ABSTRACT
@#An on-line HPLC-DPPH system was developed to determine the antioxidant activity of 16 batches of Polygoni Multiflori Radix Praeparata. By analyzing the chromatographic and biological activity fingerprints of 16 batches of Polygoni Multiflori Radix Praeparata, the dose-effect relationship was established and the total antioxidant activity was quantified by activity addition.The results suggested that the online HPLC-DPPH method can evaluate the antioxidant activity of different bathches of Polygoni Multiflori Radix Praeparata, with different processing methods, aiming to provide datasupport and scientific basis forquality evaluation of Polygoni Multiflori Radix Praeparata.
ABSTRACT
Objective: To evaluate the antioxidant capacity of the main components from Dracaena cochinchinensis by HPLC-DPPH and provide a foundation for "spectrum-effect" quality control standard. Methods: The determination was developed on Phenomenex lura C18 column (250 mm × 4.6 mm, 5 μm) with gradient elution of methanol-acetonitril-0.2% H3PO4 and the detective wavelength was set at 306 nm. The column temperature was 35℃. Results: The DPPH free radical scavenging abilities of these five antioxidants were as follows: pterstilbene > resveratrol > luoreirin B > luoreirin A > 7,4'-dihydroxyflavone. The analysis on the structures of the five compounds showed that the hydroxymethylation didn't decrease the antioxidant activities of stilbenes. The symmetry of B ring of dihydrochalcone has the significant effect on the antioxidant activities. However, 7,4'-dihydroxyflavone didn't show the related activity in D. cochinchinensis. Conclusion: HPLC-DPPH can not only be used for screening the components with antioxidant potency but also for the purpose of quality evaluation of D. cochinchinensis, and the method proves to be selective, simple, and reproducible.