Ternifoliasaponin, a new triterpenoid saponin from the roots of Gardenia ternifolia Schumach & Thonn (Rubiaceae)

A new triterpenoid saponin, Ternifoliasaponin (1), together with four known compounds (2–5) chikusetsusaponin IVa (2), chikusetsusaponin IVa methyl ester (3), bonushenricoside B (4) and Dianoside C (5) were isolated from roots of Gardenia ternifolia Schumach. & Thonn (Rubiaceae). The structures of isolated compounds were elucidated on the basis of spectroscopic analysis and chemical methods. The antibacterial activities of compounds (3), and (4) were performed by the Muller–Hinton agar diffusion method. The antimicrobial activities of the compounds were studied on Salmonella typhi (Enterobacteriaceae), Staphylococcus aureus and Pseudomonas aeruginosa microorganisms. Compound (3) at 25 mg/mL, showed moderately sensitive effect (8.0 ˂ DIZ ˂14.0 mm) on S. typhi, S. aureus and P. aeruginosa. Compound (4) at 25 mg/mL and compound (3) at 12.5 mg/mL exhibited moderately sensitive effect on S. typhi and S. aureus. Compound (4) inhibited moderately sensitive the S. typhi and P. aeruginosa colonies at 12.5 mg/mL.