Willow active extract of the bark, called salicin, was isolated to its crystalline form in 1828 by Henri Leroux, a French pharmacist, and Raffaele Piria, an Italian chemist, who then succeeded in separating out the compound in its pure state. In 1897, Felix Hoffmann created a synthetically altered version of salicin (in his case derived from the "Spiraea" plant), which caused less digestive upset than pure salicylic acid. The new drug, formally acetylsalicylic acid, was named Aspirin by Hoffmann's employer Bayer AG. This gave rise to the hugely important class of drugs known as nonsteroidal anti-inflammatory drugs (NSAIDs). Some of humans'
Clavulanic acid Clavulanic acid Clavulanic acid is a β-lactam drug that functions as a mechanism-based β-lactamase inhibitor. While not effective by itself as an antibiotic, when combined with penicillin-group antibiotics, it can overcome antibiotic resistance in bacteria that secrete β-lactamase, which otherwise inactivates most penicillins. In its most common form, the potassium salt potassium clavulanate is combined with: Clavulanic acid was patented in 1974. For the treatment of pyelonephritis during pregnancy, and for the treatment of pyelonephritis caused by gram-positive organisms, amoxicillin or amoxicillin-clavulanate potassium is preferred. The name is derived from strains of "Streptomyces clavuligerus", which produces clavulanic acid. Clavulanic acid