penicillin


pen·i·cil·lin

noun \ˌpe-nə-ˈsi-lən\

: a medicine that is used to kill harmful bacteria

Full Definition of PENICILLIN

1
:  any of several relatively nontoxic antibiotic acids of the general formula C9H11N2O4SR that are produced by molds (genus Penicillium and especially P. notatum or P. chrysogenum) or synthetically and are used especially against gram-positive cocci; also :  a mixture of such acids
2
:  a salt or ester of a penicillin or a mixture of such salts or esters

Origin of PENICILLIN

New Latin Penicillium
First Known Use: 1929

Other Biochemistry Terms

bile, biodegradable, capsaicin, keratin, metabolism

pen·i·cil·lin

noun \ˌpen-ə-ˈsil-ən\   (Medical Dictionary)

Medical Definition of PENICILLIN

1
: a mixture of relatively nontoxic antibiotic acids produced especially by molds of the genus Penicillium (as P. notatum or P. chrysogenum) and having a powerful bacteriostatic effect against various chiefly gram-positive bacteria (as staphylococci, gonococci, pneumococci, hemolytic streptococci, or some meningococci)
2
: any of numerous often hygroscopic and unstable amido acids (as penicillin G, penicillin O, and penicillin V) that have a structure in which a four-membered lactam ring shares a nitrogen and a carbon atom with a thiazolidine ring to which it is fused and that are components of the penicillin mixture or are produced biosynthetically by the use of different strains of molds or different media or are synthesized chemically
3
: a salt or ester of a penicillin acid or a mixture of such salts or esters

penicillin

noun    (Concise Encyclopedia)

Antibiotic derived from the Penicillium mold. It was discovered in 1928 by Alexander Fleming; by 1940, Howard Walter Florey, Ernst Boris Chain, and others had produced commercial quantities that proved vital to the treatment of war casualties, making penicillin the first successful antibiotic for human bacterial infections. Many natural and semisynthetic (ampicillin, amoxicillin) variants have since been produced. All work by inhibiting the enzymes responsible for bacterial cell wall synthesis (and therefore do not work against microorganisms without cell walls or with certain variant cell walls; e.g., the tuberculosis bacillus). Among the bacteria susceptible to penicillin are those causing strep throat, spinal meningitis, gas gangrene, and syphilis. Overuse has led to drug resistance in some strains. Penicillin's chief side effect is allergy, which can be life-threatening.

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