Perilla (Perilla frutescens (L.) Britt.) is a medicinal plant native to Asia, rich in polyphenolic compounds, anthocyanins, essential oil and fatty acids. In the present study, the variability of phytochemical characteristics, antioxidant activity and oil seed composition of the three varieties Iranian green-red and Chinese red and green-red at two phenological stages (pre-flowering and seed set) were investigated. The results showed a wide variation in phytochemical properties among plant samples and harvest stages. The highest total phenol and antioxidant activity were observed in the Chinese green-red variety at both harvesting stages. A remarkable variation in phenolic acid content was observed among the plant samples. The essential oil content (%w/w) ranged from 1.04% in Iranian green-red variety to 1.37% in Chinese red variety, both at pre-flowering stage. Examination of essential oil constituents showed a significant variation between varieties and harvest time and three groups could be identified based on the composition of essential oil compounds. Perilla ketone (0.20-53.77%), methylgeranate (0.52-52.62%), ß-dehydro-elsholtzia ketone (0.41- 53.42%) and β-caryophyllene (3.11- 15.75%) were the major compounds in the plant samples collected at different phonological stages. Palmitic acid (C16: 0), stearic acid (C18: 0), oleic acid (C18: 1), linoleic acid (C18: 2) and α-linolenic acid (C18: 3) were the major fatty acids in samples. α-Linolenic acid was the predominant fatty acid in all the samples studied, ranging from 58.61 to 61.77%. The results revealed that Perilla varieties and phenological stages could affect on phytochemical profile.
