Polar constituents, protection against reactive oxygen species, and nutritional value of Chinese artichoke (Stachys affinis Bunge)

In the present work, we studied the chemical composition of S. affinis tubers, by analysing their polar constituents and the macro- and micro- nutrients. A total of nine compounds were isolated from the tuber ethanolic extract and structurally elucidated by NMR and MS. Apart from the oligosaccharide stachyose and the organic acid succinic acid, phenylethanoid and iridoid glycosides were the marker compounds. The macronutrient profile was dominated by carbohydrates (36.9% dw), whereas potassium (2.36%) was the most abundant micro-nutrient. The tuber ethanolic extract was able to efficiently protect human cells (Caco-2, SHSY-5Y and K562) against t-BHP-induced oxidative damage.