Mutasynthesis of geldanamycin by the disruption of a gene producing starter unit: Generation of structural diversity at the benzoquinone ring

(Chemical Equation Presented) A not so familiar ring. We describe results obtained from a mutasynthetic study based on geldanamycin (1), and demonstrate that this technique can be used to extend the structural diversity of the benzoquinone ring of 1. Our results show that geldanamycin PKS modules tolerate polyketide intermediate chains that bear unnatural benzoate components, and that they extend these structures further to produce mature polyketides (see scheme).