Flavonoid-muster,systematik und evolution bei Valerianella

Leaf extracts from 40 Valerianella species were hydrolyzed and subjected to 2-D chromatography. Luteolin and its methyl ethers, diosmetin and chrysoeriol, are evidently typical for the genus. The distribution of these derivatives and of 6-hydroxyluteolin parallel recent cytological and morphological findings and support a new systematic arrangement. Asiatic species form flavonols, while the North American and Mediterranean-Oriental groups appear progressively more advanced by the appearance of flavones and some 6-hydroxylation.     

The flavonoids of Tanacetum parthenium and T. vulgare and their anti-inflammatory properties.

The lipophilic flavonoids in leaf and flower of Tanacetum parthenium and T. vulgaris have been compared. While those of T. parthenium are methyl ethers of the flavonols 6-hydroxykaempferol and quercetagetin, the surface flavonoids of T. vulgare are methyl ethers of the flavones scutellarein and 6-hydroxyluteolin. Apigenin and two flavone glucuronides are surprisingly present in glandular trichomes on the lower epidermis of the ray florets of T. parthenium. The opportunity has been taken to revise the structures of the four 6-hydroxyflavonol methyl ethers of T. parthenium based on NMR measurements. These are now shown to be uniformly 6- rather than 7-O-methylated. Tanetin, previously thought to be a new structure, is now formulated as the known 6-hydroxykaempferol 3,6,4'-trimethyl ether. The vacuolar flavonoids of both plants are dominated by the presence of apigenin and luteolin 7-glucuronides; nine other glycosides were present, including the uncommon 6-hydroxyluteolin 7-glucoside in T. vulgare. When the major flavonol and flavone methyl ethers of the two plants were tested pharmacologically, they variously inhibited the major pathways of arachidonate metabolism in leukocytes. There were significant differences in potency, with the tansy 6-hydroxyflavones less active than the feverfew 6-hydroxyflavonols as inhibitors of cyclo-oxygenase and 5-lipoxygenase.     

Flavonoid glycosides from illuminated cell suspension cultures of Petroselinum hortense

Twenty-four different flavonoid glycosides were isolated from illuminated cell suspension cultures of parsley (Petroselinum hortense). The chemical structures of fourteen of these compounds were further characterized. The aglycones identified were the flavones apigenin, luteolin and chrysoeriol, and the flavonols quercetin and isorhamnetin. The flavones occurred either as 7-O-glucosides or as 7-O-apioglucosides, while the flavonols were 3-O-monoglucosides or 3,7-O-diglucosides. One-half of these glycosides were electrophoretically mobile and substituted with malonate residues.     

Systematics ofNama (Hydrophyllaceae): Flavonoids and phyletic position of sect.Arachnoidea and sect.Cinerascentia

Eight flavonoids, four 6-oxygenated flavones, two methyl ethers of luteolin, apigenin 6,8-C-diglucoside and quercetin 3-O-glucoside, were isolated fromNama lobbii andN. rothrockii, sole members of sects.Arachnoidea andCinerascentia, respectively. Both taxa diverge markedly from other namas in morphology and chromosome number and their placement inNama has been questioned. The occurrence of 6-oxygenated flavones in these taxa adds to their already distinctive nature. Flavonoid evidence argues that both are more closely allied toEriodictyon than either is toNama.     

