Chemical modification of tylosin: synthesis of amino derivatives at C-20 position of tylosin and demycarosyltylosin.

Chemical modification of tylosin. Thioether derivatives of tylosin and demycarosyltylosin.

Thioether derivatives of tylosin and demycarosyltylosin were synthesized by Michael-type addition of thiol to C-11 of the enone moiety on the aglycone. Some of tylosin derivatives were effective to macrolide resistant Staphylococcus aureus, and their in vivo activities were same or superior than that of tylosin.

Syntheses and antimicrobial activities of 9-O-acyl derivatives of tylosin and demycarosyltylosin.

Chemical modification of tylosin.

20-Homo tylosin, 20-nor tylosin, 20-deoxy-19,20-didehydro tylosin (6-vinyl tylosin) and 2",3"-didehydro-3"-deoxy tylosin were prepared by multi-step procedures. 20-Homo tylosin was about twice less active than tylosin while the other compounds exhibited very weak antibacterial activity.

A high prevalence of tylosin resistance among Staphylococcus aureus strains isolated from bovine mastitis

The macrolides appear to have considerable effects for treatment of bovine mastitis because of excellent diffusion into the mammary gland, long half-life, low protein binding, high intracellular concentration and lipid solubility. Acquired resistance to macrolides in Staphylococcus aureus is primarily related to target-site modification through acquisition of an erm gene. In t...

Synthesis and antimicrobial evaluation of 20-deoxo-20-(3,5-dimethylpiperidin-1-yl)desmycosin (tilmicosin, EL-870) and related cyclic amino derivatives.

A series of 20-deoxo-20-cyclic (alkylamino) derivatives of tylosin, desmycosin, macrocin and lactenocin was prepared by reductive amination of the C-20 aldehyde group. The majority of the compounds were prepared using metal hydrides (sodium cyanoborohydride or sodium borohydride) as the reducing agents and a suitable cyclic alkylamine. Subsequently, a more convenient procedure was developed usi...