Antioxidative Activities and Components of Gardenia jasminoides

From the total methanolic extract of Gardenia jasminoides (Rubiaceae), various antioxidative characteristics were identified in terms of nitrite scavenging ability, 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical cation inhibition, superoxide dismutase (SOD)-like activity, and elongation effect of lipid peroxidation using Rancimat. After successive partitioning with n-hexane, chloroform, n-butanol, and water, potent nitrite scavenging abilities were shown in the n-butanol fraction and water fraction, and $IC_{50}$ values were 183 ppm and 194 ppm, respectively. As for ABTS radical cation inhibition, the chloroform fraction was most potent and its $IC_{50}$ was 159 ppm. SOD-like activity was slightly low in all of the fractions. The elongation effect of lipid peroxidation also increased dose-dependently and the antioxidative index (AI) of the total methanolic extract was 2.93 in 1000 ppm, which was more effective than 1.66 of butylated hydroxy anisol in the same concentration. The compounds I and II were isolated through silica gel column chromatography of the active fractions, and identified as geniposide and crocin, respectively, by $^1H-NMR$ spectral data. The $IC_{50}$ values for the nitrite scavenging abilities of geniposide and crocin were 940 ppm and 77 ppm, respectively. In ABTS radical cation inhibition, the $IC_{50}$ values of geniposide and crocin were 684 ppm and 549 ppm, respectively. And the $EC_{50}$ value for SOD-like activity of crocin was 259 ppm, which was much smaller than 453 ppm by the positive control, chlorogenic acid. The $EC_{50}$ value of geniposide could not be identified.

치자의 항산화 활성 및 활성성분의 분리

치자의 항산화 활성과 유지산화 지연효과를 측정하고 활성을 보인 분획에서 주성분인 geniposide와 crocin을 분리하고 그 구조를 확인하였다. 여러 분획 중 부탄올 분획과 물 분획의 항산화성이 가장 우수함을 확인하고 그 분획의 주성분으로 분리된 geniposide와 crocin의 단일물질로서의 항산화력을 측정 비교한 결과, crocin의 항산화력이 더 강함을 알 수 있었다. 특히 SOD 유사활성 시험에서 여러 분획의 활성이 총 메탄올 추출물보다도 낮음에 비하여 crocin 단일 물질은 양성 대조군 cholorogenic acid의 $EC_{50}$ 값 453 ppm에 비하여 절반정도 낮은 $EC_{50}$값 259 ppm으로 매우 높은 활성을 보였다. 유지 산화 지연효과도 치자의 총 메탄올 추출물 250 ppm 이상의 농도에서의 AI값은 BHA 1000 ppm에서의 AI값 1.66 보다 큰 1.81 이상임을 보여 유지 산화 지연효과가 우수함을 나타내었다. 이 논문의 연구결과로 치자의 항산화 기능성 식품 및 첨가제로서의 개발가능성이 확인되었다고 사료된다.