... resulted in the isolation of the oxindol alkaloids: gelsemine, gelsevirine, humantenine and gelsenicine. Their structures have been determined on the basis of the IR, MS, 1H- and 13 C- NMR ... dung m i n-hexan, etyl axetat v n-butanol. C t loại dung m i thu đ c c c cặn d ch chi t t ng ng. T c n d ch chi t n-butanol axit h a b ng HCl lo *ng v ki m h a b ng NaHCO3sau đ chi t ... lại b ng CHCl3, thu đ c ancaloit t ng. T c n ancaloit ny, b ng s c ký c t th ng, s c ký 102ny đ c ch ng minh th m qua phổ 13 C- NMR v phổ DEPT: ph a tr ng thấp c t n hiệu c a nh m cacbonyl...