumor inoculation, followed by four consecutive days of twice daily intraperitoneal (i.p.) administration of 10,000 units human recombinant interleukin-2 (rIL-2). This chemoimmunotherapy regimen consistently cured 70% of tumor-bearing animals. Mice cured by this chemoimmunotherapy regimen did not reject subsequent reinoculation with Renca, indicating absence of specific antitumor immunity as a result of the treatment. While FAA and rIL-2 have no demonstrable in vitro cytotoxicity for Renca, they are excellent boosters of in vivo NK activity. These data suggest a potential alternative treatment method for metastatic RCC, a tumor type for which no efficient cytostatic drugs are available.

Animals↗
PubMed2003

Inhibitory effects of total flavones of Hippophae Rhamnoides L on thrombosis in mouse femoral artery and in vitro platelet aggregation.

Total flavones of Hippophae Rhamnoides L (TFH) are extracted from Sea buckthorn, a Chinese herbal medicine. Sea buckthorn has antioxidant, anti-ulcerogenic and hepato-protective actions, and its berry oil is reported to suppress platelet aggregation. Though it is frequently used for patients with thrombosis, the likely mechanism(s) and effects of TFH on thrombogenesis remain unclear. Thus, we have investigated the effect in-vivo of TFH on thrombogenesis and in vitro on platelet aggregation, comparing them to those of aspirin. We measured thrombotic occlusion time in a mouse femoral artery thrombosis model by the photochemical reaction between intravenously injected rose bengal and green light irradiation. In vitro platelet aggregation in whole blood was measured by single platelet counting. Thrombotic occlusion time was 8.5 +/- 0.6 min in the control group. TFH at a dose of 300 micro g/kg, intravenously administered 15 min before the rose bengal injection, significantly prolonged it to 11.6 +/- 1.0 min (P < 0.05), a similar effect on in-vivo thrombogenesis to that of aspirin. TFH at a concentration of 3.0 micro g/ml significantly (P < 0.01) inhibited in vitro platelet aggregation induced by collagen (2 micro g/ml) in a concentration dependent manner, in contrast TFH did not affect aggregation induced by arachidonic acid (80 micro M) and ADP (0.3 micro M). The results of the present study, in which TFH prevented in-vivo thrombogenesis, probably due to inhibition of platelet aggregation, suggest a possible clinical approach for the prevention of thrombosis.

Animals↗
PubMed2000

Pyrano chalcones and a flavone from Neoraputia magnifica and their Trypanosoma cruzi glycosomal glyceraldehyde-3-phosphate dehydrogenase-inhibitory activities.

The fruits of Neoraptua magnifica var. magnifica afforded three new flavonoids: 2'-hydroxy-4,4',-dimethoxy-5',6'-(2'',2''-dimethylpyrano)chalcone, 2'-hydroxy-3,4,4'-trimethoxy-5',6'-(2'',2''-dimethylpyrano)chalcone, and 3',4'-methylenedioxy-5,7-dimethoxyflavone which were identified on the basis of spectroscopic methods. The known flavonoids 2'-hydroxy-3,4,4',5-tetramethoxy-5',6'-(2'',2''-dimethylpyrano)chalcone, 2'-hydroxy-3,4,4',5,6'-pentamethoxychalcone, 3',4'-methylenedioxy-5,6,7-trimethoxyflavone, 3',4'-methylenedioxy-5',5,6,7-tetramethoxyflavone, 3',4',5',5,7-pentamethoxyflavanone and 3',4',5'5,7-pentamethoxyflavone were also identified. The latter flavone was the most active as glyceraldehyde-3-phosphate dehydrogenase-inhibitor.

Animals↗
PubMed1994

An acylated flavone C-glycoside from Glycyrrhiza eurycarpa.

A new acylated flavone C-glycoside, apigenin 6-C-alpha-L-rhamnopyranoside-8-C-[6"-(3-hydroxy-3-methyl-glutaroyl )-beta-D-glucopyranoside], was isolated from rhizomes of Glycyrrhiza eurycarpa and its structure was established on the basis of spectroscopic data.

Apigenin↗
PubMed2001

Enzymatic halogenation of flavanones and flavones.

The whole cells and the chloroperoxidase enzyme of Caldariomyces fumago were capable of halogenating the flavanones, naringenin and hesperetin, at C-6 and C-8 in the presence of either Cl- or Br-. However, they did not act on other test flavones. The biohalogenated products of naringenin and hesperetin were isolated and found to be identical to those obtained from chemical reactions using molecular halogen and hypohalous acid.

Ascomycota↗
PubMed2001

Flavones and phenylpropenoids in the surface exudate of Psiadia punctulata.

