• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1403-1408
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• 2000

The methanol soluble fraction of the hot water extracts from Hovenia dulcis Thunb showed antioxidative and antimicrobial activity. The methanol fraction was successively purified with solvent fractionation, silica gel adsorption column chromatography, Sephadex LH-20 column chromatography, and octadecylsilane column chromatography. The purified active substances were isolated by high performance liquid chromatography. The isolated substances were identified as 3-methoxy-4-hydroxybenzoic acid (vanillic acid) and 3-methoxy- 4-hydroxycinnamic acid (ferulic acid) by LC-MS and GC-MS. Vanillic acid and ferulic acid showed antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria and yeast. The DPPH-radical scavenging activity of ferulic acid appeared more active than that of vanillic acid. DPPH-radical scavenging concentration of ferulic acid and vanillic acid were $14\;{\mu}g/mL\;(SC_{50})$, $100\;{\mu}g/mL\;(SC_{10})$, respectively.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.988-993
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• 2003

The ethyl acetate-soluble acidic fraction of juice, hot water, and MeOH extract of Allium fistulosum L. showed DPPH radical-scavenging activity. Each fraction was purified through silica gel adsorption column chromatography, and the active substances in the juice and hot water extract were identified as succinic acid, fumaric acid, 4-hydroxybenzoic acid, 4-hydroxy-3-methoxybenzoic acid, 4-hydroxycinnamic acid, and 4-hydroxy-3-methoxycinnamic acid. For the MeOH extract, 4-hydroxybenzoic acid, 4-hydroxy-3-methoxybenzoic acid, 4-hydroxycinnamic acid, and 4-hydroxy-3-methoxycinnmic acid were identified as the active substances by GC-MS. The contents of these compounds were determined by GC analysis, and their anti-oxidative activities were measured using the DPPH radical-scavenging assay. The results obtained showed that 4-hydroxy-3-methoxycinnamic acid was the dominant antioxidant in Allium fistulosum L.

• Korean Journal of Pharmacognosy
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• v.44 no.3
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• pp.220-223
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• 2013

In the course of screening tyrosinase inhibitory activity, total methanolic extract and EtOAc-soluble fraction of Smilax china leaves showed significant inhibitory activity. Further fractionation and isolation of the EtOAc-soluble fraction resulted in 12 phenolic compounds, which were identified as 4-hydroxybenzoic acid (1), 3,4-dihydroxybenzaldehyde (2), 3,4-dihydroxybenzoic acid (3), 3,4-dihydroxyacetophenone (4), 3-hydroxy-4-methoxy benzoic acid (5), trans-p-hydroxycinnamic acid (6), cis-p-hydroxycinnamic acid (7), trans-resveratrol (8), cis-resveratrol (9), dihydroresveratrol (10), moracin M (11) and kaempferol (12). Compounds 1-11 were first reported from this plant. Among the isolated compounds, compounds 2, 8, 9 and 12 showed strong inhibition on tyrosinase activity.

• YAKHAK HOEJI
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• v.42 no.2
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• pp.165-169
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• 1998

Inhibitory effects of 16 cinnamic acid analogs on formyl-Met-Leu-Phe(fMLP)-induced chemotaxis of rat polymorphonuclear leukocytes were determined by using a microchemotaxis appa ratus. 3,4-Dlhydrocinnamic acid called as caffeic acid exhibited the highest inhibitory effect on the chemotaxis among cinnamic acid analogs tested in this study. Hydroxycinnamic acids exhibited stronger inhibitory effects on the chemotaxis than cinnnamic acid. Hydroxycinnamic acids with one hydroxy group at ortho, meta or para position exhibited similar inhibitory effects on the chemotaxis with corresponding methoxy cinnamic acids, but 3,4-dihydroxycinnamic acid did stronger inhibitory effects than 3,4-dimethoxycinnamic acid. 3,4-Dimethoxycinnamic acid exhibited weaker inhibitory effects on the chemotaxis than 1,2-dimethoxy-4-propenylbenzene and 3,4-dimethoxy cinnamonitrile with -CH=CHCN or -CH=$CHCH_3$, group instead of -CH=CHCOOH group. 4-Hydroxy cinnamic acid and 3,4-dihydroxycinnamic acid exhibited stronger exhibitory effects on the chemotaxis than 3-(4-hydroxyphenyl) propionic acid and 3,4-dihydroxyhydrocinnamic acid with -$CH_2CH_2$COOH group instead of -CH=CHCOOH group.