Paleobiochemistry of North American fossil Liriodendron sp.

Organic geochemical analyses are presented for a fossil Liriodendron sp. from the Miocene, Clarkia Flora of Northern Idaho. Flavonoid profiles determined for the fossil and two extent species of Liriodendron (L. chinense and L. tulipifera) confirm the generic status of the fossil material, but owing to a generic uniformity in flavonoid composition, fail to resolve taxonomic affinities at the species level. Steroid and other cycloalkane-alkene profiles indicate that the fossil taxon has a greater chemical similarity with L. chinense than L. tulipifera, despite the general leaf outline similarity between the fossil species and extent L. tulipifera. The morphologic and chemical data are interpreted as evidence for mosaic evolution within the genus, and the non-canalization of character states in some Miocene species.     

Chemotaxonomy and flavonoid profiling of Torilis species by HPLC/ESI/MS2

The flavonoid profiles of Turkish Torilis Gaertn. (Apiaceae) species were studied by TLC, HPLC-UV and HPLC/ESI/MS² (negative mode). O-glycosides of luteolin, apigenin and chrysoeriol were identified from crude extracts with the help of mass spectra in different MS/MS modes, such as full scan, precursor ion scan and product ion scan. Luteolin-7-O-glucoside and luteolin-7-O-rutinoside were common to all species. Flavonoid profiles usually differ from one species to another and can be put to use for a genus such as Torilis which has been little studied. By the help of different flavonoid profiles, it is concluded that, the plants, which are recognised as less rayed subspecies of Torilis arvensis (Huds.) Link. in various floras including Turkish one, must be classified in species category as Torilis chrysocarpa and Torilis purpurea. Flavonoid profiles seem to be in relation with evolutionary biogeography of the species. Because the most isolated species of the genus, endemic Torilis triradiata, has the most different flavonoid pattern. Moreover, geographically isolated species, T. triradiata and Torilis leptocarpa, do not share any flavonoid except for the two which are common to all species.     

Flavonoids in leaves and inflorescences of australian Cyperus species

A survey of the flavonoids of some 92 species of Australian Cyperus, mainly of subtropical or tropical origin, has confirmed a correlation previously reported in this family between flavonoid pattern and plant geography. The pattern found was similar to that of African and South American Cyperaceae, particularly in the occurrence of the rare marker substance, luteolin 5-methyl ether. Tricin and luteolin are relatively common, in glycosidic form, in the leaves while the flavonol quercetin is infrequent. When present, quercetin occurs either in glycosidic form or free as a methyl ether. The 3-monomethyl and 3, 7-dimethyl ethers of kaempferol and quercetin and the 3, 7, ?-trimethyl ether of quercetin are reported for the first time from the Cyperaceae. The flavonoid pattern of inflorescences is distinct from that of the leaves in that tricin is not detectable and that luteolin 5-methyl ether appears to be replaced by 7, 3′, 4′-trihydroxyflavone. In addition, the aurone aureusidin is more commonly present than in the leaves and is occasionally accompanied by two further aurones. The glycoxanthones mangiferin and isomangiferin occur rarely in all three species examined in the section Haspani, i.e. in C. haspan, C. prolifer and C. tenuispica. In general, however, the flavonoid data do not offer any markers which separate off different sections within the genus; there are, however, some significant correlations between the frequency of the flavonoid classes and subgeneric groupings.     

Phytochemical support for the existence of two species in the genus Hymenophyton

Evidence based on flavonoid constituents is cited in support of the existence of two species in the genus Hymenophyton, H. flabellatum and H. leptopodum. A number of apigenin 6,8-di-C-pentosides and pentoside-hexosides are common to both species but the proposed additional species, H. leptopodum, is distinguished from H. flabellatum by the presence of kaempferol di- and triglycosides. This is the first detailed study of the flavonoid chemistry of any member of the order Metzgeriales and the significance of the findings is discussed.     

Silica bodies and their systematic implications in Pteridaceae (Pteridophyta)

Wet ashing was used to study the occurrence of silica bodies in the fern family Pteridaceae. They were recovered in 48 of the 77 species examined. Silica bodies of Pteridaceae are elongate, ranging from 90–1320 × 5–40 µm, linear to elliptic, with blunt or acute apices and smooth to sinuate sides. All previous records of silica bodies and venuloid idioblasts among Pteridaceae that were examined were confirmed by the results of this study, corroborating our assumptions regarding the presence of silica bodies. In contrast, assumptions regarding the absence of silica bodies were incorrect; in many species of Adiantum, for example, silica bodies are present but cannot be seen with the naked eye. Farris optimization demonstrates that the distribution of epidermal silica bodies is homoplastic within Pteridaceae, but that they act as a potential synapomorphies for several different groups within the family. These include the adiantoid clade: Adiantum and the 11 vittaroid genera, and in some pteridoid fern clades such as the sister pair Onychium and Actiniopteris and the genus Pityrogramma. They are also present in Pterozonium brevifrons and some species of the polyphyletic genus Pteris. Among cheilanthoid ferns, they were found in Mildella intramarginalis and two species of Aspidotis. Morphology of silica bodies differs between major lineages, reflecting their independent origins. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161 , 422–435.     