Three flavones, 5,7-dihydroxy-2',3',4',5'-tetramethoxyflavone, 5,4'-dihydroxy-7,2',3',5'-tetramethoxyflavone, and 5,7,4'-trihydroxy-2',3',5'-trimethoxyflavone were isolated from the leaf exudate of Psiadia punctulata, together with the previously reported 5-hydroxy-7,2',3',4',5'-pentamethoxyflavone and 5,7,3'-trihydroxy-2',4',5'-trimethoxyflavone. The two phenylpropenoids, Z-docosyl-p-coumarate and E-docosyl-p-coumarate were also isolated. The structures were determined on the basis of spectroscopic evidence.

Asteraceae↗
PubMed2001

Cloning of parsley flavone synthase I.

A cDNA encoding flavone synthase I was amplified by RT-PCR from leaflets of Petroselinum crispum cv. Italian Giant seedlings and functionally expressed in yeast cells. The identity of the recombinant, 2-oxoglutarate-dependent enzyme was verified in assays converting (2S)-naringenin to apigenin.

Apigenin↗
PubMed2001

Flavone C-glycosides from Scleranthus uncinatus.

Two flavone C-glycosides, 5,7,4'-trihydroxy-3'-methoxyflavone-8-C-beta-D-xylopyranoside-2"-O-glucoside, 5,7-dihydroxy-3'-methoxy-4'-acetoxyflavone-8-C-beta-D- xylopyranoside-2"-O-glucoside and one known maltol beta-D-glucopyranoside were isolated for the first time from the Scleranthus uncinatus and their structures deduced by high field 1D and 2D 400 MHz NMR and (+) FAB-MS spectra.

Carbohydrate Conformation↗
PubMed2002

Flavone-coumarin hybrids from Gnidia socotrana.

Phytochemical investigation of leaves and twigs of Gnidia socotrana (Balf. f.) Gilg (Thymelaeaceae), a plant occurring endemically on Socotra Island (Yemen), afforded six novel natural products: two compounds consisting of a flavone and a coumarin moiety connected by a C-C linkage, 7,7'-dihydroxy-3,8'-biscoumarin and three substances with the rare spiro-bis-gamma-lactone structure. The structures were elucidated on the basis of their spectroscopic data.

Coumarins↗
PubMed2003

Meliternatin: a feeding deterrent and larvicidal polyoxygenated flavone from Melicope subunifoliolata.

We screened more than 60 Malaysian plants against two species of insects and found that Melicope subunifoliolata (Stapf) T.G. Hartley (Rutaceae) showed strong feeding deterrent activity against Sitophilus zeamais Motsch. (Curculionidae) and very good larvicidal activity against Aedes aegypti L. (Diptera). One anti-insect compound, meliternatin (3,5-dimethoxy-3',4',6,7-bismethylendioxyflavone) (6) and six other minor polyoxygenated flavones were isolated from M. subunifoliolata.

Aedes↗
PubMed2003

A flavone and an unusual 23-carbon terpenoid from Andrographis paniculata.

Phytochemical investigation of the roots and aerial parts of Andrographis paniculata Nees yielded a new flavone, 5-hydroxy-7,2',6'-trimethoxyflavone and an unusual 23-carbon terpenoid, 14-deoxy-15-isopropylidene-11,12-didehydroandrographolide together with five known flavonoids and four known diterpenoids. The structures of these compounds were determined on the basis of spectral and chemical studies.

Alkenes↗
PubMed2003

Flavone C-glycosides from Lupinus hartwegii.

From the aerial parts of Lupinus hartwegii, two new flavone C-glycosides apigenin-7-O-beta-apiofuranosyl-6, 8-di-C-beta-glucopyranoside (1) and apigenin-7-O-beta-apiofuranosyl-6-C-beta-glucopyranosyl-8-C-(6z.qprime;-O-E-feruloyl)- beta-glucopyranoside (2) have been isolated together with two known isoflavonoid glucosides genistein-7-O-beta-glucopyranoside (3) and genistein-7, 4'-di-O-beta-glucopyranoside (4) as well as two known compounds ferulic acid 4-O-beta-glucopyranoside (5) and sparteine (6). The structures of the isolated compounds were verified by means of MS and NMR spectral analyses.

Carbohydrate Conformation↗
PubMed2003

Cissampeloflavone, a chalcone-flavone dimer from Cissampelos pareira.

From the aerial parts of Cissampelos pareira L. (Menispermaceae), a chalcone-flavone dimer has been isolated which, mainly from NMR spectroscopic and MS data, was proved to be 2-(4-hydroxy-3-methoxyphenyl)-7-(4-methoxyphenyl)-6-(2-hydroxy-4,6-dimethoxybenzoyl)-furano[3,2-g]benzopyran-4-one. This has been assigned the trivial name cissampeloflavone. The compound has good activity against Trypanosoma cruzi and T. brucei rhodesiense and has a low toxicity to the human KB cell line.

Animals↗