Elucidation of the Herbicidin Tailoring Pathway Offers Insights into Its Structural Diversity
摘要:
The biosynthetic gene clusters for herbicidins (hbc) and aureonuclemycin (anm) were identified in Streptomyces sp. KIB-027 and Streptomyces aureus, respectively. The roles of genes possibly involved in post-core-assembly steps in herbicidin biosynthesis in these clusters and a related her cluster were studied. Through systematic gene deletions, structural elucidation of the accumulated intermediates in the mutants, and in vitro verification of the encoded enzymes, the peripheral modification pathway for herbicidin biosynthesis is now fully established.
Better late than never! Two herbicidins, members of an important family of nucleoside antibiotics, have been synthesized for the first time. The route integrates a stereoselectiveC‐glycosylation with several reagent‐controlled stereoselective transformations and a surprisingly facile and highly diastereoselective late‐stage N‐glycosylation.
The biosynthetic gene clusters for herbicidins (hbc) and aureonuclemycin (anm) were identified in Streptomyces sp. KIB-027 and Streptomyces aureus, respectively. The roles of genes possibly involved in post-core-assembly steps in herbicidin biosynthesis in these clusters and a related her cluster were studied. Through systematic gene deletions, structural elucidation of the accumulated intermediates in the mutants, and in vitro verification of the encoded enzymes, the peripheral modification pathway for herbicidin biosynthesis is now fully established.
Total Synthesis of Herbicidin C and Aureonuclemycin: Impasses and New Avenues
The undecose nucleoside antibiotics herbicidinC and aureonuclemycin are biologically highly active and represent challenging targets for total synthesis. Herein, the gradual evolution of our synthetic strategy toward these natural products is described in detail. The initial route encompasses metalate addition chemistry but suffers from poor stereochemical control. In contrast, the ultimately successful