Optimum Nutrition for Biosynthesis of Pharmaceutical Compounds in Celandine and Catmint Under Outside Hydroponic Conditions

ABSTRACT

Several experiments were performed to improve the management of biosynthesis of some pharmaceutical compounds (alkaloids, essential oil, tannins, and vitamin C) of medicinal plants celandine poppy (Chelidonium majus L.) and lemon catmint (Nepeta cataria L. f. citriodora) under outside hydroponics of Ararat Valley of Armenia. It was found that growing media and nutrient solutions that differed in concentrations and ratios of nitrogen (N), phosphorus (P), and potassium (K) influenced various pharmaceutical compounds of these herbs. Celandine under hydroponics conditions (with high N at a ratio of N₇₀P₁₅K₁₅ atom%) had an alkaloid content up to 1.53% (calculated in dry raw material), while under soil the content was no higher than 1.22%. The content of tannins in celandine was up to 7.58% in hydroponics and 5.76% in soil. The content of vitamin C was up to 131.67 mg/% when grown in hydroponics and 94.92 mg/% when grown in soil (based on fresh raw material). In catmint, the maximum content and yield of essential oil were 0.246% (with high P at a ratio of N₁₅P₇₀K₁₅ atom%), and 1.56 ml/plant (with high N) under hydroponics conditions, while 0.183% and 0.20 mL/plant were obtained in soil. The highest content of tannins reached in hydroponics was 5.53%, while in soil it was 4.72%. The content of vitamin C reached 119.20 mg/% in hydroponics (with high P) and 93.43 mg/% in soil. The mathematical modeling of results according to Homes predicted that in celandine and catmint optimum ratios of N:P:K (50:22:28 and 53:40:7 atom%, respectively) in nutrient solution should give a maximum content of alkaloids (1.83%) in celandine, and maximum yield of essential oil (2.49 mL/plant) in catmint.