Prodelphinidin in Hot Water Extract of Bayberry Leaves (Myrica rubra Sieb. et Zucc.) and Its Antioxidant Activity:Influence of Infusion Conditions

Effect of hot water extraction on composition and antioxidant activity of prodelphinidins (PDs) from two cultivar bayberry leaves (Biqi and Dongkui) were studied. Composition of PDs were analyzed by NPHPLC-DAD/UV-ESIMS. Dimers to tetramers were separated and each polymers consisted of more than one compounds. Oligomer contents in Biqi extract were considerable, just like high polymers in Dongkui extract. Most dimers (similar to 4 mg/g) and trimers (similar to 2.2 mg/g) of Biqi was extracted at 75 degrees C while most tetramers (similar to 1.7 mg/g) and other polymers (similar to 11 mg/g) was extracted at 100 degrees C. The highest content of dimers (similar to 4 mg/g) in Dongkui existed at 50 degrees C. Other polymers showed highest content nearly at 100 degrees C. Antioxidant results (DPPH and FRAP) proved that hot water extract possessed antioxidant activity. In a word, composition of PDs were affected by hot water extraction. Proper extraction condition and materials should be chosen according to your purpose.