| [on the cardenolides of roots of asclepias tuberosa l]. | | 1966 | 5232699 |
| biometric evidence of natural selection in asclepias tuberosa. | | 1953 | 16578427 |
| 8,14-secopregnane glycosides from the aerial parts of asclepias tuberosa. | twenty pregnane glycosides, tuberoside a(1)-l(5), were isolated from the diethyl ether-soluble fraction of the meoh extract from the aerial parts of asclepias tuberosa (asclepiadaceae). the pregnane glycosides were composed of 8,12;8,20-diepoxy-8,14-secopregnane as aglycon, and d-cymarose, d-oleandrose, d-digitoxose and/or d-glucose as the component sugars. their structures were established using nmr spectroscopic analysis and chemical methodologies. | 2009 | 19703695 |
| [phyto-constituents of asclepias tuberosa l. (asclepiadaceae)]. | | 1975 | 1182063 |
| root dynamics in an artificially constructed regenerating longleaf pine ecosystem are affected by atmospheric co(2) enrichment. | differential responses to elevated atmospheric co(2) concentration exhibited by different plant functional types may alter competition for above- and belowground resources in a higher co(2) world. because c allocation to roots is often favored over c allocation to shoots in plants grown with co(2) enrichment, belowground function of forest ecosystems may change significantly. we established an outdoor facility to examine the effects of elevated co(2) on root dynamics in artificially constructed ... | 2001 | 11378173 |
| pregnane glycosides from the roots of asclepias tuberosa. | sixteen glycosides of pregnanes, including ikemagenin, lineolon, and a new pregnane, 3beta8beta,14beta,15beta,16alpha-pentahydroxy-++ +5alpha-pregnan-20-one, termed pleurogenin, were isolated from the roots of asclepias tuberosa. among ikemagenin and lineolon glycosides, one (1) was a known glycoside, and eight (2-7, 10, 13) were glycosides with new combinations of ikemagenin or lineolon and known sugar sequences composed of d-cymarose, d-oleandrose, d-thevetose and d-glucose. the structures of ... | 2000 | 10923833 |
| an androstane bioside and 3'-thiazolidinone derivatives of doubly-linked cardenolide glycosides from the roots of asclepias tuberosa. | steroidal compounds in the roots of asclepias tuberosa were investigated and 17alpha-hydroxyandrosta-4,6,15-trien-3-one 17-o-alpha-l-arabinopyranosyl-(1-->6)-beta-d-glucopyranoside, termed ascandroside, was isolated from the chcl3-soluble fraction. among five doubly-linked cardenolide glycosides, two were identified as 3'-spiro-linked thiazolidinone (4) and s-oxythiazolidinone derivatives (5) of delta5-calotropin. the stereochemistry at the c-3' in these two cardenolides is discussed. 3'-o-beta- ... | 2000 | 10923828 |
| evaluation of host range and larval feeding impact of chrysolina aurichalcea asclepiadis (villa): considerations for biological control of vincetoxicum in north america. | a biological control program has been initiated against european swallow-worts vincetoxicum nigrum (l.) moench. and v. rossicum (kleopow) barbar., which are invasive in north america. a population of the leaf beetle chrysolina aurichalcea asclepiadis (villa) originating from the western alps has been under evaluation as a part of this program. the preliminary host range of c. a. asclepiadis was determined among 37 potential host plants. in addition, a prerelease impact study was conducted to det ... | 2011 | 22217758 |
| phytotoxicity of antofine from invasive swallow-worts. | pale swallow-wort (vincetoxicum rossicum) and black swallow-wort (v. nigrum) are two emerging invasive plant species in the northeastern united states and southeastern canada that have shown rapid population expansion over the past 20-áyears. using bioassay-guided fractionation, the known phytochemical phenanthroindolizidine alkaloid, (-)-antofine, was identified as a potent phytotoxin in roots, leaves, and seeds of both swallow-wort species. in seedling bioassays, (-)-antofine, at ++m concentra ... | 2011 | 21739223 |
| 8,12;8,20-diepoxy-8,14-secopregnane glycosides from roots of asclepias tuberosa and their effect on proliferation of human skin fibroblasts. | a pregnane glycoside fraction from the roots of asclepias tuberosa l. caused normal human skin fibroblasts to proliferate. this fraction contained 21 pregnane glycosides whose structures were established using nmr spectroscopic analysis and chemical evidence. the aglycones of most of these compounds were identified as 8,12;8,20-diepoxy-8,14-secopregnanes, such as tuberogenin or 5,6-didehydrotuberogenin, the same aglycones as constituents of the aerial parts of this plant. some of these compounds ... | 2011 | 21703653 |
| investigation of some characteristics of polyhydroxy milkweed triglycerides and their acylated derivatives in relation to lubricity. | most industrial lubricants are derived from nonrenewable petroleum-based sources. as useful as these lubricants are, their unintended consequences are the pollution of the earth's environment as a result of the slow degradation of the spent materials. native seed oils, on the other hand, are renewable and are also biodegradable in the environment, but these oils often suffer a drawback in having lower thermal stability and a shorter shelf life because of the intrinsic -c-c- unsaturation in their ... | 2011 | 21428293 |
| 8,12;8,20-diepoxy-8,14-secopregnane glycosides from the aerial parts of asclepias tuberosa. | further study of constituents from the aerial parts of asclepias tuberosa afforded twenty-two new steroidal glycosides along with tuberoside b(5) and g(5). these glycosides were confirmed to contain 8,12;8,20-diepoxy-8,14-secopregnanes, tuberogenin and its congeners, as their aglycones. the structure of each of these compounds was elucidated based on the interpretation of nmr and ms measurements and from chemical evidence. | 2010 | 20118575 |
| interspecific variation within the genus asclepias in response to herbivory by a phloem-feeding insect herbivore. | induced plant responses to leaf-chewing insects have been well studied, but considerably less is known about the effects of phloem-feedings insects on induction. in a set of laboratory experiments, we examined density-dependent induction by the milkweed-oleander aphid, aphis nerii, of putative defenses in four milkweed species (asclepias incarnata, asclepias syriaca, asclepias tuberosa, and asclepias viridis). we hypothesized that high aphid density would lead to increased cardenolide expression ... | 2007 | 17929096 |
| effects of elevated atmospheric carbon dioxide on biomass and carbon accumulation in a model regenerating longleaf pine community. | plant species vary in response to atmospheric co2 concentration due to differences in physiology, morphology, phenology, and symbiotic relationships. these differences make it very difficult to predict how plant communities will respond to elevated co2. such information is critical to furthering our understanding of community and ecosystem responses to global climate change. to determine how a simple plant community might respond to elevated co2, a model regenerating longleaf pine community comp ... | 2006 | 16825468 |
| properties of single k and cl channels in asclepias tuberosa protoplasts. | potassium and chloride channels were characterized in asclepias tuberosa suspension cell derived protoplasts by patch voltage-clamp. whole-cell currents and single channels in excised patches had linear instantaneous current-voltage relations, reversing at the nernst potentials for k(+) and cl(-), respectively. whole cell k(+) currents activated exponentially during step depolarizations, while voltage-dependent cl(-) channels were activated by hyperpolarizations. single k(+) channel conductance ... | 1987 | 16665712 |