Flavonoids as taxonomic markers in old world Lupinus species

In a leaf survey of 54 specimens of 11 Old World Lupinus species three classes of flavonoids were detected: flavones (in 82%), flavonols (in 36%) and flavone C-glycosides (in 55%). The rough-seeded species were clearly distinguished from the smooth-seeded taxa by the presence of a novel 2′-hydroxyflavone, luteolin and flavone C-glycosides as major leaf constituents and by the absence of flavonols. Within the smooth-seeded species, there are three flavonoid patterns: (a) flavonols only, L. albus; (b) flavones and flavonols, L. luteus, L. hispanicus and L. angustifolius; and (c) flavones only, L. micranthus. L. angustifolius further differed in uniquely producing diosmetin as a major leaf constituent. These divisions coincide exactly with previous groupings based on alkaloidal and morphological data. Amongst the 12 samples of L. angustifolius three chemical races were distinguished and a number of diosmetin glucoside malate esters detected. The flower flavonoid aglycone patterns of the nine Old World species surveyed differed markedly from the corresponding leaf profiles by the presence of flavones: luteolin and apigenin in eight and chrysoeriol in seven species as major constituents, while flavone C-glycosides were found only in trace amount in three species. In a leaf flavonoid survey of 13 representative New World Lupinus taxa, glycoflavones were major leaf components, a variety of methylated flavones were identified and flavonols were absent. The presence of the novel 2′-hydroxyflavone in five New World species may indicate some evolutionary link with the rough seeded taxa of the Old World.     

黄酮和黄酮醇通过诱导PIG3表达引发人食管癌细胞凋亡

采用两株人食管癌细胞(鳞癌KYSE-510和腺癌OE33)为肿瘤模型,在体外探讨黄酮、黄酮醇化合物诱导细胞凋亡的分子机制．DNA片段化、吖啶橙染色以及流式细胞术的分析结果表明,3种黄酮(木犀草素、白杨素、芹菜素)和3种黄酮醇(槲皮素、山奈酚、杨梅素)均能诱导两株食管癌细胞发生凋亡．荧光定量RT-PCR和Western-blot分析结果表明,黄酮和黄酮醇是通过诱导PIG3 mRNA和蛋白质的表达、经线粒体途径以非p53依赖的方式,引发两株食管癌细胞凋亡．同时,这一过程可能受到p63和p73的调节．     

Flavonol methyl ethers from Chrysothamnus viscidiflorus

Two new flavonols, 5,7,4′-trihydroxy-3,6,8,3′-tetramethoxyflavone and quercetagetin 3,5,6,3′-tetramethyl ether, were identified in leaves of Chrysothamnus viscidiflorus. Eight known methyl ethers based on kaempferol, quercetin or their 6-hydroxy derivatives were also detected.     

A survey of leaf flavonoids in the portulacaceae

A survey of 26 species in 12 genera of the Portulacaceae showed the presence of flavonoids in 24, and their absence in two, Hectorella caespitosa Hooker fil. and Lyallia kerguelensis Hooker fil. Of the 24 positive species, 16 are reported for the first time. In all 24 however, flavonols and flavones did not occur together suggesting that this dichotomy might be useful for classification at and below the generic level in the Portulacaceae, e.g. the genera Silvaea Philippi (syn. Philippiamara Kuntze), Ceraria Pearson & Stephens and Portulacaria Jacquin which were previously grouped together on palynological characteristics have now been shown to differ in their leaf flavonoids, subsidiary cells of the stomata and geographical location: Silvaea possesses flavones and is endemic to South America, while Ceraria and Portulacaria possess flavonols and are endemic to Africa. The dichotomy also occurs below the generic level. In Calandrinia H.B.K. and Portulaca L. the dichotomy amongst their species is supported by other new taxonomic characters from cytology, palynology, pubescence of surfaces, type of subsidiary cells surrounding the leaf stomata and seed morphology recently elucidated by the author.     

Biosystematics of the monocotyledoneae—flavonoid patterns in leaves of the liliaceae

