Phenolic acids in the genus Lycopodium

The dihydric phenolics from the leaves of 170 Ecuadorian Lycopodium specimens representing 49 species and varieties have been examined as semiquinones by EPR spectroscopy. An ester of dihydrocaffeic acid was observed in 137 extractors of specimens all confined to the subgenus Urostachya. The ester was not present in the subgenera Lycopodium and Lycopodiella, where the dominant phenolic acid was chlorogenic acid. The concentrations of the “Urostachyaester” were found to increase with increasing altitude. Hydroquinone and protochatechuic acid have been observed in a few specimens.     

A molecular phylogenetic assessment of the advanced Asiatic and Malesian didymocarpoid Gesneriaceae with focus on non-monophyletic and monotypic genera

Based on a considerably enlarged sampling, a phylogenetic analysis of the largest group of didymocarpoid Gesneriaceae, the ??advanced Asiatic and Malesian genera??, was performed, covering all but 3 of the 60 genera presently recognised in this group (20 of these, mostly from China, are monotypic). The results suggest that no fewer than 17 out of the 57 genera examined are poly- (or rarely para-)phyletic. Highly polyphyletic are Briggsia, Chirita, Henckelia and Raphiocarpus. Only a dozen of the non-monotypic genera (including the three species-richest genera, Cyrtandra, Aeschynanthus and Agalmyla) are confirmed as monophyletic entities, though some exhibit considerable genetic variation. For eight genera, no statement can be made, as only one (of two or several) species was included in the analysis. For a dozen of the (particularly Chinese) monotypic genera a close relationship (or possible congenerity) with other genera was found. In China, only Allostigma, Cathayanthe, Conandron and Metapetrocosmea seem to have no strong affinities to other genera, indicating that they represent phylogenetically isolated lineages or represent remnants of previously larger and earlier diversified groups. The present study forms the foundation for targeted molecular, morphological and phytogeographic studies of the polyphyletic and monotypic genera and particular of clades of genera with interrelations uncovered here for the first time.     

The leaf flavonoids of the Zingiberales

A survey of flavonoids in the leaves of 81 species of the Zingiberales showed that, while most of the major classes of flavonoid are represented in the order, only two families, the Zingiberaceae and Marantaceae are rich in these constituents. In the Musaceae (in 9 species), Strelitziaceae (in 8 species) and Cannaceae (1 of 2 species) flavonol glycosides were detected in small amount and in the Lowiaceae no flavonoids were fully identified. In the Zingiberaceae kaempferol (in 22%), quercetin (72%) and proanthocyanidins (71%) are distributed throughout the family. The two subfamilies of the Zingiberaceae may be distinguished by the presence of myricetin (in 26%), isorhamnetin (10%) and syringetin (3%) in the Zingiberoideae and of flavone $\text{C-}\text{glycosides}$ (in 86% of taxa) in the Costoideae. A number of genera have distinctive flavonol profiles: e.g. Hedychium species have myricetin and quercetin. Roscoea species isorhamnetin and quercetin and Alpinia species kaempferol and quercetin glycosides. A new glycoside, syringetin 3-rhamnoside was identified in Hedychium stenopetalum. In the Zingiberoideae flavonols were found in glycosidic combination with glucuronic acid, rhamnose and glucose but glucuronides were not detected in the Costoideae or elsewhere in the Zingiberales. The Marantaceae is chemically the most diverse group and may be distinguished from other members of the Zingiberales by the occurrence of both flavone $\text{O-}$ and $\text{C-}\text{glycosides}$ and the absence of kaempferol and isorhamnetin glycosides. The distribution of flavonoid constituents within the Marantaceae does not closely follow the existing tribai or generic limits. Flavonols (in 50% of species). flavones (20%) and flavone $\text{C-}\text{glycosides}$ (40%) are found with similar frequency in the two tribes and in the genera Calathea and Maranta both flavone and flavonol glycosides occur. Apigenin- and luteolin-7-sulphates and luteolin-7,3′-disulphate were identified in Maranta bicolor and M. leuconeura var. kerchoveana and several flavone $\text{C-}\text{glycosides}$ sulphates in Stromanthe sanguinea. Anthocyanins were identified in those species with pigmented leaves or stems and a common pattern based on cyanidin-and delphinidin-3-rutinosides was observed throughout the group. Finally the possible relationship of the Zingiberales to the Commelinales, Liliales, Bromeliales and Fluviales is discussed.     

