Showing papers on "Flavanone published in 2001"

Anti-inflammatory properties of plant flavonoids. Effects of rutin, quercetin and hesperidin on adjuvant arthritis in rat.

Abstract: The anti-inflammatory activities of three flavonoids were investigated in rats using the Mizushima et al. model of acute and chronic inflammation. Intraperitoneal administration of rutin, quercetin (flavonols) and hesperidin (flavanone), given at daily doses equivalent to 80 mg/kg, inhibited both acute and chronic phases of this experimental model of inflammation. Rutin was the most active in the chronic phase.

Biological properties of citrus flavonoids pertaining to cancer and inflammation.

Abstract: Citrus flavonoids encompass a diverse set of structures, including numerous flavanone and flavone O- and C-glycosides and methoxylated flavones. Each of these groups of compounds exhibits a number of in vitro and in vivo anti-inflammatory and anticancer actions. These biological properties are consistent with their effects on the microvascular endothelial tissue. Evidence suggests that the biological actions of the citrus flavonoids are possibly linked to their interactions with key regulatory enzymes involved in cell activation and receptor binding. The citrus flavonoids show little effect on normal, healthy cells, and thus typically exhibit remarkably low toxicity in animals. The citrus flavonoids extend their influence in vivo through their induction of hepatic phase I and II enzymes, and through the biological actions of their metabolites. Evidence clearly indicates to the potential health promoting properties of these dietary compounds.

Cytotoxic flavonoids with isoprenoid groups from Morus mongolica

Abstract: A new pyranoflavanone, sanggenol L (1), a Diels-Alder type adduct regarded as a cycloaddition product of a dehydrogeranylflavanone and a prenylchalcone, sanggenol M (2), along with four new 2-arylbenzofurans with isoprenoid units, mulberrofurans W-Z (3-6), were isolated together with 10 known flavonoids from Chinese Morus mongolica. The structures of these novel compounds were elucidated by spectroscopic methods. All flavanones investigated here showed higher cytotoxicity against human oral tumor cell lines (HSC-2 and HSG) than against normal human gingival fibroblasts (HGF). Among them, the cytotoxicity of compound 2 and the Diels-Alder type flavanone sanggenon C (7) isolated from Morus cathayana were the most potent. On the other hand, seven 2-arylbenzofurans exhibited lower cytotoxicity and tumor specificity as compared with flavanones.

Gene expression in flavonoid biosynthesis: Correlation with flavonoid accumulation in developing citrus fruit

Abstract: Two genes active in the early steps of flavonoid biosynthesis were isolated from a citrus cDNA library, and their expression patterns were analyzed during citrus (Citrus unshiu Marc.) fruit development in relation to flavonoid contents. The respective cDNA clones from chalcone isomerase (CHI, CitCHI) and flavanone 3-hydroxylase (F3H, CitF3H) are 931 and 1360 bp long, encoding 222 and 362 amino acid residues. CitCHI seems to be a single-copy gene, whereas a few CitF3H-related sequences are present in the citrus genome. Messenger RNA levels of the flavonoid biosynthetic genes CitCHI and CitF3H and two previously isolated chalcone synthases (CHS, CitCHS1, and CitCHS2) were analyzed in various tissues during fruit development. Transcript levels for CitCHS1, CitCHS2, CitCHI, and CitF3H were generally high in young tissues and low in senescent tissues. Flavonoid changes were analyzed in relation to gene expression. High flavonoid contents were found in young tissues. The high expression of flavonoid biosynthetic genes and high accumulation of flavonoids in young fruits suggest that flavonoids are synthesized in the early developmental stage.

Antiproliferative Activity of Diarylheptanoids from the Seeds of Alpinia blepharocalyx

