Novel Antiallergic Catechin Derivatives Isolated from Oolong Tea

• Published in: Journal of agricultural and food chemistry 1999-05, Vol.47 (5), p.1906-1910
• Main Authors: Sano, Mitsuaki, Suzuki, Masazumi, Miyase, Toshio, Yoshino, Kyoji, Maeda-Yamamoto, Mari
• Format: Article
• Language: English
• Subjects: anaphylaxis; Anaphylaxis - prevention & control; Animals; Anti-Allergic Agents - chemistry; Anti-Allergic Agents - isolation & purification; Anti-Allergic Agents - pharmacology; antiallergic activity; antiallergic properties; Biological and medical sciences; Catechin - analogs & derivatives; Catechin - chemistry; Catechin - isolation & purification; Catechin - pharmacology; chemical composition; chemical structure; Coffee, tea and other stimulative beverage industries; cultivars; derivatives; epigallocatechin 3-o-(3-o-methyl)gallate; epigallocatechin 3-o-(4-o-methyl)gallate; fermentation; flavonols; Food industries; Fundamental and applied biological sciences. Psychology; high performance liquid chromatography; Histamine and antagonists. Allergy; immunotherapy; inhibition; leaves; Magnetic Resonance Spectroscopy; Medical sciences; medicinal properties; Mice; oral administration; Ovalbumin - immunology; Pharmacology. Drug treatments; Plant Leaves; Spectrometry, Mass, Fast Atom Bombardment; Taiwan; tea; Tea - chemistry
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf981114l

Two catechin derivatives (C-1 and C-2) with potent antiallergic activity were isolated from Taiwanese oolong tea by HPLC techniques. From NMR and FAB-MS analyses, the structures of C-1 and C-2 were elucidated as (−)-epigallocatechin 3-O-(3-O-methyl)gallate and (−)-epigallocatechin 3-O-(4-O-methyl)gallate, respectively. The oolong tea leaves contained 0.34% (dry weight) C-1 and 0.20% C-2. Traces of C-2 were detected in only 1 of 15 varieties of green tea tested. C-1 was detected in 13 of 15 green tea varieties; C-1 was most concentrated in tea cultivars classified as Assam hybrids (0.50−0.82% of dry weight). Quantitative analyses of green tea, oolong tea, and black tea manufactured from same batches of tea leaves showed that neither catechin derivative was produced during the fermentation process. Oral doses of C-1 and C-2 (5−50 mg/kg) significantly inhibited type I allergic (anaphylactic) reactions in mice sensitized with ovalbumin and Freund's incomplete adjuvant. These inhibitory effects exceeded that of the major tea catechin, (−)-epigallocatechin 3-O-gallate, which has known antiallergic properties. Keywords: Tea; catechin; antiallergic reaction; O-methylated galloyl epigallocatechin; EGCG