Hybridization between Arctostaphylos viscida and A. canescens in Oregon

Evidence of natural hybridization betweenArctostaphylos viscida andA. canescens in southwestern Oregon was obtained from morphological studies of field populations. Hybridization occurs where populations ofA. viscida andA. canescens meet in areas where serpentine and nonserpentine soils abut. At these contacts,A. viscida forms large populations only on serpentine andA. canescens only on nonserpentine. Most of the indentifiable hybrids survive on either transitional or nonserpentine soils. The small proportion that are found on serpentine are considered to be backcrosses toA. viscida. The hybrid plants are similar to several putative species maintained in the standard floras, and it is suggested that these no longer be given taxonomic recognition.     

Chemical constituents from Flourensia resinosa S.F. Blake (Asteraceae)

β-eudesmol (1), cryptomeridiol (2), ilicic acid (3), 5,7-dihydroxyflavone (chrysin, 4) and 7-O-methyl-chrysin (tectochrysin, 5) were isolated as the major constituents from the acetone extract of the aerial parts of Flourensia resinosa S.F. Blake (Asteraceae), along with flourensiadiol (6), spathulenol (7), p-acetophenol (8), lupeol (9), β-sitosterol (10), triacontanol (11) and squalene (12). Based on previous studies, this chemical composition for F. resinosa is in accordance with the chemical profile of other species of Flourensia. The profile of flavonoids, sesquiterpenes and benzofurans may have chemotaxonomic significance within this genus.     

On the natural occurrence of gossypetin 7- and 8-monomethyl ethers

The 7-methyl ether of gossypetin occurs, as a mixture of 4 glycosides, in the yellow inflorescence of Eriogonum nudum. In contrast to previous reports, however, it does not occur in Lotus corniculatus flowers, nor is it present in leaves of Medicago sativa. The 8-methyl ether, which is present in Lotus flowers, has been found for the first time in the Compositae, in flowers of Geraea canescens.     

Leaf flavonoids of Glycine subgenus Glycine in relation to systematics

A survey of leaf flavonoids and isoflavonoids in several taxa of the genus Glycne subgenus Glycine was undertaken to see if this would help interpret inter- and intraspecific relationships in the genus. C-Glycosylflavones based on apigenin were found in Glycine tomentelia, G. tabacina and G. falcata. Glycosides of quercetin and kaempferol were also detected in G. tabacina. In the cultivated soybean, G. max, and its wild annual relative, G. soja, only quercetin and kaempferol glycosides have been reported. Interspecific hybrids of Glycine species sometimes show additive flavonoid patterns in F₁ hybrid leaf tissue. All perennial wild species analysed including Glycine canescens and G. latifolia have the isoflavonoids genistin (genesitein 7-O-glucoside), daidzein and coumestrol in the leaves.     

Structural Diversity and State of Knowledge of Flavonoids of the <Emphasis Type="Italic">Scutellaria</Emphasis> L. Genus

The review presents the results of scientometric analysis of data on the level of study and chemical diversity of flavonoids of the Scutellaria L. genus species of the world’s flora. Flavonoid composition in 63 species of skullcap is reported, together with the data on distribution in plants, structure, and sources of 301 flavonoids belonging to the groups of flavones, flavanones, flavanonols, flavonols, chalcones, isoflavones, flavolignans, and bioflavonoids. The greatest number of flavonoids was shown to be isolated from plants of S. indica, S. baicalensis, S. barbata, S. amoena, S. prostrata, S. galericulata, S. discolor, S. ramosissima, and S. supina. Scientometric studies indicate the constantly growing interest in the study of species of the Scutellaria L. genus by scientists of various branches of science, including phytochemists, biologists, and pharmacologists. Information provided in the review can be used to address issues of chemosystematics of plants of the Scutellaria L. genus.     

