Catalysis of the reaction: (9Z,12Z,15Z)-octadecatrienoate + O2 = (9R,10E,12Z,15Z)-9-hydroperoxyoctadeca-10,12,15-trienoate. Also converts linoleate to (9R,10E,12Z)-9- hydroperoxyoctadeca-10,12-dienoate.
linolenate 9R-lipoxygenase activity