545-26-6Relevant articles and documents
New cardenolides from biotransformation of gitoxigenin by the endophytic fungus alternaria eureka 1e1bl1: Characterization and cytotoxic activities
Bedir, Erdal,Do?an, Gamze,Kü?üksolak, Melis,Karakoyun, ?i?dem,Kuru, Gülten,Yusufo?lu, Hasan
, (2021)
Microbial biotransformation is an important tool in drug discovery and for metabolism studies. To expand our bioactive natural product library via modification and to identify possible mammalian metabolites, a cytotoxic cardenolide (gitoxigenin) was biotransformed using the endo-phytic fungus Alternaria eureka 1E1BL1. Initially, oleandrin was isolated from the dried leaves of Nerium oleander L. and subjected to an acid-catalysed hydrolysis to obtain the substrate gitoxigenin (yield; ~25%). After 21 days of incubation, five new cardenolides 1, 3, 4, 6, and 8 and three previously-identified compounds 2, 5 and 7 were isolated using chromatographic methods. Structural elucida-tions were accomplished through 1D/2D NMR, HR-ESI-MS and FT-IR analysis. A. eureka catalyzed oxygenation, oxidation, epimerization and dimethyl acetal formation reactions on the substrate. Cytotoxicity of the metabolites were evaluated using MTT cell viability method, whereas doxorubicin and oleandrin were used as positive controls. Biotransformation products displayed less cytotoxicity than the substrate. The new metabolite 8 exhibited the highest activity with IC50 values of 8.25, 1.95 and 3.4 μM against A549, PANC-1 and MIA PaCa-2 cells, respectively, without causing toxicity on healthy cell lines (MRC-5 and HEK-293) up to concentration of 10 μM. Our results suggest that A. eureka is an effective biocatalyst for modifying cardenolide-type secondary metabolites.
Plant-derived wildlife repellents
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, (2008/06/13)
Products from the plant species Nerium oleander and, Urginea maritima, are prepared and tested as wildlife repellents comparing them with digitalis products. Chemical compounds derived from these plants including oleandrin, oleandrigenin, scillirosidin, digitoxigenin and digoxigenin are shown to cause nausea and emesis at low doses in pigeons and to repel, mice, rats, gophers, meadow voles and mountain beavers. After ingestion these animals quickly learn to avoid targets treated with the plant-derived repellents. When the remembrance of a treated food or other target lasts for an extended period of time it can be termed an aversion conditioning agent. Such products can be used for the protection of other plants, seeds, buildings, structures, communication cables and animals exposed to wildlife.
Cardiac Glycosides. 6. Gitoxigenin C16 Acetates, Formates, Methoxycarbonates, and Digitoxosides. Synthesis and Na+, K+ -ATPase Inhibitory Activities
Hashimoto, Toshihiro,Rathore, Hargovind,Satoh, Daisuke,Hong, George,Griffin, Jane F.,et al.
, p. 997 - 1003 (2007/10/02)
A series of 17 gitoxigenin 16β-formates, acetates, and methoxycarbonates was synthesized, including their 3β-acetates, formates, and digitoxosides.A 16β-formate group was generally found to increase activity 30 times, a 16β-acetate group 9-12 times, while a 16β-methoxycarbonate decreased activity by two-thirds. 3β-Formates and acetates had little effect on activity by themselves, but sometimes reduced the activity-increasing properties of 16β-formates and acetates.A 3β-digitoxoside increases the activity of ditoxigenin by 15 times, but the effect is less ifthe 16β-group is esterified.And finally, a 16-one decreases activity dramatically.These data suggest an important role for C16 esters and possibly the presence of a separate binding site on Na+, K+ -ATPase corresponding to the cardenolide C16 position.
