Abstract

Two new phenolic compounds, 3,4-dihydroxyphenethyl 5-hydroxy-4-oxopentanoate (1) and 3-(4-hydroxy-2,5-dimethoxyphenyl)-3-oxopropyl acetate (2), together with fifteen known compounds, 3 to 17, were isolated from the dried whole plants of Clematis connata DC. Their structures were elucidated by extensive spectral analysis, especially 2D NMR techniques. Compounds 1 to 5 were evaluated for their in vitro cytotoxicities against acute promyelocytic leukemia HL-60, hepatocellular carcinoma Hep-G2, oropharyngeal epidermoid carcinoma KB and breast cancer cells MDA-MB-231. Compounds 1 and 3 exhibited the most potential with IC₅₀ values of 0.63 and 1.27 μM against MDA-MB-231 and HepG2, respectively. The antibacterial activities experiment of all the isolated compounds showed that only Compounds 3 to 5 exhibited weak activities against Staphylococcus aureus, methcillin-resistant S. aureus and b-lactamase positive S. aureus, and Compound 9 and 17 showed weak activities against S. aureus.

Key words: Clematis connata DC., phenolic constituents, cytotoxicities, antibacterial activities.