Enzymatic Synthesis of Novel Phenol Acid Rutinosides Using Rutinase and Their Antiviral Activity in Vitro

Novel rutinosides of vanillic acid, sinapic acid, ferulic acid, and caffeic acid were prepared via a rutinase-catalyzed transglycosylation reaction. Reaction mixtures containing rutin, phenolic acid, and rutinase derived from tartary buckwheat (Fagopyrum tataricum) seeds were incubated in 20 mM acetate buffer (pH 5.0) at 40 °C. The resulting rutinoside of each phenolic acid was purified by HPLC, and the structure was determined by NMR and FAB-MS analysis. Antiviral activity was determined using feline calicivirus (FCV) strain F9, which is a typical norovirus surrogate. It was found that rutinosylation of the phenolic acids increased their antiviral activity against FCV, with the sinapic acid rutinoside being the most effective. These results will contribute to the development of antiviral agents against noroviruses

Soybean-Derived Glycine–Arginine Dipeptide Administration Promotes Neurotrophic Factor Expression in the Mouse Brain

Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, plays an important role in cognitive abilities, including memory and learning. We demonstrated that soybean protein hydrolysate (SPH) diet suppresses age-related cognitive decline via the upregulation of BDNF in a mouse model of senescence. Our purpose was to identify novel bioactive peptides in SPH, which enhance BDNF expression. We treated mouse primary astrocytes with SPH as well as with its positively charged chromatographic fraction. Significant increases in the expression of BDNF were observed in the treatment with positively charged fraction of SPH. Among the synthesized peptides, the dipeptide glycine–arginine (GR) increased BDNF expression in vitro, and LC-TOF-MS analysis showed the presence of GR in the SPH. Furthermore, its administration in vivo increased the expression of BDNF in the cerebral cortex and the number of neurons in hippocampus and cerebral cortex. These data indicate that GR might promote neurogenesis by upregulating BDNF levels