l-Menthyl alpha-D-glucopyranosyl-(1-->4)-alpha-D-glucopyranosid(alpha-MenG(2)), a novel glycoside of l- menthol, was synthesized enzymatically, and its physicochemical properties were characterized. Production of alpha-MenG(2) from l-menthyl alpha-D-glucopyranoside (alpha-MenG) was attempted since we had already succeeded in the high-yield production of alpha-MenG using a Xanthomonas campestris enzyme (Nakagawa, H., et al., J. Biosci. Bioeng., 89, 138-1441. 2000). Through production tests on enzymes, it was confirmed that cyclodextrin glucanotransferase (CGTase) from Bacillus macerans produced l-menthyl alpha-D-maltooligosides (alpha-MenG(n)), containing alpha-MenG(2), from alpha-MenG and soluble starch. When 10 ml of a 10 mM citrate-10 mM phosphate buffer (pH 6.0) containing 150 mg of alpha-MenG, 3 g of soluble starch and CGTase was shaken at 70degreesC for 24 h, a total of 81.8% alpha-MenG was reacted. The molar conversion yields of alpha-MenG(2) and alpha-MenG(n) with alpha-glucose degrees of polymerization of 3-18, based on the amount of alpha-WenG supplied, reached 16.1% and 65.7%, respectively. For efficient production of alpha-MenG(2), the reaction mixture was treated with a-amylase of Aspergillus oryzae, and alpha-MenG(n) were mainly converted into alpha-MenG: finally, the molar conversion yield of alpha-MenG(2) reached 74.2% based on the amount of alpha-MenG supplied. alpha-MenG(2) was purified and its molecular structure was confirmed by C-13-NMR, H-1-NMR and two-dimensional HMBC (heteronuclear multiple-bond coherence).alpha-MenG(2) and its aqueous solution tasted bitter and a little sweet at first, but in a few minutes, a refreshing flavor and sweetness spread. At 20degreesC the solubility of alpha-MenG(2) in pure water was 29.6 g/100 ml, approximately 1570-fold that of alpha-MenG.