New species of stromatoporoidea from the Upper Ordovician and Silurian of the Subpolar Urals

Stromatoporoidea are widespread in the Upper Ordovician and Silurian beds of the Kozhim River (western slope of the Subpolar Urals). Five new species Cystostroma prodigiosum sp. nov., Stylostroma flabellatum sp. nov., Labechiina arguta sp. nov., Ecclimadictyon faveolatum sp. nov., and Araneosustroma astroplexum sp. nov. are described.     

Flavonoid aglycones from leaf resins of two species of Heterotheca (compositae)

Twenty-nine flavonoid aglycones have been identified from two populations each of Heterotheca grandiflora and H. psammophila. Considerable qualitative variation was found between populations of the same species. Overall, H. grandiflora is more complex in its flavonoid profile, accumulating a total of 24 compounds based on eight skeletal types, compared with 13 compounds based on four skeletal types in H. psammophila.     

A systematic study of the genus hulsea (Asteraceae)

A systematic treatment based on genetic, biochemical, and morphological studies is presented for the 11 recognized taxa ofHulsea. A uniform diploid complement of 38 chromosomes was found in the 37 populations examined, including all species and representing first reports forH. brevifolia, H. californica, andH. mexicana. Thirteen flavonoid compounds, based on the aglycones quercetin, apigenin, cyanidin, and the 4′-O-methyl ether of luteolin, were detected inHulsea. Patterns of the flavonoid compounds are discussed with respect to the systematic treatment. The results of 595 synthetic crosses indicate thatHulsea species are self-incompatible, relatively cross-compatible, and that their F₁ hybrids are relatively fertile. Heterozygosity for one or two translocations is reported for 11 interspecific and intersubspecific hybrid combinations.     

Flavonoid patterns in the farina of goldenback and silverback ferns

Most species of the fern genus Pityrogramma show a farinose indument caused by a deposit of exuded flavonoid aglycones. Some 220 samples, comprising 14 species, have been studied for the chemical composition of their farinas. Flavones, flavonols and C-methylated flavonoid are rarely found. The presence of certain chalcones and dihydrochalcones, however, appears to be to some extent characteristic for the genus. In some cases the farina flavonoid pattern is species-specific; in one species also variety-specific patterns and even chemotypes are observed. In general, the flavonoid chemistry in Pityrogramma parallels frond morphology to a great extent. This supports the concept that around a core of generalized species a few variant species exist which are best treated as belonging to Pityrogramma.     

Antimicrobial activity of Calotropis procera Ait. (Asclepiadaceae) and isolation of four flavonoid glycosides as the active constituents

Antimicrobial activity of solvent extracts and flavonoids of Calotropis procera growing wild in Saudi Arabia was evaluated using the agar well-diffusion method. A bioassay-guided fractionation of the crude flavonoid fraction (Cf₃) of MeOH extract which showed the highest antimicrobial activity led to the isolation of four flavonoid glycosides as the bioactive constituents. Structure of compounds have been elucidated using physical and spectroscopic methods including (UV, IR, ¹H, ¹³C-NMR, DEPT, 2D ¹H–¹H COSY, HSQC, HMBC and NOESY). Compounds were found to be the 3-O-rutinosides of quercetin, kaempferol and isorhamnetin, besides the flavonoid 5-hydroxy-3,7-dimethoxyflavone-4′-O-β-glucopyranoside. Most of the isolated extracts showed antimicrobial activity against the test microorganisms, where the crude flavonoid fraction was the most active, diameter of inhibition zones ranged between 15.5 and 28.5 mm against the tested bacterial strains, while reached 30 mm against the fungal Candida albicans. The minimal inhibitory concentrations varied from 0.04 to 0.32 mg/ml against all of the tested microorganisms in case of the crude flavonoid fraction. Quercetin-3-O-rutinoside showed superior activity over the remainder flavonoids. The Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) were more susceptible than the Gram-negative (Pseudomonas aeruginosa and Salmonella enteritidis) and the yeast species were more susceptible than the filamentous fungi. The study recommend the use of such natural products as antimicrobial biorationals.     

