Alcohol and petrol extracts of the seeds of Aframomum danielli inhibit the soya 5-lipoxygenase enzyme and thus may show antiinflammatory activity. Compounds isolated from the active fractions were shown to be long chain polyprenyl benzoquinone derivatives. Phytylplastoquinone was isolated from the petrol extract and plastoquinone-7 (heptaplastoquinone) from the alcohol extract. The presence of these two known benzoquinones in A. danielli and their ability to inhibit 5-lipoxygenase are reported here for the first time.