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.     

Flavonoids of the Muhlenbergia montana complex

Specimens from natural populations of Muhlenbergia montana (Nutt.) Hitch. and related species were analysed for their flavonoid content. Twenty-four flavonoids from 14 species were separated and 22 of the compounds identified. Most were glycosylated derivatives of luteolin, apigenin and tricin. Two flavonols, quercetin 3-O-rutinoside and quercetin 3-O-glycoside, and two flavanones were also identified. Flavonoid patterns were distinct for all perennial species and identical for the two annual species examined. Phenetic analysis of the flavonoid characters does not support the inclusion of the annual species M. crispiseta and M. peruviana as part of the M. montana complex.     

The chemosystematics of Egyptian Trigonella species

Flavonoid glycosides of eight Trigonella species belonging to four sections of the Leguminosae [Gamal El Din, E.M. and Hassan, A.E. (1995) Taeckholmia, in press] were investigated. Fifteen glycosides were found based on the aglycones kaempferol, quercetin and the less common 7,4′-dihydroxyflavone and 7,3′,4′-trihydroxyflavone. One isoflavone (formononetin) was found in all Trigonella species. Chemosystematic relationships are discussed.     

Apigenin di-C-glycosylflavones of Angiopteris (Marattiales)

A survey of the flavonoids of four species of Angiopteris indicates that di-C-glycosylflavones and flavone-O-glycosides may be characteristic of this distinct group of eusporangiate ferns. Derivatives of flavonols, which are typical of leptosporangiate ferns and Ophioglossum, or biflavones, which are characteristic of the Psilotaceae, were not detected in Angiopteris.     

Flavonoids as taxonomic markers in some cocosoid palms

Flavonoid surveys of hydrolysed and direct leaf extracts of fifty two cocosoid palms revealed tricin, glycoflavones, proanthocyanidins, quercetin, flavonoid sulphates, isorhamnetin, and luteolin as regular constituents; present in 87, 77, 53, 47, 36, 26 and 26% of species, respectively. Kaempferol was found in 15% of the sample and apigenin in only one taxon ofAttalea. Attalea andSyagrus were chemically heterogeneous groups. The flavonoid evidence suggested the removal ofPolyandrocosus from theAllagoptera unit, the recognition of twoMaximiliana species, the separation ofArecastrum andArikuryroba fromSyagrus and thatJubaea was closer toButia thanJubaeopsis. Five morphologically similar Central AmericanScheelea species were distinguished by their flavonoid profiles.     

Negatively charged flavones and tricin as chemosystematic markers in the palmae

A survey of 125 species of the Palmae revealed a complex pattern of flavonoids in the leaf. C-Glycosylflavones, leucoanthocyanins and tricin, luteolin and quercetin glycosides were common, being present in 84, 66, 51, 30 and 24% of the species respectively. Apigenin and kaempferol were recorded in only a few species and isorhamnetin only once. Eighteen flavonoids were identified: the 7-glucoside, 7-diglucoside and 7-rutinoside of both luteolin and tricin, tricin 5-glucoside, apigenin 7-rutinoside, quercetin 3-rutinoside-7-galactoside, isorhamnetin 7-rutinoside, orientin, iso-orientin, vitexin, isovitexin and vitexin 7-O-glucoside. Many of the C- and O-flavonoid glycosides were present as the potassium bisulphate salts and negatively charged compounds were detected in 50% of the species. The distribution patterns are correlated with the taxonomy of the family in several ways. Thus, the Phoenicoideae and Caryotoideae have distinctive flavonoid patterns, there is evidence to support the separation of the subfamilies Phytelephantoideae and Nypoideae, and tricin is a useful marker at tribal level. At the generic level, Cocos is clearly separated from Butia, and other Cocoseae and Mascarena and Chamaedorea form well defined groups within the Arecoideae. A numerical analysis of these biochemical data, together with morphological characters, produces a new classification which suggests that the flavonoid data may have more systematic value than is indicated when they are applied to the traditional classification.     