Cenomanian (Upper Cretaceous) bivalves from the Hameimat Massifs,north of Tebessa,Algeria: Systematics,biostratigraphy, palaeoecological and taphonomical remarks

In the eastern Saharan Atlas, particularly in the northern area of Tebessa Province (NE Algeria), the widely outcropping Cenomanian strata display a highly diversified macrofauna, among which bivalves are prominently represented. Twenty-eight bivalve species are here reported for the first time from the Cenomanian of Hameimat Massifs. Based on the stratigraphic distribution of these bivalves, five bivalve zones were recognized, i.e., Costagyra olisiponensis - Gyrostrea delettrei, Rhynchostreon suborbiculatum - Exogyra conica, Ceratostreon flabellatum, Ilymatogyra africana, and Pycnodonte vesicularis vesiculosa - Rastellum carinatum zones. Correlation to the ammonite biozones of the same region as follows: the Costagyra olisiponensis - Gyrostrea delettrei and the Rhynchostreon suborbiculatum - Exogyra conica zones occur respectively in the Sharpeiceras schlueteri and Mantelliceras saxbii subzones of the lower Cenomanian Mantelliceras mantelli Zone. The Ceratostreon flabellatum Zone is correlated with the middle Cenomanian Acanthoceras rhotomagense Zone. The Ilymatogyra africana Zone is correlated with the upper Cenomanian Calycoceras naviculare and the Metoicoceras geslinianum zones. Finally, the Pycnodonte vesicularis vesiculosa - Rastellum carinatum Zone represents the uppermost Cenomanian. Detailed analysis of biometrical and morphological features of these bivalve specimens provides the most reliable tool within the scope of palaeo-environmental reconstitution and the many palaeo-ecological variables that had driven the development and distribution of these macro-invertebrates. Comparison of these new data to those of adjacent south Tethyian areas supports the homogeneity of the Cenomanian bivalve faunas. Such an affinity underlines more vividly the favorable marine communications and currents driving the geographic dispersal of these bivalves during the Cenomanian.     

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.     

Leaf flavonoid chemistry and taxonomy of Coreopsis sect. Coreopsis

Seventeen flavonoid glycosides were isolated from the leaves of the nine species of Coreopsis sect. Coreopsis. The compounds include two flavones, four flavonols, a 6-hydroxyflavone, a 6-hydroxyflavonol, two 6-methoxyflavones, a 6-methoxyflavonol and three chalcone-aurone pairs. Chemistry distinguishes all species except C. auriculata and C. intermedia. The mean flavonoid similarity for pair-wise comparison of the four species of annuals (C. basalis, C. nuecensis, C. nuecensoides and C. wrightii) is 0.63 whereas it is 0.66 for the five perennial species (C. auriculata, C. grandiflora, C. intermedia, C. lanceolata, C. pubescens) and 0.54 for comparison of annuals with perennials. This indicates that on the average there is slightly higher flavonoid similarity among species of annuals and among species of perennials than there is between annuals and perennials. Lack of the chalcone-aurone pair coreopsin-sulfurein in perennials is the only consistent chemical difference between annuals and perennials. Leaf flavonoid chemistry supports the hypothesis that C. nuecensis and C. nuecensoides are closely related species but flavonoid data are not concordant with the hypothesis of close relationship between C. basalis and C. wrightii, intermedia, Coreopsis pubescens and C. lanceolata are considered closely related and flavonoid chemistry is concordant with this hypothesis. Coreopsis lanceolata is also viewed as closely allied to C. auriculata, but flavonoids suggest the latter species is more similar to C. intermedia. Coreopsis grandiflora is the only perennial species lacking flavonols and has the fewest number of compounds of any species in the section; chemical data support the view that C. grandiflora is quite distinct from other perennial species of sect. Coreopsis.     

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.     

Species Specific Flavone Glucuronides in Elodea Species

The flavonoid patterns of plants of Elodea canadensis, E. ernstae and E. nuttallii apigenin were investigated. The main flavonoids of E. canadensis are apeginin, luteolin and chrysoeriol 7-O-diglucuronides, of E. nuttalli apigenin and luteolin 7-O- diglucuronides, and of E. ernstae apigenin and luteonin 7-O-monoglucoronides. The qualitative stability of these flavonoid patterns is checked by chromatographic comparison of various populations from a wide area of the three species, it is shown that the flavonoid patterns are valuable criteria for the separation of these species.     

