Aloin isobarbaloin

N.A. Aloin isobarbaloin, aloeresin A, B, aloesin glycone, aloesone, emodin, chrysophanic acid, 1,8-dihydroxy-anthracene derivatives, barbaloin, anthaquinone glycosides.99-100 108 109 510-511 Purgative, eupeptic, and cholagogue effect. It is a laxative and cathartic. Juice from leaves used for cuts and other skin problems. 

Occurrence. The sugar is encountered infrequently. Cathartic-acting glycosides (aloins) such as barbaloin, isobarbaloin, nataloin, and homo-nataloin from plants of the genus Aloe A. barbadensis) yield D-arabinose 39). The glycosidic union is very resistant to hydrolysis. The sugar occurs in the furanose modification as a constituent of the polysaccharide fraction of tubercle bacilli 40). 

Plants of the genus Aloe contain a reduced form of aloe-emodin as the C-glucoside of the corresponding anthrone, which is called aloin. Lemon yellow aloin is a mixture of two isomers. The major product (S)-aloin or (S)-P-D-glucopyranoside-aloe-emodin is referred to as aloin A (or barbaloin, 9-162), the (l )-isomer is aloin B (isobarbaloin). Related glycosides called aloinosides a and b contain a-L-rhamnopyranose bound by an O-glycosidic bond to the hydroxymethyl group at C-3. 

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