RESUMO
Chemical and electrochemical oxidation of dienonic moiety of desmycosin were carried out. Successive chemical oxidation of desmycosin with m-chloroperbenzoic acid afforded a family of 12,13-dihydro-12,13-dihydroxy derivatives. Indirect electrochemical oxidation via hypobromite as an intermediate gave rise to the new bicyclo derivative of desmycosin, 13-hydroxy-3-dehydroxy-3,12-oxa-desmycosin.
Assuntos
Antibacterianos/química , Tilosina/análogos & derivados , Tilosina/química , Bactérias/efeitos dos fármacos , Eletroquímica , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Oxirredução , Tilosina/farmacologiaRESUMO
PROBLEM: The role of antibodies against fetal or maternal antigens in maintaining or losing pregnancy is not clear. METHOD OF STUDY: Term-pregnant mice were injected with monoclonal antibodies against only fetal or fetal and maternal major histocompatibility complex class I molecules. The development of pregnancy was then followed. RESULTS: Antibodies against maternal, but not fetal, major histocompatibility complex class I molecules induced abortion in mice. The abortion occurred 6-8 hr after the administration of autoreactive antibodies. The abortion could only be induced after the formation of placenta. Antibodies against tumor necrosis factor-alpha could not prevent or postpone the abortion. Extensive bleeding has been detected in the placenta of aborting mice 3 hr after the administration of the antibodies. CONCLUSIONS: This study indicates that autoreactive antibodies present risk for pregnancy and that the damage leading to abortion induced by such antibodies most likely occurs at the maternal side of placenta.
