Increasing 5-lipoxygenase inhibitory activities by oxidative conversion of o-methoxyphenols to catechols using a Cu2+-ascorbic acid-O2 system.

Several complicated o-methoxyphenols were oxidized with high selectivity to catechols by a Cu2(+)-ascorbic acid-O2 system. In this way, the RBL-1 5-lipoxygenase inhibitory activities of o-methoxyphenols were greatly increased. [6]-Norgingerol (4), a novel compound derived from [6]-gingerol (3), shows promise as a lead compound for new drugs because of its high inhibitory potency (IC50 = 5.0 x 10(-8) M).