反应详情

To 1 g of tannic acid according to Japanese Pharmacopoeia (available from Iwaki Seiyaku Co., Ltd.), there were added 50 ml of methanol and 25 ml of acetate buffer (pH 5.5) and the resultant mixture was stirred at 50° C. for 18 hours. After distilling off methanol under a reduced pressure, the residue was extracted three times with ethyl acetate and then the solvent was distilled off under a reduced pressure. This crude product was fractionated by HPLC (YMC-PACK, D-ODS-5 20×250 mm; eluent=methanol: tetrahydrofuran: phosphate buffer (pH 4.5)=3:1:7) to obtain 282 mg of 1,2,3,4,6-penta-O-galloyl-β-D-glucose.

1. distillationAfter distilling off methanol under a reduced pressure
2. extractionthe residue was extracted three times with ethyl acetate
3. distillationthe solvent was distilled off under a reduced pressure