Salicylic acid is found in varying degrees in a wide range of plants including potatoes, tobacco, unripe fruits (including blackberries and blueberries, cantaloupe, kiwi, green pepper, tomato and olives), mushrooms, and, of course, willow.

A phenolic compound, together with cytokinins, auxins, gibberellins, ethylene and abscisic acid, salicylic acid plays a role in plant growth and development, photosynthesis and nitrogen metabolism, albeit these processes are not well-understood.

The compound also helps plants deal with environmental stresses such as extreme or sudden cold, drought, salinity, poor diet, heat and even heavy metals. This is done, at least in part, by the salicylic acid inducing different gene expressions within the plant; for example, in times of high temperatures, salicylic acid in some plants will induce gene expressions necessary to encode chaperone, a heat shock protein.

Salicylic acid is also key to some plants’ resistance to pathogens. When attacked by a microbe, the salicylic acid levels in these plants’ infected areas increase and help mediate the accumulation of pathogenesis related proteins that help the plant fight the invader.

Effective therapy for people as well as plants, humans have harvested salicylic acid from willow bark since ancient times, when the Babylonians, Chinese and Assyrians all used it for medicinal purposes. In fact, the “father of medicine,” Hippocrates (460-375 BC), even prescribed it for pain and to relieve fever.

Salicylic acid was first isolated by Edward Stone in 1763. Nearly one-hundred years later, Charles Frederic Gerhardt was the first to turn it into aspirin, aka acetylsalicylic acid, when he mixed sodium salicylate (a salt of salicylic acid) and acetyl chloride.

Bayer chemists produced their own synthesized version of it in 1897. Designed to be less upsetting to the stomach than salicylic acid, it was derived from Spiraea a ulmaria and called salicin. This designer acetylsalicylic acid was named Aspirin by Bayer after the plant’s name, as well as spirsäure, and old German word for salicylic aspirin.

If you liked this article, you might also enjoy our new popular podcast, The BrainFood Show (iTunes, Spotify, Google Play Music, Feed), as well as:

• The Pharmaceutical Company Bayer Coined the Name “Heroin” and Marketed the Drug as a Non-Addictive Cough Medicine
• Does Alcohol Really Prevent Hypothermia?
• Do Fish Really Like Eating Earthworms?
• Is Aloe Vera Really Good For Your Skin?
• What Causes Headaches?

Bonus Facts

• Around the same time Bayer was developing Aspirin, they also were working on Heroin. The originally trademarked name of Heroin is thought to derive the German word “heroisch” (heroic), due to the way the workers who tested Heroin on themselves reported that it made them feel.  Bayer ultimately lost the trademark for Heroin in a few key markets at the same time they were forced to give up their trademark on Aspirin, thanks to WWI.  During WWI, Bayer’s assets, including their trademark rights, in the U.S. and the Triple Entente allies (UK, France, and Russia) were confiscated and it became common to simply refer to all brands of the drug as “Aspirin” in those countries, among others.  Finally, after the signing of the Treaty of Versailles, Bayer officially lost their trademarks on Heroin and Aspirin in the U.S., France, Russia, and the UK.
• Interestingly, one of the common early uses of Heroin was as a “non-addictive” medicine to help treat people who were addicted to morphine, even though Heroin ultimately proved to be more addictive.  Funny enough, when morphine was first isolated from opium in 1805, one of its early uses was as a “non-addictive” drug to treat people who were addicted to opium.
• When aspirin was first recommended to Heinrich Dreser for Bayer to move forward with, he rejected it, stating “The product has no value”.  Today, over 40 billion tablets of aspirin are consumed annually.  Once Heroin’s star began to fall as people began to realize how addictive it was, he revisited his decision on Aspirin, which quickly became Bayer’s best selling product.
• After Heinrich Dreser left Bayer, he once again is thought to have picked Heroin over Aspirin, this time to his doom when he eventually died of a stroke. It is rumored that in his waning years, he began taking heroin daily, rather than aspirin, to treat his health problems.   What is ironical about this, of course, is that a daily dose of aspirin may have prevented his stroke.
• Bayer was started by Friedrich Bayer and Johann Friedrich Weskott in 1863 as a chemical company making various paints, rather than pharmaceuticals.  Another major company today that started out making dyes and now is famous for making something completely different is Crayola.  Read more about this here: Where the Words Crayola and Crayon Come From
• Bayer had their legacy significantly tarnished during WWII when they became part of the Farben German chemical company conglomerate that is known to have used slave labor during WWII, including managing slave labor camps.  Further, Farben was the group that manufactured Zyklon B.  Why is this important?  Because Zyklon B was the cyanide based pesticide used in the Nazi gas chambers.  Bayer was forced to separate from Farben after WWII.
• One of Bayer’s executive officers during WWII, Fritz ter Meer, who was the chairman of Bayer’s supervisory board, was tried and convicted during the Nuremberg War Crimes Tribunal and sentenced to seven years in prison. He reportedly was involved in various experiments done at Auschwitz on human subjects.  Specifically, the charges he was convicted of were: “guilty of count two, plunder and spoliation, and count three, slavery and mass murder.”
• A sudden spike in death rates among young people in October 1918 was preceded by a recommendation to take a large amount of aspirin: “1 gm. (15 grains) every three hours . . . until symptomatic relief is secured.” Salicylate accumulates in the body, with toxic results that include vomiting, hyperventilation and pulmonary edema. In the 1918 pandemic, many deaths occurred early in the infection, and a great number of these were from “wet” or hemorrhagic lungs. During an autopsy on one of the victims, the examiner noted that the amount of lung that was “pneumonic” seemed to be too small to account for the death, although the lungs, which appeared as if they had been drowned, were filled with a “thin, watery, bloody liquid.” About 50% of these early deaths suffered from cerebral edema as well. Since pulmonary and cerebral edema are often found today in the autopsies of people who die from aspirin toxicity, some researchers have theorized that many of the deaths from the 1918 influenza outbreak were from over-prescribing aspirin.