Willow bark of the willow tree have been mentioned in ancient texts from Assyria, Sumer and Egypt as a remedy for aches and fever, and in Ancient Greece the physician Hippocrates wrote about its medicinal properties in the fifth century BC. Native Americans across the Americas relied on it as a staple of their medical treatments. It provides temporary pain relief. Salicin is metabolized into salicylic acid in the human body, and is a precursor of aspirin. In 1763, its medicinal properties were observed by the Reverend Edward Stone in England. He notified the Royal Society, which published his findings. The
Tetrolic acid (water, ethanol) and may be recrystallized from non polar solvents (such as heptane, toluene). The compound is a white crystalline solid which can exist in two polymorphous crystalline forms. The proton nuclear magnetic resonance (H-NMR) spectrum in deuterated dimethyl sulfoxide shows a characteristic singlet peak at 1.99 ppm corresponding to the -CH protons. Tetrolic acid Tetrolic acid (2-butynoic acid) is a short-chain unsaturated carboxylic acid, described by the formula CH-C≡C-COH. Salts and esters of tetrolic acid are known as tetrolates. The first reported synthesis of tetrolic acid is believed to be by German chemist Johann Georg Anton Geuther in 1871