Morpholine antifungals and their mode of action.

Introduction The fungicidal properties of morpholines with large ring N-substituents was first reported in 1965 [ l ] and since then several (Fig. 1) have been marketed for the control of plant pathogenic fungi. Dodemorph, tridemorph, aldimorph and fenpropimorph are used to control powdery mildews and have both protective and eradicant properties. They are systemic in action, being absorbed through the roots and leaves and translocated in the apoplast. Fenpropimorph has all the properties of the N-alkylmorpholines but is superior in that it also controls rusts and has a strong fumigant action because of its volatility. Amorolfine, though highly active against phytopathogenic fungi, is under clinical evaluation as a topical antifungal for human infections caused by dermatophytes. Fenpropimorph and amorolfine are used as racemic mixtures but in both cases the S-enantiomer is significantly more active than the R enantiomer [ 2, 31.