Showing papers on "Flavanone published in 1989"
TL;DR: Analysis of structure-activity data revealed a model of the minimal essential features required for PKC inhibition by flavonoids: a coplanar flavone structure with free hydroxyl substituents at the 3', 4' and 7-positions.
460 citations
TL;DR: Tests have been carried out with several plant flavonoids to detect their ability to suppress mutagenesis in Salmonella typhimurium strain TA100 NR induced by the direct-acting carcinogen N-methyl-N'-nitro-N-nitrosoguanidine.
Abstract: Tests have been carried out with several plant flavonoids to detect their ability to suppress mutagenesis in Salmonella typhimurium strain TA100 NR induced by the direct-acting carcinogen N-methyl-N'-nitro-N-nitrosoguanidine. Among the most effective flavonoids are the isoflavone, biochanin A, the flavanone glycoside, naringin, and its aglycone, naringenin, and several flavonols, e.g. morin, fisetin, kaempferol, gossypetin and quercetin, including a flavonol glycoside, rutin. In particular, naringin possesses exceptional antimutagenic activity, in as much as, less than half the equimolar amount can reduce the mutagenic potency of this carcinogen by 50%. These flavonoids appear to act either by preventing passage of the carcinogen into bacterial cells or by altering some cellular processes.
127 citations
TL;DR: The present results suggests that certain flavonoids, notably polyhydroxylated flavonols, may have potential anticarcinogenic activity against AFB1.
Abstract: Eighteen flavonoids have been tested for their ability to inhibit the mutagenicity of aflatoxin B1 (AFB1) towards strains TA100 and TA98 of Salmonella typhimurium provided with a rat liver activation system. These flavonoids belong to 5 different groups: flavone, isoflavone, flavanone, flavanol and flavonol, and many individual members are natural products present in edible portions of a variety of food plants. Several flavonoids exhibited significant inhibitory ability in both strains. Flavonols in general are more active in this regard, while flavanones show a strain-specific response. The flavanol group of compounds did not display any activity. Among the most effective flavonoids are kaempferol, morin, fisetin, biochanin A and the glycoside rutin, all of which exhibit a dose-dependent inhibition pattern. Kaempferol and rutin, in particular, show exceptional activity inasmuch as, on a molar basis, only a 10-fold excess dose of each can inhibit the mutagenic activity of AFB1 in strain TA98 by 50%. The action of flavonoids is possibly mediated through interaction with microsomal activating enzymes. Previous evidence from this laboratory about their inhibitory action on DNA-adduct formation and metabolic activation together with the present results suggests that certain flavonoids, notably polyhydroxylated flavonols, may have potential anticarcinogenic activity against AFB1.
97 citations
TL;DR: Flavanone, which differs from flavone only by the degree of unsaturation of the pyrone ring, produced only a weak increase in monooxygenase activity, but the increase in phase II enzyme activities was as great as that for flavone treatment.
Abstract: 1. The influence of the dietary flavonoids, chrysin, quercetin, tangeretin, flavone and flavanone, on the components of the rat liver drug-metabolizing enzyme system was examined and compared with two well-known synthetic flavonoids 7,8-benzoflavone and 5,6-benzoflavone. 2. Polyhydroxylated molecules such as quercetin and chrysin, produced no significant changes on phase I and phase II enzyme activities. 3. Flavone was the most potent inducer, and resulted in a mixed type of induction. 7-Ethoxycoumarin O-deethylase (ECOD), 7-ethoxyresorufin O-deethylase (EROD) and pentoxyresorufin depentylase (PROD) activities were increased 2, 30 and 15-fold respectively. p-Nitrophenol UDP-glucuronyltransferase (UDPGT 1), p-hydroxybiphenyl UDP-glucuronyltransferase (UDPGT 2) and glutathione transferase (GST) activities were also induced. 4. Flavanone, which differs from flavone only by the degree of unsaturation of the pyrone ring, produced only a weak increase in monooxygenase activity, but the increase in phase II enzyme activities was as great as that for flavone treatment. 5. Tangeretin displayed a mixed pattern of induction, with increases in ECOD, EROD and PROD, and UDPGT 1 and UDPGT 2 activities, but these were less than with flavone treatment. 6. 7,8-Benzoflavone and 5,6-benzoflavone showed induction patterns similar to those of 3-methylcholanthrene. Nevertheless dietary treatment with 5,6-benzoflavone caused changes which were not as great as those usually described when this compound is administered i.p.
