Analysis of chlorogenic acid and two flavonoids in mulberry leaves of different harvest periods and origins and HPLC fingerprint study for quality control

Research about mulberry leaf with different producing area and harvest period will promote its quality control method and utilization in terms of active ingredient extraction and health products research. This study focused on the establishment of fingerprint of mulberry leaves from different harvest periods and different origins, the determination of chlorogenic acid , rutin as well as astragalin with ultrasound assisted liquid extraction. The extraction rate was optimized using response surface method . The optimized conditions were as follows: methanol for extraction, ultrasonic power of 240 W, extraction time of 77 min, methanol concentration of 59 % (v/v) and solid-to-liquid ratio of 1:48 (g/mL). Three ingredients in mulberry leaves were successfully extracted, and the HPLC fingerprint of mulberry leaves was established with 23 common peaks. Good similarity higher than 85.7 % was obtained among the 14 batch of samples from different harvest periods and different origins. The optimized extraction process was stable, reliable and suitable for extracting chlorogenic acid and two flavonoids from mulberry leaf. The established fingerprint exhibited good stability and repeatability, and provided comprehensive chromatographic peaks information. This method can be relied upon for the identification and comprehensive quality control of mulberry leaf.