SIMULTANEOUS DETERMINATION OF 18 POLYKETIDES TYPICAL OF ALOE BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY AND PHOTODIODE-ARRAY DETECTION

A high performance liquid chromatorgraphic method has been developed f or the simultaneous separation, identification and quantification of s econdary products characteristic of Aloe species (Asphodelaceae). The standard compounds comprised eleven anthrone-C-glycosyls in diastereom erically pure state, two anthrone aglycones, three anthraquinone aglyc ones, a tetrahydroanthracene aglycone and a 2-alkylchromone-C-glucosyl . The chromatographic system consisted of a reversed phase silica colu mn (C-18, 5 mum) and a combination of linear gradient and isocratic el ution with acetonitrile, water and phosphoric acid. Photodiode array d etection enabled a specific determination of the compounds even from c rude methanolic extracts of plant material from Aloe. The technique de scribed could replace the conventional qualitative thin layer chromato graphic systems as a routine method in applied research on Aloe (i.e. for plant physiology, chemotaxonomy, pharmacognosy and pharmacokinetic s).