Identification of antioxidants from rhizome of Davallia solida

• Published in: Food chemistry Vol. 107; no. 2; pp. 684 - 691
• Main Authors: Chen, Yung-Husan, Chang, Fang-Rong, Lin, Yih-Jer, Hsieh, Pei-Wen, Wu, Ming-Jiuan, Wu, Yang-Chang
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 15.03.2008; Elsevier
• Subjects: acid hydrolysis; antioxidants; Biological and medical sciences; Davallia; Davallia solida; DPPH; ferns and fern allies; Food industries; fractionation; free radical scavengers; Fundamental and applied biological sciences. Psychology; medicinal plants; phenols; plant extracts; purification; rhizomes; Trolox equivalent antioxidant capacity (TEAC); DPPH; Davallia solida; Trolox equivalent antioxidant capacity (TEAC); Identification; Antioxidant; Rhizome
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2007.08.066

Davallia solida rhizome has long been used as an herb tonic to treat osteoporosis, arthralgia, and arthritis. The aqueous extract of D. solida rhizome contains a high content of phenolic compounds [210.8 ± 4.6 mg catechin equivalents (CE)/g dry weight] and shows a strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity (IC 50 = 15.93 ± 1.21 μg dry weight/ml). Further solvent partition of the aqueous extract yielded chloroform, n-butanol, and water layers. Among them, n-butanol layer has the highest phenol content (806.3 ± 12.3 mg CE/g dry weight) and DPPH scavenging potential (IC 50 = 3.93 ± 0.31 μg dry weight/ml). Isolation and purification from the n-butanol layer identified 12 compounds. They included four new compounds: 3′- O- p-hydroxybenzoylmangiferin ( 1), 4′- O- p-hydroxybenzoylmangiferin ( 2), 6′- O- p-hydroxybenzoylmangiferin ( 3), and 3- O- p-hydroxybenzoylmangiferin ( 4); as well as eight known compounds: mangiferin ( 5), 2- C-β- d-xylopyranosyl-1,3,6,7-tetrahydroxyxanthone ( 6), 4β-carboxymethyl-(−)-epicatechin ( 7), 4β-carboxymethyl-(−)-epicatechin methyl ester ( 8), eriodictyol ( 9), eriodictyol-8- C-β- d-glucopyranoside ( 10), icariside E 5 ( 11), and icariside E 3 ( 12). DPPH scavenging and Trolox equivalent antioxidant capacity (TEAC) analyses revealed that the most potent antioxidants are 1, 2, and 3, which exerted more than triple activity as compared with the positive controls, α-tocopherol and Trolox.