| Summary: | 碩士 === 國立中興大學 === 食品暨應用生物科技學系所 === 100 === After the severe EV71 outbreak in Taiwan in 1988, EV71 has been observed every spring and summer in Asia annually and another outbreak occurred again in Taiwan in 2008. EV71 infections are generally mild, causing hand, foot and mouth disease (HFMD). However, extreme cases show symptoms of severe central nervous system (CNS) syndromes which progress to acute cardiopulmonary edema and even death. Unfortunately, there are no effective anti-EV71 drugs or vaccines in clinical use. In the previous work of our laboratory, Ficus pumila L. 95% ethanol extract showed both great anti-EV71 activity and low cytotoxicity (IC50=34.6 ± 0.8 μg/mL; CC50=319.4 ± 11.3 μg/mL). Therefore, the aim of this study was to isolate the major active compound against EV71. Ficus pumila L. 95% ethanol extract (specific activity was 28.9 mL/mg) was firstly subjected to Amberlite XAD-7 column chromatography and twelve fractions (Fr. A~Fr. L) were obtained (IC50=9.0 ± 0.1~>160 μg/mL). Among these fractions, Fr. J showed the lowest IC50 of 9.0 ± 0.1 μg/mL (specific activity was 111.1 mL/mg). Fr. J was subsequently subjected to semi-preparative PurospherR STAR RP-18e column chromatography and Fr. J-1~Fr. J-3 were obtained (IC50=3.7 ± 0.1~20.0 ± 0 μg/mL). Fr. J-2 was selected for futher isolation because of the highest specific activity (270.3 mL/mg). Fr. J-2 was separated by semi-preparative column chromatography again and totally four fractions (Fr. J-2-1~Fr. J-2-4) were obtained. Fr. J-2-3 and Fr. J-2-4 showed anti-EV71 activity with IC50 of 7.7 ± 0.3 and 1.3 ± 0.1 μg/mL respectively. Compared with ribavirin, Fr. J-2-4 showed higher anti-EV71 activity that the IC50 was only 0.8% of positive control. However, Fr. J-2-4 also showed a moderately high cytotoxicity (CC50=3.6 ± 0.1 μg/mL). Fr. J-2-4 was characterized by nuclear magnetic resonance (NMR) spectrometer, Mass spectrometer, Fourier transform infrared spectrometer (FTIR) and UV/Vis spectrometer. The data were confirmed with reported meroterpene compound bakuchiol. This was the first time bakuchiol isolated from Ficus pumila L. and demonstrated its anti-EV71 activity. In this study, bakuchiol, a meroterpene compound with anti-EV71 activity was first isolated from Ficus pumila L. with Amberlite XAD-7 and semi-preparative PurospherR STAR RP-18e column chromatography.
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