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'-ß-glucosides of oxyresveratrol by biotransformation with cultured Phytolacca americana cells. On the other hand, gnetol (3,5,2',6'-tetrahydroxystilbene) was converted into 2'-ß-glucoside of gnetol by cultured P. americana cells. Oxyresveratrol 2'-ß-glucoside and gnetol 2'-ß-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 Ester-linked Docetaxel-glycoside Conjugate and Its Application to Drug Delivery System using Immunoliposome Targeted with Trastuzumab.

Chemo-enzymatic synthesis of the ester-linked monosaccharide conjugate of docetaxel, 7-glycolyldocetaxel 2"-O-ß-D-galactopyranoside, was achieved by using lactase as a biocatalyst. The water-solubility and, EE and LE values for the liposome of 7-glycolyldocetaxel 2"-O-ß-D-galactopyranoside were much higher than those of docetaxel. The immunoliposome containing 7-glycolyldocetaxel 2"-O-ß-D-galactopyranoside showed effective suppression of tumor growth.

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 ß-D-glucoside.

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 (ß-glucosides) and diglycosides (ß-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'-ß-glucosides. Pterostilbene was slightly transformed into its 4'-ß-glucoside by P. americana cells. Piceatannol was readily converted into piceatannol 4'-ß-glucoside, with the highest yield among the three substrates. The 3- and 4'-ß-glucosides of resveratrol were subjected to further glycosylation by CGTase to give 3- and 4'-ß-maltoside derivatives. The inhibitory action of resveratrol and pterostilbene toward histamine release induced with compound 48/80 from rat peritoneal mast cells was improved by ß-glucosylation and/or ß-maltosylation (i.e., the inhibitory activity for histamine release of the 3- and 4'-ß-glucosides of resveratrol, the 3- and 4'-ß-maltosides of resveratrol, and the 4'-ß-glucoside of pterostilbene was higher than that of the corresponding aglycones, resveratrol and pterostilbene, respectively). In addition, the phosphodiesterase (PDE) inhibitory activity of resveratrol and pterostilbene was enhanced by ß-glucosylation and/or ß-maltosylation (i.e., the PDE inhibitory activities of the 3- and 4'-ß-glucosides of resveratrol, the 4'-ß-maltoside of resveratrol, and the 4'-ß-glucoside of pterostilbene were higher than those of the corresponding aglycones, resveratrol and pterostilbene, respectively).

Synthesis of Resveratrol Glycosides by Plant Glucosyltransferase and Cyclodextrin Glucanotransferase and Their Neuroprotective Activity.

Resveratrol was converted by glucosyltransferase from Phytolacca americana into its 3- and 4'-O-ß-D-glucosides. On the other hand, further glycosylation of resveratrol 4'-O-ß-D-glucoside by cyclodextrin glucanotransferase gave the 4'-O-ß-maltoside, 4'-O-ß-maltotrioside, 4'-O-ß-maltotetraoside, and 4'-O-ß- maltopentaoside of resveratrol. The six resveratrol glycosides synthesized here showed higher phosphodiesterase inhibitory activity than resveratrol.

Synthesis of ε-Viniferin Glycosides by Glucosyltransferase from Phytolacca americana and their Inhibitory Activity on Histamine Release from Rat Peritoneal Mast Cells.

Glycosylation of (+)-ε-viniferin was investigated using glucosyltransferase from Phytolacca americana (PaGT3) as a biocatalyst. (+)-ε-Viniferin was converted by PaGT3 into its 4b- and 13b-ß-D-glucosides, the inhibitory activities on histamine release from rat peritoneal mast cells of which were higher than that of (+)-ε-viniferin.

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.

Regioselective hydroxylation and glucosylation of alpha- and beta-pinenes with cultured cells of Eucalyptus perriniana.

