PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “FLAVONES”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 19 recordsLinked to original sources
PubMed2002

7-OH-flavone is sulfated in the human liver and duodenum, whereas 5-OH-flavone and 3-OH-flavone are potent inhibitors of SULT1A1 activity and 7-OH-flavone sulfation rate.

1. The aim of this investigation was to see whether 7-OH-flavone, 5-OH-flavone and 3-OH-flavone, which are present in edible vegetables, fruit and wine, are substrates or inhibitors of human liver and duodenum sulfotransferase. 2. An assay was set up to study the sulfation of 7-OH-flavone, and using this assay, it was observed that 7-OH-flavone was sulfated and the rate of sulfation (mean +/- SD) was 324 +/- 87 pmol min(-1) mg(-1) (liver) and 584 +/- 164 pmol min(-1) mg(-1) (duodenum; p < 0.0001). 3. 7-OH-flavone sulfotransferase followed Michaelis-Menten kinetics and the K(m) (mean +/- SD) was 0.2 +/- 0.04 microM (liver) and 1.1 +/- 0.3 microM (duodenum; p = 0.008). V(max) (mean +/- SD) was 392 +/- 134 pmol min(-1) mg(-1) (liver) and 815 +/- 233 pmol min(-1) mg(-1) (duodenum; p = 0.016). 4. 5-OH-flavone and 3-OH-flavone were not sulfated and were inhibitors of human liver and duodenum SULT1A1 activity and 7-OH-flavone sulfation rate. 5. The IC50 of 5-OH-flavone for SULT1A1 was 0.3 +/- 0.06 microM (liver) and 0.3 +/- 0.1 microM (duodenum; n.s.) and those of 3-OH-flavone were 1.0 +/- 0.1 microM (liver) and 1.6 +/- 0.03 microM (duodenum; p = 0.0006). 6. There was inhibition of 7-OH-flavone sulfation rate by 5-OH-flavone and 3-OH-flavone. The IC(50) of 5-OH-flavone for the sulfation rate of 7-OH-flavone was 3.5 +/- 0.5 microM (liver) and 69 +/- 18 microM (duodenum; p < 0.0001) and for 3-OH-flavone it was 18 +/- 3.4 microM (liver) and 213 +/- 47 microM (duodenum; p < 0.0001). 7. The position of the hydroxy group confers to the molecules of OH-flavones the quality of substrate or inhibitor of sulfotransferase.

Adult↗
PubMed1975

[Flavonols and flavones of vegetables. V. Flavonols and flavones of root vegetables (author's transl)].

Root vegetables contain flavon(ol) glycosides in tracers up to small amounts, while the level of their leaves are in part considerable (to more than 1 g/kg, calculated as aglycon). Radish, rutabagas, scorzoneras, and beets contain less than 1 mg/kg kaempferol and/or quercetin; carrots less than 1 mg/kg apigenin and luteolin; celery roots ca. 75 mg apigenin/kg and 14 mg luteolin/kg; horseradish about 20 mg kaempferol/kg and small radish 1-10 mg kaempferol/kg, whereby all these flavones and flavonols occur as glycosides in the vegetables. In leaves of small radish, variety "Eiszapfen", we found besides isoquercitrin (quercetin-3-glucoside) a quercetin-3-0-diglycoside and a kaempferol-0-diglycoside, both with the sugars rhamnose and arabinose, by tlc.

Arabinose↗
PubMed2002

A new flavone glycoside: 5,7,3',4'-tetrahydroxy-3-methoxy flavone-7-O-beta-D-galactopyranosyl-(1-->4)-O-beta-D-glucopyranoside from the stem of Acacia catechu Willd.

A new bio-active flavone glycoside, m.p. C28H32O17, mp 283-284-C, M-640 [EIMS] was isolated from the ethylacetate soluble fraction of the ethanolic extract of the stems of Acacia catechu and its structure was characterised as 5,7,3',4'-tetrahydroxy-3-methoxy flavone-7-O-beta-D-galactopyranosyl-(1-->4)-O-beta-D-glucopyranoside by various chemical degradations and spectral analyses.

Acacia↗
PubMed1998

A new flavone glycoside: 5,7,4'-trihydroxy-6,3'-dimethoxy flavone 5-O-alpha-L-rhamnopyranoside from the leaves of Tridax procumbens Linn.

Tridax procumbens Linn. (N.O. Compositae) is commonly known as Tikki Kasa in Hindi. It is distributed throughout in India up to 2400 m above sea level and in all hot countries. The present paper deals with the isolation and identification of a new flavone glycoside, 5,7,4'-trihydroxy-6,3'-dimethoxy-flavone 5-O-alpha-L-rhamnopyranoside 1, from the leaves of this plant.

Asteraceae↗
PubMed1999

Molecular cloning and biochemical characterization of a novel cytochrome P450, flavone synthase II, that catalyzes direct conversion of flavanones to flavones.

Cytochrome P450 cDNAs, AFNS2 and TFNS5, were isolated from snapdragon and torenia petal cDNA libraries, respectively, based on the sequence homology with licorice CYP93B1 cDNA encoding (2S)-flavanone 2-hydroxylase. They were expressed in yeast and identified to encode flavone synthase II catalyzing direct conversion of flavanones to flavones probably via 2-hydroxyflavanones.

