갈파래(Ulva lactuca)의 용매별 분획의 항산화활성 측정을 위해 갈파래를 95% ethanol로 추출하고 diethyl ether, ethyl acetate, $H_2O$ 등의 용매로 분획하였다. 각 분획을 HPLC로 분석한 결과 각 분획에서 단일 peak가 검출되었으며 용출시간이 서로 달랐다. 각 분획의 항산화 활성을 DPPH 라디칼 소거능, 지질과산화억제활성 방법으로 검증하였다. 각 분획의 DPPH 라디칼 소거활성은 농도의존성을 나타내었고 활성은 수층, ethyl acetate 층, diethyl ether층 분획의 순서였다. 지질과산화 억제활성은 diethyl ether 분획에서 가장 높게 나타났으며 같은 농도의 $alpha-tocopherol$과 비슷하였다. 본 연구 결과는 갈파래를 이용한 천연 항산화제 생산에 응용이 가능할 것으로 생각된다.
The fractions of Ulva lactuca were studied to verify the antioxidant activities. The fractions from the ethanol extract of U. lactuca were prepared by the systematic extraction procedure with the solvents such as hexane, ethyl ether, ethyl acetate, butanol and $H_2O$. Furthermore, ethyl ether, ethyl acetate and aqueous fractions of U. lactuca were purified using HPLC. The antioxidant activities of purified samples from ethyl ether, ethyl acetate, and aqueous fractions were investigated using 1,1-diphenyl-2-picryl-hydrazil (DPPH). L-ascorbic acid, a positive control showed the highest DPPH radical scavenging activity. In addition, purified sample from aqueous fraction also showed relatively high activity. Purified sample from ethyl acetate fraction showed moderate activity, but purified sample from ethyl ether fraction showed the lowest activity. Dose dependent patterns were observed on all three samples tested. The lipid peroxidation inhibition activities of these three purified samples were also investigated. Purified sample from ethyl ether fraction of U. lactuca showed the highest activity and as strong activity as that of $alpha-tocopherol$, a positive control. These results suggest that U. lactuca may be a useful candidate for a natural antioxidant agent.
