Cephalosporins semisynthetic compounds, product

Fermentation has produced natural products such as antibiotics and the cholesterollowering agents pravastatin and lovastatin. Modification of fermentation products has led to semisynthetic compounds such as simvastatin (see Figure 1.2), penicillins, and cephalosporins. With increased capability in genetic engineering,... 

Although investigations to determine the structures and establish the beneficial properties of semisynthetic penicillins were aimed first and foremost at the production of more and more of such compounds, a number of examples can be found in the literature concerning their functional modifications (term suggested by Heusler) and nuclear analogues . Work on these unusual /3-lactam structures has been on the increase since the middle of the sixties, and the search for new cephalosporin syntheses has produced a vast number of compounds. 

During recent years, the cephalosporins [461, e.g., X = CO(CH2)3CH-(NH2)COOH, for cephalosporin C] have commanded a great deal of attention because of their outstanding antibiotic properties the first realization of this activity, and of the close structural relation of the penicillins (460) and cephalosporins (461), led to the production and biological screening of large numbers of compounds of this basic pattern. A determined effort to find examples of therapeutic value has met with success several of the semisynthetic derivatives are now in regular clinical use.363... 

In the 1970s and the 1980s, the pathways to the penicillins and the cephalosporins including cephamycin C were worked out especially after cell-free systems became available [59]. Late in the 1970s came reports on the production of P-lactam antibiotics which were neither penicillins nor cephalosporins. The most important was clavulanic acid from streptomycetes, which possessed only weak antibiotic activity but was an excellent inhibitor of P-lactamase [60]. It became a blockbuster compound by being coformulated with broad-spectrum semisynthetic penicillins which are susceptible to P-lactamase, for example, with amoxycillin, the combination is known as Augmentin. 

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