Abstract: The invention provides compounds of the formula: wherein L1 and L2 are independently selected from O and S; R1 is C3-C6 straight or branched alkyl, C3-C7cycloalkyl, C5-C7cycloalkenyl, adamantly, phenyl or saturated heterocyclyl, any of which being optionally substituted; R2 is H, methyl or ethyl; R5 is NRxCORy, NRxRy, CH2COCH3, CH2C?N, or a 5- or 6-membered heteroaryl group which is optionally substituted; X, Y and Z are independently N or CH; Rx is independently H or C1-C4alkyl; Ry is independently H, CrC4alkyl, phenyl or benzyl, either of which is optionally substituted; n is 0-3; salts, hydrates and N-oxides, wherein the optional substituents are further defined in the claims. The compounds have utility in the prophylaxis or treatment of trypanosomal diseases, such as T. cruzi (Chagas disease).

Abstract: Deoxyuridine derivatives of the formula where R1 is H or various substituents; D is —NHCO—, —CONH—, —O—, —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, —OH; R11 is H, F, —CH3, —CH2NH2, —CH2OH, CH(OH)CH3, CH(NH2)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.

Abstract: Deoxyuridine derivatives of the formula where A is O, S or CH2; B is O, S or CHR3; R1 is H, or various substituents; R2 is H, F; R3 is H, F, OH, NH2; or R2 and R3 together form a chemical bond; D is —NHCO—, —CONH—, —O—, —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 have utility in the prophylaxis o treatment of parasitic diseases such as malaria