Cardenolides detection

Protocol of ELISA for cardenolide detection in plant extracts... 

The present volume reflects these developments, and there is a growing emphasis on bioactive natural products. Articles in this volume include those on structure-activity relationships of highly sweet natural products, chemical constituents of cchinodenns, diterpenoids from Rabdosia and Eremophila sp., structural studies on saponins, marine sesquiterpene quinoncs and antimicrobial activity of amphibian venoms. The reviews on bioactive metabolites of Phomopsis, cardenolide detection by ELISA, xenocoumacins and bioactive dihydroisocoumarins, CD studies of carbohydrate-molybdate complexes, oncogene function inhibitors from microbial secondary metabolites and Gelsemium and Lupin alkaloids present frontier developments in several areas of natural product chemistry. It is hoped that the present volume, which contains articles by eminent authorities in each field, will be received with the same enthusiasm as the previous volumes of this series. 

This soluble, cytosolic enzyme catalyses the 15 -0-acetylation of cardenolide tri- and tetrasaccharides. Using acetyl co-enzyme A as the acetyl donor, acetyl co-enzyme A digitoxin 15 -0-acetyltransferase (DAT) activity was detected... 

A clone of cardenolide 16 -0-glucohydrolase cDNA (CGH I) was obtained from D. lanata. The amino acid sequence derived from CGH I showed high homology to a widely distributed family of (3-glucohydrolases (glycosyl hydrolases family 1). The recombinant CGH I protein produced in Escherichia coli had CGH 1 activity. CGH 1 mRNA was detected in leaves, flowers, stems and fruits of D. lanata (Framm et ah, 2000). 

In addition to the above methods utilizing conventional ionization modes, the field ionization technique has appeared [75]. The very intense electric field (about 1 V/A), produced by an electrode, results in the ionization of molecules in the gas phase. This soft ionization technique is often used competitively with Cl, since it does not pollute the source and may yield sufficiently reproducible results. The transit time of ions in the source is on the order of 10 to 10 second. The radical molecular ions (M ) produced are characterized by a low internal energy, and thus can be detected easily. As a result of dispersion within the source, however, sensitivity is about two orders of magnitude lower than that of El. As in the case of El, the fragments produced by FI can furnish interesting structural data on carbohydrates, amino acids, peptides and cardenolides [76],... 

Fig. 4C In vi.sible light a similar TLC fingerprint (compared with Kedde detection) of corresponding grey to violet-grey cardenolide zones is given.

Scillae buibus var. alba (3-5). The white squill samples (3,4) contain predominantly pro.scillaridin, seen as a major light-brown fluorescent zone at R, 0.6 (T/a). The glycoside scillaren A (R, — 0.4/b) dominates the standardized commercial extract 5. Three additional cardenolide zones (e.g. glucoscUlaren R, — 0.2) are detectable as yellow-browii fluorescent zones. Sciliirosidin glycosides are absent in white squill. 

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