Different Antioxidative and Antiapoptotic Effects of Piceatannol and Resveratrol.

Resveratrol affords protection against reactive oxygen species (ROS)-related diseases via activation of SIRT1, an NAD-dependent deacetylase. However, the low bioavailability of resveratrol limits its therapeutic applications. Since piceatannol is a hydroxyl analog of resveratrol with higher bioavailability, it could be an alternative to resveratrol.

Glycosylation of Stilbene Compounds by Cultured Plant Cells.

Oxyresveratrol and gnetol are naturally occurring stilbene compounds, which have diverse pharmacological activities. The water-insolubility of these compounds limits their further pharmacological exploitation. The glycosylation of bioactive compounds can enhance their water-solubility, physicochemical stability, intestinal absorption, and biological half-life, and improve their bio- and pharmacological properties.

Synthesis of Daidzein Glycosides, α-Tocopherol Glycosides, Hesperetin Glycosides by Bioconversion and Their Potential for Anti-Allergic Functional-Foods and Cosmetics.

Daidzein is a common isoflavone, having multiple biological effects such as anti-inflammation, anti-allergy, and anti-aging. α-Tocopherol is the tocopherol isoform with the highest vitamin E activity including anti-allergic activity and anti-cancer activity. Hesperetin is a flavone, which shows potent anti-inflammatory effects.

Identification of Stevioside Using Tissue Culture-Derived Stevia () Leaves.

Stevioside is a natural sweetener from Stevia leaf, which is 300 times sweeter than sugar. It helps to reduce blood sugar levels dramatically and thus can be of benefit to diabetic people. Tissue culture is a very potential modern technology that can be used in large-scale disease-free stevia production throughout the year.

Synthesis, oxygen radical absorbance capacity, and tyrosinase inhibitory activity of glycosides of resveratrol, pterostilbene, and pinostilbene.

The stilbene compound resveratrol was glycosylated to give its 4'-O-β-D-glucoside as the major product in addition to its 3-O-β-D-glucoside by a plant glucosyltransferase from Phytolacca americana expressed in recombinant Escherichia coli. This enzyme transformed pterostilbene to its 4'-O-β-D-glucoside, and converted pinostilbene to its 4'-O-β-D-glucoside as a major product and its 3-O-β-D-glucoside as a minor product. An analysis of antioxidant capacity showed that the above stilbene glycosides had lower oxygen radical absorbance capacity (ORAC) values than those of the corresponding stilbene aglycones.

Optical Resolution of (RS)-Denopamine to (R)-Denopamine P-D- Glucoside by Glucosyltransferase from Phytolacca americana Expressed in Recombinant Escherichia coli.

The optical resolution of racemic compounds by stereoselective glucosylation was investigated using plant glucosyltransferase from Phytolacca americana expressed in recombinant Escherichia coli. The glucosyltransferase glucosylated chemoselectively the phenolic hydroxyl group of phenol compounds. The (R)-stereoselective glucosylation of (RS)-denopamine by glucosyltransferase occurred to give (R)-denopamine β-D-glucoside.

Hydroxylation and Glycosylation of Phenylpropanoids by Cultured Cells of Phytolacca americana.

Hydroxylation and glycosylation of cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid were investigated using cultured plant cells of Phytolacca americana as biocatalysts. Regioselective hydroxylation at the 4-position of cinnamic acid and 3-position of p-coumaric acid was observed. Although cinnamic acid was transformed to mono-glucoside products, di-glycosylation occurred in the case of the biotransformation of p-coumaric acid, caffeic acid, and ferulic acid.

Synthesis and pharmacological evaluation of glycosides of resveratrol, pterostilbene, and piceatannol.

To enhance their water solubility and pharmacological activities, the stilbenes resveratrol, pterostilbene, and piceatannol were glycosylated to their monoglucosides (β-glucosides) and diglycosides (β-maltosides) by cultured cells and cyclodextrin glucanotransferase (CGTase). Cultured cells of Phytolacca americana and glucosyltransferase (PaGT) were capable of glucosylation of resveratrol to its 3- and 4'-β-glucosides. Pterostilbene was slightly transformed into its 4'-β-glucoside by P.

Enzymatic Synthesis of Quercetin Monoglucopyranoside and Maltooligosaccharides.

Quercetin 3-O-β-monoglucopyranoside and quercetin 3-O-β-maltooligosaccharide were synthesized from quercetin using glucosyltransferase-3 from Phytolacca americana and cyclodextrin glucanotransferase.

Regioselective Glycosylation of 3-, 5-, 6-, and 7-Hydroxyflavones by Cultured Plant Cells.

Regioselective glycosylation of 3-, 5-, 6-, and 7-hydroxyflavones was investigated using cultured plant cells of Eucalyptus perriniana and Phytolacca americana as biocatalysts. 3- and 7-Hydroxyflavones were practically glycosylated into the corresponding β-D-glucosides by E. perriniana and P.

Glycosylation of artepillin C with cultured plant cells of Phytolacca americana.

Biotransformation of artepillin C was investigated using cultured plant cells as biocatalysts. Artepillin C was converted into its 4- and 9-beta-D-glucosides, and 4,9-beta-D-diglucoside by cultured cells of Phytolacca americana. In contrast, cultured lpomoea batatas cells glucosylated artepillin C to only its 4- and 9-beta-D-glucosides.

Glycosylation of quercetin with cultured plant cells and cyclodextrin glucanotransferase.

Quercetin was glucosylated by cultured plant cells of lpomoea batatas to its 3- and 7-O-beta-D-glucosides, and 3,7-O-beta-D-diglucoside. On the other hand, further glycosylation of quercetin 3-O-beta-D-glucoside by cyclodextrin glucanotransferase gave the 3-O-beta-maltoside, 3-O-beta-maltotrioside, and 3-O-[beta-maltotetraosides of quercetin.