Cephaloridine

Antibiotics. Cephaloridine and Cephalothin (Glaxo) were early thiophene-containing, cephalosporin antibiotics. They have largely been replaced by later products, of which Cefoxitin [35607-66-0] (Merck) (51) is the principal thiophene-containing example (see Antibiotics). 

Cephalosporins first entered the marketplace in 1964, when cephalothin (27) and cephaloridine (51), which are both injectable, were launched. By the late 1970s, the injectable cephalosporins had become important therapeutic agents in the hospitals. Also in 1964 the first oral cephalosporin, cephaloglycin [3577-01 -3] C gH N OgS, was launched only to be displaced by the end of the year by cephalexin (12). For years cephalexin was the leading oral cephalosporin on the market. It has since been displaced by cefaclor (13). With the advent of the more -lactamase stable cephalosporins such as cefoxitin (23) and cefuroxime (35), and the more potent agents such as cefotaxime (36) and other third-generation compounds, cephalosporins now dominate the antibiotic market worldwide. 

Although most /3- lactam antibiotics bind covalently to some or all of the same six proteins, there are decided differences among them in terms of their relative affinities. For example, cefoxitin (see Table 1 for structures) fails to bind to protein 2 while cephacetrile binds very slowly to proteins 5 and 6. Cephaloridine binds most avidly to protein 1, the transpeptidase, and inhibits cell elongation and causes lysis at its minimum inhibitory concentration. On the other hand, cephalexin binds preferentially to protein 3 and causes inhibition of cell division and filament formation (75PNA2999, 77MI51002). 

Thienylacetarnidocephalosporanic acid (7.0 g) was suspended in water (60 ml) and stirred with pyridine (7 ml) until the acid dissolved. The resulting solution (pH 5.9) was kept at 35°C for 3 days, then filtered and extracted with methylene chloride (4 x 60 ml). The methylene chloride extract was back-axtracted with a little water and the total aqueous solutions were then percolated through a column of Dowex 1x8 resin, (100 to 200 mesh, 150 g) in the acetate form at pH 4.3. The column was washed with water until the optical rotation of the eluate fell to zero and the eluate (500 ml) was freeze-dried. The residual white solid was dissolved in the minimum volume of methanol and after a few minutes the pyridine derivative crystallized this is the cephaloridine product. 

Aminocephalosporanic acid Cefazolin sodium Ceftizoxime Cephacetriie sodium Cephalogiycin Cephaloridine Cephalothin sodium Cephapirin sodium 2-Amino-5-chlorobenzonitrile Ciorazepate dipotassium 2-Amino-5-chlorobenzophenone Chlordiazepoxide HCi Pinazepam Prazepam... 

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