Seeds of Moringa peregrina (Moringaceae), on treatment with myrosinase, produce 2-propyl, 2-butyl and 2-methylpropyl isothiocyanate in addition to 5,5-dimethyl-oxazolidine-2-thione, all new to the family but known as natural derivatives from other sources. 4-(4'-O-Acetyl-α-L-rhamnosyloxy)benzyl isothiocyanate, not previously described, together with substantial quantities of its non-acetylated counterpart, formerly recognized as a component in hydrolysed seeds of M. oleifera, constitute the additional mustard oils observed in seeds of M. peregrina.