Isao Yuasa

Anti-steatosis compounds from leaves of Mallotus furetianus

Abstract There is no drug administration-approved therapy for non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). In this study, eight compounds, gallic acid (1), methyl gallate (2), corilagin (3), 3,4,8,9,10-pentahydroxydibenzo[b,d]pyran-6-one (4), repandinin B (5), (Z)-3-hexenyl-β-D-glucopyranoside (6), (+)-lyoniresinol-3α-O-α-L-rhamnopyranoside (7) and mallophenol A (8) were isolated from the active fractions of Mallotus furetianus. Three compounds, (6, 7 and 8) revealed potent anti-steatosis activity in the oleic acid (OA)-induced steatosis cell model, with the minimum effective concentration of 0.05 (6), 0.0005 (7) and 0.0005 (8) μg/mL, which were much lower than the control compound, fibrate (72.4 μg/mL).

Purification and Characterization of α-D-Mannosidase from the Seeds of Kaya, Torreya nucifera

Alpha-D-mannosidase was purified from the extract of seeds of Kaya, Torreya nucifera. The purified enzyme had a molecular mass of ˜ 3.6 × 105 daltons. This enzyme had an optimum pH at 4.5, and was stable at pH between 5.5 and 6.5. This enzyme appeared to be a metal enzyme containing Zn2+. The enzyme hydrolyzed p-nitrophenyl-α-D-mannoside, methyl-α-D-mannoside, α-1-»3-mannobiose, and α-1»6-mannobiose, with Km of 0.785 mM, 0.236 M, 2.505 mM, and 0.268 mM, respectively. The hydrolysis of various z-linked mannobioses indicated that the enzyme hydrolyzes the α-mannobioses in the order of α-(1→2)> -(1→6)> -(1→3).