Several polyenylidene thiazolidinedione or 2-thioxo-4-thiazolidinone derivatives were synthesized and their retinoidal activities were examined in terms of the differentiation- inducing ability towards human promyelocytic leukemia HL-60 cells and inhibitory effect on interleukin (IL)-1α-induced IL-6 production in MC3T3-E1 cells. Compounds containing a trimethylcyclohexenyl ring induced HL-60 cell differentiation with weaker activity than ...