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A lactam is a cyclic amide, formally derived from an amino alkanoic acid through cyclization reactions. The term is a portmanteau of the words lactone + amide . Nomenclature
Lactones are usually named according to the precursor acid molecule (aceto = 2 carbon atoms, propio = 3, butyro = 4, valero = 5, capro = 6, etc.), with a -lactone suffix and a Greek letter prefix that specifies the number of carbon atoms in the heterocycle — that is, the distance between the relevant -OH and the -COOH groups along said backbone.
β-Lactam antibiotics are indicated for the prevention and treatment of bacterial infections caused by susceptible organisms. At first, β-lactam antibiotics were mainly active only against gram-positive bacteria, yet the recent development of broad-spectrum β-lactam antibiotics active against various gram-negative organisms has increased their usefulness.
Lactam is a blend of lactone (from the Latin lactis, milk, since lactic acid was isolated from soured milk) and amide. The suffix -ase , indicating an enzyme, is derived from diastase (from the Greek diastasis , "separation"), the first enzyme discovered in 1833 by Payen and Persoz.
A lactam is a cyclic amide, and beta-lactams are named so because the nitrogen atom is attached to the β-carbon atom relative to the carbonyl. The simplest β-lactam possible is 2-azetidinone. β-lactams are significant structural units of medicines as manifested in many β-lactam antibiotics. [2]
The β-lactam core structures. (A) A penam.(B) A carbapenam.(C) An oxapenam.(D) A penem.(E) A carbapenem.(F) A monobactam.(G) A cephem.(H) A carbacephem.(I) An oxacephem. This is a list of common β-lactam antibiotics—both administered drugs and those not in clinical use—organized by structural class.
Caprolactone is treated with ammonia at elevated temperatures to give the lactam: (CH 2) 5 CO 2 + NH 3 → (CH 2) 5 C(O)NH + H 2 O. Carbonylation of caprolactone gives, after hydrolysis, pimelic acid. The lactone ring is easily opened with nucleophiles including alcohols and water to give polylactones and eventually the 6-hydroxyadipic acid.
Glucono-δ-lactone (GDL), also known as gluconolactone, is an organic compound with the formula (HOCH) 3 (HOCH 2 CH)CO 2. A colorless solid, it is an oxidized derivative of glucose . It is typically produced by the aerobic oxidation of glucose in the presence of the enzyme glucose oxidase .