Biosynthesis of rhodiocyanosides in Lotus japonicus: Rhodiocyanoside A is synthesized from (Z)-2-methylbutanaloxime via 2-methyl-2-butenenitrile

► 2-Methyl-2-butenenitrile is new intermediate in biosynthesis of rhodiocyanosides. ► The aglycon of rhodiocyanoside A cyclizes to 3-methyl-2(5H)-furanone. ► Biosynthesis of cyanogenic glucosides and rhodiocyanosides branch at Ile-oxime. ► Transformation of Ile-ox to 2-methyl-2-butenenitrile is catalyzed by a P450.