64 citations
TL;DR: Data indicate that Citrus contains a flavonoid pathway similar to that studied in other species, and chalcone-synthase and UDP-glucose:flavanone-7-O-glUCosyl-transferase activities in cell-free extracts of Citrus are detected.
Abstract: Previous indirect evidence suggested that the biosynthesis of flavonoids in Citrus may not proceed via the usual chalcone synthase reaction and that glycosylation occurs during chalcone formation and not afterward, as has been reported in other species. We detected chalcone-synthase and UDP-glucose:flavanone-7-O-glucosyl-transferase activities in cell-free extracts of Citrus. The glucosylated flavanone was further rhamnosylated when exogenous UDP-glucose and NADPH were added to the extract. Chalcone-synthase activity was detected in cell-free extracts derived from young leaves and fruits. Young fruits (2 millimeter diameter) had the highest chalcone synthase activity. UDP-glucose:flavanone-7-O-glucosyl-transferase activity was measured in cell-free extracts derived from young leaves and fruits of Citrus mitis and Citrus maxima. The highest UDP-glucose:flavanone-7-O-glucosyl-transferase activity was found in young C. maxima leaves. These data indicate that Citrus contains a flavonoid pathway similar to that studied in other species.
61 citations
TL;DR: Analysis of the bark and seed pods of plant material assigned to Millettia ferruginea and M. darassana shows patterns of flavonoid production do not appear to distinguish the two subspecies.
48 citations
TL;DR: From the roots, leaves and pods of Tephrosia pentaphylla three new 6-oxygenated rotenoids (dihydrostemonal, 9-demethyldihydroidstemonal and 6-acetoxydihydristemonal) were isolated and characterized.
45 citations
TL;DR: In this paper, the same authors showed that immature grapefruits are capable of biosynthesizing flavonoids from simple precursors and suggest that multiple-glycosylation of flavanones may occur by the addition of discrete single sugar units.
45 citations
TL;DR: From a methanolic root extract of Salvia texana, 5-hydroxy-7,4′-dimethoxyflavone and (+)-2(S)-5-hydroxymethoxy-7-methoxyFlavanone were isolated and characterized by spectroscopy.
31 citations
TL;DR: Five flavonoids and an acetophenone derivative were isolated from Artemisia campestris subsp.
30 citations
TL;DR: Two new flavanones were isolated from the roots of Euchresta formosana in addition to four known Flavanones (xambioona, euchrestaflavanones A, B and C) and a pterocarpan (maackiain), and by spectroscopic analysis, the structures of euchrenones a5 and a6 were determined to be 7-hydroxy-8-γ,γ-dimethyl-allyl and 5
TL;DR: A new prenylated isoflavanone was isolated from the stem bark of ERYTHRINA BERTEROANA Urb.
Abstract: A new prenylated isoflavanone was isolated from the stem bark of ERYTHRINA BERTEROANA Urb. Based on chemical and spectroscopic evidence, the structure of a previously isolated flavanone was revised.
TL;DR: Investigations of phenylalanine ammonia-lyase and chalcone synthase activities in anthers of various systems indicated that the observations made for Tulipa c.v. Apeldoorn do not represent a unique but a widespread phenomenon.
01 Jan 1989
TL;DR: The biflavonoid larixinol, isolated from Larix gmelini, a condensation product of dihydrokaempferol and (−)-epiafzelechin, comes closest to a representative of the crossed flavanone-flavan-3-ol biflavanoids as discussed by the authors.
Abstract: The biflavonoids and proanthocyanidins constitute the two major classes of oligomeric flavonoids found in plants (126, 136). The biflavonoids are oxidative coupling products leading to biflavones, flavanone-flavones, and biflavanones. These compounds always carry carbonyl functions at the C-4 positions (126). In contrast, the proanthocyanidins are products of the reduction of flavanonols such as flavan-3,4-diols or oligomeric flavan-3-ols with an interflavanoid bond at C-4 being coupled to a terminating flavan-3-ol (136). Natural compounds that are crossed products between these two classes, such as a flavan-3-ol linked through C-4 to a flavanone or a flavanone oxidatively coupled to a flavan-3-ol, are extremely rare. The unusual biflavonoid larixinol, isolated from Larix gmelini, a condensation product of dihydrokaempferol and (−)-epiafzelechin, comes closest to a representative of the crossed flavanone-flavan-3-ol biflavanoids (336). It is likely, therefore, that this classification of oligomeric flavanoids into two categories will undoubtedly be used for some time to come.
