Showing papers on "Polygonum published in 1987"

Flavonoid Chemistry of Polygonum sect. Echinocaulon: A Systematic Survey

Abstract: Thirteen species of Polygonum sect. Echinocaulon were examined for leaf flavonoid constituents. Thirty-six flavonoid compounds were isolated and identified, most of which were glycosylated and/or methoxylated derivatives of the flavonols kaempferol, quercetin, and myric- etin, and of the flavones apigenin and luteolin. Among them, quercetin 3-0-glycosides were major flavonoid constituents, and present in all species. Species of section Echinocaulon exhibit relatively complex patterns of leaf flavonoid constituents. Although the flavonoid data for some species are lacking, those available appear to be very useful for species delimitation and for recognizing species relationships in the section. Most species of section Echinocaulon are readily distinguished by their flavonoid profiles, and the cladogram based on nine flavonoid characters suggests four basic chem- ical lineages in the section. Section Echinocaulon of Polygonum (Polygo- naceae), first recognized by Meisner (1832), is morphologically distinct and characterized by recurved prickles on the angles of the stems, petioles, and midribs. Additional characters separating this from other sections of Polygo- num include scandent to climbing habit and el- liptic to triangular leaf shapes with sagittate to

Polygoacetophenoside, A New Acetophenone Glucoside from Polygonum multiflorum1.

Abstract: Polygoacetophenoside ( 3), a new acetophenone glucoside, was isolated from POLYGONUM MULTIFLORUM (Polygonaceae), together with quercetin 3- O-galactoside ( 1) and arabinoside ( 2). The structure of the new glucoside was deduced to be 2,3,4,6-tetrahy-droxyacetophenone 3- O-beta- D-glucoside ( 3) by its chemical and spectral data.

Cytotaxonomic studies on Polygonum section Polygonum in eastern Canada and the adjacent United States

Abstract: A total of 183 chromosome counts on plants representing nine species of Polygonum section Polygonum in eastern Canada and the United States is presented. Documented counts are published here for the first time for P. franktonii (2n = 60) and P. neglectum (2n = 40 and 60). In addition, previously unreported counts for P. achoreum (2n = 60), P. aviculare (2n = 40), and P. fowled (2n = 60) are presented. A review of previously published counts and an examination of voucher specimens have revealed a number of errors, negating many reported counts, including all of those for P. erectum and most of those for P. buxiforme. Polygonum arenastrum and P. raii are entirely tetraploid (2n = 40) and P. franktonii and P. ramosissimum entirely hexaploid (2n = 60), whereas the remaining species have both tetraploid and hexaploid elements. In contrast to previous reports, no diploid or octoploid plants have been detected.

Antimutagenic factors in aquatic plants

Abstract: Antimutagenic activity was screened in water extracts from 13 kinds of aquatic plant and it was found that curled pondweed ( Potamogetan crispus L.), European cut-grass ( Leersia japonica Makino ) and smartweed ( Polygonum hydropiper L.) had large antimutagenic effects. Antimutagenic factors in these extracts were heat-resistant. The factors in curled pondweed and European cut-grass reduced the mutagenicities of benzo[ a ]pyrene and 2-nitrofluorene, but did not reduce the mutagenicity of AF-2. The factor in smartweed reduced the mutagenicity of benzo[ a ]pyrene, but did not reduce the mutagenicity of 2-nitrofluorene and AF-2. The factor in curled pondweed had molecular weight (mol. wt.) above 300 000. The factors in European cut-grass and smartweed existed in both fractions with mol. wt. above and below 300 000. The active factors in curled pondweed and smartweed may act as the desmutagen, but that in European cut-grass does not act as a desmutagen.

Stimulation ofBradyrhizobium japonicum by allelochemicals from green plants

Abstract: Yeast extract-mannitol broth supplemented with 3 mg.ml−1 extract from aerial parts of plants was noculated withB. japonicum 3I1b110. Filter-sterilized water extracts of foxtail (Setaria viridis), lambsquarters (Chenopodium album), Johnsongrass (Sorghum halepense) and Pennsylvania smartweed (Polygonum pensylvanicum) stimulated growth of the bacterium by 3–4 times after 48 h incubation; however, similar extracts from several other plants were marginally stimulatory. Autoclaved water extracts and methanol (75%) extracts were less stimulatory than filter-sterilized water extracts. Autoclaved water extracts of nutsedge (Cyperus esculentus) and ragweed (Ambrosia psilostachya), and methanol extracts of smartweed, peat and ragweed depressed growth of the bacterium. Filter-sterilized water extracts from shoots of foxtail and lambsquarters increased growth of the bacterium linearly up to 6 mg.ml−1. At that level growth in the presence of lambsquarters shoot extract was almost 20 times that of the control. Comparable growth stimulation by this extract was also found in four other strains ofB. japonicum. The water extracts from roots and stems of lambsquarters, and roots, shoots and inflorescences of foxtail at 3 mg.ml−1 stimulated growth of the bacterium by more than 40 times the control.

Isolation and identification of some flavonoids from Polygonum species.

Abstract: Several flavonoids were isolated from the leaves of Polygonum filiforme var. neofiliforme, flaccidum, P. Blumei, P. Y o kusaianum, and P. senticosum. Their structures we re identified as myricetin 3-rhamnoside, quercetin 3-(2-O-galloylrhamnoside), quercetin 3-rutinoside, quercetin 3-rhamnoside, kaempferol 3-glucoside, isorhamnetin, quercetin, and apigenin 7(glucuronide 6-methyl ester) by the comparison of their TLC, HPLC, and spectroscopic data with those of the authentic samples. It was clarified that quercetin 3-(2-O-galloylrhamnoside)is distributed in P. filiforme var. neofiliforme and P. flaccidum.

Polygonum avicular extracts

Abstract: Compositions for topical application contain extracts of the plant Polygonum aviculare. The extracts are aqueous ones, or extracts in oily substances or in physiologically acceptable organic solvents. The preparations are of value in the treatment of eczemas, acne, chipped skin, bleeding gums, and afflictions of the mucosa.