Optimization of Extraction by BP-ANN and Determination of Flavonoids in Three Varieties of Polygonati Rhizoma Before and After Irradiation by HPLC Chromatographic Fingerprint

Objective:Back propagation artificial neural network(BP-ANN)was designed to optimize the yield rate of seven flavonoids from Polygonatum sibiricum,Polygonatum odoratum and Polygonatum filipes,to determine the content changes of flavonoids before and after electron beam irradiation of different varieties of Polygonati Rhizoma,and to establish chromatographic fingerprint. Methods:The determination was performed by high performance liquid chromatography(HPLC),Inertsil ODS-3,C₁₈ column(250 mm×4.6 mm,5 μm)was used,the mobile phase consisted of 0.02% phosphoric acid(A)-acetonitrile(B),gradient elution at a flow rate of 1.2 mL/min,and the column temperature was 43 ℃,the detection wavelength was set at 270 nm. The fingerprint of Polygonati Rhizoma flavonoids under different irradiation doses was established,and the content changes of Polygonati Rhizoma flavonoids under different irradiation doses were compared. Results:The established HPLC method could accurately determine the contents of rutin,myricetin,liquiritigenin,quercetin,apigenin,kaempferol and isorhamnetin in Polygonati Rhizoma. All the 7 chemical constituents in the Polygonati Rhizoma could produce complete peaks,with the separation degree was more than 1.5,and the components had a good linear relationship within the corresponding concentration range(R²>0.999),and the recovery rate was 97.95%~103.71%. The optimized extraction results by BP-ANN technology showed that under the conditions of solid-liquid ratio of 1:50,extraction time of 2 h,extraction temperature of 90 ℃,and ethanol concentration of 70%,the maximum extraction efficiency(0.0622%)of flavonoids from Polygonati Rhizoma could be obtained. The results of the sample determination showed that only the Polygonatum sibiricum contained all 7 kinds of flavonoids,while the flavonoids in the other two kinds of Polygonati Rhizoma were not the same. The content of flavonoids decreased with the increase of irradiation dose. Conclusion:BP-ANN has high precision and good fitting effect to fit yield rate of flavonoids in Polygonati Rhizoma. The HPLC for the determination of seven flavonoids in Polygonati Rhizoma has high sensitivity and specificity,and can be used for the determination of flavonoids in Polygonati Rhizoma.