Determination of cardenolides in hairy root cultures of Digitalis lanata by enzyme-linked immunosorbent assay.

A competitive ELISA technique using digoxin-specific antibody has been developed to determine digoxin and its related compounds in hairy root cultures of Digitalis lanata. The ELISA could detect 0.2-2 nM digoxin and closely related cardenolides. Hairy roots cultured in the dark accumulated very small amounts of cardenolides (0.02-0.07 micrograms/g dry wt), while the content of cardenolides in green hairy roots cultured in the light was increased maximally 600-fold (16.5 micrograms/g dry wt) compared to those in the dark.

High-performance liquid chromatographic determination of secondary cardiac glycosides in Digitalis purpurea leaves.

An analytical method for the determination of secondary cardiac glycosides in Digitalis purpurea leaves by high-performance liquid chromatography (HPLC) is described. The procedure consisted of extraction of dry leaf powder with ethanol-chloroform (2:1) and clean-up by Sep-Pak cartridges prior to HPLC analysis. HPLC was performed on an octylsilyl bonded silica column, using acetonitrile-methanol-water (4:4:5) for trisdigitoxosides and acetonitrile-methanol-water (8:30:43) for strospeside; the effluent was monitored by ultraviolet detection (at 220 nm). Quantitation of these cardiac glycosides was carried out by the internal standard method. The amounts of digitoxin, gitoxin, gitaloxin and strospeside per 100 mg of dry leaf powder were estimated to be 22.6, 14.0, 54.7 and 1.9 micrograms, respectively. The method is sufficiently sensitive and reproducible to assay secondary glycosides in Digitalis purpurea leaves.

Isolation and quantitative determination of some cardioactive glycosides from Digitalis lanata by high-performance liquid chromatography.

A rapid extraction method followed by high-performance liquid chromatographic assay was developed for the quantitative determination of the cardioactive glycosides of Digitalis lanata. The leaf samples were extracted with water or aqueous alcohols. The simple extraction method gives a better yield than the methods described previously. Lanatoside C and its metabolites have been separated on a reversed-phase column with various mixtures of acetonitrile, methanol, and water as mobile phases for isocratic elution. Extraction and quantitative determination of lanatoside C and digoxin from a leaf sample require not more than 30 min.

[Polyphenols (acid-phenols, flavonoids, anthraquinones) from Digitalis grandiflora Mill. ( = D. ambigua Murr.)]. / Sur les polyphénols (acides-phénols, flavonoídes, anthraquinones) de Digitalis grandiflora Mill. ( = D, ambigua Murr.)

In Digitalis grandiflora, flavonoids are mainly constituted by flavone glycuronides which are found in all aerial organs, except the seeds; in the flowers are supplementary flavonoids, particularly, in the stamens, a kaempferol derivative.