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.     

Flavonoids in Parahebe and Veronica: a chemosystematic study

Flavone glycosides are the main flavonoid leaf constituents in the related genera Parahebe and Veronica (Scrophulariaceae), in agreement with former chemical studies of the family. In Parahebe there are groups of species in which there are mainly luteolin glycosides, and groups in which 6-hydroxyluteolin dominates. Small amounts of apigenin occur in many taxa. Glycosylation is usually in the 7-position but 4′- and 5-glycosides were also found. In Veronica a larger variety of flavone aglycones was found: e.g. luteolin, apigenin, chrysoeriol, tricin and three different 6-hydroxyflavones. They are often present in the plants in the form of glucuronides. Glycosylation is in the 7-or-5-position. Most species of both genera have a distinctive pattern of flavonoid glycosides in their leaves which can be used for identification. Populations of P. catarractae are an exception in showing three different patterns, but here the variety in flavone profiles corresponds to the pattern of morphological and geographic variation within this taxon. Anthocyanins are responsible for the blue, mauve and pink colours of the flowers in the two genera. In Veronica they are based on delphinidin, whereas in Parahebe catarractae on both delphinidin and cyanidin.     

Cyclic fatty acyl glycosides in the glandular trichome exudate of Silene gallica

Chemical investigation of the glandular trichome exudate from Silene gallica L. (Caryophyllaceae) resulted in isolation of 10 cyclic fatty acyl glycosides (gallicasides A–J). The cyclic structures were characterized by a glycosidic linkage of the glucose moiety to either the C-12 or the C-13 position of the octadecanoyl moiety, and by an ester linkage between the C-2 hydroxy group of the glucose moiety and the carboxyl group of the oxygenated octadecanoic acid. The structures of the cyclic fatty acyl glycosides were further distinguished from one another by acetylation and/or malonylation on the glucose moiety. Of these compounds, the 1,2′-cyclic ester of 12(R)-(6-O-acetyl-3-O-malonyl-β-d-glucopyranosyloxy)octadecanoic acid (gallicaside J) was the most abundant (30.7%). These secondary metabolites were found specifically in the glandular trichome exudate rather than in other aerial parts.     

Leaf flavonoid patterns in the winteraceae

In a leaf flavonoid survey of 59 specimens of the Winteraceae and related families, representing nine genera, luteolin 7,3′-dimethyl ether (in 77%) and flavonols (in 81%) were found to be major constituents. Indeed the high incidence of luteolin 7,3′-dimethyl ether chemically isolates the family from all other angiosperm groups, including families and genera that have been taxonomically associated with the Winteraceae in the past. Simple flavones (in 16%), on the other hand, were found only in some Drimys s. str., Tasmannia and Pseudowintera species. Similarly, the distribution of flavone C-glycosides was restricted to specimens of T. piperita and one specimen of D. winteri. The frequent occurrence of procyanidin (in 60%) and dihydroquercetin (in 44%) reflects the primitive and woody nature of the family. The combined flavonoid data clearly support previous cytological, morphological and phylogenetic studies in the division of the Winteraceae into three groups of genera: (1) Bubbia, Belliolum, Exospermum and Zygogynum; (2) Drimys s. str. and Pseudowintera and (3) Tasmannia. Some generic variations were found within the Bubbia, Belliolum, Expospermum and Zygogynum group but apart from minor geographic variations within Belliolum the flavonoid results do not appear to provide suitable evidence for subgeneric taxonomy.     

