Crocetenone, a new rotenoid with an unusual trans-fused ring system from Iris crocea.

Crocetenone, a new rotenoid (1), along with five known compounds apocyanin (2), tectorigenin (3), 5,2',3'-trihydroxy-7-methoxy flavanone (4), tectoridin (5) and tectoridin glycoside (6), were isolated from the methanolic extract of the root of Iris crocea. The structure of compounds was elucidated on the basis of 1D- and 2D-NMR spectroscopic and MS analysis. Antibacterial and antioxidant activities of compounds 1-6 were evaluated. Crocetenone (1) showed a prominent antibacterial activity.