• Journal of the Korean Chemical Society
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• v.48 no.4
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• pp.394-398
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• 2004

From Sargassum thunbergii which is widely distributed in coastal area of Korea, three norisoprenoids, (+)-epiloliolide (1), (-)-loliolide (2), and apo-9'-fucoxanthinone (3) were isolated by using column chromatography and reverse-phase HPLC. Compound 1, 2 and 3 were for the first time isolated from the Brown Alga Sargassum thunbergii. Particularly, Compound 1 was for the first time isolated the marine organism although it was reported from the terrestrial plant. Their structures have been determined by extensive 2-D NMR experiments such as $^1H COSY, NOESY, HMQC$, and HMBC and by comparison with the reported data in the literature.

• Natural Product Sciences
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• v.20 no.1
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• pp.22-28
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• 2014

A new natural product, tetrastigmol A (1), and several known compounds as flavonoids (2 - 8), steroids (9 - 10), bergenin and its derivative (11 - 12), stilbens (13 - 15), lignan (16), benzenecarboxylic derivative (17) and two norisoprenoid (18 - 19) were isolated from the stem of Tetrastigma erubescens Planch. (Vitateae). Their structures were determined on the basis of NMR spectroscopic data. This is the first report on chemical constituents of this plant. Compounds 1, 6 - 8 and 12 - 15 showed strong antioxidant activity using two methods including DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging and lipid peroxidation inhibitory assays.