| antimicrobial agents from higher plants. the quaternary alkaloids of ptelea trifoliata. | quaternary alkaloid extracts of ptelea trifoliata showed potentially interesting antimicrobial activity. chromatographic examination showed the presence of six components. of these, choline and o-4-methyl ptelefolinium were known compounds. rational structures are proposed for the new alkaloids, o-4-methylhydroxyluninium, neohydroxylunine and pteleatinium salts. pteleatinium salt is responsible for the antimicrobial activity of the extracts of the plant. | 1975 | 1094214 |
| the importance of the ontogenetic niche in resource-associated divergence: evidence from a generalist grasshopper. | geographic variation in resource use can produce locally adapted populations that exhibit genetic and phenotypic divergence. in the bird-winged grasshopper (schistocerca emarginata = [lineata]), we investigate whether genetic data exist in accordance with geographic variation in resource (host) use and coloration. in texas, juvenile grasshoppers feed almost exclusively on one of two host plants, rubus trivialis (rosaceae) or ptelea trifoliata (rutaceae), whereas adults of both forms are dietary ... | 2002 | 12038531 |