6-APA ((+)-6-aminopenicillanic acid) is a chemical compound used as an intermediate in the synthesis of
β-lactam antibiotic
β-lactam antibiotics (beta-lactam antibiotics) are antibiotics that contain a beta-lactam ring in their chemical
structure. This includes penicillin derivatives (penams), cephalosporins and cephamycins (cephems), monobactams, carbapenems and ...
s. The major commercial source of 6-APA is still natural
penicillin G
Benzylpenicillin, also known as penicillin G (PenG) or BENPEN, and in military slang "Peanut Butter Shot" is an antibiotic used to treat a number of bacterial infections. This includes pneumonia, strep throat, syphilis, necrotizing enteroco ...
: the
semi-synthetic penicillins derived from 6-APA are also referred to as penicillins and are considered part of the penicillin family of antibiotics.
In 1958,
Beecham scientists from
Brockham
Brockham is a village and civil parish in the Mole Valley district of Surrey, England. It is approximately east of Dorking and west of Reigate. The village lies south of Box Hill, with the River Mole flowing west through the village. At t ...
Park,
Surrey, found a way to obtain 6-APA from
penicillin. Other β-lactam antibiotics could then be synthesized by attaching various side-chains to the nucleus.
[F.P. Doyle, J.H.C. Nayler, G.N. Rolinson ''US Patent 2,941,995'', filed July 22, 1958, granted June 21, 1960. Recovery of solid 6-aminopenicillanic acid.] The reason why this was achieved so many years after the commercial development of penicillin by
Howard Florey and
Ernst Chain lies in the fact that penicillin itself is very susceptible to
hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile.
Biological hydrolys ...
, so direct replacement of the side-chain was not a practical route to other β-lactam antibiotics.
References
Beta-lactam antibiotics
Sulfur heterocycles
Amines