Frangula purshiana (DC.) A. Gray - syn.Rhamnus purshianus DC.; Rhamnus purshiana (DC.) Cooper - Rhamnaceae \\
cascara buckthorn, cascara sagrada, **Amerikanischer Faulbaum**, Cascara

Tree up to 10m high, native to western North America.

"The dried bark of cascara has been used for centuries as an herbal laxative – first by Native Americans in the Pacific Northwest, and then later by European/U.S. colonizers." [[https://en.wikipedia.org/wiki/Rhamnus_purshiana]]

"A tree, 4-10m high, with reddish-brown bark and hairy twigs. Leaves petiolate, elliptical, acuminate, serrulate, or sometimes entire, with 10-15 pairs of veins, dull green upper surface and pubescent underside. Inflorescence an axillary umbellate cyme of small greenish flowers. Fruit a turbinate, purplish-black drupe, about 8mm long, composed of 3 indehiscent cocci. \\
The fresh bark contains free anthrones and must be dried for at least 1 year or artificially aged by heat or aeration before therapeutic use. \\
Contains not less than 8.0% hydroxyanthracene glycosides of which not less than 60% consists of cascarosides, both calculated as cascaroside A. Quantitative analysis is performed by spectrophotometry at 515nm. A high performance liquid chromatography method for the quantitative analysis of cascarosides has been reported.
The active constituents are hydroxyanthracene glycosides (6-9%). Of these, 70-90% are C-10 glycosides, with the 8 -O-glycosides, aloins A and B, and 11-desoxyaloins A and B (chrysaloins A and B) accounting for 10-30%. The diastereoisomeric pairs, cascarosides A and B and cascarosides C and D and cascarosides E and F constitute 60-70% of the total O-glycosides. Other major hydroxyanthracene glycosides (10-20%) include the hydroxyanthraquinones, chrysophanol-8 -O-glucoside and aloe-emodin-8 -O-glucoside." \\
[Cortex Rhamni Purshianae, WHO Monographs on Selected Medicinal Plants - Volume 2, 2004] [[http://apps.who.int/medicinedocs/en/d/Js4927e/25.html#Js4927e.25]]

"Parts used: Dried trunk and stem bark (Rhamni purshiani cortex). Fresh bark tends to cause nausea and griping, so it is stored for one year (or artificially aged) before use. Therapeutic category: Stimulant laxative. Active ingredients: The dry bark contains 6-9% hydroxyanthraquinone glycosides, the bulk of which is made up of O-glycosides of aloeemodin, chrysophanol and emodin or C-glycosides, so-called [[http://www.znaturforsch.com/ac/v29c/29c0444.pdf|cascarosides A,B,C, and D]]; also aloin A,B." \\
[Medicinal Plants of the World. Ben-Erik Van Wyk and Michael Wink, Pretoria 2004, 269] 

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