Suitability of dried herbarium specimens for NMR metabolomics of mushrooms. A comparison of four species of the genera Kuehneromyces and Hypholoma (Strophariaceae)

Herbarium specimens are a treasure trove for biochemical studies. However, this implies understanding of the chemical changes during the drying and storage of the specimen. We compared herbarium specimens at different ages and fresh samples of four mushroom species (Kuehneromyces mutabilis, Hypholoma capnoides, Kuehneromyces lignicola, Hypholoma fasciculare) of two genera in the family Strophariaceae by using proton nuclear magnetic resonance (¹H NMR) spectroscopy combined with principal component analysis (PCA). 25 metabolites were identified. No significant alterations were found between herbarium samples at different ages, suggesting that they are stable enough for comparative studies. The most dominant differences between fresh and herbarium samples was that sugars such as α-α-trehalose, and fumaric and malic acids were more abundant in fresh fungi. Total contents of fatty and amino acids, uracil and γ-aminobutyric acid (GABA) were higher in herbarium specimens. In addition, pyroglutamic acid was observed only in Kuehneromyces mutabilis and fasciculic acid E in Hypholomafasciculare. Hence, based on results of the studied taxa, we conclude that NMR metabolomics can be used for both fresh and dried mushrooms when such alterations are properly addressed.     

The flavonoids of ferns in the isolated genera Loxsoma and Loxsomopsis

Kaempferol and quercetin 3-O-glucosides and 3-O-rhamnoglucosides are common to both Loxsoma cunninghamii and Loxsomopsis costaricensis, but in the former the new flavonoid glycosides, kaempferol and quercetin 3-O-glucoside-7-O-arabinoside have also been identified. The data are consistent with the proposed taxonomic relationship between these geographically isolated genera. Comparative flavonoid chemistry indicates that the Loxsomaceae may be a primitive family, not closely related to the Hymenophyllaceae or the Cyatheaceae.     

A chemosystematic study of the genus Gomphostemma and related genera (Lamiaceae)

Species in the genera Gomphostemma, Chelonopsis and Bostrychanthera were systematically studied with reference to their flavonoid and phenolic acid compounds in order to investigate whether the profiles of these compounds would support a classification of the genus and related genera based on morphological characters. Thirty-five flavonoid glycosides, eight phenolic acids and derivatives were identified by LC-UV-MS/MS analysis of aqueous 80% MeOH extracts on the basis of their UV and mass spectra, retention times and comparison with in-house library. The occurrence of individual compounds was not particularly informative in Gomphostemma, although the overall chemical profile supported G. subgen. Pogosiphon and vicenin-2 was a characteristic component of Gomphostemma leptodon and Gomphostemma curtisii. In contrast, the flavonoids and phenolic acids of Chelonopsis were informative at infrageneric level. Glycosides of 6-substituted flavones were well represented in Ch. subgen. Aequidens, including Ch. forrestii, Ch. rosea, Ch. odontochila, Ch. lichiangensis and C. giraldii. A dicaffeoylquinic acid was produced in Ch. subgen. Chelonopsis, (for example, in Ch. longipes and Ch. Moschata), but absent from Ch. subgen. Aequidens. The same dicaffeoylquinic acid was also found in the genus Bostrychanthera and suggests a close relationship with Ch. subgen. Chelonopsis, in agreement with a recent DNA based phylogeny. There is correlation between trichome type and phenolic acid compound distribution in Chelonopsis, but this is not observed in Gomphostemma.     

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.     

Distribution of some triterpenes and phenolic compounds in the extractives of endemic dipterocarpaceae species of Sri Lanka

Extractives of bark and/or timber of 11 species belonging to the genera Cotylelobium, Hopea, Shorea, Vateria and Vatica yielded a fatty-acid ester, a sitosteryl ester, β-amyrin acetate, β-amyrin, dipterocarpol, ursolic acetate, lupeol, sitosterol, ursolic acid, betulinic acid, hexamethyl-coruleoellagic acid, tetramethylellagic acid, chrysophanol and scopoletin. The distribution of these compounds in 18 other species was examined by TLC screening.     

Are unusual plasmodesmata in the embryo-suspensor restricted to species from the genus Sedum among Crassulaceae?