Cultured plant cells of Eucalyptus perriniana regioselectively hydroxylated (+)- and (-)-alpha-pinenes to the corresponding (+)- and (-)-verbenols. In addition, (+)- and (-)-verbenols were converted into mono-beta-D-glucosides. On the other hand, (+)- and (-)-beta-pinenes were transformed into (+)- and (-)-pinocarveol 3-O-beta-D-glucosides via (+)- and (-)-pinocarveols.

Glucosylation of taxifolin with cultured plant cells.

Cultured plant cells of Eucalyptus perriniana glucosylated taxifolin to its 3'- and 7-O-beta-D-glucosides and 3',7-O-beta-D-diglucoside. On the other hand, taxifolin was converted into 3'- and 7-O-beta-D-glucosides by cultured cells of Nicotiana tabacum and Catharanthus roseus.

Regioselective hydroxylation and glucosylation of flavanones with cultured plant cells of Eucalyptus perriniana.

Cultured plant cells of Eucalyptus perriniana catalyzed reduction, regioselective hydroxylation, and regioselective glycosylation of flavanones. (2S)-Flavanone was converted into (2S)-flavan-4-ol, (2S)-flavan-4,7-diol, (2S)-flavan-7-ol, (2S)-flavan-7-yl glucoside, and (2S)-flavan-7-yl gentiobioside. The cells glucosylated (2S)-flavan-6-ol to (2S)-flavan-6-yl glucoside. (2S)-Flavan-2'-ol was transformed to (2S)-flavan-2',4-diol, (2S)-flavan-2',7-diol, (2S)-flavan-2'-yl glucoside. In addition, (2S)-flavan-4'-ol was transformed to (2S)-flavan-4,4'-diol, (2S)-flavan-4',7-diol, (2S)-flavan-4'-yl glucoside.

Synthesis of resveratrol glycosides by cultured plant cells.

Incubation of cultured cells of Glycine max with trans-resveratrol gave its 3-O-beta-D- and 4'-O-beta-D-glucosides. Cultured Gossypium hirsutum cells glycosylated trans-resveratrol to its 3-O-beta-D-, 4'-O-beta-D-, and 3,4'-O-beta-D-diglucosides. On the other hand, trans-resveratrol was converted into cis-resveratrol 4'-O-beta-D-glucoside, together with trans-resveratrol 3-O-beta-D-glucoside and trans-resveratrol 4'-O-beta-D-glucoside, by Eucalyptus perriniana.

Formation of tetrahydrocurcumin by reduction of curcumin with cultured plant cells of Marchantia polymorpha.

Cultured plant cells of Marchantia polymorpha, Nicotiana tabacum, Phytolacca americana, Catharanthus roseus, and Gossypium hirsutum were examined for their ability to reduce curcumin. Only M. polymorpha cells converted curcumin into tetrahydrocurcumin in 90% yield in one day. Time-course experiment revealed a two-step formation of tetrahydrocurcumin via dihydrocurcumin.

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

Biotransformation of cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid by plant cell cultures of Eucalyptus perriniana.

Biotransformations of phenylpropanoids such as cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid were investigated with plant-cultured cells of Eucalyptus perriniana. The plant-cultured cells of E. perriniana converted cinnamic acid into cinnamic acid ß-D-glucopyranosyl ester, p-coumaric acid, and 4-O-ß-D-glucopyranosylcoumaric acid. p-Coumaric acid was converted into 4-O-ß-D-glucopyranosylcoumaric acid, p-coumaric acid ß-D-glucopyranosyl ester, 4-O-ß-D-glucopyranosylcoumaric acid ß-D-glucopyranosyl ester, a new compound, caffeic acid, and 3-O-ß-D-glucopyranosylcaffeic acid. On the other hand, incubation of caffeic acid with cultured E. perriniana cells gave 3-O-ß-D-glucopyranosylcaffeic acid, 3-O-(6-O-ß-D-glucopyranosyl)-ß-D-glucopyranosylcaffeic acid, a new compound, 3-O-ß-D-glucopyranosylcaffeic acid ß-D-glucopyranosyl ester, 4-O-ß-D-glucopyranosylcaffeic acid, 4-O-ß-D-glucopyranosylcaffeic acid ß-D-glucopyranosyl ester, ferulic acid, and 4-O-ß-D-glucopyranosylferulic acid. 4-O-ß-D-Glucopyranosylferulic acid, ferulic acid ß-D-glucopyranosyl ester, and 4-O-ß-D-glucopyranosylferulic acid ß-D-glucopyranosyl ester were isolated from E. perriniana cells treated with ferulic acid.

