A summary of the scope and range of sulfated molecules achievable with Me3NSO3 complex are listed in Table . Triethylamine sulfur trioxide complex An alternative sulfur trioxide amine complex example is triethylamine SO3 complex (Et3N•SO3), which was also utilised for the sulfation of a wide range of small organic molecules such as flavonoids, polysaccharides, proteins, and steroids. For instance, the sulfation of polyphenolic flavonoids such as protocatechuic acid (PCA), quercetin, and catechin were reported using Et3N•SO3 complex. PCA sulfate lower the production of interleukin-6 (IL-6) and vascular cell adhesion molecule-1 (VCAM-1), pro-inflammatory cytokine genes that are linked to cardiovascular diseases. Gutierrez-Zetina and co-workers have described the mono-sulfation reaction of PCA using superstoichiometric equivalents of Et3N•SO3 (10-fold) at 40 °C for 3 h. As a result, two compounds were isolated as PCA-3-sulfate and PCA-4-sulfate, respectively (Scheme 9). Scheme 9. General procedure for sulfation of PCA using Et3N•SO3 affording either PCA-3-sulfate or PCA-4-sulfate.