(Chem.) A glucoside (C14H17NO6) obtained from woad (indigo plant, Isatis Tinctoria) and other plants (see indigo), as a yellow or light brown sirup. When purified it is obtained as spear-shaped crystals. It has a nauseous bitter taste. By the action of acids, enzymes, etc., it breaks down into sugar and indigo. It is the source of natural indigo. Chemically it is the 3-glucoside of indole, H-indol-3-yl-beta-D-glucopyranoside.
