6-Aminopenicillanic Acid (syn: (+)-6-Aminopenicillanic Acid; 6-APA) is an organic dipeptide and the chemical core or "nucleus" of penicillin antibiotics. It was discovered in 1958 (Beecham Group, UK). It is produced from Penicillin by Penicillin amidase. 6-Aminopenicillanic Acid, a β-lactam, is used as a starting compound for synthesis of semisynthetic Penicillins and may be substituted at the 6-amino position, resulting in a variety of antibacterial properties. It is a precursor to Ampicillin and Amoxicillin.
