Deoxyuridine derivatives of the formula (I) where R1 is H or various substituents; D is —NHCO—, —CONH—, -0-, —C(═O)—, —CH═CH, —C≡C—, —NR5—; R4 is hydrogen or various substituents; R5 is H, C1-C4 alkyl, C1-C4 alkanoyl; E is Si or C; R6, R7 and R8 are independently selected from C1-C8 alkyl, C2-C8 alkenyl, C2-C8 alkynyl or a stable monocyclic, bicyclic or tricyclic ring system; G is —O—, —S—, —CHR10—, —C(═O)—; J is —CH2—, or when G is CHR10 may also be —O— or —NH—; R10 is H, F, —CH3, —CH2NH2, —CH2OH; —OHR11 is H, F, —CH3, —CH2NH2, —CH2OH, —CH(OH)CH3, CH(NH3)CH3; or R10 and R11 together define an olefinic bond, or together form a —CH2-group, thereby defining a cis or trans cyclopropyl group; have utility in the prophylaxis or treatment of protozoal diseases such as malaria.