Determination and Isolation of Antioxidative Serotonin Derivatives, N-(p-Coumaroyl)serotonin and N-feruoylserotonin from Safflower Seeds

In the methanol extract from safflower seeds, two kinds of antioxidant were detected by preparative HPLC [$\mu$-Bondapak $C_{18}$ column ($7.8{\times}300\;mm$)]. Two unknown compounds were defined as CA and CB which had peaks at 22.1 min and 24.5 min, respectively. Antioxidant activity was measured by their scavenging ability on the stable tree radical of 1,1-diphenly-2-picrylhydrazyl (DPPH). For bulk extraction of antioxidants, the methanol extract was fractionated with hexan, chloroform, ethyl acetate and butanol. The ethyl acetate traction showing the highest DPPH radical scavenging activity was further purified by silica gel column chromatography to CA and CB. By NMR analysis, CA and CB were identified as N-(p-Coumaroyl)serotonin and N-feruoylserotonin, respectively. The content of N-(p-Coumaroyl)serotonin and N-feruoylserotonin were analyzed by reverse phase HPLC using a $\mu$-Bondapak $C_{18}$ column ($3.9{\times}300\;mm$) with linear gradient elution from 10% acetonitrile to 50% acetonitrile for 30min on UV detector at 300 nm. The contents of N-(p-Coumaroyl)serotonin and N-feruoylserotonin were 4.11 mg/g DW and 7.29 mg/g DW, respectively, and these two DPPH radical scavengers were detected only in the hull of seeds.

홍화종자에서 항산화성 Serotonin계 화합물, N-(p-Coumaroyl)serotonin과 N-feruoylserotonin의 분리 및 정량분석

홍화종자의 메탄올 추출물에서 preparative HPLC($\mu$-Bondapak $C_{18}$ column($7.8{\times}300mm$) 분석을 통하여 DPPH radical 소거 활성도가 높은 두 종류의 항산화 물질(CA와 CB)을 확인하였다. 확인된 항산화물질의 대량 추출을 위하여 hexane, chloroform, ethyl acetate 그리고 butanol 등의 유기용매를 이용하였으며 이 중 ethyl acetate 분획에서 DPPH radical 소거 활성이 높은 물질이 추출되었다. Ethyl acetate 분획물을 silica gel chlomatography하여 CA와 CB를 분리하였고, $^1H$-NMR과 $^{13}C$-NMR 분석에 의하여 CA는 N-(p-Coumaroyl) serotonin, 그리고 CB는 N-feruoylserotonin으로 동정되었다. 홍화종자에서 N-(p-Coumaroyl) serotonin과 N-feruoylserotonin의 함량을 $\mu$-Bondapak $C_{18}$ column($3.9{\times}300\;mm$)으로 300nm에서 acetonitrile의 용매로 10%에서 분석을 시작하여 30분 동안 50%까지 기울기 모드로 분석한 결과 N-(p-Coumaroyl)serotonin의 함량은 4.11 mg/gDW, N-feruoylserotonin의 함량은 7.29 mg/gDW이었으며, 이 두 가지 항산화 물질은 모두 종자껍질에서만 추출되었다.