Daniel Poeckel, Timo H.J. Niedermeyer, Hang T.L. Pham, Annett Mikolasch, Sabine Mundt, Ulrike Lindequist, Michael Lalk and Oliver Werz Pages 591 - 595 ( 5 )
We have recently presented the synthesis of 2-amino-1,4-benzoquinones by nuclear amination of phydroquinones with primary aromatic amines using fungal laccases as catalysts. In the present report, a series of selected 2-amino-1,4-benzoquinones was tested for biological activities, such as inhibition of human 5-lipoxygenase and antiproliferative/ anti-neoplastic effects. Compound 9 (2-[4-(iso-propylphenyl)-amino]-5,6-dimethyl-1,4-benzoquinone) was identified as the most potent aminoquinone derivative, suppressing 5-lipoxygenase in intact human polymorphonuclear leukocytes as well as in crude enzyme preparations in the low micromolar range (IC50 = 6 μM). Structure-activity relationships are discussed. Of interest, the 5-lipoxygenase inhibitory properties of 2-amino-1,4-benzoquinones in intact cells correlated to the anti-neoplastic activities of the compounds in breast and urinary bladder cancer cell lines. Based on these features, bioactive 2-amino-1,4-benzoquinones may possess potential for the pharmacological treatment of diseases associated with elevated 5-lipoxygenase activity, in particular certain types of cancer.
Aminoquinones, antineoplastic activity, lipoxygenase, cancer
Department of Pharmaceutical Analytics, Institute of Pharmacy, Eberhard-Karls-University Tubingen, Auf der Morgenstelle 8, 72076 Tubingen, Germany.