Sarmentosin is a glycoside and that is found in several plant species, notably Ribes nigrum (blackcurrants) and Sedum sarmentosum.
Sarmentosin has a molecular formula of C<sub>11</sub>H<sub>17</sub>NO<sub>7</sub> and a molecular weight of 275.25 g/mol. Its IUPAC name is (E)-2-(hydroxymethyl)-4-[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxybut-2-enenitrile.
Sarmentosin can be extracted from plants in the Rhodiola genus and blackcurrants. Recent studies have specifically identified sarmentosin as a key bioactive compound in blackcurrants that contributes to its monoamine oxidase inhibitory effects.
At least two Parnassius butterflies, Parnassius apollo and Parnassius smintheus, sequester sarmentosin and other hydroxynitrile glucosides in their bodies from the Sedum plants they eat.