R-C9H11N2O4S (Penicillin)
The Chemistry
A lot of how Penicillin works is more related to biology than chemistry, so here is a simple breakdown:
An essential component of bacterial cell walls is a complex molecule called peptidoglycan. Penicillin prevents bacteria from successfully producing it. Here's a flow chart I made.
The History
Alexander Fleming.
Penicillin, the first antibiotic, was discovered by Alexander Fleming in 1928. After being studied in the UK and US, doctors in military hospitals began to use it to treat soldiers in WWII. Check out the stats.
Death from disease or wounds
16.5 per 1,000 (WWI) -> 0.6 per 1000 (WWII)
Death rate for soldiers admitted to hospitals
8% (WWI) -> 4% (WWII)
Penicillin Units made by US companies per month
650 BILLION!
Despite the success of penicillin in World War II, it is in no way a panacea for all diseases. Since its development many common pathogens such as tuberculosis have developed resistance, and its complex protein nature can trigger allergic reactions in some people.