Chemosystematics of the hydrophyllaceae: Flavonoids of three species of eriodictyon

Eleven flavonoids, nine aglycones and two glycosides were isolated from Eriodictyon tomentosum, E. angustifolium and E. Californicum. Aglycones included the flavanone homoeriodictyol, the flavones apigenin, luteolin, chrysoeriol, 6-methoxyapigenin, 6-methoxyapigenin 7-methyl ether, 6-methoxyapigenin 4′-methyl ether, 6-methoxyluteolin and 6-methoxyluteolin 3′-methyl ether, glycosides were the 3-O-glucosides of quercetin and kaempferol.     

PROLAMIN AND IMMUNOLOGICAL STUDIES IN THE POACEAE. III. SUBFAMILY CHLORIDOIDEAE

Prolamin size variation and structural similarities were used as molecular characters to address questions pertaining to tribal structure and phylogenetic origin of the Chloridoideae. Prolamin polypeptides were resolved by SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis), and the immunological cross-reactivities were measured by ELISA (enzyme-linked immunosorbent assay) and immunoblotting. Thirty-three species were examined from 24 genera belonging to six chloridoid tribes and three outgroup subfamilies (Arundinoideae, Panicoideae, and Pooideae). The study supports the inclusion of the Cynodonteae, Eragrosteae, and Sporoboleae under one tribe. Members of the Pappophoreae and Spartineae appeared as distinct lineages. The results suggest a strong evolutionary relationship between the Chloridoideae and Arundinoideae.     

Foliar flavonoids of Annonaceae from Brazil: taxonomic significance

Foliar flavonoids of 31 species of the Annonaceae native to Brazil, amounting to 76 compounds, were isolated and identified. All phenols found were glycosides of either flavones (apigenin, scutellarein, hispidulin and luteolin) or flavonols (kaempferol, rhamnocitrin, 6-hydroxyrhamnocitrin, quercetin, isorhamnetin and rhamnetin), with the latter predominating. Some members of the tribe Bocageeae are distinctive for accumulating 6-oxygenated flavones and flavonols, in addition to 7-O-methylated flavonols, a feature possibly linked to the assumed advanced condition of the tribe within the family. Members of Duguetia stand out for the apparent absence of quercetin glycosides. Anaxagorea dolichocharpa seemingly lacks flavones and flavonols entirely. A UPGMA analysis based on the distribution of flavonoids does not group the analyzed species according to the available tribal division of the Annonaceae. However, several taxonomically meaningful groupings emerged through the multivariate analysis.     

Flavonoids of Pallenis spinosa (Asteraceae)

Pallenis spinosa was investigated for its flavonoid content. Two mono- and diglycosides of patuletin, a quercetin monoglycoside, two tricin monoglycosides, and four methoxylated flavonols were reported.     

Leaf surface flavonoids of Eriodictyon trichocalyx

Extraction of the leaf resin of Eriodictyon trichocalyx var. trichocalyx ether, yielded naringenin, eriodictyol, eriodictyol 3′-methyl ether, apigenin, 6-methoxy-apigenin, luteolin, 6-methoxyluteolin, chrysoeriol, luteolin 3′,7-dimethyl ether and isorhamnetin. The flavonoid profile agrees weil in most respects with the types of compounds exhibited by other Eriodictyon species, particularly with regard to the presence of 6-substituted flavones and a moderate level of O-methylation. Flavonoid variation in E. californicum is briefly discussed.     

Flavonoids and the systematics of Luffa

Flavonoids were characterized from leaves and flowers of six species of Luffa. Each species had a distinct flavonoid pattern. Based on leaf flavonoids, Luffa is separable into two groups of species: L. graveolens and L. operculata contain only flavonols. L. acutangula, L. aergyptiaca, L. echinata and L. forskalii contain only flavones. Flavonoid data indicate that the New World disjunct species. L. operculata, is most closely related to L. graveolens.     

