Author/Authors :
Hong، نويسنده , , Seong Su and Cai، نويسنده , , Xing Fu and Hwang، نويسنده , , Bang Yeon and Lee، نويسنده , , Hong Sub and Su، نويسنده , , Bao-Ning and Hong، نويسنده , , Young-Soo and Lee، نويسنده , , Dongho، نويسنده ,
Abstract :
Two tricyclic geldanamycin analogues, DHQ5 (1) and DHQ6 (2), were produced by a combinatorial mutant (AC15) contained a site-directed mutagenesis on the geldanamycin polyketide synthase (PKS) gene with inactivation of the post-PKS tailoring genes (gel7) of Streptomyces hygroscopicus JCM4427. The structural diversity of tricyclic geldanamycin analogues is due to the formation of unusual additional rings, which are formed by alkylation of the C-21 position by C-12 in DHQ5 (1) and by electrophilic addition of the C-15 hydroxyl group to the double bond (C-8–C-9), which leads to the migration of the double bond (to C-7–C-8) and the elimination of a carbamoyloxy group in DHQ6 (2).
