Source:http://linkedlifedata.com/resource/umls/id/C1154686
GO: The chemical reactions and pathways involving any antibiotic that contains the condensed beta-lactamthiazolidine ring system. Penicillins are produced naturally during the growth of various microfungi of the genera Penicillium and Aspergillus. [GOC:jl, ISBN:0198506732]