Cytotoxic and antioxidant activities of alkylated benzoquinones from Maesa lanceolata

The natural and semi‐synthetic analogs of substituted 1,4‐benzoquinones were evaluated for in vitro cytotoxic and antioxidant activities. Maesanin, dihydromaesanin, maesanin dimethyl ether and isomeric mixtures of 3‐[(Z)‐10′‐pentadecenyl]‐benzoquinone derivatives exhibited cytotoxic activity against HL‐60 cell line (IC 50 values 4.5, 2.2, 0.43 and 2.8 µg/mL, respectively), while it was found to be inactive against ROS (Reactive Oxygen Species) generation in HL‐60. In contrast, the isomeric acylated benzoquinones with shorter alkyl substituents, namely, 2‐acetoxy‐5‐hydoxy‐6‐methyl‐3‐tridecyl‐1,4‐benzoquinone and 2‐hydoxy‐5‐acetoxy‐6‐methyl‐3‐tridecyl‐1,4‐benzoquinone showed most prominent antioxidant and antiproliferative effect on HL‐60 (IC 50 values 6.2 and 2.2 µg/mL, respectively), as well as cytotoxicities against SK‐MEL, KB, BT‐549 and SK‐OV‐3 carcinomas (IC 50 values <1.1–4.2 µg/mL). All benzoquinones were found to be inactive against cell aggregation and cell adhesion assays, thus showing no effect on immune responses and inammation. Copyright © 2003 John Wiley & Sons, Ltd.