[Study on the total flavonoid content and antioxidant activity of Morus nigra Linn. from different origins in Xinjiang].

ABSTRACT

OBJECTIVE: Optimization of the extraction process of total flavonoids from Morus nigra Linn. based on response surface design, to compare the differences in total flavonoid content of Morus nigra Linn. from different origins in Xinjiang and its relationship with antioxidant activity. METHODS: A one-way test was used to investigate the effects of ethanol volume fraction, material-liquid ratio, ultrasonic power and ultrasonic time on total flavonoid content analysis of Morus nigra Linn. , Box-Behnken response surface design optimisation was used to derive the optimal extraction process parameters. Meanwhile, the in vitro antioxidant activity of Morus nigra Linn. was evaluated by antioxidant activity indexes such as hydroxyl radical scavenging capacity and ferric ion reducing capacity. RESULTS: The optimal extraction condition was 45% ethanol by volume, 1∶20 g/mL material-liquid ratio, 300W ultrasound power and 60 min ultrasound time. The total flavonoid content of Morus nigra Linn. s from six origins was detected and the result showed that Kuche >Kashgar >Kuche Wuqia Town>Hetian >Ying jisha >Yutian, in which the total flavonoid content of mulberry in Kucha city was(27.159±0.091)mg/g. The difference in the total flavonoid content of Morus nigra Linn. s in different origicns was statistically significant(P<0.05). In vitro antioxidant activity analysis showed that the antioxidant activity of mulberry from Kuche and Hetian was stronger, and the hydroxyl radical scavenging capacity, ferric ion reducing capacity, and total antioxidant capacity of mulberry from various origins were statistically significant(P<0.05). The correlation analysis showed that the total flavonoid content of Morus nigra Linn. was correlated with the antioxidant capacity to improve the scavenging of hydroxyl radicals. CONCLUSION: The ultrasonic-assisted method of extracting total flavonoids from Morus nigra Linn. is simple, and the model constructed has a high degree of fit, which can better compare the total flavonoids content of Morus nigra Linn. from different origins in Xinjiang.