Changes in intra-abdominal pressure and spontaneous breath volume by magnitude of lifting effort: highly trained athletes versus healthy men.

Intra-abdominal pressure (IAP) is closely related to breathing behavior during lifting. Abdominal muscles contribute to both IAP development and respiratory function. The purpose of this study was to examine whether spontaneous breath volume and IAP altered with increased isometric lifting effort, and to compare the effect of different abdominal muscle strengths on these parameters. Maximal IAP during the Valsalva maneuver (maxIAP) and maximal isometric trunk flexor strength were measured in 10 highly trained judo athletes (trained) and 11 healthy men (controls). They performed isometric lifting with 0 (rest), 30, 45, 60, 75, 90, and 100% of maximal lifting effort (MLE). Natural inspiratory and expiratory volumes were calculated from air-flow data immediately before and after the start of lifting. IAP, measured using an intra-rectal pressure transducer during lifting, was normalized by maxIAP (%maxIAP). Trained athletes had higher maxIAP and stronger trunk flexor muscles than controls. A significant main effect of lifting effort was found on %maxIAP and respiratory volume. An interaction (lifting effort by group) was found only for %maxIAP. No significant group main effect or interaction was found for respiratory volume. Inspiratory volume increased significantly from tidal volume to above 60 and 45% of MLE in trained athletes and controls, respectively. Expiratory volume decreased significantly from tidal volume at above 30% of MLE in both the groups. These results suggest that spontaneous breath volume and IAP development are coupled with increased lifting effort, and strong abdominal muscles can modify IAP development and inspiratory behavior during lifting.

Biotransformation of naringin and naringenin by cultured Eucalyptus perriniana cells.

The biotransformation of naringin and naringenin was investigated using cultured cells of Eucalyptus perriniana. Naringin (1) was converted into naringenin 7-O-beta-D-glucopyranoside (2, 15%), naringenin (3, 1%), naringenin 5,7-O-beta-D-diglucopyranoside (4, 15%), naringenin 4',7-O-beta-D-diglucopyranoside (5, 26%), naringenin 7-O-[6-O-(beta-D-glucopyranosyl)]-beta-d-glucopyranoside (6, beta-gentiobioside, 5%), naringenin 7-O-[6-O-(alpha-l-rhamnopyranosyl)]-beta-D-glucopyranoside (7, beta-rutinoside, 3%), and 7-O-beta-D-gentiobiosyl-4'-O-beta-d-glucopyranosylnaringenin (8, 1%) by cultured cells of E. perriniana. On the other hand, 2 (14%), 4 (7%), 5 (13%), 6 (2%), 7 (1%), naringenin 4'-O-beta-D-glucopyranoside (9, 4%), naringenin 5-O-beta-D-glucopyranoside (10, 2%), and naringenin 4',5-O-beta-D-diglucopyranoside (11, 5%) were isolated from cultured E. perriniana cells, that had been treated with naringenin (3). Products, 7-O-beta-D-gentiobiosyl-4'-O-beta-D-glucopyranosylnaringenin (8) and naringenin 4',5-O-beta-D-diglucopyranoside (11), were hitherto unknown.

Glycosylation of sesamol by cultured plant cells.

The glycosylation of sesamol was investigated using cultured cells of Nicotiana tabacum and Eucalyptus perriniana. The cultured suspension cells of N. tabacum converted sesamol into its beta-glucoside (7%) as well as the disaccharide, sesamyl 6-O-(beta-D-glucopyranosyl)-beta-D-glucopyranoside (beta-gentiobioside, 30%). On the other hand, sesamyl 6-O-(alpha-L-rhamnopyranosyl)-beta-D-glucopyranoside (beta-rutinoside, 56%), together with the beta-glucoside (3%), was produced when sesamol was incubated with suspension cells of E. perriniana.

