ABSTRACT
As one of the largest families of flowering plants, orchids (family Orchidaceae) colonize almost every habitat on Earth, mainly in the tropical and subtropical regions. They are often used as ornamental flowers for their unique morphologies and colors. As one of the main distribution centers in Yunnan Province, more than 100 species have been cultivated and used as herbal medicine. Among them, “Shi-Hu” (from Dendrobium species) and “Tianma” (from Gastrodia elata) are two of the best-known traditional Chinese medicines. In fact, more than 30 Dendrobium species are used as “Shi-Hu” and they mainly contain polysaccharides, aromatics (e.g. stilbene), sesquiterpenes, and alkaloids with immunomodulatory, cytotoxic, anticoagulant, anti-aging, and hypoglycemic activities, whereas for G. elata, over 90 chemical constituents have been isolated, and pharmacological activities such as sedative, anticonvulsant, pain-easing, and ischemic cerebral injury protection properties have been reported. This chapter will provide details of the chemistry and biological activities of these orchids from Yunnan.
