120 years ago today, Dr. Felix Hoffmann, a young chemist working at Bayer, reported having synthesized what was about to become the world’s most popular painkiller: aspirin, or acetylsalicylic acid.

The anti-inflammatory properties of salicylic acid were well known at the time and it had been long used to treat rheumatic patients. The taste, however, was horrible and it irritated the stomach.

Encouraged by his father, who suffered terrible nausea from the salicylic acid, Felix managed to produce a stable and tolerable compound. “Due to its physical properties such as an acid taste without any corrosive effect,” Hoffman wrote in his report, “acetylsalicylic acid differs advantageously from salicylic acid and is being examined for its usefulness with just that in mind.”

Willow leaves and salicin

But, way before there was any salicylic acid, acetylated or not, there were willow leaves and barks. In 400 B.C, Hippocrates advised people to chew willow bark as a remedy for fever and to relieve the pain in childbirth. Even before that, the ancient Sumerians and Egyptians used the extract of willow leaves for joint pain.

The 18th and 19th century brought a deeper understanding of how the willow leaves work to alleviate the pain and swollenness. In 1793, the Reverend Edward Stone carried one of the first clinical trials, using willow bark powder in patients with malaria. Later, Johann Buchne and Henri Leroux purified willow bark to obtain salicin, a yellow, needle-like crystal. But it was the Italian Raffaele Piria who discovered and described, in 1838, the chemical structure of salicin (a glycoside). He then split the salicin molecule into salicylic acid, thus turning the yellow crystals into colorless ones. By 1859, industries started to make salicylic acid at a large scale, widening its use as a medicine.

Bayer’s patent

The newly synthesized acetylsalicylic acid was easily absorbed by the body and, therefore, did not provoke discomfort. Once it had been ingested, it returned to the salicylic form, thus maintaining the anti-inflammatory properties. Thousands of rheumatic patients, including Felix’s father, rejoiced. On March 6th, 1899, Bayer filed the patent and trademarked the acetylsalicylic acid with the brand name “Aspirin.” During the World War I, the company lost the patent and Aspirin became a generic drug.

This is how the story was told for a long time. And for a long time, a man’s name, whose role was central to the development of Aspirin, remained obscured.

In 1895, Arthur Eichengrun, the German Jew head of the Bayer’s chemical department, asked Hoffmann to work on an alternative to the salicylic acid. Other groups had already produced salicylic derivatives, which remained unnoticed for a long time. Hoffmann developed his work having these derivatives as a basis, under Eichengrun’s close supervision and guidance.

Eichengrun presented the newly synthesized molecule to Bayer’s board members. Heinrich Dreser, head of the experimental pharmacology, exerted his right of veto; “the product had no value” and could even be harmful to the heart. But Eichengrun was convinced of the drug’s potential and secretly sent samples to his physician friends. Then, he reached out to the responsible for Bayer research, Carl Duisberg. When Hoffmann wrote his report on the 10th of August, the acetylsalicylic acid was already being tested in humans.

Duiberg asked Dreser to test and give credibility to the product. At this point, everyone who tried aspirin was marveled by the lack of side effects and its rapid action. Dreser was the one who wrote the first article about Aspirin. And, because he had royalties on every new drug he introduced, he was also the one who got rich with it. Eichengrun and Hoffmann received nothing.

The struggle of a Jew scientist

In 1934, Bayer credited the discovery of Aspirin to Hoffmann, and there was not even a mention to Eichengrun. By that time, Eichengrun had left Bayer and set his company. But, however successful his business was, he was still a Jew living in an anti-Semitic country. He had no rights to exert civil services or have an independent position in his profession. Thus, he had no credit for his scientific achievements.

When the War was over, Eichengrun wrote a paper where he claims his importance in the discovery of the acetylsalicylic acid. “In 1941,” he recalled “there stood in […] the German Museum in Munich a showcase filled with white crystals, with the inscription, ‘Aspirin: inventors Dreser and Hoffmann.’ Dreser had nothing whatsoever to do with the discovery, and Hoffmann carried out my chemical instructions in the first place without knowing the aim of the work. […]. But, at the main entrance to the museum there hung a large sign which forbade non-Aryans from entering this institute! Those who understand will read between the lines.”

References:

Jack, David B. “One hundred years of aspirin.” The Lancet 350.9075 (1997): 437.

Sneader, Walter. “The discovery of aspirin: a reappraisal.” Bmj 321.7276 (2000): 1591-1594.

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