A new phenylethanoid glycoside, 3'''-O-methylcampneoside I (1), was isolated from the 90% ethanolic extract of the roots of Incarvillea compacta, together with three known compounds, campneoside I (2), ilicifolioside A (3), and campneoside II (4). Their structures were determined spectroscopically and compared with previously reported spectral data. Compound 1 existed as epimers and displayed better 1,1-diphenyl-2-picrylhydrazyl (DPPH)-free radical scavenging activity using di-tert-butyl-4-methylphenol (BHT) as the positive control. In addition, pretreatment of human HepG2 cells with compound 1 significantly increased the viability on CCl4-induced cell death.
Keywords: 3′′′-O-methylcampneoside I; Bignoniaceae; Incarvillea compacta; antioxidant activity; hepatoprotective effect; phenylethanoid glycoside.