Bioactive natural products from orchids native to the Americas - A review.

The purpose of this review is to provide information on the traditional uses, phytochemical and pharmacological studies performed with species of orchids native to the Americas and the Caribbean Islands. The treatment of inflammation is the most traditional use for plants of this family, specially in Central America, while anti-inflammatory and anticancer assays are oftenly reported in pharmacological investigations. From the chemical point of view, they are sources of phenanthrenoids and stilbenes, rare secondary metabolites not commonly found in other families of plants, as well as cycloartane triterpenes, pyrrolizidine alkaloids and flavonoids. Since just few species were chemically and pharmacologically studied, in comparison to the large number of native species (less than 0.5% of the total), the orchids of the New World may be an interesting niche for the discovery of new, bioactive natural products.