Enzymes from the plants Tecoma stans, Jasminum grandiflorum and Zea mays are flavoproteins containing copper. They are part of enzyme systems that form either anthranil (2,1-benzoisoxazole) (Tecoma stans), anthranilate (Jasminum grandiflorum) or both (Zea mays) as the final product. A second enzyme from Tecoma stans is not a flavoprotein, does not require copper, and is part of a system that forms anthranilate as the final product.