Effects of salinity on growth,membrane permeability and root hydraulic conductivity in three saltbush species

The species of the genus Atriplex have been introduced in West Asia and North Africa to determine their adaptability for use as fodder species. These halophytes are well adapted to extreme environmental conditions and may possess interesting properties for soil rehabilitation. The effect of NaCl stress on growth, water relation and mineral nutrition were investigated in three xero-halophyte species of Atriplex used for rehabilitation of arid steppe in Algeria. Atriplex halimus, Atriplex canescens and Atriplex nummularia, were cultivated in hydroponic conditions and treated with increasing doses of NaCl (0–300 mM). All species showed positive plant growth for low and moderate levels of salinity. A. halimus had higher dry weight production than A. nummularia and A. canescens in high salinity concentration. Increasing concentration of salinity induced decrease in chlorophyll content (Chl a and b) and root hydraulic conductivity (L₀) in all species, especially in A. canescens. All three species showed marked increase in electrolyte leakage across the salinity gradient. In addition all species were able to accumulate a large quantity of sodium (Na), chloride (Cl) and proline and to maintain higher relative water content, which was probably associated with a greater capacity for osmotic adjustment, whereas potassium (K) and calcium (Ca) decreased with increase salinity. The data suggest that salt tolerance strategies in all Atriplex species could involve a delicate balance among ion accumulation, osmotic adjustment, production of osmotica and maintenance of relative water content and growth.     

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.     

Comparative Benzofuran Chemistry of Enceliopsis

Enceliopsis (Asteraceae) is a small genus of herbaceous perennials from the Great Basin desert of the U.S.A. Phytochemical analysis revealed the presence of several benzofuran derivatives in Enceliopsis argophylla, E. covillei and E. nudicaulis. The compounds were either identical or very similar to benzofurans isolated from Encelia and Flourensia which supports the close affinity of these genera, as suggested previously, based on morphological, cytological and breeding studies.     

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.     

The systematic position of Sophora inhambanensis (Fabaceae: Sophoreae)

The phylogenetic position of Sophora inhambensis (one of only three species of Sophora that occur in Africa — the others are the widespread S. tomentosa and S. velutina) is inferred from an analysis of internal transcribed spacer (ITS) sequences for the core genistoid legumes. This species was thought to be closely related to the Podalyrieae based on chemical data (alkaloids and seed flavonoids), but molecular data indicates that it is strongly supported within the genus Sophora, close to the type species, S. tomentosa. Sophora velutina also groups with Sophora sensu stricto.     

Flower pigment composition of Crocus species and cultivars used for a chemotaxonomic investigation

A survey of floral anthocyanins and other flavonoids by analytical high-performance liquid chromatography (HPLC) was performed among 70 species and subspecies, 43 cultivars and six artificial hybrids of Crocus and the results were compared with taxonomical delimitations established by Mathew (The Crocus. B.T. Batsford Ltd, London, 1982).Nine anthocyanins were detected. The Crocus species and cultivars were placed into seven chemotypes according to their contents of 3,7-di-O-, 3,5-di-O-glucosides or 3-O-rutinosides of delphinidin and petunidin and to the presence of 3,7-di-O-malonyl-glucosides of petunidin and malvidin and delphinidin 3-O-glucoside-5-O-malonylglucoside. These malonated anthocyanins have only been found in Crocus and may be characteristic for this genus.The same 18 flavonoids were detected in every taxon. However, quantitative differences were noted and four chemotypes of Crocus were defined by their major contents of flavonoids. Six of the flavonoids appear to be unique for Crocus.The anthocyanin/flavonoid patterns of some of the taxa provide a valuable supplement to the taxonomy based on morphological and cytological patterns. Most chemotypes were represented in several series but the chemical data were useful in distinguishing different species. For all series except Series h the chemical data were very similar for all subspecies or accessions within a species, and chemotypes within a series were more similar than between series. However for six species, the analyses suggest that they should be further investigated using other methods, to evaluate their relations to other series.     

Chemosystematics of Aniba

A taxonomic subdivision of the genus Aniba (Lauraceae) which comprises 41 recognized species is, for the major part, compatible with a chemical subdivision of the genus which can be made on the basis of the mutually exclusive presence of neolignans vs benzophenones, pyrones and flavonoids. While the presence of neolignans is considered a primitive character of the genus Aniba, the occurrence of pyrones and biosynthetically related compounds is regarded as an advanced character. The chemistry of two closely allied species, of which one produces neolignans, the other pyrones plus an allylphenol, gives a clue for the understanding of the chemical evolution within this genus, for which a unified biosynthetic scheme is presented.     

