Phytochemical and chemotaxonomic study on Fallopia dentatoalata (Fr. Schm.) Holub

Phytochemical study of Fallopia dentatoalata gave seventeen compounds, two sterols (8 and 10), three anthraquinones (5, 16 and 17), one chromone (13), two stilbenes (3 and 4), two amides (11 and 12), six flavonoids (1, 2, 6, 7, 14 and 15) and one fatty acid (9). Their structures were elucidated by spectroscopic methods and in comparison with the reported data. Compound 11 was obtained from genus Fallopia for the first time, and all of the compounds were firstly isolated from F. dentatoalata. The chemotaxonomic significance of these compounds was also discussed, which demonstrated the relationships between F. dentatoalata and some other species of genus Fallopia.     

Chemical variability of the invasive neophytes Polygonum cuspidatum Sieb. and Zucc. and Polygonum sachalinensis F. Schmidt ex Maxim

Crude extracts of roots and stems of Polygonum cuspidatum Sieb. and Zucc. and Polygonum sachalinensis F. Schmidt ex Maxim from China and Switzerland were analyzed by online HPLC/UV/ESI-MS to ascertain the phytochemical differences between the original and invasive exotic varieties. A total of 36 constituents were identified by comparing their retention times, UV data, mass spectra with those of standards or with literature data. Certain constituents, such as flavanol gallate dimers, were reported for the first time from these species.     

Chromosome number and DNA ploidy level reports from Central Europe — 2

Second part of commented chromosome number and DNA ploidy level reports from Central Europe comprising the whole Carpatho-Pannonian region includes the data for following taxa: Tephroseris aurantiaca (2n = 96), T. capitata (2n = 64) and T. integrifolia (2n = 48) by J. Kochjarová from Poland and Slovakia (reports nos. 12–14); Urtica diocia and U. kioviensis (both 2n = 26) by M. Kolník & K. Goliašová from Slovakia (nos. 15–16); Viola hirta (2n = 20), V. odorata (2n = 20), V. reichenbachiana (2n = 20), V. riviniana (2n = 40, 2n ∼ 8x, based on x = 5), V. suavis (2n = 40) and V. × bavarica [V. reichenbachiana × v. riviniana] (2n ∼ 6x, based on x = 5) by P. Mereďa jun., I. Hodálová, P. Mártonfi & V. Kolarčík from Slovakia (nos. 17–22); Fallopia × bohemica [F. japonica × F. sachalinensis] (2n = 66), Thladiantha dubia (2n = 18) and Hieracium longifoliosum (2n = 36) by P. Mráz from Romania and Slovakia (nos. 23–25); Amsinckia calycina (2n = 34) by M. Perny & H. Šípošová from Slovakia (no. 26). For further details and arrangements of reports see the first part (Mráz, 2005).     

Taxonomy of the Polygonum douglasii (Polygonaceae) complex with a new species from Oregon

The taxonomy of the Polygonum douglasii complex is revised. A summary of relevant taxonomic information is provided, along with a key to the species and subspecies, plus typification, synonymy, discussion, distribution, and ecology. Morphology and micromorphology of stems, leaves, perianth, pollen, and achenes are analyzed and illustrated. Based on these data, 12 species and two subspecies are recognized. A new species, P. gabrielae, is described and illustrated from Oregon.     

Estrogenic activity of constituents from the rhizomes of Rheum undulatum Linné

Stilbenes have been reported to be phytoestrogen compounds owing to its structural similarity to the estrogenic agent diethylstilbestrol. To find new stilbene-derivative phytoestrogens, isolation of stilbene-rich R. undulatum was performed and led to identify six new compounds (1–5 and 28), one newly determined absolute configurations compound (27) together with 21 previously reported compounds (6–26). The structures of compounds were determined on the basis of extensive spectroscopic methods including 1D and 2D NMR and CD spectra data. All the isolated compounds were tested for their estrogenic activities in HepG2 cells transiently transfected with ERα, ERβ and ERE-reporter plasmid. Among them, stilbene-derivatives, piceatannol 3′-O-β-d-xylopyranoside (12), cis-rhaponticin (16) and rhapontigenin 3′-O-β-d-glucopyranoside (17), showed the more potent binding affinity for estrogen receptors than 17β-estrodiol.     

