New oxindole alkaloids and iridoid from Carolina jasmine (Gelsemium sempervirens Ait. f.).
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Three new gelsedine-type oxindole alkaloids, GS-1, GS-2, and GS-3, and one new iridoid, GSIR-1, were isolated from the stems and leaves of cultivated Carolina jasmine (Gelsemium sempervirens AIT. f.) and their structures were determined by spectroscopic analysis. (+info)
Comparison of pollen transfer dynamics by multiple floral visitors: experiments with pollen and fluorescent dye.
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BACKGROUND AND AIMS: Most plant species are visited by a diversity of floral visitors. Pollen transfer of the four most common pollinating bee species and one nectar-robbing bee of the distylous plant Gelsemium sempervirens were compared. METHODS: Naturally occurring pollen loads carried by the common floral visitor species of G. sempervirens were compared. In addition, dyed pollen donor flowers and sequences of four emasculated recipient flowers in field cages were used to estimate pollen transfer, and the utility of fluorescent dye powder as an analogue for pollen transfer was determined. KEY RESULTS: Xylocopa virginica, Osmia lignaria and Habropoda laboriosa carried the most G. sempervirens pollen on their bodies, followed by Bombus bimaculatus and Apis mellifera. However, B. bimaculatus, O. lignaria and H. laboriosa transferred significantly more pollen than A. mellifera. Nectar-robbing X. virginica transferred the least pollen, even when visiting legitimately. Dye particles were strongly correlated with pollen grains on a stigma, and therefore provide a good analogue for pollen in this system. The ratio of pollen : dye across stigmas was not affected by bee species or interactions between bee species and floral morphology. However, dye transfer was more sensitive than pollen transfer to differences in floral morphology. CONCLUSIONS: The results from this study add to a growing body of literature highlighting that floral visitors vary in pollination effectiveness, and that visitors carrying the most pollen on their bodies may not always be the most efficient at depositing pollen on stigmas. Understanding the magnitude of variability in pollinator quality is one important factor for predicting how different pollinator taxa may influence the evolution of floral traits. (+info)
New iridoids from Gelsemium species.
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Four new iridoids structurally related to gelsemide (5) were isolated from two Loganiaceous plants, Gelsemium elegans and G. rankinii. Among them, GEIR-1 (1) has a novel tetracyclic caged structure. (+info)
Confirmation of gelsemium poisoning by targeted analysis of toxic gelsemium alkaloids in urine.
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The gelsemium plants are highly poisonous but toxicological evaluation of suspected poisoning cases has been hampered by the chemical complexity of the gelsemium toxins involved. A novel liquid chromatography-tandem mass spectrometry protocol was optimized for the collective detection of gelsemine and related alkaloids from Gelsemium elegans. The screening protocol was applied to the clinical investigation of unexplained intoxications following the ingestion of seemingly nontoxic herbs. In three clusters of toxicological emergencies ranging from severe dizziness to respiratory failure, Gelsemium elegans mistaken for various look-alike therapeutic herbs was suspected to be the hidden cause of poisoning. Nine cases of gelsemium poisonings were thus ascertained by the diagnostic urine alkaloid profiles. Gelsemine was sustained as the main urinary marker of Gelsemium exposure. (+info)
Dose-effect study of Gelsemium sempervirens in high dilutions on anxiety-related responses in mice.
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Gelsenicine from Gelsemium elegans attenuates neuropathic and inflammatory pain in mice.
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Gelsemium elegans BENTH and its crude extract are widely used to treat pain in China despite its apparent toxicity. The analgesic effects of gelsenicine, an active component of G. elegans, however, have not been reported. The current study examined potential analgesic effects of subcutaneously injected gelsenicine using acetic acid-induced writhing, formalin-induced nociceptive behavior, and thermal hyperalgesia caused by chronic constriction injury (CCI) in mice. Gelsenicine produced dose-dependent analgesic effects in both inflammatory and neuropathic pain models. The ED(50), for either the inflammatory pain (10.4 microg/kg for writhing test, 7.4 microg/kg for formalin test) or neuropathic pain (9.8 microg/kg for thermal hyperalgesia caused by CCI model), was far below the LD(50) (95% confidence interval at 100-200 microg/kg). Repeated subcutaneous injections of gelsenicine in CCI mice led to sustained attenuation of neuropathic pain after drug discontinuation. These results revealed that gelsenicine could be used safely to attenuate both inflammatory and neuropathic pain. (+info)
Two new koumine-type indole alkaloids from Gelsemium elegans Benth.
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