Morphological and cytological evidence for polyphyletic allopolyploidy inArctostaphylos mewukka (Ericaceae)

The central Sierran tetraploidArctostaphylos mewukka Merriam has been reported to be an allopolyploid originating from the diploid species,A. patula Greene and eitherA. viscida subsp.viscida Parry orA. viscida subsp.mariposa (Dudley)P. V. Wells, although without conclusive evidence. Morphometrics and the verification and determination of chromosome numbers were used to substantiate the evolutionary relationships among these species. A closely related species,Arctostaphylos truei Knight, was also examined using these methods to determine its separability fromA. mewukka. The morphometric analyses support a hypothesis for a polyphyletic origin ofA. mewukka from different races ofA. viscida andA. patula. The chromosomal data, although inclusive, also support this hypothesis. The data do not support the recognition ofA. truei as a taxonomic entity separate fromA. mewukka at the species level.     

Phenolic compounds of Siberian and Dahurian larch phloem

The paper presents results of the investigation of phenolic compounds of the bark of the Siberian larch (Larix sibirica Ledeb.) and the Dahurian larch (Larix gmelini (Rupr.) Rupr). The flavonoids, stilbenes, phenolic acids have been identified on the basis of chemical, chromatographic and spectral data. Quercetin-3-O-??-L-rhamnopyranoside has been found for the first time in the bark of the Larix genus. Phenolic compounds with pyrocatechol type of substitution of aromatic ring have been found to dominate in the phloem of the larch species considered.     

Chemotaxonomy studies on the genus Hedysarum

In combination with phytochemical results, the pilot chemotaxonomy study on genus Hedysarum by using HPLC methods revealed differences between section Fruticosa and the three other sections Multicaulia, Obscura and Subacaulia, but there was a closer genetic relationship with Multicaulia and Subacaulia. Isoflavonoids and pterocarpans were proved to be the common constituents of genus Hedysarum, whereas pterocarpans, benzofurans, and coumestans were the characteristic constituents of section Fruticosa, and chalcones were the chemical markers of section Multicaulia and section Subacaulia. The present finding is consistent with the classical morphological classification of genus Hedysarum, and provides supporting evidences for dividing Hedysarum into two subgenera, i.e. subgenus Hedysara and subgenus Ruticosa.     

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.     

Variations in flavonoid patterns within the genus Chondropetalum (restionaceae)

HPLC and chemical analyses of the flavonoids in culms of 11 Chondropetalum species divide the genus into two groups: seven, with glycosides of myricetin larycitin and syringetin; and four, with glycosides of kaempferol, quercetin, gossypetin, gossypetin 7-methyl ether and herbacetin 4′-methyl ether. This chemical dichotomy is correlated with anatomical differences and confirms the view that the genus requires taxonomic revision. HPLC measurements on those species with myricetin derivatives show that taxa with a qualitatively similar pattern of glycosides can be readily separated on quantitative grounds. Syringetin 3-arabinoside and a glycoside of herbacetin 4′-methyl ether are reported for the first time from the genus.     

Chemosystematics of Brassicales

The order Brassicales, sensu APG III, belongs to Eurosids, and comprises 17 families and 398 genera. The present work discusses the chemical features of Brassicales through the micromolecular chemical data of its taxa and selected taxonomic markers to assess pertinent affinities between its families by correlating their chemosystematic parameters. Although the chemical data of all families were obtained, the data of Brassicaceae, Capparaceae, and Cleomaceae were the most studied. The chemistry of the Brassicales species is diverse, but it reveals the chemical affinity of its families due to occurrence of flavonoids (35%) and glucosinolates (25%), which were characterized as good chemical markers. The flavonoids consist primarily of flavones and flavonols, presenting a low flavone/flavonol ratio. These micromolecules commonly contain unprotected hydroxyls, which are mainly protected by glucosilation, revealing the basal features of its taxa. In Brassicales, the predominantly allyl glucosinolates are usually found in Brassicaceae, Capparaceae, and Cleomaceae families. In the present study, the results of the chemosystematic analysis confirmed the affinity among the Brassicaceae, Capparaceae, and Cleomaceae families, and supported the concept of their monophyly in the Brassicales order. However, more chemical data of the other families is required to improve the chemosystematic conclusions.