The Crassulaceae family comprises mainly herbaceous leaf succulents, some of which have an ornamental value. During embryogenesis, they produce a suspensor with a giant polyploid basal cell. It has recently been shown that in Sedum acre and S. hispanicum this cell has compound plasmodesmata with an unusual dome of electron-dense material associated on the cell's side. These compound plasmodesmata differ from the typical ones occurring in other angiosperms. In this study, the hypothesis was tested that the unusual plasmodesmata in the embryo-suspensor are a feature not only restricted to species from the genus Sedum, but are also found in other Crassulaceae genera. Suspensors of example species from the genera Sempervivum and Jovibarba, which have vegetative morphologies quite different from Sedum and which are placed in the traditional classification into another subfamily, were first examined using an electron microscope. It was found that the unusual compound plasmodesmata in the suspensor are not only restricted to species from the genus Sedum but are also found in species from other Crassulaceae genera (Sempervivum arachnoideum and Jovibarba sobolifera). It should be noted that some ultrastructural features of compound plasmodesmata in the analyzed genera (e.g. the character of the wall with plasmodesmata, plasmodesmata diameter or occurrence of the electron-dense material) are different from the suspensor plasmodesmata recorded in species from the Sedum genus. We found that in Sempervivum arachnoideum the size of the plasmodesmata diameter varies according to the micropylar-chalazal axis of the embryo. This is the first report of variation in the diameter of the plasmodesmata within the embryo of angiosperms. Further study will be needed to show whether compound plasmodesmata occur in other Crassulaceae clades, whether they are a stable feature at the genus level in this family, and also whether they have evolved several times or only once in Crassulaceae.     

Secondary metabolites from Centaurea ensiformis P.H. Davis

Centaurea ensiformis P.H. Davis was evaluated for its secondary metabolites. 20 different compounds have been isolated and identified; four phenolic compounds, one aminoacid, two acetophenone glycosides, three phenylpropanoide glycosides, one coumarin glucoside, four flavon glycosides, two neolignan glycosides, two megastigmane glycosides and schikimic acid methyl ester.     

Shading Influence on the Sterol Balance of Nicotiana tabacum L

Tobacco plants (Nicotiana tabacum L.) were grown in the field and the apex was removed at the 42-day stage. Shading screens were set up which produced 0, 26, 67, and 90% shade. Plants were grown an additional 25 days before leaves from top, middle, and bottom stalk positions were harvested. Each leaf group was analyzed for free sterol, steryl ester, steryl glycoside, and acylsteryl glycoside. The free sterol content was lowest in top leaves and highest in bottom leaves; however, the top leaves had more steryl ester than the bottom leaves. Leaf position had no effect on steryl glycosides and acylsteryl glycosides. Shading did not influence the level of any sterol class; but in general, shading increased stigmasterol and decreased sitosterol. This trend was observed for all sterol classes, and the free sterols showed the largest and most consistent change. The younger top leaves showed a greater response than the older bottom leaves, but bottom leaves always had more stigmasterol than sitosterol even without shade.     

The flavonoids of Stenosiphon (Onagraceae)

Stenosiphon linifolius is a monotypic genus of the tribe Onagreae of the Onagraceae. The species is widespread in, but restricted to, the Great Plains of the United States. Three flavonol glycosides, kaempferol 3-O-rhamnoside, quercetin 3-O-rhamnoside and myricetin 3-O-rhamnoside, were found to occur in methanolic extracts of Stenosiphon leaves. Similar compounds are found in the leaves of such related genera as Oenothera and Gaura, but in the latter genera, additional flavonols exhibiting greater substitutional variation also are found.     

New reports on flavonoids,benzoic- and chlorogenic acids as rare features in the Psychotria alliance (Rubiaceae)

Five flavonoid glycosides, three chlorogenic and one benzoic acid were isolated from leaves of seven species belonging to the genera Notopleura, Palicourea and Psychotria. In most species, common flavonol glycosides based upon quercetin and kaempferol were recorded, which corresponds well to literature data on other species of the Psychotria alliance. From Notopleura polyphlebia, however, the new dihydroflavonol glycoside (2R,3R)-7,4′-O-dimethyl-aromadendrin 5-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside (1) was isolated, which is remarkable in terms of both the structure of the aglycone as well as the rarity of apiose as sugar moiety. In addition to flavonoids, benzoic and chlorogenic acids are a common and frequently neglected feature in the alliance, but all appear to be of limited chemosystematic significance when compared to tryptamine-iridoid alkaloids prominently known from this group.     

