Isolation and Identification of 3-Methoxy-4-hydroxybenzoic acid and 3-Methoxy-4-hydroxycinnamic acid from Hot Water Extracts of Hovenia dulcis Thunb and Confirmation of Their Antioxidative and Antimicrobial Activity

헛개나무 열수추출물로부터 항산화 및 항미생물 활성을 갖는 3-methoxy-4-hydroxybenzoic acid 와 3-methyoxy-4-hydroxycinnamic acid의 분리 및 동정

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.

헛개나무 어린 줄기와 잎의 열수추출물에서 얻어진 MeOH 가용 획분에 항미생물 및 항산화 활성을 보여, 이들 활성 본체를 규명하고자 활성물질을 solvent fractionation, silica gel adsorption column chromatography, Sephadex LH-20 column chromatography, ODS column chromatography로 순차정제하고, HPLC등에 의해 두 종의 활성물질을 단리하여 LC-MS, GC-MS 분석에 의해 vanillic acid와 ferulic acid로 각각 동정하였다. 두 활성물질은 그람 양성 세균 및 그람 음성 세균 그리고 효모 등의 미생물에 항균 활성을 보였다. 또한, vanillic acid와 ferulic acid의 항산화 활성은 vanillic acid보다 ferulic acid가 강한 활성을 나타내, DPPH 자유라디칼 소거능을 나타내는 농도는 ferulic acid가 $14\;{\mu}g/mL(SC_{50})$을, 그리고 vanillic acid가 $8\;{\mu}g/mL(SC_{10})$이었다.