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-beta-D-glucopyranosylbenzophenone (9%), diphenylmethyl beta-D-glucopyranoside (14%), and diphenylmethyl 6-O-(beta-D-glucopyranosyl)-beta-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-beta-D-glucopyranosylbenzophenone, diphenylmethyl beta-D-glucopyranoside, and diphenylmethyl 6-O-(beta-D-glucopyranosyl)-beta-D-glucopyranoside were 15, 27, and 22%, respectively. Bisphenol A was converted into three glycosides, 2,2-bis(4-beta-D-glucopyranosyloxyphenyl)propane (16%), 2-(4-beta-D-glucopyranosyloxy-3-hydroxyphenyl)-2-(4-beta-D-glucopyranosyloxyphenyl) propane (8%), and 2-(3-beta-D-glucopyranosyloxy-4-hydroxyphenyl)-2-(4-beta-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-beta-D-glucopyranosyloxyphenyl)propane (24%), 2-(4-beta-D-glucopyranosyloxy-3-hydroxyphenyl)-2-(4-beta-D-glucopyranosyloxyphenyl) propane (15%), and 2-(3-beta-D-glucopyranosyloxy-4-hydroxyphenyl)-2-(4-beta-D-glucopyranosyloxyphenyl)propane (11%).

Glycosylation of daidzein by the Eucalyptus cell cultures.

The sequential glycosylation of a soybean isoflavone, daidzein, with cultured suspension cells of Eucalyptus perriniana and cyclodextrin glucanotransferase was studied. Daidzein was converted into two glycosylation products, daidzein 7-O-beta-D-glucopyranoside (39%) and daidzein 7-O-[6-O-(beta-D-glucopyranosyl)]-beta-D-glucopyranoside (beta-gentiobioside, 6%), by cultured E. perriniana cells. Further glycosylation of daidzein 7-O-beta-glucoside with cyclodextrin glucanotransferase gave daidzein 7-O-[4-O-(alpha-D-glucopyranosyl)]-beta-D-glucopyranoside (beta-maltoside, 26%), daidzein 7-O-beta-maltotrioside (15%), and daidzein 7-O-beta-maltotetraoside (7%).

Glycosylation of hesperetin by plant cell cultures.

The biotransformation of hesperetin by cultured cells of Ipomoea batatas and Eucalyptus perriniana was investigated. Three glycosides, hesperetin 3'-O-beta-D-glucopyranoside (33 microg/g fr. wt of cells), hesperetin 3',7-O-beta-D-diglucopyranoside (217 microg/g fr. wt of cells), and hesperetin 7-O-[6-O-(beta-D-glucopyranosyl)]-beta-d-glucopyranoside (beta-gentiobioside, 22 microg/g fr. wt of cells), together with three hitherto known glycosides, hesperetin 5-O-beta-d-glucopyranoside (23 microg/g fr. wt of cells), hesperetin 7-O-beta-D-glucopyranoside (57 microg/g fr. wt of cells), and hesperetin 7-O-[6-O-(alpha-L-rhamnopyranosyl)]-beta-D-glucopyranoside (beta-rutinoside, hesperidin, 13 microg/g fr. wt of cells), were isolated from cultured suspension cells of E. perriniana that had been treated with hesperetin. Oligosaccharide chains were regioselectively formed at the C-7 position of hesperetin to afford beta-gentiobioside and beta-rutinoside. On the other hand, cultured I. batatas cells converted hesperetin into hesperetin 3'-O-beta-D-glucopyranoside (60 microg/g fr. wt of cells), hesperetin 5-O-beta-D-glucopyranoside (23 microg/g fr. wt of cells), and hesperetin 7-O-beta-D-glucopyranoside (110 microg/g fr. wt of cells).