| 摘要 |
<p>Cephalosporin derivs. and salts of formula (I) are prepared. In (I), R1 is ester-bonded-alpha-beta- or gamma-amino acid with NH2 opt. substd. 1 or 2 C1-4 alkyl; R2 is 1-alkanoyloxyalkyl, 1alkoxycarbonyloxyalkyl, phthalidyl, or 5-methyl-1,3-dioxolin-2-on4- methyl; R3 is carbamoyloxymethyl, opt. substd.; R4 is H or OH; pref. D-configuration. (I) are stable sol., readily absorbable cephalosporins for P.O. admin. readily enzymically hydrolyzed in vivo to unesterified deriv. (II), maintained for long periods at high blood conc. and with high antibacterial activity.</p> |
