A Competitive Solid-Phase Enzyme Immunoassay for the Evaluation of Tropane Alkaloids in Plant Material, using Anti-DL-Tropic Acid Antibodies

Abstract

Antibodies were obtained from the immunization of rabbits with DL-tropic acid conjugated to bovine serum albumin. Their wide specificity enabled us to analyse simultaneously every main tropane alkaloid of Solanaceous plants: hyoscyamine, atropine (DL-hyoscyamine), and scopolamine. The competitive ELISA assay used for this analysis was found to be a very rapid, sensitive method with good accuracy for the dosage of alkaloids in plant material: purified extracts, crude extracts, and dry powdered material. A tropine could be detected with a sensitivity of 0.1 ng. A racemization step was necessary to detect hyoscyamine and scopolamine with the same sensitivity.