Subscribe to RSS
DOI: 10.1055/s-0034-1395066
Phenolic lignans and flavonoids and their bioactivities from the root and the stem of Sassafras randaiense (Hayata) Rehder
Sassafras randaiense (Hayata) Rehder is a medium-sized deciduous tree, endemic to Taiwan and grows in broad-leaved forests from 900 to 2,400 m through the Island. The chemistry of Taiwan sassafras was not extensively studied, and only five biphenyl components, magnolol, isomagnolol, randaiol, randainal and randainol, and β-sitosterol were isolated from root part. The methanolic extract of the root and the stem of this plant showed potent anti-tubercular, anti-oxidant and anti-inflammatory activities. The aim of this study is the isolation of chemical constituents from the root and the stem of this species, and evaluation of their biological activities. Bioassay-guided fractionation of S. randaiense led to isolation of two new neolignans, (+)-sassarandailin (1), (R)-(-)-sassarandainol (18), one first isolated from nature, (R)-(+)-5,7,3',5'-terahydroxy-flavanone (13), along with 22 known compounds including β-sitosterol (2), stigmasterol (3), magnolol (4), trans-docosanylferulate (5), magnaldehyde D (6), (2R,3R)-(-)-3-hydroxy-5,7-dimethoxy-3',4'-methylenedioxyflavan (7), neolitacumone C (8), (-)-5,3'-di-O-methylepicatechin (9), (-)-taxifolin (10), (±)-syringaresinol (11), magnolignan A (12), quercetin (14), (+)-catechin (15), (+)-9,9'-di-O-trans-feruloyl-5,5'-dimethoxysecoisolariciresinol (16), (7R,8R,8'R)-(+)-lyoniresinol (17), γ-tocopherol (19), β-sitosterone (20), subamolide B (21), 2β-methoxyclovan-9α-ol (22), palmitic acid (23), erythro-7'-hydroxy strebluslignanol (24) and threo-strebluslignanol (25). The structures of these isolates were elucidated by spectral analysis. The major compound 4 exhibited anti-tubercular activity against Mycobacterium tuberculosis H37Rv in vitro, with the MIC value of 45.0 µg/ml. Compounds 1, 11, 15 and 17 exhibited anti-oxidant activity with the SC50 values of 28.9, 14.0, 13.9 and 19.9µM in ABTS radical scavenging assay, and 11, 15 and 17 with the SC50 values of 19.2, 15.3 and 28.7µM in DPPH radical scavenging assay, respectively.
Keywords: Sassafras randaiense, Lauraceae, Stem, Root, Anti-tubercular activity, Anti-oxidant activity