Search

Additional file 1: Figure S1. Calibration graph using different R1 values. Figure S2. shows the experimental data and its fitting. Figure S3. shows the flowchart for calculating the impedance; (a) Transmitting end, and (b) Receiving end. Figure S4. shows the rate of proliferation with respect to impedance (a) Time point vs. change in impedance and average cell count per image, and (b) Normalized impedance vs. frequency plot. Figure S5. shows morphology of the C2C12 cells present near the electrode (a) 6 h, (b) 18 h, (c) 36 h, (d) 48 h, and (e) 72 h; Scale bar: 20 μm. Table S1. Cost comparison of the device in USD.

One of the known cytotoxic lignans is (−)-1- O -feruloyl-secoisolariciresinol designated as hanultarin, which was isolated from the seeds of Trichosanthes kirilowii . In this Letter, we described the first synthesis of 1- O -feruloyl-secoisolariciresinol, 1,4- O -diferuloyl-secoisolariceresinol and their analogues. The cytotoxicities of these compounds were evaluated against several cancer cell lines. Interestingly, we found that the feruloyl diester derivative of secoisolariciresinol was the most active cytotoxic compound against all the cancer cells tested in this experiment. The IC 50 values of the1,4- O -diferuloyl-secoisolariceresinol were in the range of 7.1–9.8 μM except one cell line. In considering that both ferulic acid and secoisolariciresinol are commonly found in many plants and have no cytotoxicity, this finding is remarkable in that simple covalent bonds between the ferulic acid and secoisolariciresinol cause a cytotoxic effect.