In this study, three dicaffeoylquinic acids (DCQAs) isolated from Gnaphalium affine D. DON. extracts were structurally identified and evaluated for their antioxidant activities, cellular protective effects, and tyrosinase inhibitory activities. The ethyl acetate fraction of G. affine was chromatographed, which yielded 3 DCQA derivatives of 1-3 : 3,5-dicaffoylquinic acid (3,5-DCQA, 1), 4,5-dicaffeoylquinic acid (4,5-DCQA, 2), 1,5-dicaffoylquinic acid (1,5-DCQA, 3). The structure of each compounds was determined using 1H NMR and MS analyses. Compounds of 1-3 showed strong free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities (FSC50 = 3.70, 5.80, and 5.50 μM, respectively) compared to those of a commonly used lipophilic antioxidant, (+)-α-tocopherol (21.90 μM). Cellular protective effects of 1-3 compounds on the 1O2 sensitized photohemolysis of human erythrocytes were similar to (+)-α-tocopherol. 1-3 compounds also exhibited higher tyrosinase inhibitory effects (IC50 = 0.15, 0.16, and 0.13 mM) compared to arbutin (0.33 mM), known as a skin-whitening agent. These results indicate that three DCQA derivatives may be applied as an antioxidant and a skin whitening agent in food or cosmetic industries.

본 연구에서는 떡쑥 추출물로부터 3가지 dicaffeoylquinic acid (DCQA)를 분리 정제하여 구조를 결정하고, 항산화 활성, 세포보호효과, 그리고 tyrosinase 저해 활성을 평가하였다. 떡쑥 추출물의 에틸아세테이트 분획에 대하여 크로마토그래피, 1H-NMR 및 MS 분석을 한 결과, 분리된 화합물은 총 3가지 DCQA 유도체 : 3,5-dicaffoylquinic acid (3,5-DCQA,1), 4,5-dicaffeoylquinic acid (4,5-DCQA, 2), 1,5-dicaffoylquinic acid (1,5-DCQA, 3)로 나타났다. 분리된 compound 1-3의 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical 소거활성(FSC50)은 각각 3.70, 5.80 및 5.50 μM로 지용성 항산화제로 알려진(+)-α-tocopherol (FSC50 = 21.90 μM)과 비교하여 더 큰 free radical 소거활성을 나타내었다. compound 1-3의 1O2로 유도된 사람 적혈구의 광용혈에 대한 세포보호효과는 (+)-α-tocopherol과 유사한 세포보호활성을 나타내었다. Compound 1-3의 tyrosinase 저해활성(IC50)은 각각 0.15, 0.16, 및 0.13 mM로 미백성분으로 알려진 arbutin (IC50 = 0.33 mM)과 비교하여 높은 tyrosinase 억제효과를 나타내었다. 이상의 결과들은 세 가지 DCQA가 식품 또는 화장품 산업에서 항산화 및 미백 기능성 소재로서 응용가능성이 있음을 시사한다.