Flavonoid pigments in swallowtail butterflies

Flavonoid pigments have been identified in the swallowtail butterfly Eurytides marcellus and its larval foodplant Asimina triloba (Annonaceae). Although quercetin 3-glycoside, quercetin 3-rutinoside and quercetin 3-rutinoside-7-glucoside are present in the plant, only quercetin 3-glucoside is sequestered by the insect. Flavonoids have also been found in 10 out of 27 other papilionid species examined. These were mainly 3- and 7-glycosides of the flavonols quercetin and kaempferol. The sequestration of flavonoids by papilionid butterflies appears to be related both to the phylogeny of the Papilionidae and to the choice of larval foodplants by the various phylogenetic groups.     

Flavonoid systematics of ten sections of Ludwigia (Onagraceae)

Data for the flavonoids of 19 species in 10 sections of Ludwigia are presented. Eight flavonoids, comprising four glycoflavones, of which vitexin and isovitexin are reported for the first time in Ludwigia, and four flavonol glycosides, based on quercetin, are present in these species. Each section treated here has either glycoflavones or flavonols; presence of only onte class is considered to be advanced in the genus as a whole, compared with the presence of both glycoflavones and flavonols in the more generalized sects Myrtocarpus Cinerascentes, and Pterocaulon, which were examined earlier. Only glycoflavones are present in sects Macrocarpon (four species), Seminuda (five species), the ditypic African sect. Africana, the monotypic African sects Brenania, Cryptosperma, and Prieurea, the monotypic east Asian sect. Nipponia, and the monotypic pantropical section Fissendocarpa. Only flavonols are present in the monotypic Old Wodd section Caryophylloidea and sect. Oligospermum, which comprises nine species widespread in the OId and New Worlds.     

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.     

Flavonoid pigments of butterflies in the genus Melanargia

Flavonoid pigments (18) were identified in the wings and body of Melanargia galathea: tricin, tricin 7-glucoside, tricin 7-diglucoside, tricin 4′-glucoside, luteolin, luteolin 7-glucoside, luteolin 7-diglucoside, luteolin 7-triglucoside, apigenin, apigenin 7-glucoside, orientin, orientin 7-glucoside, iso-orientin, iso-orientin 7-glucoside, vitexin 7-glucoside, vitexin 7-glucoside, isovitexin, isovitexin 7-glucoside and a novel but incompletely identified tricin 4′-conjugate. Examination of the wings and bodies of individual M. galathea, M. galathea var. procida, M. lachesis, M. russiae, M. larissa, M. occitanica and M. ines butterflies from a number of different populations in Europe by 2D PC revealed that variation in their flavonoid patterns was so minor that the flavonoid pattern of these Melanargia spp. may be considered constant. The concentration of flavonoids in the wings of each butterfly was greater than that in the body, as is the covering of scales. Not all flavonoids are located in the scales; some are also located in the reproductive tissues of the female. With the exception of the tricin 4′-conjugate which was absent from the egg and first instar larvae before feeding commences, these flavonoids were present in all the life stages of M. galathea. The presence of tricin 4′-conjugate in Melanargia but its absence from the larval food plants suggests that this compound is synthesized by the insect and that flavonoids are not merely sequestered from the diet but are also partly metabolized.     

The phylogenetic significance of flavonoids in Crambe L. (Cruciferae)

A total of 21 flavonoid compounds has been detected in 14 species of Crambe. In general, both the sections of the genus and the species can be distinguished easily by their flavonoid patterns. The members of Crambe sections Crambe and Dendrocrambe seem to be the most primitive with their perennial or rhizocarpous habit. They show a diversity of flavonol glycosides, derived from either kaempferol or quercetin. The presumed presence of proanthocyanidins confers an additional primitive character to Crambe section Dendrocrambe. In contrast, members of Crambe section Leptocrambe show a relatively poor pattern where the quercetin glycosides have disappeared. In the case of C. hispanica and C. abyssinica flavonols are completely absent while two flavones, luteolin and apigenin appear in glycosidic form; these are probably the most evolved Crambe species and exhibit an annual habit. A dendrogram exclusively based on data of the presence or absence of flavonoids has been constructed. It is similar to the one that could have been expected from use of morphological data alone, but it does provide some hints on the possible phylogenetic relationships between the species. Flavonoid evidence also supports the hypothesis on an east-west Mediterranean disjunction within the genus.     

