FIGURE 5.

Conversion of Fur-P1 into furaquinocin C. A, HPLC analysis of the ethyl acetate extract from the S. albus/pWHM-Fur2_del7 culture supplemented with Fur-P1. Extracts were prepared at 0 and 15 h after the addition of Fur-P1. B, Identification of furaquinocin C (3) by HPLC-MS/MS. The standard (std.) 3 and the isolated product (*) were separated according to the method as described under “Experimental Procedures.” Compound 3 was identified using the combinations 369/259 and 369/228 m/z in the multiple reaction monitoring mode. mAU, milli-AU; cps, count per second.