Identification of isoflavones in Acca sellowiana and two Psidium species (Myrtaceae)

Several types of isoflavonoid-like immunoreactivity were detected in water-ethanolic extracts from Acca sellowiana (Berg) Burret, Psidium guajava L. and Psidium littorale Raddi (Myrtaceae) leaves. Chromatographic mobility of the immunoreactive substances was compared to that of authentic standards, revealing a spectrum of isoflavonoid metabolites in both genera. Aglycones as well as glycosides were detected, namely daidzin, genistin, daidzein, genistein, formononetin, biochanin A, prunetin, and several incompletely characterized isoflavones. Subsequent HPLC–MS study verified the identities of the main immunoreactive isoflavones and found several others, namely glycitein, glycitin, ononin, sissotrin, including the malonylated and acetylated glucosides. It is concluded that the isoflavonoid metabolic pathway is present in the Myrtaceae family.     

Apigenin and amentoflavone glycosides in the psilotaceae and their phylogenetic significance

Documentation of amentoflavone O-glucosides as the predominant flavonoid glycosides in both genera of the Psilotaceae clearly distinguishes this family from all other families of vascular plants. Psilotum and Tmesipteris also possess apigenin C- and O-glycosides as common flavonoid types. Apigenin 7-O-rhamnoglucoside occurs in both genera and the previously undocumented apigenin 7-O-rhamnoglucoside-4′-O-glucoside, although identified only in Tmesipteris, may also be present in Psilotum. The existence of flavone C-glycosides in both genera may provide a phytochemical relationship between the Psilotaceae and some ferns. The phylogenetic significance of these results is discussed.     

The role of lipophilic and polar flavonoids in the classification of temperate members of the Anthemideae

Lipophilic and vacuolar flavonoids were separately identified in representative temperate species of the genera Anthemis, Chrysanthemum, Cotula, Ismelia, Leucanthemum and Tripleurospermum. The four Anthemis species investigated variously produced four main surface constituents, in leaf and flower: santin, quercetagetin 3,6,3′-trimethyl ether, scutellarein 6,4′-dimethyl ether and 6-hydroxyluteolin 6,3′-dimethyl ether. By contrast, surface extracts of disc and ray florets of the species of Chrysanthemum, Cotula, Ismelia, Leucanthemum and Tripleurospermum surveyed yielded five common flavones in the free state: apigenin, luteolin, acacetin, apigenin 7-methyl ether and chrysoeriol. Polar flavonoids were isolated and identified in leaf, ray floret and disc floret of all the above plants. Anthemis species were distinctive in having flavonol glycosides in the leaves, whereas the leaf flavonoids of the other taxa were generally flavone O-glycosides. The 3-glucoside and 3-rutinoside of patuletin were characterised for the first time from Anthemis tinctoria ssp. subtinctoria. Two new flavonol glycosides, the 5-glucuronides of quercetin and kaempferol, were obtained from the leaf of Leucanthemum vulgare, where they co-occur with the related 5-glucosides and with several flavone glycosides. The ray florets of these Anthemideae generally contain apigenin and/or luteolin 7-glucoside and 7-glucuronide, whereas disc florets have additional flavonol glycosides, notably the 7-glucosides of quercetin and patuletin and the 7-glucuronide of quercetin. A comparison of the flavonoid pattern encountered here with those previously recorded for Tanacetum indicate some chemical affinity between Anthemis and Tanacetum. Flavonoid patterns of the other five genera are more distinct from those of Tanacetum and suggest that those genera form a related group. All 14 species surveyed for their flavonoid profiles have distinctive constituents and the chemical data are in harmony with modern taxonomic treatments of the “Chrysanthemum complex” as a series of separate genera.