992-69-8

Selective: The deoxygenation of simple and complex natural products employing a readily synthesized phosphoramidite and tetrazole catalysts can be executed as a two-step process, without the need to isolate intermediate deoxygenation precursors. Furthermore, a peptide-based tetrazole catalyst controls the site selectivity of deoxyerythromycin synthesis (see scheme), thus overcoming the notorious challenges with unprotected erythromycin A. Copyright

The role of the erythromycin 4″-hydroxyl group has been explored on the motilin agonist potential in the 9-dihydroerythromycin series of motilides. The compounds show potencies 2- to 4-fold superior to the corresponding hydroxylated compounds. The relationship is maintained when the 9-hydroxyl is alkylated to generate the corresponding 4″-deoxy-9-O-acetamido-9- dihydroerythromycins. However, concomitant with this increase in potency is an increase in hERG inhibition.

Novel 4″-O-carbamoyl erythromycin-A derivatives were designed, synthesized, and evaluated for their in-vitro antibacterial activities. All of the 4″-O-carbamoyl derivatives showed excellent activity against erythromycin-susceptible Staphylococcus aureus ATCC25923, Streptococcus pyogenes, and Streptococcus pneumoniae ATCC49619. Most of the 4″-O-arylalkylcarbamoyl derivatives displayed potent activity against erythromycin-resistant S. pneumoniae encoded by the mef gene and greatly improved activity against erythromycin-resistant S. pneumoniae encoded by the erm gene or the erm and mef genes. In particular, the 4″-O-arylalkyl derivatives 4c-4e and 4g were found to possess the most potent activity against all the tested erythromycin-susceptible strains, which were comparable to those of erythromycin, clarithromycin, or azithromycin. 4″-O-Arylalkyl derivatives 4e and 4g were the most effective against erythromycin-resistant S. pneumoniae encoded by the mef gene (0.25 and 0.25 μg/mL). 4″-O-Arylalkyl derivatives 4a and 4b exhibited significantly improved activity against erythromycin-resistant S. pneumoniae encoded by the erm gene. In contrast, the 4″-O-alkylcarbamoyl derivatives hardly showed improved activity against all the tested erythromycin-resistant strains.

(Chemical Equation Presented) Reversal: Simple peptide-based nucleophilic catalysts can perturb the inherent reactivity hierarchy of the polyol natural product erythromycin A (see picture). Such catalyst-dependent modifications that reorganize natural product architecture may be of utility for generation of natural product analogs.

A new approach to 4″-substituted derivatives of erythromycin and clarithromycin was developed by converting them into corresponding 4″-malonic monoesters. Subsequent carbodiimide coupling with alcohols and amines provided new macrolide derivatives that are capable of binding to 50S ribosomal subunits and inhibiting protein synthesis in cell-free system.