Integerrima A-E, phenylethanoid glycosides from the stem of Callicarpa integerrima

Five new phenylethanoid glycosides integerrima A-E (1-5) were isolated from the stem of Callicarpa integerrima for the first time. Their structures were elucidated by extensive spectroscopic analyses. In addition, cytotoxicity, anti-adipogenic and antioxidant activities were evaluated. All the phenylethanoid glycosides would be nontoxic to the normal human hepatocytes LO-2 and pre-adipocytes 3T3-L1 cell lines, significantly promote the proliferation of normal hepatocytes, thus displaying the potential for hepatoprotective. Integerrima A (1), C (3) and D (4) exhibited selectively moderate cytotoxic activity against the hepatoma cell lines Bel-7402, with the IC₅₀ value at 72.66, 80.43 and 84.88 μmol/L, respectively. Moreover, integerrima D (4) had significant activities on reducing lipid droplet formation, with the inhibition rate of 48.02% on the concentration of 200 μg/mL. Finally, the result of FRAP assays exhibited remarkable antioxidant activity in integerrima E (5), which was close to the positive control ascorbic acid with the concentration of 100 μg/mL.