Abstract: The 95% EtOH extract of the seeds of Alpinia blepharocalyx (Zingiberaceae) showed significant antiproliferative activity towards human HT-1080 fibrosarcoma and murine colon 26-L5 carcinoma cells. Chemical investigation of the extract led to the isolation of forty-four new (1-44) and one known (45) diarylheptanoids, eleven phenolic compounds (46-56) together with beta-sitosterol glucoside (57). Almost all the isolated compounds showed significant antiproliferative activity in a concentration-dependent manner. Among the compounds, epicalyxin F (17) exhibited the most potent activity against the proliferation of colon 26-L5 carcinoma cells with an ED50 value of 0.89 microM, while calyxin B (2) exhibited the most potent activity against human HT-1080 fibrosarcoma cells with an ED50 value of 0.69 microM. Moreover, calyxins B (2) and K (11), epicalyxins F (17), I (20) and K (22), 6-hydroxycalyxin F (25), blepharocalyxin B (27) and mixtures of 7 and epicalyxin G (18) and of calyxin J (10) and epicalyxin J (21) possessed more potent activity than a clinically used anticancer drug, 5-fluorouracil, towards HT-1080 fibrosarcoma cells. Analysis of the structure activity relationship suggested that the position of the attachment of a chalcone or a flavanone moiety does not affect the activity, although their presence in association causes a substantial enhancement of the antiproliferative activity. Moreover, the conjugated double bond of the chalcone moiety and the phenolic hydroxyl group potentiate the antiproliferative activity of the compounds.

Flavanone glycosides from Citrus junos and their anti-influenza virus activity.

Abstract: By bioactivity-guided fractionation, a new flavanone triglycoside, naringenin 7-O-(2",6"-di-O-alpha-rhamnopyranosyl)-beta-glucopyranoside (1), as well as hesperetin 7-O-(2", 6"-di-O-alpha-rhamnopyranosyl)-beta-glucopyranoside (2), hesperidin (3) and narirutin (4) have been isolated from the fruits of Citrus junos Tanaka (Rutaceae). In addition, hesperetin 7-O-(2",6"-di-O-alpha-rhamnopyranosyl)-beta-glucopyranoside (2) is reported for the first time from this plant and inhibits the influenza A virus.

Flavonoids differentially inhibit guinea pig epidermal cytosolic phospholipase A2

Abstract: Cytosolic phospholipase A2 (cPLA2) is believed to involve the regulation of essential cellular processes. Like other cell types, epidermal cPLA2 may participate in various metabolic processes including eicosanoid generation. In this investigation, we demonstrated the presence of cPLA2 in guinea pig epidermis. The epidermal cPLA2 is Ca2+-dependent, active at micromolar concentration of Ca2+ and resistant to disulfide-reducing agents. Furthermore, it is inhibited by methyl arachidonyl fluorophosphonate (MAFP), a selective inhibitor of cPLA2, while 12-epi-scalardial (a sPLA2 inhibitor) did not cause inhibition. A test of several flavonoids revealed that quercetin (flavonol) weakly inhibited cPLA2, while flavanone had negligible inhibitory activity. In contrast, amentoflavone and ginkgetin (biflavones) markedly inhibited cPLA2 activity in the epidermis. These results underscore that different flavonoids do vary in their capability to exert differential effects on arachidonate metabolism in the skin via modulation of epidermal cPLA2 activity.

Ozone induces a differential accumulation of phenyalanine ammonia-lyase, chalcone synthase and chalcone isomerase RNA transcripts in sensitive and resistant bean cultivars

Abstract: On exposure to a realistic ozone dose, an enhanced mRNA accumulation for phenyalanine ammonia-lyase (EC 4.3.1.5), naringenin–chalcone synthase [malonyl–CoA:4-coumaroyl–CoA malonyltransferase (cyclising); EC 2.3.1.74] and chalcone isomerase [flavanone lyase (decyclising); EC 5.5.1.6] genes, whose products are involved in the biosynthesis of phenylpropanoid molecules, flavonoid pigments and isoflavonoid phytoalexins, was observed in primary leaves of the bean (Phaseolus vulgaris L.) cv. Pinto. This cultivar was previously known to be ozone-sensitive on the basis of the appearance of macroscopic foliar injury, but not in coeval leaves of the bean cv. Groffy, known to be ozone-resistant on the basis of the aforementioned criterion. Distinct time patterns were observed in Pinto leaves for the ozone-dependent enhanced mRNA accumulation for the aforementioned genes, which in all cases largely preceded the appearance of visible injury symptoms. These results lend support to the view of ozone as an abiotic elicitor of plant defence responses. By analogy with other case studies, it is also suggested that proneness to develop visible ozone symptoms might rest on a sequence of molecular events similar to that leading to the hypersensitive response during plant–pathogen incompatible interactions.

Isolation and Identification of Two New Flavanones and a Chalcone from Citrus kinokuni

Abstract: Two new flavanones and one chalcone were isolated from the peel of Citrus kinokuni Hort. ex Tanaka and identified as (2S)-5,6,7,8,4'-pentamethoxyflavanone (1), (2S)-5,6,7,3',4'-pentamethoxyflavanone (2) and 2'-hydroxy-3,4,3',4',6'-pentamethoxychalcone (3). The structures of new compounds were elucidated by spectroscopic analysis.

