Research on Alkaloids of Dendrobium officinale Based on UPLC-Q-TOF-MS Technology
Dendrobium is a traditional precious Chinese medicine with the effects of nourishing the stomach, generating fluids, nourishing yin, and tonifying deficiency. Used for fever and fluid damage, dry mouth, restlessness and thirst, insufficient stomach yin, insufficient food intake, dry vomiting, post illness deficiency heat that does not subside, yin deficiency and excessive fire, bone steaming and fatigue heat, unclear vision, and weak muscles and bones. Its chemical composition is relatively complex, with the main components including alkaloids, polysaccharides, sesquiterpenes, dibenzene, phenanthrene, coumarins, steroids, etc. Dendrobium pendant Roxb. is a plant species in the Orchidaceae family, native to southern Yunnan, as well as Southeast Asian countries such as Myanmar and Thailand. This plant has a medium to large size, with a bitter stem texture and swollen nodes in a bead like shape. As a traditional Chinese medicine, Dendrobium officinale has a long history of use.
Alkaloids and polysaccharides are the two main pharmacological active ingredients of Dendrobium officinale, and there have been many studies on Dendrobium polysaccharides. The research on dendrobium alkaloids started earlier, and alkaloids have the effects of clearing heat and reducing inflammation. There are more than 10 species of dendrobium involving alkaloids, but the research efforts are insufficient. The alkaloid content of Dendrobium officinale is high, and health and consumption practices have shown that it has important functional potential and exploration value. In order to comprehensively understand the alkaloid composition of Dendrobium officinale plants, this study systematically studied the alkaloid composition and content in the stems, flowers, and leaves of Dendrobium officinale. The total alkaloids of Dendrobium officinale were extracted using methanol extraction and chloroform extraction methods, respectively. The alkaloid components of Dendrobium officinale were qualitatively and relatively quantitatively studied using ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) technology, in order to provide theoretical basis for the structure-activity analysis and development and utilization of Dendrobium officinale.

This experiment characterized 15 alkaloids from the common structure of Dendrobium pluvialis: dendrobine (1), dendrobine C (2), dendrobine (3), dendrobine (4), dendrobine (5), dendrobine (6), dendrobine (7), dendrobine B (8), dendrobine D (9), dendrobine B (10), red star alkaloid A (11), N-isopentene dendrobine (12), N-isopentene dendrobine (13), dendrobine D (14), N-p-p Cinnamoyl tyramine (15). This study first discovered the presence of alkaloids in Dendrobium officinale, mainly of the octahydroindolizine alkaloid type. Dendrobium is usually consumed mainly from its stem, and the alkaloids in its swollen stem are mainly sesquiterpenes. The types and contents of alkaloids in its stems, flowers, and leaves are abundant. The content of alkaloids in the flowers of Dendrobium officinale is higher than that in the stems and leaves. The flowers are mainly composed of octahydroindolizine alkaloids such as dendrobine, dendrobine B, dendrobine, dendrobine C, and dendrobine D. This experiment extracted components through chloroform and methanol methods, indicating that the chloroform method extracted a wide range of components with high content. It is recommended to use chloroform as the main method and methanol as a supplement for alkaloid extraction.