연교의 메탄올 추출물로부터 caspase 저해물질을 분리하였으며, ESI-MS, $^1H-NMR$, $^13C-NMR$, DEPT 등의 기기분석 자료에 의하여 rengyolone으로 동정하였다. 이 물질은 $IC_{50};6.25;{mu}g/mL$의 농도에서 etoposide가 처리된 U937 세포주의 caspase-3 유도 저해를 나타내었다. 또한 rengyolone은 $Interleukin-1{eta}$가 처리된 D10S 세포에서 caspase-1의 유도저해활성을 나타내었으며, $IC_{50}$값은 $7.5;{mu}g/mL$이었다.
During the screening of inhibitors of caspase-3 induction in U937 human monocytic leukemia cells from natural sources, Forsythiae fructus, which showed a high level of inhibition, was selected. And then, the compound was purified from the methanol extract using silica gel column chromatography and HPLC. The inhibitor was identified as rengyolone, by spectroscophic methods of ESI-MS, $^1H-NMR$, $^{13}C-NMR$, DEPT, and HMBC. Rengyolone showed inhibitory activity of caspase-3 induction, a major protease of apoptosis cascade, with an $IC_{50}$ value of $6.25;{mu}g/mL$ after 7 h of treatment in U937 cells. It also showed inhibitory activity of caspace-1 induction, with an $IC_{50}$ value of $7.50;{mu}g/mL$ after 40 h of treatment in D10S cells. In addition, it showed protective effect against cell death with an $IC_{50}$ value of $11;{mu}g/mL$ on U937 cells induced by etoposide after 24 h of treatment, but did not show any cytotoxicity at the same condition without etoposide, a caspase 3 inducing agent.
