Mi. Rubino et al., CONVERSION OF PHENOLICS TO LIGNANS - SINAPIC ACID TO THOMASIDIOIC ACID, Journal of the American Oil Chemists' Society, 72(12), 1995, pp. 1465-1470
Changes in sinapic acid when exposed to aqueous alkaline conditions we
re elucidated. Sinapic acid was exposed to a volatile buffer (pH 8.5)
for 24 h, lyophilized, acidified, extracted, and characterized using n
uclear magnetic resonance and mass spectroscopy. The product obtained
was identified as the lignan thomasidioic acid. This identification wa
s confirmed by comparison with a synthesized authentic sample of thoma
sidioic acid. Conversion of sinapic acid to thomasidioic acid under al
kaline conditions previously has not been reported. Thomasidioic acid
was present after exposure of sinapic acid to pH 8.5 for as few as 6 h
. Thomasidioic acid also was formed at pH 7.