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

Abstract

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 (∼4 mg/g) and trimers (∼2.2 mg/g) of Biqi was extracted at 75°C while most tetramers (∼1.7 mg/g) and other polymers (∼11 mg/g) was extracted at 100°C. The highest content of dimers (∼4 mg/g) in Dongkui existed at 50°C. Other polymers showed highest content nearly at 100°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.