In a leaf survey of 168 species of the Liliaceae, most of the major flavonoid classes were found to be represented in the family. Flavonols occurred most frequently: quercetin and kaempferol were detected in 40% and 42% of the sample respectively, while the flavones luteolin and apigenin were present in only 24% and 20% of the sample. Methylated derivatives, i.e. isorhamnetin, diosmetin and tricin were rare. Procyanidins were present in 17 species, flavonoid sulphates in only one species and flavone C-glycosides in only three species. Anthraquinone pigments were identified in species of Aloe Asphodeline and Asphodelus. Three new flavonoid glycosides were characterised during the course of the survey: diosmetin 7-diglucoside in Colchicum byzanthinum and tricin 7-fructosylglucoside and tricin 7-rutinoside-4′-glucoside in Hyacinthus orientalis cv. ‘Quean of the Pinks’. On the basis of the flavonoid survey, the subfamilies of the Liliaceae may be grouped into those containing flavonols only, those with flavones only or those having both flavonols and flavones. Members of the related families: Amaryllidaceae (17 species), Agavaceae (1 species) and Xanthorrhoeaceae (1 species) contained only flavonols. The subfamilies Scilloideae, Asphodeloideae and Melanthioideae show the most chemical variation whilst the Wurmbaeoideae and Lilioideae are the most homogeneous groups. The tribe Scilleae is unusual in that both flavone- and flavonol-containing genera occur and a wide variety of flavonoid types are represented. A comparison of the leaf flavonoids of the Liliaceae with those found in families related to the grasses showed that all except two classes of flavonoid compound (5-methylated flavones and 5-deoxyflavonoids) found in the Juncaceae. Cyperaceae, Palmae and Gramineae are present in the Liliaceae thus supporting the view that all four families could have arisen from Liliaceae-like ancestors.     

Structural requirements of flavonoids for inhibition of antigen-Induced degranulation,TNF-alpha and IL-4 production from RBL-2H3 cells

To clarify the structure-activity relationships of flavonoids for antiallergic activity, the inhibitory effects of various flavonoids on the release of beta-hexosaminidase, as a marker of degranulation of RBL-2H3 cells, were examined. Among them, luteolin (IC(50)=3.0 microM), diosmetin (2.1 microM), and fisetin (3.0 microM) were found to show potent inhibitory activity, and the results suggested the following structural requirements of flavonoids: (1) the 2-3 double bond of flavones and flavonols is essential for the activity; (2) the 3- or 7-glycoside moiety reduced the activity; (3) as the hydroxyl groups at the 3'-, 4'-, 5-, 6-, and 7-positions increased in number, the inhibitory activities become stronger; (4) the flavonols with a pyrogallol type moiety (the 3',4',5'-trihydroxyl groups) at the B ring exhibited less activity than those with a phenol type moiety (the 4'-hydroxyl group) or catechol type moiety (the 3',4'-dihydroxyl groups) at the B ring; (5) the activities of flavones were stronger than those of flavonols; and (6) methylation of flavonols at the 3-position reduced the activity. However, (7) several flavones and flavonols with the 4'- and/or 7-methoxyl groups did not obey rules (3), (4), and (5). In addition, several flavonoids, that is apigenin, luteolin, diosmetin, fisetin, and quercetin, inhibited the antigen-IgE-mediated TNF-alpha and IL-4 production from RBL-2H3 cells, both of which participate in the late phase of type I allergic reactions.     

An NADPH and FAD dependent enzyme catalyzes hydroxylation of flavonoids in position 8

Yellow flavonols contribute to flower pigmentation in Asteraceae. In contrast to common flavonols, they show additional hydroxyl groups in position 6 and/or 8 of the aromatic A-ring in addition to the basic 5,7-hydroxylation pattern. An enzyme introducing a hydroxyl group in position 8 of flavonols and flavones was demonstrated for the first time with enzyme preparations from petals of Chrysanthemum segetum. Flavanones, dihydroflavonols and glucosylated flavonols and flavones were not accepted as substrates. The enzyme was localized in the microsomal fraction and uses NADPH and FAD as cofactors. Experiments with carbon monoxide/blue light and with antibodies specific for cytochrome P450 reductase did not indicate the involvement of a classical cytochrome P450 dependent monooxygenase in the reaction. Thus, the flavonoid 8-hydroxylase represents a novel type of hydroxylating enzyme in the flavonoid pathway. Apart from flavonoid 8-hydroxylase activity, the presence of all enzymes involved in the formation of flavonoid 7-O-glucosides in C. segetum was demonstrated. The pathway leading to 8-hydroxyflavonoids in C. segetum has been derived from enzyme activities and substrate specificities observed.     

