Identification, characterisation, and quantification of phenolic compounds in the antioxidant activity-containing fraction from the seeds of Korean perilla (Perilla frutescens) cultivars

► The 80% methanol extract of perilla seeds exhibited strong antioxidant properties. ► Nine phenolic compounds were characterised for the first time in perilla seeds. ► Rosmarinic acid derivatives were the predominant components in perilla seeds. ► Individual and total phenolic contents were remarkable differences in each cultivar. ► Antioxidant effect of perilla seeds was correlated with phenolic compound content.