Effect of Flavonoids on the Differentiation of 3T3-L1 Adipocytes

Abstract: The effect of dietary flavonoids (flavone, isoflavone, flavanone, chalcone, flavonol, and flavonol derivatives) on the differentiation of 3T3-L1 adipocytes was investigated. Glycerol-3-phosphate dehydrogenase (GPDH) activity, which is a hallmark of 3T3-L1 differentiation, was measured. The GPDH activity in the cells treated with quercetin, kaempferol, and isorhamnetin was significantly lower than that in the control cells. A low lipid accumulation in cells stained with Oil-Red O was observed following treatment of these flavonols. The anti-differentiation action of quercetin was more potent than that of its derivatives. Quercetin directly inhibited the activity of GPDH extracted from mature 3T3-L1 adipocytes. The inhibitory action of quercetin on the differentiation of 3T3-L1 cells may involve the direct inhibition of GPDH, which is a key enzyme lipid synthesis.

Two new isoflavanoids from bolusanthus speciosus

Abstract: . The structures of two new isoflavonoids from the combined ethyl acetate/methanolic extracts of the stem bark of Bolusanthus speciosus have been established as 4,7,2' -trihydroxy-4' -methoxyisoflavanol (1) and 5,7,3' ,4' -tetrahydroxy-5' -(2-epoxy-3-methylbutyl)isoflavanone (2). Five other known isoflavonoids, 5,7,3' -trihydroxy-4' -methoxy-5' -γγ; -dimethylallylisoflavanone, 5,7,2' -trihydroxy-4' -methoxy-6,5' -di)(γγ -dimethylallyl)isoflavanone, 5,7,2' ,4'-tetrahydroxy-8,5'2; -di(γγ -dimethylallyl)flavanone, 5,7,2' ,4' -tetrahydroxy-8,3' -di(γγ -dimethylallyl)-isoflavanone, and derrone were also isolated. Compound 2 showed moderate activity against gram positive bacteria and weak activity against gram negative bacteria, while compound 1 was weakly active against both organisms in a TLC bioautography assay. (Received March 22, 2001; revised August 13 2001) Bull.Chem.Soc.Ethiop. 2001, 15(2), 131-136

Flavone/flavanone derivatives for the systemic treatment and prophylaxis of uv-induced dermatoses

Abstract: The invention relates to the use of flavone/flavanone derivatives of general fortnula (I) for the production of medicaments for the systematic treatment and prophylaxis of UV-induced dermatoses, in particular polymorphic light dermatoses and the sub-types thereof and/or the undesired long-term consequences of UV-radiation, in particular light-aging. The invention further relates to the use of the compounds of general formula (I) for the systematic treatment and prophylaxis of the above UV-induced dermatoses.

Cosmetic or dermatological preparations, useful e.g. for treating inflammatory skin disorders, pigmentation disorders or aging, containing combination of alpha-lipoic acid and (iso)flavone, flavanone or flavonoid

Abstract: New active agent combinations comprise (A) alpha -lipoic acid and (B) at least one of flavones, flavanones, isoflavones or flavonoids. An Independent claim is included for cosmetic or dermatological preparations containing the (A)/(B) active agent combinations.

Methods and compositions for determining isomerase enzymatic activity

Abstract: This disclosure provides crystalline flavonoid or flavanone isomerases, isolated non-native isomerase having the structural coordinates of said crystalline isomerase, and nucleic acids encoding such non-native isomerase. Also disclosed are methods of predicting the activity and/or substrate specificity of a putative isomerase, methods of identifying potential isomerase substrates, and methods of identifying potential isomerase inhibitors.

Studies on Biological Activity of Wood Extractives(VI) - Flavonoids in heartwood of Prunus sargentii -

Abstract: The structures of six flavonoids isolated from heartwood of Prunus sargentii(Rosaceae) were analyzed by Mass and NMR spectrometry. These flavonoids were grouped into dihydroflavonol, flavanone, and flavanone glycoside, and identified as follows : 3,3',4',5,7-pentahydroxyflavanone(taxifolin) as a dihydroflavonol, 5-hydroxy-7-methoxyflavanone(pinostrobin), 4',5,7-trihydroxyflavanone(naringenin), 3',4',5,7-tetrahydroxyflavanone(eriodictyol), 5,7-dihydroxyflavanone(pinoccmbrin) as a flavanone and 7-hydroxyflavanone 5-O--D-glucopyranoside(verecundin) as a flavanone glycoside.

