Perilla frutescens (L.) Britton: In Vitro Culture and the Production of Caffeic Acid

Abstract

Perilla frutescens (L.) Britton var. crispa (Thunb.) Decaisne, belonging to the family Labiatae, is distributed widely in Japan, China, and southeast Asia. It is an annual herb about 1 m in height, and includes several forms such as f. purpurea Makino (Chirimen-aka-shiso or Aka-shiso) (Fig. 1) and f. viridis Makino (Chirimen-ao-shiso or Ao-shiso) having deep red-purple and green leaves, respectively. Perilla plants contain essential oil at about 0.5% of fresh leaf weight and give out a fragrance, principles of which are Perilla-aldehyde (55%), d-limonene (20–30%), and α-pinene (Yoshiki 1911); linoleic, stearic, and palmitic acids are also contained as the major aliphatic acids. According to the extensive study on pigments of Chirimen-aka-shiso (Ishikura 1981), 16 kinds of flavonoids including five antho-cyanins, two flavones, and nine flavone glycosides are present in the mature dark-red leaves and seeds. Among these flavonoids, the 3-p-coumaroylglucoside-5-glucoside of cyanidin (shisonin) and the 7-caffeoylglucosides of apigenin and luteolin are the major component in the leaves. In seeds, apigenin and luteolin are present in a ratio of about 1:1. With other phenolics, a large amount of caffeic acid derivatives are present in the leaves.