Novel substituted 4-aminopiperidine derivatives of the formula I: wherein n, R 1 , Y, (A), and (B) are as defined in claim 1 and optically pure enantiomers, mixtures of enantiomers, racemates, diastereomers, mixtures of diastereomers, diastereomeric racemates, mixtures of diastereomeric racemates and meso-forms, as well as salts and solvent complexes of such compounds, and morphological forms, that exhibit useful parasite aspartic proteases inhibiting properties and can thus be used in the form of pharmaceutical compositions as antimalarial medicines.