salicin
noun
sal·i·cin ˈsa-lə-sən 
: a bitter white crystalline glucoside C13H18O7 found in the bark and leaves of several willows and poplars and used in medicine like salicylic acid
Example Sentences
Recent Examples on the Web Compared to salicylic acid, which is created using a chemical process, salicin is naturally found in willow bark and has antioxidative, antimicrobial, and soothing properties. 
Beth Janes, Good Housekeeping, 7 Feb. 2020
Beth Janes, Good Housekeeping, 7 Feb. 2020 Word History
Etymology
French salicine, from Latin salic-, salix willow — more at sallow
First Known Use
1830, in the meaning defined above
Medical Definition
salicin
noun
sal·i·cin ˈsal-i-sin
: a bitter white crystalline glucoside C13H18O7 found in the bark and leaves of several willows and poplars, yielding saligenin and glucose on hydrolysis, and formerly used in medicine as an antipyretic, antirheumatic, and tonic