Research Progress on the Alkaloids of Dendrobium nobile: Substantiation, Key Components, Pharmacological Activity, and Biosynthetic Pathways

Dendrobium nobile Lindl. is a valuable medicinal orchid in traditional Chinese medicine. It abounds in alkaloids with extensive pharmacological properties, holding promising prospects for pharmaceutical development. In this review, the relevant literature was systematically retrieved from PubMed, Web of Science and CNKI using the keywords Dendrobium nobile Lindl., alkaloids, dendrobine, pharmacological activities and biosynthetic pathways. We comprehensively summarize the chemical composition, pharmacological effects, biosynthetic routes, clinical application potential and research prospects of alkaloids derived from D. nobile. The main alkaloid components including dendrobine, dendramine and nobilonine are classified into dendrobine, dendroxine and nobiline structural types. This paper further elaborates the anti-inflammatory, antioxidant and neuroprotective effects of these alkaloids, as well as their regulatory mechanisms on apoptosis-associated proteins and signaling cascades. Key enzymes and regulatory genes participating in the mevalonate pathway-mediated biosynthesis of sesquiterpenoid alkaloids are also discussed. Collectively, this review provides a theoretical basis and reference for subsequent basic research and therapeutic development of D. nobile alkaloids.