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21.
Summary Life stages of the primitive Australian ithomiine butterflyTellervo zoilus and its larval hostplant, the apocynaceous vineParsonsia straminea, were quantitatively assayed for pyrrolizidine alkaloids (PAs). PAs were found in all stages, mainly as N-oxides, being most concentrated in larvae and freshly-emerged adults. Although adults feed at various confirmed PA sources this probably does not compensate for losses, as wild-caught adults had considerably lower concentrations of PAs. The main alkaloid present in both freshly-emerged adults and in leaves of the host-plant was lycopsamine (1b), stored by butterflies in the N-oxide form. Its presence in higher proportion, in relation to intermedine (1a), in larvae, pupae and adults ofTellervo in relation to the host-plants suggests the inversion of intermedine to lycopsamine by the insects. No 14-member ring macrocyclic PAs were detected in either food-plant or butterflies. Several other PAs were found in wild-caught adults reflecting visits to other PA sources. PAs were also found in high concentrations in freshly-emerged individuals of the danaineEuploea core bred onParsonsia straminea. Wild-caughtDanaus affinis had high PA levels acquired from adult feeding. Freshly emergedEuploea raised onIschnocarpus frutescens andDanaus raised onIschnostemma carnosum (both PA-free) were preyed on by the orb weaving spiderNephila maculata, and showed no PAs. In all cases where PAs were present, most butterflies were liberated, usually cut out of the web unharmed, byNephila. The spider's response was not closely linked to PA concentration, however, and may also depend on hunger levels and previous experience with PA-containing butterflies. All control and other non-PA containing butterflies were consumed although rejection of some body parts of freshly-emergedDanaus affinis suggests that compounds other than PAs may be involved. 相似文献
22.
Ingo?NarberhausEmail author Claudine?Theuring Thomas?Hartmann Susanne?Dobler 《Chemoecology》2004,14(1):17-23
Summary. Several species of Longitarsus take up, metabolize and
store pyrrolizidine alkaloids (PAs) from their host plants. In feeding experiments using
radioactively labeled PAs of different types we examined the time course of the sequestration
process in L. jacobaeae and
L. aeruginosus. We found that adapted species efficiently
store PAs for at least two weeks without major losses. During that time, there is virtually
no change in the ratio of tertiary alkaloids to stored non-toxic
N-oxides, regardless of chemical form fed to the beetles. This
implies a transient N-oxidation process where the alkaloids are
only temporarily accessible to the enzyme. A dissection experiment with
L. aeruginosus six days after uptake of labeled PAs
showed that the tertiary alkaloids are not found in the hemolymph but are stored in the
elytra and other body compartments. This conforms with earlier experiments that localized the
enzymes site of action in the hemolymph. Furthermore we show that different total alkaloid
doses in the diet of L. jacobaeae and the potentially less
adapted L. succineus do not affect the ratio of recovered
N-oxides to tertiary molecules. Thus, the efficiency of the
N-oxidizing enzyme is not dependent on the concentration of
alkaloids offered. 相似文献
23.
Rainer Brüggemann Andreas Kaune Laszlo Zelles Anton Hartmann Christian Steinberg 《Umweltwissenschaften und Schadstoff-Forschung》1995,7(5):265-274
Die ?kotoxikologie mu? sich mit biologischen Systemen und ihren Antworten auf schadstoffinduzierten Stre? auseinandersetzen.
Die hierzu verwendete experimentelle Technik eilt dabei den M?glichkeiten dynamischer, proze?orientierter mathematischer Modellierung
weit voraus.
In dieser methodisch orientierten Arbeit werden Techniken aus der mathematischen Disziplin der Verbandstheorie vorgestellt,
die eine Datenanalyse unter den Aspekten vergleichender Bewertung erlauben. Wichtige Ergebnisse sind dabei
相似文献
– | • Aussagen zur Diversit?t mikrobieller Systeme (soweit durch die hier verwendeten Muster von vier Phospholipidfetts?uren erfa?bar), |
– | • Analysen ordinaler Abh?ngigkeiten sowie |
– | • komprimierte Darstellung komplexer Befunde im Zusammenhang mit der Toxizit?t von Huminstoff-Chemikalien-Systemen. |
24.
Max Hartmann 《Die Naturwissenschaften》1944,32(27-39):231-231
25.
F. Hartmann 《Die Naturwissenschaften》1949,36(12):378-378
26.
27.
The Science of Nature - 相似文献
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