TL;DR: One flavanone, euchrestaflavanone A and four isoflavonoids (lupinalbin A-C, and a previously unreported 4′-methyl ether of wighteone) were isolated from Lotus creticus as mentioned in this paper.
TL;DR: A new flavanone isosakuranetin 7- O -rhamnoside was isolated from Cyclotrichium niveum together with known flavanones apigenin and eriodictyol 7-O -glucoside as discussed by the authors.
TL;DR: Competitive experiments with [3H]flavanone and [14C]chalcone as the substrates for isoflavone synthase revealed that flavanone is the true substrate for this enzyme reaction and the possible role of chalcone in the reaction is excluded.
Abstract: Liquiritigenin and isoliquiritigenin were converted into daidzein by a microsomal fraction of cell suspension cultures of Pueraria lobata OHWI, which had been treated with an endogenous elicitor prepared by hydrolysis of their own cell walls with a fungal endopolygalacturonase. Competitive experiments with [3H]flavanone and [14C]chalcone as the substrates for isoflavone synthase revealed that flavanone is the true substrate for this enzyme reaction and the possible role of chalcone in the reaction is excluded.
TL;DR: The methylated flavonoids, peonidin and isorhamnetin, found in pigment extracts of maize tissues are the products of methylation by the S-adenosylmethionine-flavonoid 3´-Omethyltransferase, which suggests that methylation occurs sometime prior to the glucosylation reaction which is thought to occur near the end of the biosynthetic sequence for the flavonoid compounds in maize.
01 Jan 1989
TL;DR: Puddumin-B, a new flavanone glycoside (naringenin-4′-methyl-ether - 7-O-β-D-galactoside) has been isolated from Prunus cerasoides and characterised by spectroscopic and chemical methods as discussed by the authors.
Abstract: Puddumin-B, a new flavanone glycoside (naringenin-4′-methyl-ether - 7-O-β-D-galactoside) has been isolated from Prunus cerasoides and characterised by spectroscopic and chemical methods.Prunus cerasoides D. Don (syn. P. puddum Rosaceae), is a tree distributed in the temperate Himalayas to an altitude of 1700 m (1,2). The stems are reported to be antipyretic, refrigerant and useful in vomiting, leprosy and leucoderma (1,2). Chemical examination of P. cerasoides has been done by various workers (3–12). The present paper reports the isolation, and characterisation of a new flavanone glycoside, naringenin-4-methyl ether-7-O-β-D-galactoside from the stem bark of P. cerasoides.
TL;DR: From the fresh leaves of Lindera umbellata Thunb. var. lancea Momiyama a new flavanone, named neolinderatone (6), was isolated and the structure was established by spectroscopic and chemical means as (2S-, 3"S__-, 4"R__-, 3"'S-, 4"'R__-)-5, 7-dihydroxy-6, 8-bis(4-isopropyl-1-methylcyclohexl-en-3-yl)flavanone RE
Abstract: From the fresh leaves of Lindera umbellata Thunb. var. lancea Momiyama a new flavanone, named neolinderatone (6), was isolated and the structure was established by spectroscopic and chemical means as (2S__-, 3"S__-, 4"R__-, 3"'S__-, 4"'R__-)-5, 7-dihydroxy-6, 8-bis(4-isopropyl-1-methylcyclohexl-en-3-yl)flavanone.
TL;DR: Grapefruit (Citrus paradisi) tissue cultures were examined for qualitative and quantitative changes in flavanone-neohesperidoside content during somatic embryogenesis.
Abstract: Grapefruit (Citrus paradisi) tissue cultures were examined for qualitative and quantitative changes in flavanone-neohesperidoside content during somatic embryogenesis. Embryos cultured in vitro contain naringin and a rhamnosyl-transferase activity which is capable of rhamnosylating position 2 on the flavanone glucosides. Rhamnosylation is carried out only in embryos cultivated on solid medium but not in embryos grown in suspension cell cultures.
