-----O------ | | CH_{2}OH·CHOH·CH·CHOH·CH·CH | | O S | / |/ C=N[trb]C_{3}H_{5} This compound usually breaks down into glucose and mustard oil; but by special treatment it is possible to obtain from it thioglucose, C_{6}H_{11}O_{5}·SH. This indicates that in the original glucoside the glucose is linked with the mustard oil through the sulfur atom. =Sinalbin=, C_{30}H_{42}O_{15}N_{2}S_{2}, from white mustard seeds, when hydrolyzed by myrosin, yields glucose, sinalbin mustard oil (a paraoxybenzyl derivative of allyl isosulfocyanide) and sinapin acid sulfate; according to the equation C_{30}H_{42}O_{15}N_{2}S_{2}+H_{2}O = C_{6}H_{12}O_{6}+C_{7}H_{7}O·NCS Sinalbin Glucose Sinalbin mustard oil + C_{16}H_{24}O_{5}N·HSO_{4}. Sinapin acid sulfate The sinalbin mustard oil may be represented by the formula ____ / \ HO-CH CH-CH_{2}NCS. Hydrolysis of the sinapin acid sulfate converts \____/ it into sinapinic acid, C_{6}H_{2}OH·(OCH_{3})_{2}·CH=CH·COOH, choline, N(CH_{3})_{4}C_{2}H_{4}OH (see page 152), and H_{2}SO_{4}. It is, therefore, a very complex glucoside. TEE DIGITALIS GLUCOSIDES The five, or more, glucosides which are present in the leaves and seeds of the foxglove (_Digitalis purpurea_) have been extensively studied, as they are the active principles in the various digitalis extracts which are used in medicine as a heart stimulant. =Digitoxin=, C_{34}H_{54}O_{11}, which is the most active of these glucosides in its physiological effects, when hydrolyzed, yields digitoxigenin, C_{22}H_{32}O_{4}, and a sugar having the formula C_{6}H_{12}O_{4}, which is known as "digitoxose" and is supposed to be a dimethyl tetrose. =Digitalin=, C_{35}H_{56}O_{14}, is also strongly active. When hydrolyzed, it yields digitaligenin, C_{22}H_{10}O_{3}, glucose, and digitoxose. =Digitonin=, C_{54}H_{92}O_{28}, constitutes about one-half of the total glucosides in the extract which is obtained from most species of the digitalis plants. It is much less active than the others. It is a saponin (see page 90) in type. On hydrolysis, it yields 2 molecules of glucose, 2 of galactose, and one of digitogenin. =Gitonin=, C_{49}H_{80}O_{23}, containing 3 molecules of galactose, one of a pentose sugar, and one of gitogenin; and =gitalin=, C_{28}H_{48}O_{10}, containing digitoxose and gitaligenin, have also been isolated from digitalis extracts.