Tosylproline analogs of formula (I), where R1 is -COOH, -CONH¿2?, -SO3H, -SO2NH2, -PO3H2; R?2¿ is C¿1-16? alkyl optionally substituted with -COOH, -CONH2, -CONHR?3¿, -CONHCOR4, -CONHSO¿2?R?4, -SO¿3H, -SO2NH2, -SO2NHR3, -SO2NHCOR4, -SO2NHSO2R4, -PO3H2, -4-(1,2,3-triazolyl), -5-tetrazolyl, -5-(3-oxo-1,2,4-triazolyl), -S(O)m-4-(1,2,3-triazolyl), -S(O)m-5-tetrazolyl, or -S(O)m-5-(3-oxo-1,2,4-triazolyl); R3 is a group such that R3-NH2 is an amino acid; R4 is C¿1-4? alkyl, trifluoromethyl, or phenyl optionally substituted with methyl, trifluoromethyl, or nitro; m is 0, 1, or 2; each X and Y, which may be the same or different, is independently selected from methyl, ethyl, isopropyl, ethenyl, ethynyl, fluoro, chloro, bromo, methylthio, hydroxy, methoxy, carboxy, and methoxycarbonyl; n is 0, 1, 2, or 3; p is 0, 1, or 2; q is 1 or 2; R?5¿ is -COOH, -CONH¿2?, -CONHR?2, -SO¿3H,-SO2NH2, -SO2NHR2, or -PO¿3?H2, as an individual stereoisomer or mixture of stereoisomers, or a pharmaceutically acceptable salt or ester thereof, methods of making them, pharmaceutical compositions containing them, and methods for their use. The compounds are thymidylate synthase inhibitors; and are useful as anti-tumor agents and as anti-parasitics, anti-bacterials, anti-fungals, and anti-virals.