480-41-1

10236-47-2

480-41-1

The general procedure for synthesizing naringin from naringin is as follows: 1. 52g of naringin was mixed with 5% (w/v) hydrochloric acid solution at a solid-liquid ratio of 1:100 (g/mL) and hydrolyzed at 100°C for 1 hour. After completion of the reaction it was rapidly cooled to room temperature and left to settle for 12 hours to allow the solids to precipitate. The solids were collected by filtration and washed with purified water to neutrality to obtain 24.5 g of wet crude naringenin with 25% water content. 2. The crude naringenin obtained in step (1) was added to a 30% (w/v) acetic acid solution with a solid-liquid ratio of 1:7 (g/mL) and stirred for 30 minutes at room temperature. Subsequently, the same concentration of acetic acid solution was added and treated for 15 minutes, filtered and the solids were washed with water to neutrality. 3. The treated solid was dissolved in 95% (v/v) ethanol at a solid-liquid ratio of 1:10 (g/mL) and purified by passing through a neutral alumina column. 100 mL of 95% (v/v) ethanol eluate was collected and the solutions after column chromatography were combined. 4. Activated carbon equal to 10% by volume of the solution was added to the combined solution, stirred for 30 minutes at room temperature and filtered. Repeat this activated carbon treatment step once. 5. Concentrate the filtrate to 1/3 of the original volume, add an equal volume of distilled water, cool to room temperature and place in a refrigerator at 5°C for 24 hours to precipitate white mother-of-pearl-like crystals. The crystals were collected by filtration, and naringenin wet product was obtained. 6. Naringenin wet good to 1:6 (g/mL) solid-liquid ratio of heating dissolved in 95% ethanol, add an equal volume of distilled water for a recrystallization. The precipitated white needle-like crystals were collected by filtration and dried to obtain 14 g of naringenin. Under this condition, the purity of naringenin was 99.92% and the yield was 26.9%.