Phytoremediation of Benzophenone and Bisphenol A by Glycosylation with Immobilized Plant Cells

Benzophenone and bisphenol A are environmental pollutions, which have been listed among “chemicals suspected of having endocrine disrupting effects” by the World Wildlife Fund, the National Institute of Environmental Health Sciences in the USA and the Japanese Environment Agency. The cultured cells of Nicotiana tabacum glycosylated benzophenone to three glycosides, 4-O-β-D-glucopyranosylbenzophenone (9%), diphenylmethyl β-D-glucopyranoside (14%), and diphenylmethyl 6-O-(β-D-glucopyranosyl)-β-D-glucopyranoside (12%) after 48 h incubation. On the other hand, incubation of benzophenone with immobilized cells of N. tabacum in sodium alginate gel gave products in higher yields, i.e. the yields of 4-O-β-D-glucopyranosylbenzophenone, diphenylmethyl β-D-glucopyranoside, and diphenylmethyl 6-O-(β-D-glucopyranosyl)-β-D-glucopyranoside were 15, 27, and 22%, respectively. Bisphenol A was converted into three glycosides, 2,2-bis(4-β-D-glucopyranosyloxyphenyl)propane (16%), 2-(4-β-D-glucopyranosyloxy-3-hydroxyphenyl)-2-(4-β-D-glucopyranosyloxyphenyl) propane (8%), and 2-(3-β-D-glucopyranosyloxy-4-hydroxyphenyl)-2-(4-β-D-glucopyranosyloxyphenyl)propane (5%). Also the use of immobilized N. tabacum cells improved the yield of products; the glycosylation of bisphenol A with immobilized N. tabacum gave 2,2-bis(4-β-D-glucopyranosyloxyphenyl)propane (24%), 2-(4-β-D-glucopyranosyloxy-3-hydroxyphenyl)-2-(4-β-D-glucopyranosyloxyphenyl) propane (15%), and 2-(3-β-D-glucopyranosyloxy-4-hydroxyphenyl)-2-(4-β-D-glucopyranosyloxyphenyl)propane (11%)

Synthesis of Xylooligosaccharides of Daidzein and Their Anti-Oxidant and Anti-Allergic Activities

The biocatalytic synthesis of xylooligosaccharides of daidzein was investigated using cultured cells of Catharanthus roseus and Aspergillus sp. β-xylosidase. The cultured cells of C. roseus converted daidzein into its 4′-O-β-glucoside, 7-O-β-glucoside, and 7-O-β-primeveroside, which was a new compound. The 7-O-β-primeveroside of daidzein was further xylosylated by Aspergillus sp. β-xylosidase to daidzein trisaccharide, i.e., 7-O-[6-O-(4-O-(β-d-xylopyranosyl))-β-d-xylopyranosyl]-β-d-glucopyranoside, which was a new compound. The 4′-O-β-glucoside, 7-O-β-glucoside, and 7-O-β-primeveroside of daidzein exerted DPPH free-radical scavenging and superoxide radical scavenging activity. On the other hand, 7-O-β-glucoside and 7-O-β-primeveroside of daidzein showed inhibitory effects on IgE antibody production

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. Plant cell cultures are ideal systems for propagating rare plants and for studying the biosynthesis of secondary metabolites. Furthermore, the biotransformation of various organic compounds has been investigated as a target in the biotechnological application of plant cell culture systems. Cultured plant cells can glycosylate not only endogenous metabolic intermediates but also xenobiotics. In plants, glycosylation reaction acts for decreasing the toxicity of xenobiotics. There have been a few studies of glycosylation of exogenously administrated stilbene compounds at their 3- and 4′-positions by cultured plant cells of Ipomoea batatas and Strophanthus gratus so far. However, little attention has been paid to the glycosylation of 2′-hydroxy group of stilbene compounds by cultured plant cells. In this work, it is described that oxyresveratrol (3,5,2′,4′–tetrahydroxystilbene) was transformed to 3-, 2′-, and 4′-β-glucosides of oxyresveratrol by biotransformation with cultured Phytolacca americana cells. On the other hand, gnetol (3,5,2′,6′–tetrahydroxystilbene) was converted into 2′-β-glucoside of gnetol by cultured P. americana cells. Oxyresveratrol 2′-β-glucoside and gnetol 2′-β-glucoside are two new compounds. This paper reports, for the first time, the glycosylation of stilbene compounds at their 2′-position by cultured plant cells

Synthesis of Gentiooligosaccharides of Genistein and Glycitein and Their Radical Scavenging and Anti-Allergic Activity

The synthesis of gentiooligosaccharides of genistein and glycitein using cultured cells of Eucalyptus perriniana as biocatalysts was investigated. The cells of E. perriniana glycosylated genistein and glycitein to give the corresponding 4'-O-b-glucosides, 7-O-b-glucosides, and 7-O-b-gentiobiosides, which were two new compounds. The b-glucosides of genistein and glycitein showed 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging activity and superoxide-radical scavenging activity. On the other hand, 7-O-b-glucosides of genistein and glycitein and the 7-O-b-gentiobioside of glycitein exerted inhibitory effects on IgE antibody production