Guide to Harvesting Heracleum Persicum: How Essential Oil Composition and Phenolic Acid Profile Fluctuate at Different Phenological Stages?

Abstract

BACKGROUN: Heracleum persicum commonly named Golpar, is a principal native medicinal plant in Iran. Collecting H. persicum at the appropriate growing stage is the key factor to achieve the high phytochemical quality to meet consumer’s needs. In the present experiment, the aerial parts of this plant were harvested at up to six different developmental stages during the growing season to determine the phytochemical profiles. RESULTS: Our results indicated that the highest essential oil yield and extract were obtained in the mid-mature seed stage (3.5%),) and floral budding stage (10.40%). In the vegetative stage, limonene (18.05), in floral budding stage, caryophyllene (14.07), anethole (14.55%), and β-bisabolene (12.56%), in the full flowering stage, myristicin (15.02%), and hexyl butyrate (9.05%); in the early development of seeds stage, hexyl butyrate (32.08%), and octyl acetate (11.67%); in the mid-mature seeds stage hexyl butyrate (38.75%), octyl acetate (14.47%); in the late-mature/ripe seeds stage, hexyl butyrate (23.59%), and octyl acetate (10.48%) recorded as the main components. The analysis of phenolic acids demonstrated cinnamic acid, p-coumaric acid, p-hydroxybenzoic acid, ferulic acid, and rosmarinic acid as the main phenolic acids. The highest phenolic acids content was obtained in the floral budding stage (287.40 mg g –1 dry extract). Cinnamic acid was found as the major phenolic compound in the vegetative stage following by floral budding, the full flowering stage, the early development of seeds and late-mature/ripe seeds stages. P-coumaric acid was the most abundant phenolic compounds in the mid-mature seeds stage. The development stage has a significant impact on the content and composition of both essential oil and phenolic acid composition. CONCLUSION: In this regard, the harvest time of H. persicum aerial parts can be selected to achieve the highest secondary metabolites of interest. The results of this study can be used as a guideline for grower to obtain the highest amount of desirable metabolites, beneficial in the food and pharmaceutical industries as well as economic benefits.