Shigeru F. Hayashi

Synthesis and structure-activity relationships of thiotetronic acid analogues of thiolactomycin

3-Acetyl analogues of thiolactomycin, a thiotetronic acid natural product, were synthesized and profiled against livestock pathogens. Some analogues showed improved activity over thiolactomycin against Staphylococcus aureus and comparable activity against Pasteurella multocida. Several semisynthetically modified analogues of thiolactomycin showed no improvement in activity over thiolactomycin.

Cyclic homopentapeptides. 1. Analogs of tuberactinomycins and capreomycin with activity against vancomycin-resistant enterococci and Pasteurella

Abstract A 6a-(3′,4′-dichlorophenylamino) analog of viomycin was uncovered by a high-throughput screen against the animal health pathogen Pasteurella haemolytica, and has served as a novel lead structure for our infectious disease programs. We report herein the synthesis and activity of analogs of tuberactinomycins and capreomycin that are active against Pasteurella spp., methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci. This paper describes the synthesis and activity of some C-6a-substituted analogs of tuberactinomycins and capreomycin, which are active against Pasteurella spp., methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci.

Cyclic homopentapeptides 2. Synthetic modifications of viomycin

Abstract This paper describes synthetic modifications of the C-19 position of tuberactinomycin B (viomycin) and related analogs. The in vitro antibacterial activity of selected analogs against Pasteurella multocida, Escherichia coli and methicillin-resistant Staphylococcus aureus is also discussed. Although C-19 arylation and thiolation did not improve antibacterial activity, C-19 benzyl carbamates, benzyl- and phenyl ureas were found to be more potent than the parent antibiotic.

Synthesis and SAR of azalide 3,6-ketal aromatic derivatives as potent gram-positive and gram-negative antibacterial agents

3,6-Ketals of 15-membered azalide pseudoaglycones are a novel series of macrolide antibiotics. The aromatic derivatives of the azalide 3,6-ketals demonstrated potent antibacterial activities against both Gram-positive and Gram-negative bacteria.

Azalide 3,6-Ketals: antibacterial activity and structure–Activity relationships of aryl and hetero aryl substituted analogues

Aryl and hetero aryl substituted 3,6-ketals of 15-membered azalide analogues were synthesized and were found to have potent in vitro antibacterial activity against veterinary pathogens, including Staphylococcus aureus and Pasteurella multocida.