Cytotoxic iridoid glycosides from the aerial parts of .

Three previously undescribed iridoid glycosides, 6--sinapoyl-paederosidic acid ethyl ester (), 6'---feruloyl-paederosidic acid methyl ester (), and 10----coumaroyl-(4,6)-3,4-dihydro-3-ethoxypaederoside (), were isolated from the 90% EtOH extract of the aerial parts of . The structures of the new compounds were elucidated by spectral methods such as 1D and 2D (H-H COSY, HMQC, and HMBC) NMR spectrometry, HR-ESI-MS, as well as ECD data. The isolated compounds were tested for cytotoxic activity against five tumor cell lines. These results revealed that exhibited some cytotoxicities against all the tested tumor cell lines with IC value less than 20.0 μM and provided a scientific basis for further processing and utilization of .