Abstract: A compound having the formula ##STR1## wherein Y represents a 2-carboxyethylthio group or a trifluoromethylthio group and a nontoxic pharmaceutically acceptable salt thereof are useful as antibacterial agents. They may be prepared by (a) reacting a compound having the formula ##STR2## wherein X.sub.1 represents a halogen atom with a compound having the formulaY -- Hwherein Y has the same meaning as defined above, or (b) reacting a compound having the formula ##STR3## wherein R represents a protective group for the carboxyl group with a compound having the formulaY -- CH.sub.2 COX.sub.2wherein X.sub.2 represents a halogen atom and Y has the same meaning as defined above and removing the protective group for the carboxyl group from the resulting product, or (c) reacting a compound having the formula ##STR4## wherein A represents an acetoxy group or a carbamoyloxy group and Y has the same meaning as defined above with 5-mercapto-1-methyl-1H-tetrazole or its alkali metal salt.

Abstract: A compound of the formula ##STR1## wherein A represents acetoxy group, carbamoyloxy group or (1-metyl-1H-tetrazol-5-yl)thio group and Y represents propargylthio group, azidomethylthio group, 2-hydroxyethylthio group, 3-isoxazolyloxy group, 3-isoxazolylthio group, methylsulfonyl group, ethylsulfonyl group, 2-cyanoethyl-sulfonyl group or sydnon-3-yl group and nontoxic pharmaceutically acceptable salts thereof are prepared by a process which comprises reacting a compound of the formula ##STR2## wherein R represents a protective group for a carboxyl group and A has the same meaning as defined above with a carboxylic acid of the formulaY - CH.sub.2 COOHwherein Y has the same meaning as defined above or a reactive derivative thereof to give a compound having the formula ##STR3## wherein A, R and Y have the same meanings as defined above and removing the protective group for the carboxyl group from said compound.The compounds are antibacterial agents.

Abstract: New derivatives of the antibiotic butirosin A having the formula: ##STR1## in which R is a radical of formula (II): ##STR2## and pharmaceutically acceptable acid addition salts thereof. The butirosin A derivatives of formula (I) can be prepared by reduction of a 5"-azido compound having the formula (III): ##STR3## in which R' is the same groups R or a group which, on reduction, gives a group of formula (II).The butirosin A derivatives of general formula (I) and pharmaceutically acceptable acid addition salts thereof are active against a broad spectrum of Gram-positive and Gram-negative bacteria, including some butirosin-resistant strains.

Abstract: New derivative of butirosin A, 3', 4'-dideoxybutirosin A having not only broad antibacterial activities against gram-positive and -negative bacteria but also an activity against butirosin-resistant bacteria with a low toxicity. It is prepared from the corresponding 3', 4'-dideoxy-3'-eno derivative derived from butirosin A or a mixture of butirosins A and B by catalytic reduction.