	US 12,344,593 B2
	Method melt crystallization for preparing high-purity glabridin
Anzhang Li, Guangzhou (CN); Anning Wang, Guangzhou (CN); and Lushi Cheng, Guangzhou (CN)
Filed by Guangzhou Fanzhirong Cosmetics Co., LTD., Guangzhou (CN); and Guangzhou Qingnang Biotechnology Co., LTD., Guangzhou (CN)
Filed on May 8, 2024, as Appl. No. 18/657,828.
Claims priority of application No. 202311064877.2 (CN), filed on Aug. 22, 2023.
Prior Publication US 2025/0066317 A1, Feb. 27, 2025
Int. Cl. C07D 311/78 (2006.01)

CPC C07D 311/78 (2013.01)

9 Claims

1. A melt crystallization method for preparing high-purity glabridin, characterized in that the method includes the following steps:

Step 1) purification: dissolving crude glabridin with a mass percentage of ≥40% in a solvent, then adsorbing with macroporous adsorption resin AB-8, eluting with ethanol, and recrystallizing to obtain glabridin coarse material;

Step 2) heating and melting: adding the obtained glabridin coarse material into a melting crystallizer, and completely melting the material to be liquid at a melting temperature;

Step 3) cooling and crystallizing: cooling the glabridin liquid material of step 2) by controlling the cooling rate at 10° C./h to 30° C./h to a final cooling temperature of 155° C. to 160° C.: keeping said temperature constant for 0.5 to 4 hours to obtain crystals of glabridin; and collecting the uncrystallized residual liquid;

Step 4) sweating: sweating the crystals by heating the crystals up to 160° C. to 168° C. at a heating rate of 1° C./h to 15° C./h; and keeping said temperature constant for 0.5 to 2 hours, wherein the sweating liquid is discharged,

Step 5) melting: heating to raise the temperature of the crystals to above 175° C. after discharging the sweating liquid, completely melting the crystals to be molten liquid, and collecting the molten liquid;

Step 6) repeating steps 3) to 5) on the collected molten liquid of step 5) for multi-stage crystallization, after repeating one or more times, collecting the molten liquid, cooling, and crystallizing the collected molten liquid to obtain the glabridin, resulting in ultra-high-purity glabridin.