Flavonoid systematics of the genus Perideridia (Umbelliferae)

A survey of flavonoids in sixteen of the seventeen taxa in the genusPerideridia (Umbelliferae) showed the presence of thirteen glycosides of the flavonols kaempferol, quercetin, and isorhamnetin, and seven glycosides of the flavones apigenin, luteolin and chrysoeriol. An anthocyanin and four other flavonoids also occur, but remain unidentified dueto their low concentration. Several species characteristically produce speciesspecific compounds. The majority of species, however, produce flavonoids common to one or more taxa, but each taxon can be distinguished by its own specific complement of these flavonoids. Based on classes of flavonoids the genus can be divided into three groups: (1) those species which produce only flavonols; (2) those which produce mainly flavonols and a few flavones; and (3) those which produce predominantly flavones with flavonols absent or present only in trace amounts. Geographically, the flavonol-producing species are centered in California, extending northeastward to Idaho and eastward into Arizona. The flavonol/flavone producers are concentrated more towards the Pacific Northwest and eastward through the Rocky Mountains to the midwestern United States.     

Effect of Naturally Occurring Flavonoids on Lipid Peroxidation and Membrane Permeability Transition in Mitochondria

The ability of eight structurally related naturally occurring flavonoids in inhibiting lipid peroxidation and mitochondrial membrane permeability transition (MMPT), as well as respiration and protein sulfhydryl oxidation in rat liver mitochondria, was evaluated. The flavonoids tested exhibited the following order of potency to inhibit ADP/Fe(II)-induced lipid peroxidation, estimated with the thiobarbituric acid assay: 3′-O-methyl-quercetin > quercetin > 3,5,7,3′,4′-penta-O-methyl-quercetin > 3,7,3′,4′-tetra-O-methyl-quercetin > pinobanksin > 7-O-methyl-pinocembrin > pinocembrin > 3-O-acyl-pinobanksin. MMPT was estimated by the extent of mitochondrial swelling induced by 10 μM CaCl₂ plus 1.5 mM inorganic phosphate or 30 μM mefenamic acid. The most potent inhibitors of MMPT were quercetin, 7-O-methyl-pinocembrin, pinocembrin, and 3,5,7,3′,4′-penta-O-methyl-quercetin. The first two inhibited in parallel the oxidation of mitochondrial protein sulfhydryl involved in the MMPT mechanism. The most potent inhibitors of mitochondrial respiration were 7-O-methyl-pinocembrin, quercetin, and 3′-O-methyl-quercetin while the most potent uncouplers were pinocembrin and 3-O-acyl-pinobanksin. In contrast 3,7,3′,4′-tetra-O-methyl-quercetin and 3,5,7,3′,4′-penta-O-methyl-quercetin showed the lowest ability to affect mitochondrial respiration. We conclude that, in general, the flavonoids tested are able to inhibit lipid peroxidation on the mitochondrial membrane and/or MMPT. Multiple methylation of the hydroxyl substitutions, in addition to sustaining good anti-lipoperoxidant activity, reduces the effect of flavonoids on mitochondrial respiration, and therefore, increases the pharmacological potential of these compounds against pathological processes related to oxidative stress.     

Flavonoids of Helianthus series Microcephali

Ray flower and leaf flavonoids were investigated for the three species of Helianthus series Microcephali. Ray flowers of all species contain coreopsin, sulphurein, and quercetin 7-O-glucoside; those of H. microcephalus also contain quercetin 3-O-glucoside. A mixture of flavonoid aglycones, mostly methoxylated flavones, occurs in leaves of H. microcephalus, but not in H. glaucophyllus or H. laevigatus which also lack the glandular trichomes that in Helianthus are typically associated with flavonoid aglycones. The presence of compounds with the 6,8,4′ pattern of methoxylation in H. microcephalus suggests that the series is more similar in flavonoids to series Angustifolii than to series Corona-solis.