Simple detection of some plant metabolites of veterinary importance by test examinations

摘要

The plant phytochemicals (mainly the secondary metabolites) can cause different types of toxicosis in our livestock and companion animals. In such cases (or in case of a suspicion) the chemical composition is very important. The rapid simple demonstration (or exclusion) of a group of bioactive molecules can basically help the veterinarian's work. The present publication would like to give a methodical guide for the veterinarians. Our publication summaries shortly the affected active compounds and gives methodical descriptions, documented with photos. The list of required chemicals and laboratory instruments is very simple; the number of specific reagents is low. Our work is based on the simple production of a plant extract (1 g plant/20 ml extractant) and demonstrates the following metabolites: cyanogenic glycosides, coumarins, tannins, cardic glycosides, saponins, alkoids and the nitrate ion. The HCN was liberated with H2SO4 from plants in a closed tube and a reddish colour was formed on a filter paper strip. Coumarins produce a yellow colour under alkaline conditions; the tannis can react with FeCl3 molecules forming a bluish-blackish precipitation. Demonstration of cardic gylcosides is possible by Keller-Killani teach, whereras a brown-brownish ring is formed at the interface of acetic acid-FeCl3 and H2SO4. A stable foam layer, produced by shaking, can indicate the saponins. For the detection of alkaloids different reactions were used including the orange-yellow precipitation by Drangendorff reagent, the bluish-purple colour by PDAB reagent and the brownish ring at the interface by Keller reaction Nitrate ions can produce a yellow colour with diphenylamine on filtrate paper, induced by UV radiation.