Isolation of Compounds Including Two New Compounds from Asiasarum Root and Their Anti-glycation Activity

Two new glycosides, named 3-methoxy-5-methylphenol-6-O-β-glucopyranosyl-(1→6)-β-glucopyranoside (compound 1) and 1-O-feruloyl-α-arabinofuranosyl-(1→6)-β-glucopyranoside (compound 2), were isolated from Asiasarum root, together with eight known compounds. Asiasarum root (crude drug name in Latin: ASIASARI RADIX) is well known for its anti-inflammation and antitussive properties and is commonly found in Kampo formula in Japan. The structures of new compounds 1 and 2 were characterized using one- and two-dimensional (1D and 2D) NMR spectroscopy and MS. In addition, the anti-glycation activity of the isolates was evaluated. Glycation is particularly advanced in patients with diabetes and is suspected to be associated with diabetic complications such as nephropathy, osteoporosis, and Alzheimer's disease. The inhibition of this reaction is thought to be linked to the prevention and treatment of these diseases. Compounds 2 (79.4%), 4 (82.4%), 5 (79.8%), 6 (86.5%), 7 (90.1%), 9 (61.4%), and 10 (82.2%) showed activities comparable to that of aminoguanidine (45.3%) used as a positive control.