Flavonoids of some species of Chrysosplenium

The flavonoid chemistry of eight species of Chrysosplenium has been established. The species studied were C. americanum, C. echinus, C. flagelliferum, C. glechomaefolium, C. iowense, C. rosendahlii, C. wrightii and C. valdivicum. The major compounds present were O-methylated flavones having an extra hydroxyl group at positions 6 and/or 2′ except for C. valdivicum which has isorhamnetin as its major flavonoid and only a trace of a compound bearing an extra hydroxyl group. Distribution of the O-methylated compounds in the genus correlates well with Franchet's sectional view of the genus wherein he recognized alternate-leaved vs opposite-leaved groups. The flavonoids of C. valdivicum represent a link between the more advanced members of the genus and other genera of the Saxifragaceae.     

Flavonol derivatives of Desmanthodium (compositae)

The flavonoids of three species of Desmanthodium are based upon kaempferol, quercetin and quercetagetin. Sugar substitutions comprise glucosides, galactosides, rhamnosides, rutinosides and diglucosides. Four different O-methylated compounds occur in field populations of the genus, but they are found in all species and are therefore not useful for sectional or subgeneric delimitations. The flavonoid profile of Desmanthodium is very similar to that of Clibadium, which parallels their close morphological affinity.     

Chemistry and taxonomy of Ribes

Most species of Ribes are exceptionally rich in prodelphinidin and have no ellagitannins, but some species in certain subsections, nearly all montane in their habitat, contain ellagitannins and are poor in prodelphinidin. Ellagitannins, therefore seem to be produced at the expense of prodelphinidin and their presence is a derived, and not, as thought previously, a primitive character. The flavonoid pattern of the lowland species is very uniform and primitive, with unusually few irregular constituents. The possible origin of Ribes is discussed in relation to other genera of Saxifragaceae and related families, and the conclusion is reached that none of these can be considered as ancestral to Ribes. It is therefore surprising that the fossil record can trace the genus with confidence no further back than the Miocene.     

A chemotaxonomic survey of the tribe psoraleeae in africa

A study of the leaf flavonoids, furanocoumarins and essential oils of 51 species (three genera) of the tribe Psoraleeae (Fabaceae) has provided chemical data to support the recent subdivision of the large worldwide genus Psoralea into a number of segregate genera. The flavonoid patterns in most species were very similar, consisting largely of proanthocyanidins and complex mixtures of flavone O- and C-glucosides. Psoralea repens, the only maritime species to be examined, is unique in containing only rutin. Three isoflavones (daidzein, formononetin and genistein) were of widespread occurrence. The genera Psoralea and Otholobium, which could not be separated on flavonoid data, were clearly demarcated by their essential oils. Furanocoumarin patterns were useful for the characterization of species.     

Caffeic acid ester derivatives and flavonoids of genus Arnaldoa (Asteraceae,Barnadesioideae)

The phytochemical composition of Arnaldoa species is barely known. In this work, the occurrence of caffeic acid ester derivatives and flavonoids in A. argentea, A. macbrideana and A. weberbaueri was established by liquid chromatography associated to high-resolution mass spectrometry analyses and comparison with data from isolated compounds. The distribution of chlorogenic acids in the genus Arnaldoa is herein described for the first time. The metabolite profile of Arnaldoa species was compared to that of Tithonia diversifolia, a known and rich source of chlorogenic acids and sesquiterpene lactones. In addition to the mono- and dicaffeoyl quinic acids present in T. diversifolia, Arnaldoa species exhibited the mono- and dicaffeoyl tartaric acids. Furthermore, mass features correspondent to that of sesquiterpene lactones present in T. diversifolia were not observed in Arnaldoa species. The chemotaxonomic implications of caffeic acid ester derivatives and flavonoid glycosides, as well as the potential absence of sesquiterpene lactones in the genus Arnaldoa and subfamily Barnadesioideae are discussed.     

