'부지화' 잎·가지 추출물의 항염 및 항산화 활성 성분 연구

Abstract

In this study, we investigated anti-inflammatory and anti-oxidative constituents from 'Shiranuhi ((Citrus unshiu Marc. × C. sinensis Osbeck) × C. reticulata Blanco)' leaves and branches. The chemical structures of the isolated compounds were elucidated based on the spectroscopic data including NMR spectra, as well as comparison of the data to the literature values. Five phytochemicals were isolated from the extract of 'Shiranuhi' leaves; sinensetin (1), isosinensetin (2), 5-desmethylsinensetin (3), 7-hydroxy -5,6,3',4'-tetramethoxyflavone (4) and hesperidin (5). As far as we know, compounds 2, 3 and 4 were isolated for the first time from this plant. On the anti-inflammation studies using RAW264.7 cells, the EtOAc fraction and compounds 1-4 inhibited the production of NO, PGE2 and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) effectively. For the anti-oxidation tests, the compound 5 showed strong ABTS+ radical scavenging activity with SC50 25.8 μM, and its activity was comparable to a positive control BHT (SC50 29.8 μM). Seven constituents were isolated from the extract of 'Shiranuhi' branches; nobiletin (1), sinensetin (2), tetramethylscutellarein (3), 6-hydroxy-5,7,3',4'-tetramethoxyflavone (4), 5-desmethylsinensetin (5), cirsimaritin (6) and hesperidin (7). As far as we know, compounds 4, 5 and 6 were isolated for the first time from this plant. On the anti-inflammation studies using RAW264.7 cells, the EtOAc fraction and compounds 1, 3 and 4 inhibited the production of NO, PGE2 and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) effectively. For the anti-oxidation tests, the compound 4 (SC50 128.7 μM) showed stronger DPPH radical scavenging activity than BHT (SC50 402.2 μM), a positive control. Also, the compound 4 (SC50 17.9 μM) showed stronger ABTS+ radical scavenging activity than BHT (SC50 29.8 μM), a positive control. Based on these results, it was suggested that extract and isolated compounds from 'Shiranuhi' leaves and branches could be potentially applicable as anti-inflammatory and/or anti-oxidative ingredients.