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Chemical constituents
of Uncaria tomentosa (Willd.) DC

Crystal of the oxindole alkaloid isopteropodine

Besides general chemical constituents usually found in plants, quinovic acid glycosides, plant sterols and catechins have been isolated from Uncaria tomentosa (Willd.) DC to date, for which pharmacological actions have been described. However, the therapeutic relevance of these constituents remains to be discussed.


In addition to the substances cited above, two groups of oxindole alkaloids have also been isolated: the group of pentacyclic oxindole alkaloids (POA) and the group of tetracyclic oxindole alkaloids (TOA). Interesting pharmacological activities have been documented for both groups, which are therefore used as the leading candidate substances for standardisation.


When growing naturally the plant Uncaria tomentosa (Willd.) DC occurs in two chemically different variants, also known as chemotypes. One chemotype contains predominantly POA, the second predominantly TOA. Differentiation of the two chemotypes is not only interesting from the scientific point of view, but also of essential importance for the production of high-quality medicinal drugs from the plant:


POA have a pronounced effect on the body's immune system (1, 2, 3, 4)
Even minute admixtures of TOA inhibit the action of the POA; furthermore, TOA reduce the blood pressure, exert a negative effect on the strength and frequency of the heartbeat and have an inhibitory effect on blood coagulation (1, 5, 6, 7)


Products manufactured from Uncaria tomentosa (Willd.) DC should be chosen with care to ensure that these preparations have been tested for the absence of TOA and that the POA content is standardised. The effect documented in the experiments can only be expected from products that meet these stringent quality criteria.

Scientific Literature:


Wurm M. et.al.: Pentacyclic oxindole alkaloids from Uncaria tomentosa induce human endothelial cells to release a lymphocyte-proliferation-regulating factor. Planta Medica 64, 701-704 (1998) 


Wagner H. et.al.: Die Alkaloide von Uncaria tomentosa und ihre Phagozytosesteigernde Wirkung. Planta Medica 50, 419-423 (1984) 


Reinhard K.H.: Uncaria tomentosa (Willd.) DC.: Cat’s Claw, Uña de Gato, or Savéntaro. Journal of Alternative and Complementary Medicine 5, 143-151 (1999) 


Sandoval-Chacon M. et.al.: Antiinflammatory action of Cat’s Claw: the role of NF-kB. Aliment. Pharmacol. Ther. 12, 1279-1289 (1998) 


Zhu Y. et.al.: Negative chronotropic and inotropic effects of rhynchophylline and isorhynchophylline on isolated guinea pig arteria. Chinese Journal of Pharmacology and Toxicology 7, 117-121 (1993) 


Shi et al.: Effects of rhynchophylline and isorhynchophylline on blood pressure and blood flow of organs in anesthetized dogs. Acta Pharmacologica Sinica 13, 35-38 (1992) 


Shi et al.: Hypotensive and hemodynamic effects of isorhynchophylline in conscious rats and anesthetized dogs. Chinese Journal of Pharmacology and Toxicology 3, 205-210 (1989) 

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