Intra- and interspecific variations in vacuolar flavonoids among Ficus species from the Budongo Forest,Uganda

Leaves of 14 species of Ficus growing in the Budongo Forest, Uganda, were analysed for vacuolar flavonoids. Three to six accessions were studied for each species to see whether there was intraspecific chemical variation. Thirty-nine phenolic compounds were identified or characterised, including 14 flavonol O-glycosides, six flavone O-glycosides and 15 flavone C-glycosides. In some species the flavonoid glycosides were acylated. Ficus thonningii contained in addition four stilbenes including glycosides. Most of the species could be distinguished from each other on the basis of their flavonoid profiles, apart from Ficus sansibarica and Ficus saussureana, which showed a very strong intraspecific variation. However, on the whole flavonoid profiles were sufficiently distinct to help in future identifications.     

Flavonoid chemistry of arceuthobium (viscaceae)

Flavonoid compounds from 36 of the 38 known taxa of the genusArceuthobium (dwarf mistletoes) were examined. The flavonoid chemistry of the genus is rather uniform, all taxa producing 3-O-glycosides of the flavonols quercetin and myricetin. No infraspecific chemical variation was encountered, and in those instances where subspecific taxa are recognized, their chemistry was uniform. At the subgeneric level, members of subgenusArceuthobium synthesize primarily glucosides, whereas galactosides are more common in subgenusVaginata. In two of the four Old World species of subgenusArceuthobium (A. juniperi- procerae andA. oxycedri) only myricetin 3-O-glucoside was detected. There are no absolute flavonoid differences between subgenera, sections, or series. On the other hand, flavonoids are useful in several instances at the species level. In several cases, chemical data lend support to the recognition of species which in the past have been considered doubtfully distinct on the basis of morphology.     

Chemical discontinuity in Laeliinae bentham

A new dihydroflavonol glycoside, anacheiloside, has been characterized in several species of the family Orchidaceae. The distribution of the flavonoid in druse-type patterns in flowers fixed in ethanol was used as a criterion to restablish the genus Anacheilium and correlate phylogeny among Encyclia, Anacheilium and Epidendrum.     

A chemosystematic investigation on Ipomopsis

The diminutive North American desert annual species of Ipomopsis, Section Microgilia, I. depressa and I. polycladon, agree with other members of the genus in having a flavonoid syndrome based upon 6-methoxyflavonols. Patuletin is the predominant aglycone present but traces of eupatolitin and eupalitin were detected. In I. polycladon, four glycosides of patuletin and one of eupalitin were isolated and identified.     

Chemodiversity of exudate flavonoids in Dionysia (Primulaceae): A comparative study

More than 60 accessions of various Dionysia spp. were analysed for their exudate flavonoid composition. Many Dionysia spp. accumulate the typical Primula flavonoids with irregular substitution (unsubstituted flavone, its 2′,5′-substituted derivatives and corresponding 5-OH-flavones), but flavones, flavonols and flavanones with regular 5,7-diOH-substitution are also encountered in their exudates. The formation of both types of flavonoids is not mutually exclusive. This paper analyses the chemodiversity of Dionysia exudates with respect to infraspecific variability, infrageneric distribution, patterns in hybrid taxa, and comparisons of biogenetic tendencies between Dionysia and closest related species of Primula. The uniqueness of occurrence of Primula-type flavonoids in the family Primulaceae, and their presumed different biosynthetic origin, suggest significance as further character in the Primula–Dionysia assemblage. Principal component analysis was applied to test the significance of variation of flavonoid composition across Dionysia. Comparative analysis of flavonoid profiles against the current taxonomic views yielded correlations, confined to the level of smaller groups, and only in parts at level of the current infrageneric concept. Flavonoid data are further discussed against the background of morphological and biogeographic differentiation of the genus. Increased diversification of flavonoid profiles may be interpreted as a derived status in Dionysia, which agrees with current views on the phylogeny of Dionysia as a specialised group within Primula. Functional aspects of exudate flavonoid formation are shortly addressed.     

A novel phenolic acid derivative from buds of Populus lasiocarpa

The lipophilic excretion of winter buds of Populus lasiocarpa in contrast to most other species of the genus does not contain flavonoid aglycones. One of the compounds which are excreted in this plant now could be isolated and identified by chemical methods (hydrolysis, hydrogenation) and spectral analysis (UV, IR, NMR, MS) to be 1,3-p-coumaryl-2-acetyl-glycerol.     

