Isolation and identification of phenolic glycosides from quinoa seeds (Chenopodium quinoa willd)

Quinoa has a long and distinguished history in South America, where quinoa has been cultivated since 3,000 BC. As reported, quinoa seeds are superior to traditional cereals in terms of their nutritional value, with protein contents ranging between 10 and 18% and with a fat content of 4.1 to 8.8%. Furthermore, this protein is of an exceptionally high quality, because of it is particularly rich in essential amino acids, such as histidine and lysine. Traditionally, the seeds are either mechanically abraded to remove the bran, where the saponins are predominantly located, or leached with water to debitter the seeds prior to use. In our continued investigation into the chemical components of debittered quinoa seeds, a mixture of two interchangeable isomers were isolated by semi-preparative HPLC column. Their structures were determined by detailed MS and NMR techniques, especially 2D NMR. This is the first report of these new phenolic glycosides in quinoa.