Extraction methods, structural diversity and potential biological activities of Artemisia L. polysaccharides (APs): A review

Abstract

The extraction and structural characterization of polysaccharides are challenging in plants with overlapping distributions such as Artemisia, the plant genus producing antimalarial drug artemisinin discovered by the Nobel Prize 2015 winning Professor Tu You-you. The diversity in Artemisia polysaccharides (APs) is due to difference in extraction methods leading to different bioactivities. In spite of that, APs utilization is decelerated due to lack of a review portraying current advancements. This review delivers data on extraction, structural characterization and bioactivities of APs with emphasis on mechanisms of action and structure-function relationships. Outcomes indicated that various polysaccharides in 16 Artemisia species were reported and comprehensively described. The common methods for preparing APs were hot water and microwave assisted extractions with maximum yield. Maximum plant parts used to extract APs include leaves, aerial part, whole plant and seeds. The APs presented varying molecular weight, monosaccharide composition, carbohydrates, proteins, uronic acids and phenolic content with around 20 bioactivities. Data on structure-function relationships indicated that the bioactivities of APs are highly correlated with the differences in Mw and monosaccharide's type. While Artemisia species discussed here are the most studied species for their polysaccharides, other Artemisia species may offer unique polysaccharides with distinct biological properties; hence, the future research could focus on expanding the scope of species studied. Broader investigations are also needed specifically on the structure-function relationships of APs with the elucidation of impact of unknown factors on their efficacy.