β-glucan, one of the homopolysaccharides composed of D-glucose, exists widely in cereals and microorganisms and possesses various biological activities, including anti-inflammatory, antioxidant, and anti-tumor properties. More recently, there has been mounting proof that β-glucan functions as a physiologically active “biological response modulator (BRM)”, promoting dendritic cell maturation, cytokine secretion, and regulating adaptive immune responses—all of which are directly connected with β-glucan-regulated glucan receptors. This review focuses on the sources, structures, immune regulation, and receptor recognition mechanisms of β-glucan.

Methodology toward the stereoselective 1,2-cis glycoside linkage using intramolecular aglycon delivery (IAD) has been extensively developed. In the last two decades, progress has been made using various mixed acetal linkages and a number of glycosyl donor moieties to develop novel IAD strategies, mainly based on formation of acetal linkages. This account summarizes the newest naphthylmethyl (NAP) ether-mediated IAD as well as all the types of mediations for stereospecific construction of various 1,2-cis linkages, not only for β-mannopyranoside, but also for other linkages almost without exception, including β-L-rhamnoside.