Furaquinocins I and J: novel polyketide isoprenoid hybrid compounds from Streptomyces reveromyceticus SN-593.

Two novel furaquinocin (FQ) analogues, I (1) and J (2), were isolated from Streptomyces reveromyceticus SN-593 strain NRM2. Their structures were elucidated by MS and NMR analyses. Similar to the previously described FQ D (3), both 1 and 2 possessed a dihydrofuran ring fused to a polyketide naphthoquinone skeleton. The main difference between 1, 2 and 3 was the type of residue attached to C-13; these were a carboxyl, a carboxamide and a methyl residue, respectively.