Quantitative determination of 1-deoxynojirimycin in mulberry leaves from 132 varieties

Mulberry 1-deoxynojirimycin (DNJ) shows high α-glucosidase inhibitory, antioxidant, antimicrobial, and anti-inflammatory activity. This is a widely used functional food constituent in China, Japan, Korea, Thailand and many other Asian countries. In this study, the DNJ content of mulberry leaves from 132 varieties of nine Morus species was determined. The degree of maturity of the mulberry leaves affected the DNJ content significantly. The younger leaves contained higher DNJ concentrations than did the older leaves. DNJ concentrations in mature leaves varied among these 132 mulberry varieties from 0.1341 to 1.472 mg/g of dry leaves. DNJ content in leaves was variety dependent and had no obvious relationship with either the species or their place of origin.