대파에 함유된 항산화 물질을 구명하고자 대파를 3가지 다른 방법으로 추출하여 대파 착즙액, 열수추출물, MeOH 추출물을 얻었다. 이들 추출물을 각각 용매분획하여 얻어진 EtOAc 가용 산성획분을 silica gel adsorption column chromatography로 정제하여 얻어진 활성획분을 GC-MS 분석하였다. 그 결과, 대파 착즙액과 열수추출물에서는 succinic acid ,fumaric acid, 4-hydroxybenzoic acid, 4-hydroxy-3-methoxy-benzoic acid, 4-hydroxycinnamic acid 그리고 4-hydroxy-3-methoxycinnamic acid의 6종 화합물이 동정되었으며, MeOH 추출물로부터는 4-hydroxybenzoic acid, 4-hydroxy-3-methoxy-benzoic acid, 4-hydroxycinnamic acid, 4-hydroxy-3-methoxy-cinnamic acid의 4종 화합물이 동정되었다. 동정된 이들 화합물을 대상으로 DPPH radical-scavenging 활성을 검정한 결과, 4-hydroxy-3-methoxycinnamic acid가 가장 강한 항산화 활성을 나타냈다. 또한 각각의 대파추출물에 함유된 항산화 물질의 함량을 GC에 의해 정량분석한 결과, 대파 착즙액과 열수추출물 및 MeOH 추출물 모두 강한 항산화 활성을 나타내는 4-hydroxy-3-methoxycinnamic acid가 가장 많이 함유되어 있었다.
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.
