Antioxidant Activities of Citrus unshiu Extracts obtained from Different Solvents

In this study, the total polyphenol content, electron donating ability (EDA) and inhibitory activity of glutathione S-transferase (GST) of freeze-dried Citrus unshiu extracts were examined. The Citrus unshiu extracts was obtained from four solvents such as ethyl acetate, acetone, methyl chloride and methanol, to evaluate its functional properties. Total polyphenol contents were measured in the two different extracts, and the extracts were screened for their potential antioxidant activities using tests such as electron donating ability (EDA), glutathione S-transferase (GST). The total polyphenol contents of Citrus unshiu extracts were $928.48{\pm}1.19{\mu}g\;GAE/mL$ in ethyl acetate (EA), $886.03{\pm}0.44{\mu}g\;RE/mL$ in acetone (AC), $413.08{\pm}1.39{\mu}g\;GAE/mL$ in methylene chloride (MC), $12,648.60{\pm}0.56{\mu}g\;GAE/mL$ in methanol (MeOH), respectively. Also, the total polyphenol contents of EtOH Citrus unshiu extracts were $664.64{\pm}0.74{\mu}g\;GAE/mL$ in EA, $702.67{\pm}0.85{\mu}g\;RE/mL$ in AC, $429.64{\pm}0.61{\mu}g\;GAE/mL$ in MC, $16,108{\pm}0.73{\mu}g\;GAE/mL$ in MeOH, respectively. The total polyphenol contents were significantly difference (p<0.05) between the solvents. The electron donating ability of Citrus unshiu extracts were $62.80{\pm}0.36%$ in EA, $97.43{\pm}0.51%$ in AC, $52.20{\pm}0.30%$ in MC, $97.63{\pm}0.46%$ in MeOH, respectively. Also, the electron donating ability of EtOH Citrus unshiu extracts were $51.49{\pm}0.26%$ in EA, $63.17{\pm}0.31%$ in AC, $67.68{\pm}0.55%$ in MC, $96.18{\pm}0.41%$ in MA, respectively. The electron donating ability were significantly difference (p<0.05) between the solvents. The inhibitory activity of glutathione S-transferase in Citrus unshiu extracts were $76.22{\pm}0.65%$ in EA, $31.73{\pm}0.48%$ in MC, $97.48{\pm}0.56%$ in MeOH, respectively. Also, inhibitory activity of glutathione S-transferase in EtOH Citrus unshiu extracts were $75.54{\pm}0.55%$ in EA, $73.53{\pm}0.38%$ in MC, $48.70{\pm}0.46%$ in MeOH, respectively. The inhibitory activity of glutathione S-transferase were significantly difference (p<0.05) between the solvents. These results indicated that the Citrus unshiu extracts is a high-valued food ingredient and the extraction with methanol will be useful as a nutritional source with natural antioxidant activities. Considering high consumer demand beneficial health effects, Citrus unshiu extracts can be utilized to develop functional food health- promoting and natural antioxidant agents.

추출용매에 따른 진피 추출물의 항산화 활성

본 연구에서는 진피의 활용도를 높이기 위한 연구의 일환으로 유기용매별에 따른 생리활성물질의 용출량을 측정하기 위해, 진피와 에탄올 진피 추출물을 대상으로 유기용매인 에틸 아세테이트, 아세톤, 염화 메틸렌, 메탄올을 이용하여 추출한 시료를 대상으로 총 폴리페놀 함량, 전자공여능, glutathione S-transferase(GST)의 활성 저해력을 측정한 결과는 다음과 같다. 1. 총 폴리페놀 함량은 ethyl acetate인 경우 진피는 $928.48{\pm}1.19{\mu}g\;GAE/mL$, 에탄올 추출 진피는 $664.64{\pm}0.74{\mu}g\;GAE/mL$로, acetone인 경우 진피는 $886.03{\pm}0.44{\mu}g\;GAE/mL$, 에탄올 추출 진피는 $702.67{\pm}0.85{\mu}g\;GAE/mL$로, methylene chloride인 경우 진피는 $413.08{\pm}1.39{\mu}g\;GAE/mL$, 에탄올 추출 진피는 $429.64{\pm}0.61{\mu}g\;GAE/mL$로, methanol인 경우 진피는 $12,648.60{\pm}0.56{\mu}g\;GAE/mL$, 에탄올 추출 진피는 $16,108.20{\pm}0.73{\mu}g\;GAE/mL$로 나타나, 진피나 에탄올 추출 진피는 모두 methanol로 추출한 것이 상대적으로 높게 나타났으며, 총 폴리페놀의 함량 차이는 유기용매별 통계적으로 유의한 차이가 나타났다(p<0.05). 2. 전자공여능은 ethyl acetate인 경우 진피는 62.80%, 에탄올 추출 진피는 51.49%로 나타났으며, acetone인 경우 진피는 97.43%, 에탄올 추출 진피는 63.17%로 나타났으며, methylene chloride인 경우 진피는 52.20%, 에탄올 추출 진피는 67.68%로 나타났으며, methanol인 경우 진피는 97.63%, 에탄올 추출 진피는 96.18%로 나타났다. Electron donating ability(EDA)는 유기용매 중 메탄올로 추출하였을 때가 상대적으로 가장 높게 나타났으며, 유기용매별로 통계적으로 유의한 차이가 나타났다(p<0.05). 3. Glutathione S-transferase(GST)에 대한 활성 저해능은 ethyl acetate인 경우 진피는 76.22%, 에탄올 추출 진피는 75.54%로 나타났으며, methylene chloride인 경우 진피는 31.73%, 에탄올 추출 진피는 73.53%로 나타났으며, methanol인 경우 진피는 97.48%, 에탄올 추출 진피는 48.70%로 나타났다. Glutathione S-transferase(GST)에 대한 활성 저해능은 진피인 경우 유기용매 중 메탄올로 추출하였을 때가 가장 높게 나타났고, 에탄올 추출 진피인 경우는 에탄올과 methylene chloride로 추출할 때가 높게 나타났으며, 유기용매별로 통계적으로 유의한 것으로 나타났다(p<0.05).