What is "sinapinic acid"

n. (context organic compound English) A phenolic carboxylic acid, ''3-(4-hydroxy-3,5-dimethoxyphenyl)prop-2-enoic acid''

Sinapinic acid, or sinapic acid (Sinapine - Origin: L. Sinapi, sinapis, mustard, Gr., cf. F. Sinapine.), is a small naturally occurring hydroxycinnamic acid. It is a member of the phenylpropanoid family. It is a commonly used matrix in MALDI mass spectrometry. It is a useful matrix for a wide variety of peptides and proteins. It serves well as a matrix for MALDI due to its ability to absorb laser radiation and to also donate protons (H) to the analyte of interest.

Sinapic acid can form dimers with itself (one structure) and ferulic acid (three different structures) in cereal cell walls and therefore may have a similar influence on cell-wall structure to that of the diferulic acids.

Sinapine is an alkaloidal amine found in black mustard seeds. It is considered a choline ester of sinapic acid.