Uncaria genus

U. dasyoneura Korth.). The chromatographic and spectroscopic methods used in this extensive screening programme, and the behaviour of over 60 indole alkaloids found in the Uncaria genus on which this identification is based, have been thoroughly discussed. ... 

The Uncaria genus includes 34 species of vines and shrubs and is a rich source of medicinal natural products. Uncaria plants are traditionally used to heal wounds, headaches, and ulcers and to fight infections [34]. Over 150 compounds have been isolated from Uncaria tissues, and the most prominent of those are alkaloids. 

Yano S, Horiuchi H, Horie S, Aimi N, Sakai S, Watanabe K (1991) Ca channel blocking effects of Hirsutine, an indole alkaloid from Uncaria genus, in the isolated rat aorta. Planta Med 57 403 05. doi 10.1055/s-2006-960134... 

Haginiwa J, Sakai S, Takahashi K, Taguchi M, Seo S 1971 Studies of plants containing indole alkaloids. I. Alkaloids in Uncaria genus. Yakugaku Zasshi 91 575-578... 

Plants of the genus Uncaria (Rubiaceae), comprising some 34 species, are distributed mainly in tropical and subtropical Asia, Africa and tropical America. Of these about 14 species occur in Peninsular Malaysia. Early studies in the sixties by Chan yielded the pentacyclic oxindole alkaloids isopteropodine (74) and pteropodine (75) from Uncaria pleropoda [68-71]. 

The genus Uncaria Schreb., is now regarded as including the genus Ourouparia Aubl. (frequently misspelled), but Nauclea L., though closely related, is still regarded as distinct. The first chemical examination of a plant in these genera seems to be that of N. rhynchophylla Miq. under the name of 0. rhynchophylla Matsum. (177). Subsequently, the plant has been examined but almost invariably referred to as U. rhynchophylla Miq. 

Corynantheine-Heteroyohimbine-Yohimbine Group, and Related Oxindoles. A comprehensive review " of the alkaloids of Uncaria species provides a valuable summary of the considerable number of investigations reported on the alkaloid content and the chemotaxonomy of UrKoria, and it also includes Ridsdale s revision of the genus, which has resulted in the recognition of 34 species-a considerable reduction and simplification when compared with the 120 recorded in the Kew Index. 

Biologically Active Compounds from the Genus Uncaria (Rubiaceae)... 

In 1978, Ridsdale [7] systematically revised the genus Uncaria and included 34 species in the genus. In the same year, Phillipson et al. [10] extensively studied the alkaloids of Uncaria spp. from approximately 400 herbarium samples collected from across their range of distribution and identified 40 different alkaloids. Subsequently, several classes of compounds including alkaloids, flavonoids, and terpenoids were isolated and identified from this genus [10]. Among these, alkaloids are, however, recognized as the most prominent class of compounds. The phytochemical studies of Uncaria spp. for isolation of bioactive compounds started several decades ago [11]. 

Over the past few decades, much progress has been made on research on Uncaria spp. This genus plants are considered as a valuable source for the discovery and application of medicinal plant-derived namral products such as alkaloids and pentacyclic triterpenes as pharmaceutical agents. In vitro and in vivo studies evidenced the biological activity and therapeutic potential of the compounds isolated from this genus. However, further research is required for the development of potential dmg leads from the compounds of this genus in the area of inflammatory, immunomodulatory, and vascular-related disorders. 

Many clinical trials have been undertaken on the crude extracts and pure compounds derived from this genus plants. For instance, products developed from bark and other parts of U. tomentosa have been commercially available in the form of nutraceutical supplements. For instance in Austria, preparations from root are accepted for the prescription for rheumatoid arthritis. However, unauthorized products are being used worldwide without appropriate Good Manufacturing Practice. For this reason, the Council of Experts of the United States Pharmacopeial Convention prepared a monograph on the U. tomentosa in order to establish specifications for further improvement in the quality of nutraceutical supplements in this country. Further research and implementation of the regulations for safe practices would lead to potential use of Uncaria spp. as therapeutic agents. 

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