6-Aminopenicillin derivatives

Aminopenicillin derivatives became recently available by direct substitution of penicillates with N-chloro-N-sodio-carbamates 70—72). 

Chemical Class Penicillin derivative, aminopenicillin Clinical Pharmacology ... 

Fluorometric detection has been mainly employed for the determination of aminopenicillins such as amoxicillin and ampicillin in edible animal products because it confers the advantages of selectivity and sensitivity. Fluorometric detection of penicillins, however, necessitates their precolumn derivatization to produce the corresponding fluorescent derivatives. The most commonly used derivatizing reagents are formaldehyde (100, 117, 118), salicylaldehyde (83), and mercury dichloride (91). 4-Bromomethyl-7-methoxycoumarin has also been employed as a fluorescence label for the selective and sensitive detection of seven penicillins in milk (96). 

On activation of Dane s salt by an acyl halide to give a mixed anhydride, N-acylation is prevented by the enaminone moiety. The product of cyclocondensation can be hydrolysed, losing the enaminone group to yield a free aminoazetinone. Such /Mactam derivatives are of great interest due to the structural analogy to aminopenicillins and cephalosporins. 

The use of azido acids for the introduction of aminoacyl groups eliminates the need of protecting the amino group during the acylation. The azidoacyl derivatives obtained are reduced directly to the aminoacyl ones. This method was used in the preparation of aminopenicillins (19) from azidoacyl chlorides and 6-aminopenicillanic acid, Azido-... 

For cephalosporins containing an amino group in the C7 side chain such as cephalexin, cephaloglycin, and cephradine, a polymerization can be imagined to occur by intermolecular aminolysis in the same way as the polymerization of am-picillin and other aminopenicillins. Such as reaction can, however, be expected to be much less effective for the cephalosporins since an autocatalyzed intramolecular aminolysis with the formation of piperazine-2,5-dione derivatives may occur to a much larger extent than an intermolecular aminolysis (Bundgaard 1976 c, d). 

Other aminopenicillins and derivatives of ampicillin that have been introduced in recent years, especially hetacillin, metampicil-lin, epicillin and cyclacillin, offer no advantages over ampicillin. Information on the side effects of these variants is scarce. 

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