Sensitivity to ethylene: the key factor in submergence-induced shoot elongation of Rumex

Rosettes of flooding-resistant Rumex palustris plants show a submergence-induced stimulation of elongation, which is confined to the petioles of young leaves. This response increases the probability of survival. It is induced by ethylene that accumulates in submerged tissues. Flooding-intolerant Rumex acetosella plants do not show this response. We investigated whether differences in shoot elongation between the species, between old and young leaves and between the petiole and leaf blade of a R. palustris plant result from differences in internal ethylene concentration or in sensitivity to the gas. Concentrations of free and conjugated ACC in petioles and leaf blades of R. palustris indicated that ethylene is synthesized throughout the submerged shoot, although production rates varied locally. Nevertheless, no differences in ethylene concentration were found between submerged leaves of various ages. In contrast, dose-response curves showed that only elongation of young petioles of R. palustris was sensitive to ethylene. In R. acetosella, elongation of all leaves was insensitive to ethylene. We conclude that variation in ethylene sensitivity rather than content explains the differences in submergence-induced shoot elongation between the two Rumex species and between leaves of R. palustris.     

Phosphate starvation‐inducible pyrophosphate‐dependent phosphofructokinase occurs in plants whose roots do not form symbiotic associations with mycorrhizal fungi

Previously, we reported that phosphate (P_i) starvation of suspension cells or seedlings of Brassica nigra results in a large elevation in the activity of pyrophosphate-dependent phosphofructokinase (EC 2.7.1.90) (PFP). However, other researchers have found that P_i deprivation either causes a significant reduction or no change in extractable PFP activity of Catharanthus roseus suspension cells, or roots of Nicotiana tabacum and Phaseolis vulgaris seedlings. The present study was undertaken to examine the prevalence of P_i starvation-inducible PFP in seedlings, root cultures, or suspension cells of a variety of plant species differing in phylogenetic relatedness to B. nigra. In all species examined, fresh weights were decreased and acid phosphatase (EC 3.1.3.2) activities were increased by P_i limitation. Brassica napus suspension cells, Arabidopsis thaliana seedlings, and roots of B. napus, B. carinata, B. oleracea, Beta vulgaris, Fagopyrum esculentum, Sinapis alba, and S. arvensis seedlings grown with P_i-limited media contained 170–510% greater PFP activity than did nutrient-sufficient controls. In five of these species the induction of PFP activity by P_i limitation was based in part upon an increased susceptibility of the enzyme to its allosteric activator, fructose-2,6-bisphosphate. By contrast, the PFP activity in P_i-deprived Lycopersicon esculentum root cultures and Nicotiana silvestris suspension cells decreased by 45–65% relative to P_i-sufficient controls. Immunoblotting of extracts from A. thaliana seedlings, S. arvensis, F. esculentum and B. oleracea roots, and B. napus suspension cells probed with potato tuber PFP antibodies indicated that the upregulation of PFP activity by P_i stress in these species was not correlated with an alteration in the amount or subunit composition of PFP. Our findings suggest that induction of PFP during long-term P_i starvation may be characteristic of members of the Cruciferae, Chenopodiaceae and Polygonaceae families whose roots do not form symbiotic associations with mycorrhizal fungi.     

Distribution pattern of anthocyanins in the polygonaceae

A survey of anthocyanins in the flowers and other organs of thirty-three species of three genera belonging to the Polygonaceae has been carried out. There are thirteen anthocyans. Cyanidin glycosides, especially the 3-glycoside (chrysanthemin), are present most commonly and peonidin glycosides including the arabinosylglucoside are found with low frequency. The distribution of malvidin 3,5-diglucoside (malvin) is confined to the species belonging to the sectionEchinocaulon of the genusPolygonum. It is noted that cyanidin itself occurs in the stems ofPolygonum perfoliatum andP. senticosum.