A morphological and chemical analysis of geographical variation in Tilia L. of eastern North America

A statistical analysis of morphological variation and a Chromatographic analysis of flavonoid variation were performed to determine taxonomic relationships among the species ofTilia of eastern North America. No apparent morphological discontinuities were seen between populations within the sample area although two characters (involving leaf pubescence and gland length) showed definite patterns of geographical variation. Flavonoid patterns showed definite differences between northern and southern populations with an intermediate zone in the Smoky Mountain region. The continuous nature of the morphological and flavonoid variation suggested that the genus as represented in eastern North America should be regarded as one species,Tilia americana L.     

Leaf flavonoids from Croton urucurana and C. floribundus (Euphorbiaceae)

Flavonoids were isolated by PVPP column chromatography of leaf extracts of Croton floribundus Spreng and C. urucurana Baill. and identified by NMR and co-chromatography with standards. The two species revealed highly distinct flavonoid profiles. C. urucurana, belonging to the phylogenetically basal section Cyclostigma, yielded the flavone C-glycosides vitexin and orientin, quercetin and the O-glycosides quercetin 7-O-rhamnoside, rhamnitrin and rutin, in addition to tiliroside. Instead, C. floribundus, from the more derived section Lasiogyne, yielded no C-glycosides, but a high diversity of classes of flavonols, including kaempferol, three flavonol O-methyl ethers, isoquercitrin, three tri-O-galactosides, in addition to tiliroside and an isorhamnetin-coumaroyl-O-glycoside. The present work is the first report for Croton of two rhamnosides (isolated from C. urucurana). It is also the first report for Euphorbiaceae of two tri-O-glycosides obtained from C. floribundus. The distribution of flavonoids in the two species as determined by HPLC-DAD of extracts of small leaf samples of herbarium specimens is highly similar with the profiles resulting from isolation of compounds from bulky leaf samples. Differences among specimens of the same species were restricted to relative proportions of individual constituents. The results indicate that flavonoid profiles are effective to characterize and distinguish the two species. The present results, combined with literature data, supports the condition of tiliroside as a marker of Croton and the hypothesis of an evolutionary trend in the genus toward the loss of C-glycosides and a progressive complexity of flavonoid profiles.     

FLAVONOID EVOLUTION IN ROBINSONIA (COMPOSITAE) OF THE JUAN FERNANDEZ ISLANDS

Leaf flavonoids were isolated and identified from 54 populations representing all seven species of Robinsonia, a genus of dioecious rosette trees endemic to the Juan Fernandez Islands. Fourteen compounds were detected consisting of flavonols, flavones, flavanones and dihydroflavonols. The distribution of these compounds in Robinsonia largely corresponds to specific and sectional limits based on morphological data. The morphologically similar species, R. gayana and R. thurifera, have identical flavonol profiles (derivatives of quercetin). Likewise, the closely related R. evenia and R. masafuerae are unique in the genus by possessing flavones. The inclusion of Rhetinodendron (i.e., R. berteroi) in Robinsonia is supported by its strong flavonoid similarity with species in two other sections of the genus. The morphologically diverse section Eleutherolepis exhibits the greatest flavonoid variation of any section, and only here are found flavones, flavanones and dihydroflavonols. The direction of flavonoid evolution in Robinsonia is hypothesized to be from fewer to more classes of compounds. Biosynthetic considerations suggest that this gain in compounds is due both to a gain of an additional enzymatic step and to the sequestering of precursors. This interpretation of direction of flavonoid evolution is in agreement with several lines of evidence including the flavonoid chemistry of the hypothesized outgroup (i.e., species of Senecio on mainland Chile), the ages of the two islands, and morphological trends.     

The utility of leaf flavonoids as taxonomic markers for some Malaysian species of the tribe Shoreae (Dipterocarpaceae)

A flavonoid survey was carried out on 45 taxa from the genera Shorea, Hopea, Parashorea, Neobalanocarpus, and Dryobalanops of the tribe Shoreae in the Dipterocarpaceae. The study showed significant chemotaxonomic differences in leaf flavonoid aglycone patterns and the presence of tannins in these taxa. The flavonoid patterns are useful in the delimitation of some taxa. For example, the genus Parashorea is distinguished by the universal presence of kaempferol 3‐methyl ether, and the monotypic genus Neobalanocarpus is unique in not producing ellagic and gallo tannins. The presence of chalcones and flavone C‐glycosides supports the separation of the genus Hopea into two sections, section Dryobalanoides and section Hopea in Ashton's classification, which is based on the type of venation. The flavonoid distributions in this study show that they can be very useful for differentiating between the Balau group in the genus Shorea and some scaly barked Hopea species, particularly H. helferi (lintah bukit), H. nutans (giam), and H. ferrea (malut). © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 755–762.