Abstract:
Based on the adsorption-desorption tests of total flavonoids and amentoflavone from leaves of
Nageia nagi(Thunberg) Kuntze on different resins, AB-8 resin with the preferable adsorption and desorption performances was selected from four kinds of resins, which were AB-8 and D101 resins, and polyamide resins(PLA-1 and PLA-2). The optimum process was recommended as follows: for the adsorption tests, the mass concentration of total flavonoids was 1.5-3.0 g/L, the load rate was 22 mL/h and volume of loading solution was 220 mL; desorption tests was sequentially operated with 140 mL 80% ethanol-water solution as eluent at the wash rate of 44 mL/h. As a result, with the optimized processes, the content of total flavonoid and amentoflavone was significantly increased from 13.6% to 52.8% and 0.1% to 2.37%, respectively. Varieties of chromatographic techniques were used to separate and purify the extract fromleaves of
N. nagi. The structures of the compounds were identified by UV, FT-IR, MS, 1D NMR and 2D NMR. Eight compounds were isolated from the
n-butanol extract from branches and leaves of
N. nagi alcohol extract. They were catechin(
1), apigenin(
2),
epi-catechin(
3), vitexin(
4), vitexin rhamnoside(
5), amentoflavone(
6), podocarpus flavone A(
7), and bilobetin(
8). Among them, compounds
4,
5 and
8 were isolated from genus
Nageia for the first time.