Bioactive Constituents of F. esculentum Bee Pollen and Quantitative Analysis of Samples Collected from Seven Areas by HPLC

Bee pollen contains all the essential amino acids needed by humans. China is the largest producer of bee pollen in the world. In the present study, we identified 11 fatty acids in F. esculentum bee pollen oil by GC-MS analysis, and 16 compounds were isolated from F. esculentum bee pollen by column chromatography and identified. A high-performance liquid chromatography-diode array detector (HPLC-DAD) method was established for the quality control of F. esculentum bee pollen. A validated HPLC-DAD method was successfully applied to the simultaneous characterization and quantification of nine main constituents in seven samples collected from seven different areas in China. The results showed that all standard calibration curves exhibited good linearity (R(2) > 0.999) in HPLC-DAD analysis with excellent precision, repeatability and stability. The total amount in the samples from the seven regions ranged from 23.50 to 46.05 mg/g. In addition, seven compounds were studied for their bioactivity using enzymic methods, whereby kaempferol (3) showed high α-glucosidase inhibitory activity (IC(50): 80.35 μg/mL), ergosterol peroxide (8) showed high tyrosinase inhibitory activity (IC(50): 202.37 μg/mL), and luteolin (1) had strong acetylcholinesterase inhibitory activity (IC(50): 476.25 μg/mL). All results indicated that F. esculentum bee pollen could be a nutritious health food.