We identified a newradicalscavenger, 10T024A (C(15)H(12)N(2)O(4)), from a culture of the Streptomyces sp. Spectroscopic elucidation indicated that this compound is a new phenazine derivative. 10T024A showed radical-scavenging activity with an ED(50) of 125 µM. Moreover, it showed prostaglandin D(2) (PGD(2)) and leukotriene B(4) (LTB(4)) release suppressive activity in rat basophilic leukemia (RBL-2H3)