Inhibition of lens aldose reductase by flavonoids

The inhibitory activities of 73 flavonoids against rat aldose reductase were systematically investigated and cosmosiin, luteolin-7-glucuronide, lonicerin, 6-hydroxyluteolin, kaempferol-3-rhamnoside and avicularin were newly found to be highly active. The degree of inhibition appears to depend on the solvent system used. In general flavones are more active than flavonols and flavanones, glycosides are more active than aglycones, and the number of sugars present affects the activity.     

Differentiation des dihydroxy-5, 7 methoxy-6 ou 8 flavones flavonols et methyl-3 flavonols par spectrometrie de masse

5,7-Dihydroxy flavones and flavonols variously methoxylated in the 3-, 6- and/or 8-positions give characteristic fragmentation peaks. The relative abundance of M, M-1 and M-15 peaks and the presence of M-18 peak makes it possible to differentiate the 6-methoxy from the 8-methoxy isomers and three types of 6-methoxyflavones from each other.     

Correlations between flavonoid chemistry,anatomy and geography in the restionaceae

Comparisons of the flavonoid patterns in stems and inflorescences between Australasian and South African members of the Restionaceae indicate significant differences with geography. Nine of 14 Australasian species contain gossypetin or a related 8-hydroxyflavonoid and proanthocyanidins are uncommon. By contrast, the 33 South African taxa studied contain common flavonols, flavones and glycoflavones, while proanthocyanidins are present in 29. Two anatomically related South African genera, Chondropetalum and Elegia, contain, in addition, myricetin 3-galactoside, together with the 3-galactosides of the myricetin methyl ethers, larycitrin and syringetin. These results confirm the conclusions derived from anatomy that members of Hypolaena, Leptocarpus and Restio, genera represented in both Australia and South Africa, have the distinctive flavonoids characteristic of their geographic origin rather than of their systematic position. The family as a whole is different in flavonoid pattern from other monocotyledonous families with which it is sometimes associated.     

Sur l'analyse qualitative des aglycones flavoniques dans une optique chimiotaxinomique

A qualitative method is described for the analysis of flavonols and flavones in hydrolysed extracts of plant organs; the procedure involves thin layer and column chromatography of plant extracts on polyamide. Physicochemical data are given for about eighty flavonoids.     

6-Methoxyflavonoids from Brickellia californica

Two new and eleven known 6-methoxyflavonoids were identified in leaf tissue of Brickellia californica. The new flavonols are eupatin 3-SO₃ Ca_1/2 and patuletin 3-SO₃K. The known compounds include the flavones hispidulin and eupafolin and their respective 7- and 4′-monomethyl ethers and the flavonols; spinacetin, eupatin, patuletin 3-glucoside and 3-galactoside, and eupatolitin 3-galactoside.     

Caffeoylquinic Acids: Separation Method,Antiradical Properties and Cytotoxicity

Twelve chlorogenic acid derivatives and two flavones were isolated from Moquiniastrum floribundum (Asteraceae, other name: Gochnatia floribunda). Compounds were evaluated in relation to their cytotoxicity and antiradical properties. Cytotoxicity was not observed for compounds, however, chlorogenic acid derivatives showed antiradical activity and were more active than the Trolox standard. Quinic acid esterified with caffeoyl group at C‐4 position showed higher antiradical activity compared to acylation at C‐3 or C‐5 positions. Additional caffeoyl groups esterified in quinic acid increase the antiradical activity observed for 4‐caffeoylquinic acid. Excepted to 3,4‐dicaffeoylquinic acid methyl ester, methyl ester derivatives show higher capacity of trapping radicals than their respective acids. Consequently, the presence of caffeoyl group at C‐4 position of quinic acid is suggested as fundamental to obtain the highest antiradical activity.     

