Cryptoic acids A and B, benzene-containing polyketides, and cyclocryptamide, a modified diketopiperazine, from an actinomycete of the genus Cryptosporangium.

Two new benzene-containing polyketides, cryptoic acids A (1) and B (2), along with a new acylated diketopiperazine designated cyclocryptamide (3), were isolated from the culture extract of Cryptosporangium sp. YDKA-T02. The absolute configuration of amino acid components in 3 was determined by Marfey's method. While 3 was not cytotoxic and inactive against microbial test strains, 1 and 2 showed PPARγ agonistic activity in a reporter gene assay and cytotoxicity against P388 murine leukemia cells.