Method for Simultaneously Separating and Purifying Two Galloylated Myricitrins from Morella rubra Leaves, and Use therefor

A method for simultaneously separating and purifying myricetin-3-O-(2″-galloyl)-α-L-rhamnoside and myricetin-3-O-(4″-galloyl)-α-L-rhamnoside from Bayberry leaves, comprising the following steps:

• (1) alcohol extraction and concentration:
• mixing Bayberry leaves with an alcohol solution;
• extracting by ultrasound;
• filtering and collecting the filtrate;
• removing the alcohol from the filtrate and concentrating to obtain a crude Bayberry leaf flavonol alcohol extract;
• wherein the volume percentage of the alcohol solution is 50-100%;
• (2) solid-phase extraction column adsorption:
• injecting the crude Bayberry leaf flavonol alcohol extract into a solid-phase extraction column;
• washing with a mobile phase for the first gradient elution;
• and processing the collected eluent to obtain a solid-phase extraction powder rich in myricetin-3-O-(2″-galloyl)-α-L-rhamnoside and myricetin-3-O-(4″-galloyl)-α-L-rhamnoside;
• the first gradient elution process is as follows:
• first eluting with an alcohol solution with a volume percentage lower than 40% for the first elution;
• then using an alcohol solution with a volume percentage of 40-60% for the second elution;
• and collecting the eluent after the second elution;
• wherein the concentration of the alcohol solution for the first elution is above 20% by volume percentage;
• (3) preparative liquid chromatography purification:
• using a solid-phase chromatography column;
• wherein the solid-phase extraction powder obtained from step (2) is subjected to a second gradient elution with a mobile phase and then processed to obtain the target products:
• myricetin-3-O-(2″-galloyl)-α-L-rhamnoside monomer and myricetin-3-O-(4″-galloyl)-α-L-rhamnoside monomer;
• the mobile phase:
• Phase A is selected from a formic acid-water solution with a volume percentage of 0.05-5%, a trifluoroacetic acid-water solution with a volume percentage of 0.05-5%;
• Phase B is selected from an acetonitrile-water solution with a volume percentage of 40-60%, an acid-acetonitrile-water solution with a volume percentage of 40-60%;
• the volume percentage of the acid is 0.05-5%, and the acid is selected from formic acid, trifluoroacetic acid;
• the second gradient elution process is as follows:
• the volume percentage of Phase B increases from 20% to 60% within 0-10 minutes, from 60% to 90% within 10-30 minutes, and from 90% to 100% within 30-35 minutes;
• and then decreases from 100% to 20% within 35-40 minutes, collecting the target products separately;
• the alcohol solution refers to an alcohol aqueous solution, and the alcohol is selected from methanol or ethanol.