<p>Phytochemical analyses of the chloroform extract of <i>Piper betle</i> L. var. <i>birkoli</i>, Piperaceae, leaves led to the isolation of two new phenylpropanoid analogues: <i>bis</i>-chavicol dodecanoyl ester (<b>2</b>) and <i>bis</i>-hydroxychavicol dodecanoyl ester (<b>3</b>), along with one known compound: <i>allyl</i>-3-methoxy-4-hydroxybenzene (<b>1</b>) on the basis of spectroscopic data 1D (<sup>1</sup>H and <sup>13</sup>C) and 2D (<sup>1</sup>H–<sup>1</sup>H COSY and HMBC) NMR, as well as ESI-MS, FT-IR, HR-ESI-MS and LC-ESI-MS. Compound <b>2</b> and <b>3</b> exhibited excellent antioxidant DPPH radical scavenging activity with IC<sub>50</sub> values of 12.67 μg/mL and 1.08 μg/mL compared to ascorbic acid as a standard antioxidant drug with IC<sub>50</sub> value of 6.60 μg/mL. Evaluation of cytotoxic activity against two human oral cancer cell lines (AW13516 and AW8507) showed significant effect with GI<sub>50</sub> values of 19.61 and 23.01 μg/mL for compound <b>2</b> and 10.25 and 13.12 μg/mL for compound <b>3</b>, compared to Doxorubicin<sup>®</sup> as a standard cytotoxic drug with GI<sub>50</sub> value of < 10 μg/mL.</p