Phytochemical relationships of Carrpos with Corsinia and other Marchantialean Genera

The uniqe (to the Marchantiales) production of flavonols by Corsinia is confirmed and these are shown to occur as 3-O-glycuronide derivatives. The miniscule Carrpos is shown to produce biosynthetically simple flavone 7-O-glucuronides plus aureusidin 6-O-glucuronide. Corsinia, it is concluded, is an isolated and primitive member of the order Merchantiales, whilst Carrpos is strongly aligned with the reduced members of the ‘mainstream-type’ Marchantialean genera. There is no support for the suggested inclusion of both genera in the same isolated suborder Corsiniinae.     

Anthocyanin pigments and leaf flavonoids in the family araceae

Anthocyanins, variously identified in inflorescence, fruit, leaf or petiole of 59 representative species of the Araccae, are of a simple type. The most common pigment is cyanidin 3-rutinoside, while pelargonidin 3-rutinoside and cyanidin 3-glucoside are regularly present. Two rare pigments are: cyanidin 3-gentiobioside in Anchomanes and Rhektophyllum, both in the subfamily Lasioideae; and delphinidin 3-rutinoside in Schismatoglottis concinna. In a leaf survey of 144 species from 58 genera, flavone C-glycosides (in 82%) and proanthocyanidins (in 35–45%) were found as the major flavonoids. In the subfamily Calloideae, subtribe Symplocarpeae, flavonols replace glycoflavones as the major leaf components but otherwise flavonols are uncommon in the family (in 27% of the sample) and more usually co-occur with flavone C-glycosides. Two new flavonol glycosides were characterized from Lysichiton camtschatcense: kaempferol 3-(6-arabinosylgalactoside)and kaempferol 3-xylosylgalactoside. Simple flavones, luteolin and chrysoeriol (in 6%) were found only in the subtribes Arinae and Cryptocoryninae, subfamily Aroideae. Flavonoid sulphates were identified in only four taxa: glycoflavone sulphates in two Culcasia species and Philodendron ornatum and a mixture of flavone and flavonol sulphates in Scindapsus pictus. Caffeic ester sulphates were more common and their presence in Anthurium hookeri was confirmed. These results show that the Araceae are unusual amongst the monocots in their simple and relatively uniform flavonoid profile; no one subfamily is clearly distinguished, although at tribal level some significant taxonomic patterns are observed. The best defined groups are the subfamilies Lasioideae and Monsteroideae, and the tribes Symplocarpeae and Arophyteae, and the subtribe Arinae. The greatest chemical diversity occurs in Anthurium and Philodendron, but this may only reflect the fact that these are the two largest genera in the family. The origin and relationship of the Araccae to other monocot groups are discussed in the light of the flavonoid evidence.     

The level of flavonoids and amines in de-etiolated and methyl jasmonate treated seedling of common buckwheat

The effects of atmospheric methyl jasmonate on the level of flavonoids and biogenic amines in de-etiolated seedlings of common buckwheat (Fagopyrum esculentum Moench) were investigated. In cotyledons and hypocotyls of etiolated seedlings, some traces of anthocyanins were found, with no flavones and flavonols identified. A measurable content of flavones and flavonols was, however, determined in roots. De-etiolation process stimulated the accumulation of all flavonoid types. Methyl jasmonate clearly decreased the content of anthocyanins in the hypocotyl, not affecting their level in cotyledons. In case of roots, the content of anthocyanins increased after a 4-day treatment. In general, reduction in the level of flavones and flavonols was recorded only in the hypocotyl, however it was not always significant. Cotyledons of the seedlings treated with methyl jasmonate responded by a slight increase in flavonoids level. Methyl jasmonate considerably induced the accumulation of 2-phenylethylamine in all the seedling organs, increasing the content of putrescine and tryptamine in cotyledons, and decreasing the level of tryptamine in roots.