Potential defense-related prenylated isoflavones in lactofen-induced soybean

► Five prenylated isoflavones are reported for the first time in soybean. ► Two previously unreported prenylated isoflavones are described. ► Prenylated isoflavones are induced by soybean disease-resistance-inducing agents. ► Elicitor-treatment of plants for induction of new metabolites is described.