FIG 4.

All FK506 analogs, except for 9-deoxo-prolyl-FK506, exhibited antifungal activity against C. albicans SC5314. (A) Growth of C. albicans (10-fold serially diluted from an OD of 1.0) on 50% FBS agar containing 3 μg/ml of FK506 or its analogs (5 μg/ml 9D-FK506, 10 μg/ml 9D31OD-FK506, 10 μg/ml 9DP-FK506, or 3 μg/ml 31OD-FK506) at 37°C for 24 h. Growth was suppressed compared with that of the nontreated control. All FK506 analogs, except for 9-deoxo-prolyl-FK506, resulted in reduced growth rates over 1 day. (B) MIC test using 2-fold serially diluted FK506 and FK506 analogs from 10 μg/ml.