Flavonoid chemistry,chromosome number and phylogenetic relationships of Helenium chihuahuensis

Five populations of Helenium chihuahuensis were examined for flavonoid content, chromosome number and morphological characteristics. Thirteen flavonoid compounds were detected of which eleven were at least partially identified and were found to be flavones. The chromosome number was determined to be $\text{2}\text{n}\text{= 15II}$. Helenium arizonicum also was found to have a chromosome number of $\text{2}\text{n}\text{= 15II}$. Helenium chihuahuensis, H. arizonicum, H. mexicanum and H. laciniatum were compared by constructing Wagner Networks, both excluding and including flavonoid data, in order to clarify their phylogenetic relationships.     

Allelic variants from Dahlia variabilis encode flavonoid 3′-hydroxylases with functional differences in chalcone 3-hydroxylase activity

In the petals of Dahlia variabilis, hydroxylation of chalcones at position 3 can be detected, except the well-known flavonoid 3′-hydroxylation. Although the reaction is well characterized at the enzymatic level, it remained unclear whether it is catalyzed by a flavonoid 3′-hydroxylase (F3′H, EC1.14.13.21, CYP75B) with broad substrate specificity. Two novel allelic variants of F3′H were cloned from D. variabilis, which differ only in three amino acids within their 508 residues. The corresponding recombinant enzymes show significant differences in their chalcone 3-hydroxylase (CH3H) activity. A substitution of alanine at position 425 with valine enables CH3H activity, whereas the reciprocal substitution leads to a loss of CH3H activity. Interaction of the valine at position 425 with not yet identified structural properties seems to be decisive for chalcone acceptance. This is the first identification of an F3′H which is able to catalyze chalcone 3-hydroxylation to a physiologically relevant extent from any plant species.     

Flavonoids of Sullivantia: Taxonomic implications at the generic level within the saxifraginae

Sullivantia species were found to produce quercetin 3-O-glycosides, several of which contain glucuronic acid, as well as pedalitin (6-hydroxy-7-O-methyl luteolin), pedalitin 6-O-glycosides, and small amounts of luteolin. Sullivantia has a unique combination of compounds that distinguishes it from other genera in the Saxifraginae for which flavonoid data are available. The nature of the flavonoid compounds is in accordance with a general trend within the Saxifragaceae of reduction and replacement of flavonols by flavones.     

Comparative Study of the Interactive Effects of Salinity and Phosphorus Availability in Wild (Hordeum maritimum) and Cultivated Barley (H. vulgare)

The present study aimed to compare the effects of phosphorus (P) deficiency applied only or combined with salinity on root response, P partitioning, acid phosphatase activity, and phenolic compounds in wild (Hordeum maritimum) and cultivated (H. vulgare) barley species. Seedlings were grown hydroponically under low or sufficient P supply, with or without 100 mM NaCl for 55 days. Results showed that, when individually applied, P deficiency and salinity restricted the whole plant relative growth rate in both species of barley, with a more pronounced impact of the former stress. These depressive effects were more pronounced in H. vulgare than in H. maritimum. The combined effects of P deficiency and salinity were not additive neither on whole plant RGR nor on root response parameters in both species. The root area, root/shoot P content, root and leaf acid phosphatase activities, and shoot flavonoids contents increased under P deficiency conditions with and without salt in both species. Overall, the relatively better tolerance of H. maritimum plants to P deficiency applied only or combined with salinity could be explained by the capacity of this species to maintain higher P acquisition efficiency in concomitance with a larger root system, a higher root/shoot DW ratio, a higher root/shoot P content, a greater root and leaf acid phosphatase activities, and a higher flavonoid content and antioxidant capacity under combined effects of both stresses. Thus, H. maritimum constitutes a promising model to ameliorate the tolerance of the cultivated barley species under low-P soils and/or saline regions.     

Characterization and seasonal variation of individual flavonoids in Zostera marina and Zostera noltii from Norwegian coastal waters

The flavonoid content in leaves of Zostera marina and the endangered Zostera noltii, including mono- and disulphated flavonoids, from different sample localities were characterized. Seasonal variation of both individual and total flavonoid, as well as rosmarinic acid concentration were revealed. Minor amounts of luteolin 7-(6″-malonyl)glucoside (6) and apigenin7-(6″-malonyl)glucoside (11) were identified in Z. noltii for the first time. The total flavonoid content was found to be higher in Z. noltii than in Z. marina at most of the examined localities, and the qualitative flavonoid content was somewhat different in the two species. The quantitative variation of flavonoids and rosmarinic acid was found to be relatively consistent from year to year in Z. marina during a period of three years. The two species appeared though to have a different flavonoid production in the various seasons at the West coast. While Z. marina had the highest content in young leaves in May or June, with a markedly decrease from June to September and the lowest measured content in February, Z. noltii had the lowest measured flavonoid content in May/June followed by an increase from June to September and the highest measured content during wintertime in February. The observed seasonal differences may be related to the fact that Z. noltii is considered a perennial, thermophilous species, and the increasing flavonoid production during the colder seasons from September to March/April in Norway may serve as a protective function.     