Amino Acid Sequence↗
PubMed1977

[Flavonols and flavones of vegetables. VIII. Flavones of carrot leaves (author's transl)].

The flavonoid constituents of carrot leaves (Daucus carota L. ssp. sativa) were separated by means of cellulose column chromatography, and the following compounds were obtained crystalline and identified by usual procedures: luteolin 7-beta-D-glucoside as the main flavon, luteolin 4'-beta-D-glucoside, luteolin 7-beta-D-glucuronide, apigenin 7-beta-D-glucoside, apigenin 7-rutinoside, chrysoeriol 7-beta-D-glucoside. Luteolin 7-rutinoside also was identified, but could not be obtained crystalline.

Chromatography↗
PubMed1997

A new flavone C-glycoside and antiplatelet and vasorelaxing flavones from Gentiana arisanensis.

A new flavone C-glycoside, isovitexin 6"-O-glucoside (1), and three known flavonoids, quercetin, isovitexin, and luteolin-7-O-beta-D-glucoside, have been further isolated from the whole plant of Gentiana arisanensis Hayata. The new compound was characterized by spectral methods and chemical reactions. The antiplatelet effects of isovitexin 6"-O-glucoside (1), isoorientin (2), 2 peracetate (3), isovitexin (4), luteolin 7-O-beta-D-glucoside (5), luteolin (6), isoorientin 6"-O-glucoside (7), and 7 peracetate (8) were studied using washed rabbit platelets. Of the compounds tested, 6 showed potent antiplatelet effects on arachidonic acid (AA)-induced platelet aggregation (IC50 = 43.5 microM). The effect of 2, 5, and 6 on the contraction of rat thoracic aorta was also studied. Compound 6 depressed markedly the contraction induced by Ca2+ (1.9 mM) in high-K+ (80 mM) medium, with an IC50 of about 156 microM and also inhibited noradrenaline (3 microM)-induced phasic and tonic contractions, with an IC50 of about 68 and 72 microM, respectively.

Animals↗
PubMed1987

Factors involved in the anti-cancer activity of the investigational agents LM985 (flavone acetic acid ester) and LM975 (flavone acetic acid).

LM985 has been shown previously to hydrolyse to flavone acetic acid (LM975) in mouse plasma and to produce significant anti-tumour effects in transplantable mouse colon tumours (MAC). It has undergone Phase I clinical trials and dose limiting toxicity was acute reversible hypotension. Substantially higher doses of LM975 can be given clinically without dose limiting toxicity. We have investigated the activity of LM975 against a panel of MAC tumours and also the in vitro cytotoxicity of both LM985 and LM975 in two cell lines derived from MAC tumours. LM985 is considerably more cytotoxic than LM975 in vitro but increased length of exposure to LM975 results in improved activity. Single in vivo injection of LM975 showed no activity against the ascitic tumour MAC 15A, moderate activity against the s.c. poorly differentiated tumour MAC 13 and produced a significant growth delay in the well differentiated MAC 26. These latter responses were considerably enhanced by repeated injection 7 days later. Pharmacokinetic studies in mice following i.p. injection of LM985 demonstrated rapid degradation of LM985 to LM975 in the peritoneum. Length of exposure as well as drug concentration appear important factors in determining anti-tumour responses.

Adenocarcinoma↗
PubMed1993

Flavone acetic acid (FAA) with recombinant interleukin-2 (rIL-2) in advanced malignant melanoma. IV: Pharmacokinetics and toxicity of flavone acetic acid and its metabolites.

Flavone acetic acid (FAA) was administered at a dose of 4.8 g m-2 over 1 h to patients with advanced malignant disease in combination with Interleukin II. A new high performance liquid chromatography method is described to determine both the parent compound and eight drug-related products, and the conditions required to determine these components in plasma are discussed. The half-life over the first 8 h was 2.3 h, but the terminal clearance of the drug was extremely slow. Severe (WHO Grade 4) hypotension was observed in some patients. However, incidence of this did not appear to be associated with any differences in FAA plasma concentrations, nor were there differences in FAA clearance between those patients whose tumour responded to the drug combination and those who did not.

Antineoplastic Agents↗
PubMed1977

[Isolation and identification of flavon(ol)-O-glycosides in caraway (Carum carvi L.), fennel (Foeniculum vulgare Mill.), anise (Pimpinella anisum L.), and coriander (Coriandrum sativum L.), and of flavon-C-glycosides in anise. I. Phenolics of spices (author's transl)].

The flavonoid constituents of various spices were separated by means of chromatography on cellulose colums, and the following compounds were obtained crystalline: Quercetin 3-glucuronide from caraway, fennel, anise, and coriander; isoquercitrin from caraway and fennel; rutin from fennel and anise; quercetin 3-O-caffeylglucoside and kaempferol 3-glucoside from caraway; quercetin 3-arabinoside from fennel, and luteolin 7-glucoside, isoorientin and isovitexin from anise. Other constitutents which were however not obtained crystalline, but which could be identified by the usual procedures were kaempferol 3-glucuronide and kaempferol 3-arabinoside in fennel, apigenin 7-glucoside and a luteolin glycoside in anise, and isoquercitrin and rutin in coriander. The glycosides contained in the fruit of the four spices also occur in the leaves. Leaves of caraway and fennel in addition contain isorhammetin glycosides in low concentration.

Condiments↗