Advances in research on Dendrobium officinale polysaccharide: Extraction techniques, structural features, biological functions, structure-activity relationships, biosynthesis and resources

Dendrobium officinale is a famous and precious Chinese herbal medicine. Dendrobium officinale polysaccharide (DOP), main bioactive component of D. officinale, has attracted great attention and is widely used in medicine, food and health care. It the continuous deepening of the research on DOP in recent years, new progress has been made in the extraction technology, the type, biological activity and structure-activity relationship of DOP. Importantly, more and more factors that could affect the extraction efficiency, structural stability and the accuracy of characterization results of DOP have been discovered, and the modification of environmental chemical elements have made the research on the structure-activity relationship of DOP more complicated and interesting. In addition, the biosynthetic pathway or mechanism of DOP have been gradually revealed with the rapid development of multimethology and molecular biotechnology in recent years. Endophytes have been regarded as one of the most ideal research objects for the development of alternative biological resources of plant-derived active components because of their unique advantages. In recent years, the research in this field have also risen quietly. Regrettably, however, there is no comprehensive review containing the above contents. This paper provides a critical review of recent advances in DOP research, focusing on extraction technologies, structural characteristics, biological activities, and structure-activity relationships. Furthermore, we analyze current research frontiers and future perspectives, including DOP biosynthesis mechanisms and endophyte-related studies. The comprehensive review aims to offer updated insights and serve as a valuable reference for future DOP investigations.