| 摘要 |
<p>Penicillanic acid 1,1-dioxides(I; R6 = H, ester group) were prepd. by oxidation of compd.(II; R1 = H, ester group, penicillin carboxylic protecting group), (III) or (IV). Thus, Na penicillanate was oxidized by KMnO4 in HOAc to give 78% compd. (I). The esters were obtained either by esterifying I (R = H) or by oxidizing the penicillanic acid esters. Compd. (I) potentiate the bactericidal activity of penicillins and cephalosporins. Thus, Staphylococcus aureus strains for which both ampicillin and I have min. inhibitory concns. of 200μg/ml are inhivited by a mixt. of 1.56μg/ml ampicillin with 3.12μg/ml I(R = H).</p> |