Patent•
04 Oct 1989
TL;DR: In this article, the authors describe a set of compounds with a flavanone skeleton having the formula I (I) in which R1 and R2 represent hydrogen, hydroxyl, methoxyl, thiomethyl, amino or substituted amino, are endowed with expectorant, mucolytic, mucopoietic, choleretic and hypolipaemia-producing activity.
Abstract: not available for EP0122053Abstract of corresponding document: US4636569Compounds with a flavanone skeleton having the formula I (I) in which R1 and R2, which may be the same or different, represent hydrogen, hydroxyl, methoxyl, thiomethyl, amino or substituted amino, are endowed with expectorant, mucolytic, mucopoietic, choleretic and hypolipaemia-producing activity.
TL;DR: An enzyme system derived from cell cultures of Cassia didymobotrya showed, inter alia, a chalcone - flavanone isomerase which revealed a maximum activity when isolated from 22 day old cultures.
Abstract: An enzyme system derived from cell cultures of Cassia didymobotrya showed, inter alia, a chalcone - flavanone isomerase which revealed a maximum activity when isolated from 22 day old cultures. Its substrate specificity was demonstrated by using sixteen chalcones featuring different substitutions patterns in rings A and B
Patent•
14 Mar 1989
TL;DR: In this article, the authors describe a pharmaceutical preparation containing compounds of formula I (I), in which X represents unsubstituted or substituted amino or a quaternary ammonium salt; halogen, free,etherified, esterified or oxidized mercapto; free or functionally modified carboxyl, free or functional modified sulfo; acyl; nitro; an unsubstitized or substituted hydrocarbon radical; and an unsaturated or substituted heterocyclic radical, Y represents oxygen, sulfur, sulfinyl or sulfonyl but must be
Abstract: 4-14561/ZYM 34/+ Pharmaceutical preparations containing flavanone or thioflavanone derivatives, the use thereof, novel flavanones and thioflavanones, and processes for their manufacture The invention relates to pharmaceutical preparations containing compounds of formula I (I) , in which X represents unsubstituted or substituted amino or a quaternary ammonium salt; halogen, free,etherified or esterified hydroxy; free,etherified, esterified or oxidized mercapto; free or functionally modified carboxyl, free or functionally modified sulfo; acyl; nitro; an unsubstituted or substituted hydrocarbon radical or an unsubstituted or substituted heterocyclic radical, Y represents oxygen, sulfur, sulfinyl or sulfonyl but must be oxygen, sulfinyl or sulfonyl, if X is 1Himidazol-1-yl, and rings A and B are each unsubstituted or substituted, or pharmaceutically acceptable salts of such compounds that contain a salt-forming group, and to novel compounds of formula I. The compounds are useful e.g. for the treatment of diseases of the respiratory tract and of liver diseases. They are prepared by methods known per se.
TL;DR: In this paper, the PMR and IR spectra of chalcones were discussed, and the chalcone analogs were isomerized to the corresponding flavanones and isoflavones.
Abstract: Benzodioxane analogs of chalcones were isomerized to the corresponding flavanones and isoflavones. The PMR and IR spectra of these compounds were discussed.
DOI•
01 Dec 1989TL;DR: Euchrenone a2 (7) isolated from the roots of Euchresta japonica has been synthesised from 3-prenylphloroacetophenone (1) by other workers.
Abstract: Euchrenone a2 (7) isolated from the roots ofEuchresta japonica has been synthesised from 3-prenylphloroacetophenone (1) by other workers. We carried out its cyclodehydrogenation with dichloro dicyano quinone (DDQ) to obtain 6-acetyl-5,7-dihydroxy-2,2-dimethylchromene (2) which was ethoxymethylated in the 7-position to give 6-acetyl-7-ethoxymethoxy-5-hydroxychromene (3). Chalcone condensation of3 and 4-ethoxymethoxy-3-C-prenylbenzaldehyde (4) gave 4,6′-bisethoxymethoxy-2′-hydroxy-6″, 6″-dimethyl-3-C-prenylpyrano (2″, 3″–4,3) chalcone (5) which cyclised with methanolic sodium acetate to give protected 5,4′-bisethoxymethoxy-6″, 6″-dimethyl-3′-C-prenylpyrano (2″, 3″–7,8) flavanone (6). Deprotection of6 with 4% methanolic HCl yielded (7) with melting point and spectral data identical to that of the natural compound.