Eleven 1,2,3,4-tetrahydro-2-thioxopyrimidine analogs of combretastatin-A4 (CA-4) were synthesized and their cytotoxicity against the growth of two murine cancer cell lines (B16 melanoma and L1210 leukemia) in culture was determined using an MTT assay. Two 2-thioxopyrimidine analogs 8f and 9a exhibited significant activity IC50 <1 mu M for L1210 and <10 mu M for B16 cells). Exposure of A
-10 cells to 8f and 9a produced a significant reduction in cellular microtubules in interphase cells, with an EC50 value of 4.4 and 2.9 mu M, respectively, for microtubule loss. Molecular modeling studies using MacSpartan indicated that the two active 2-thioxopyrimidine analogs preferably adopt a twisted conformation, similar to CA-4, affirming that conformation and structure are connected to activity. (C) 2007 Elsevier Masson SAS. All rights reserved.
