Antimicrobial moieties

The monobactams have a single beta-lactam ring structure. The only clinically used monobactam is aztreonam. Replacement of the 1-sulfonic acids residue in monobactam with an Af-sulphonylated carbonyl amino moiety yields monocarbams [71, 72 ]. So far, however, no monocarbam derivative is on the market, probably because their antimicrobial moiety is not optimal. Since micro-organisms need iron for growth, some siderophore-conjugated monocarbams are now under evaluation [73 ]. It is reasonable to assume that it will take some time until they are marketed. One of the many problems not yet solved is the in vivo fate of the siderophore itself, since it may create some new adverse effects of its own. 

Researchers discovered that antimicrobial organofunctional silanes could be chemically bound to receptive substrates by what were believed to be Si-0 linkages. The method was described as orienting the organofunctional silane in such a way that hydrolyzable groups on the silicon atom were hydrolyzed to the silanols and formed chemical bonds with each other and to the substrate. The resultant surface modification, when an antimicrobial moiety such as a quaternary nitrogen was included, provided for the antimicrobial group to be oriented away from the surface. ... 

Mocimycin has been chemically converted to aurodox by protection of the 4-hydroxy group at the pyridone moiety as the benzoylformate, followed by /V-methylation and hydrolytic removal of the protective group (1,55). Whereas aurodox esters are active growth promotors in animals, goldinamines that are A/-acylated by acids other than goldinonic acid, such as acetic, benzoic, or arylsulfonic acids, lack useful antimicrobial or growth-promoting activity (1). 

Thiostrepton family members are biosynthesized by extensive modification of simple peptides. Thus, from amino acid iacorporation studies, the somewhat smaller (mol wt 1200) nosiheptide, which contains five thiazole rings, a trisubstituted iadole, and a trisubstituted pyridine, is speculated to arise from a simple dodecapeptide. This work shows that the thiazole moieties arise from the condensation of serine with cysteiae (159,160). Only a few reports on the biosynthesis of the thiostrepton family are available (159,160). Thiostrepton is presently used ia the United States only as a poly antimicrobial vetetinary ointment (Panalog, Squibb), but thiazole antibiotics have, ia the past, been used as feed additives ia various parts of the world. General (158) and mechanism of action (152) reviews on thiostrepton are available. 

Cefmenoxime (61) is a third generation parenteral cephalosporin whose in vitro antimicrobial spectrum approximates that of cefotaxime. Its side chains consist of the common methyltetrazo lylthio group at C-3 and the familiar oximinoether aminothiazole moiety at C-7. It is synthesized... 

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