Flavonoides de Ephera americana (pinco pinco), Acción biológica sobre el sistema inmunológico (IgE)

Abstract: In the present investigation we have developed a phytochemical study and detennined the biological activity of the aerial parts of a vegetal Peruvian species named Ephedra americana Known as "pinco-pinco". It grows in the highlands of Cusco-Peru, in the province of Calca, approximately at 3500 m.o.s.l. The powder of the sample was used to for the phytochemical screening in wich we identified the presence of alkaloids, phenolic compounds, flavonoids types, tannins, glicosydes, etc. By means of a solubility screening test, it was detennined that the secondary metabolites were moderately and highly polar.This was pruved by means of Thin Layer Chromatograpy. Also, a separation of the phenolic compouunds by Flash Column Chromatograpy has been performed, obtaining many fractions. These were purified by means of Preparative Scale Chromatograpy using various solvent systems and five flavonoids with accepted antioxidant activity were structurally elucidated: hesperidin; chrisyn; 3',4' ,5,7-tetrahidroxi-6,8-di R flavone; 3' ,5,7-trihidroxi-4' ,6-dimetoxi flavonol and 4'hidroxi- 5,7-dimetoxi flavanone. In the ethanolic extract it has been detenninated the inmunostimulant activity, the antioxidant effect, toxic action by Artemia salina, antiulcer activity, action on the intestinal motility, anti-inflammatory activity, toxicity and antimicrobial activity.

17O NMR studies on (E)-3-arylidenechromanone and -flavanone derivatives†

Abstract: 17O NMR data for some 3-arylidenechromanones and -flavanones are discussed in terms of mesomeric and steric substituent interactions. The transmission of long-range substituent effects was studied. 17O NMR chemical shifts were correlated with Hammett σp+ values for 4′-substituted derivatives. Copyright © 2001 John Wiley & Sons, Ltd.

Conjugate Addition to 3-Arylsulfinylchromones as a Synthetic Route to Homochiral 2-Substituted Chromanones: Scope and Limitations.

Abstract: A route to homochiral 2-substituted chromanones via the diastereoselective conjugate addn. of organocopper reagents to 3-(p-tolylsulfinyl)chromones has been improved and used to prep. 2,6-dimethylchromanone and LL-D253a Me ether [i.e., (2R)-2,3-dihydro-8-(2-hydroxyethyl)-5,7-dimethoxy-2-methyl-4H-1-Benzopyran-4-one]. The attempted prepn. of a 2-phenylchromanone (flavanone) using this strategy was unsuccessful due to the lability of the intermediate 2-phenyl-3-(p-tolylsulfinyl)chromanone, which underwent sulfoxide elimination at room temp. to give the corresponding 2-phenylchromone (flavone).

A New and Efficient Baeyer—Villiger Rearrangement of Flavanone Derivatives by the Methyltrioxorhenium/H2O2 Catalytic System.

Abstract: The catalytic Baeyer–Villiger rearrangement of flavanones is described by the use of the homogeneous methyltrioxorhenium (MTO)/H2O2 system. In these experimental conditions 3,4-dihydro-4-phenyl-1,5-benzodioxepin-2-ones and previously not reported para-quinone derivatives have been obtained in mild experimental conditions from acceptable to good yields.

Chemical Study on the Seeds of Hovenia acerba Lindl. L

Abstract: AIM Chemical constituents were expected to be obtained from the seeds of Hovenia acerba Lindl. L. METHODS It is extracted with 95% EtOH, isolated via column chromatography on silica gel and purified by recrystallization. RESULTS Eight compounds were obtained from the material. Among them,one is an aromatic acid, six are flavanones and one is an anthraquinone. They are vanillic acid acid(H-3),kaemferol(H-4),apigenin(H-5),4′,5,7- trihydroxy-3′,5′-dimethoxy flavanone(H-6),myricetin(H-7),quercetin(H-9), dihydromyricetin(H-11),emodin(H-2). CONCLUSIONS H-2,H-3,H-4,H-5,H-6 are isolated from the seeds of Hovenia acerba for the first time.