Chemosystematic studies in the saxifragaceae sensu lato. 8. The flavonoids of elmera racemosa (Watson) Rydberg

The flavonoid glycosides of both varieties of Elmera racemosa were isolated and identified. The compounds were the monoglucosides of kaempferol, quercetin and myricetin, the rutinosides of the same aglycones, and the rhamnosylrutinosides of kaempferol and quercetin. All glycosides were linked at position-3 of the flavonols. The two varieties (var. racemosa and var. puberulenta C. L. Hitchcock) were identical. A comparison of the flavonoid chemistry of Elmera, Heuchera, and Tellima supports the existence of Elmera as a genus. A survey of several collections of Tellima grandiflora, Heuchera micrantha, and H. cylindrica showed only minor quantitative differences in the two-dimensional thin layer chromatograms from collection to collection. The possible origin of Tellima and Elmera from ancestral stock having Heuchera-like flavonoid chemistry is discussed.     

Flavonoid and anthocyanin patterns and the systematic relationships in Collomia

Analyses of extracts among populations of the 14 species of Collomia revealed the occurrence of 13 mono-, di- and triglycosides based on the flavonoids, acacetin, kaempferol, patuletin and quercetin. The glycosides included those having arabinose, galactose, glucose and rhamnose as mono-, bio- or triosides at the 3-, 5-, 3,7- or 7-position. Analyses of floral extracts from ten species revealed the occurrence of two anthocyanins, cyanidin and delphinidin 3-(p-coumarylglucosyl)-5-glucoside. Nearly all the species express distinctive flavonoid patterns, although the differences are based on relatively minor changes in position or type of glycosidic substitution. Use of the minimum biosynthetic step distance (MBSD), an index of similarity, revealed that a mean of 5.6 steps separated the 14 species. The four perennial species of section Collomiastrum showed a high degree of similarity and differed consistently from species of the two annual sections Courtoisia and Collomia by lacking quercetin-5-glucoside and kaempferol-3-arabinosylgalactoside. In contrast, flavonoid patterns among species within sections Courtoisia and Collomia showed a relatively low degree of similarity. The dissimilarity between C. diversifolia and C. heterophylla (section Courtoisia) is consistent with their divergent patterns of pollen morphology and ecological distribution. Three groups of species within section Collomia were defined generally by shared patterns of flavonoids, which are correlated to some degree with floral, pollen and vegetative morphology.     

The leaf flavonoids of the orchidaceae

In a leaf survey of 142 species from 75 genera of the Orchidaceae, flavone C-glycosides (in 53%) and flavonols (in 37 %) were found to be the most common constituents. However, since these compounds are not found uniformly and their distribution shows a strong correlation with plant geography, it is not possible to represent the Orchidaceae by a single flavonoid profile. Thus, flavone C-glycosides are most common in tropical and subtropical species of the Epidendroid and Vandoid tribes (in 63%) and flavonol glycosides are more characteristic of temperate species of the Neottioid tribes (in 78%). By contrast 6-hydroxyflavones (in 6 species), luteolin (in 2 species) and tricin as the 5-glucoside (in 1 species) are all rare. Three new glycosides were characterised: scutellarein 6-methyl ether 7-rutinoside from Oncidium excavatum and O. sphacelatum, pectolinarigenin 7-glucoside from 0. excavatutn and Eria javanica, and luteolin 3′,4′-diglucoside from Listera ovata. The xanthones, mangiferin and isomangiferin were found in Mormolyca ringens, Maxillaria aff. luteo-alba and 5 Polystachya species and a mangiferin sulphate tentatively identified in P. nyanzensis. Other unusual phenolic constituents include 6,7-methylenedioxy- and 6,7-dimethoxycoumarins from Dendrobium densiflorum and D. farmeri, formed by the rearrangement during the extraction process from the corresponding O-glucosyloxycinnamic acids. The origin and relationship of the Orchidaceae to other monocot groups are discussed in the light of the flavonoid evidence.