Penicillin
Penicillins (P, PCN or PEN) are a group of antibiotics originally obtained from "Penicillium" moulds, principally "P. chrysogenum" and "P. rubens". Most penicillins in clinical use are chemically synthesised from naturally-produced penicillins. A number of natural penicillins have been discovered, but only two purified compounds are in clinical use: penicillin G (intravenous use) and penicillin V (given by mouth). Penicillins were among the first medications to be effective against many bacterial infections caused by staphylococci and streptococci. They are members of the β-lactam antibiotics. They are still widely used today for different bacterial infections, though many types of bacteria have developed resistance following extensive use.
About 10% of people report that they are allergic to penicillin; however, up to 90% of this group may not actually be allergic. Serious allergies only occur in about 0.03%. Those who are allergic to penicillin are most often given cephalosporin C (another β-lactam antibiotic) because there is only 10% crossover in allergy between the penicillins and cephalosporins.
Penicillin was discovered in 1928 by Scottish scientist Alexander Fleming as a crude extract of "P. rubens". Fleming's student Cecil George Paine was the first to successfully use penicillin to treat eye infection (ophthalmia neonatorum) in 1930. The purified compound (penicillin F) was isolated in 1940 by a research team led by Howard Florey and Ernst Boris Chain at the University of Oxford. Fleming first used the purified penicillin to treat streptococcal meningitis in 1942. For the discovery, Fleming shared the 1945 Nobel Prize in Physiology or Medicine with Florey and Chain.

Several semisynthetic penicillins are effective against a broader spectrum of bacteria: these include the antistaphylococcal penicillins, aminopenicillins and the antipseudomonal penicillins.
Q12187
antibiotics
Concept
Q843136
Penicillium
Concept
Q159341
mould
Concept
Q137155
P. chrysogenum
Concept
Q60969184
P. rubens
Concept
Q258450
penicillin G
Concept
Q640448
intravenous use
Concept
Q422215
penicillin V
Concept
Q804517
bacterial infection
Concept
Q199695
staphylococci
Concept
Q190161
streptococci
Concept
Q306264
β-lactam antibiotics
Concept
Q10876
bacteria
Concept
Q63391344
resistance
UNK
Q42982
allergic
Concept
Q5063335
cephalosporin C
Concept
Q37064
Alexander Fleming
PER
Q363988
ophthalmia neonatorum
Concept
Q137106
Howard Florey
PER
Q58054
Ernst Boris Chain
PER
Q48143
meningitis
Concept
Q80061
Nobel Prize in Physiology or Medicine
EVE
Q4775309
antistaphylococcal penicillins
Concept
Q471724
aminopenicillin
Concept
Q5421801
antipseudomonal penicillins
Concept
Q12190
Penicillin
Concept
Q12190
Penicillin
Concept
Q12190
Penicillin
Concept
1928-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1928
DATE
1930-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1930
DATE
1940-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1940
DATE
1942-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1942
DATE
1945-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1945
DATE
+10^^http://www.w3.org/2001/XMLSchema#decimal
10
NUMBER
+90^^http://www.w3.org/2001/XMLSchema#decimal
90
NUMBER
+0.03^^http://www.w3.org/2001/XMLSchema#decimal
0.03
NUMBER
+10^^http://www.w3.org/2001/XMLSchema#decimal
10
NUMBER
subject has role
natural product of taxon
subclass of
discoverer or inventor