Effect of hydrogen peroxide on normal and acatalasemic mouse erythrocytes.

Objectives: Normal and acatalasemic mouse erythrocytes were used to clarify the relationship between oxidative damage in HO-treated erythrocytes and catalase activity.

Design & Methods: Generation of hydrolysis-resistant erythrocytes and hemolysis were examined. The osmotic fragility test, the negative charges and the number of membrane-flickering erythrocytes among the HO-treated erythrocytes were investigated.

Glycosylation and Methylation of Quercetin and Myricetin by Cultured Cells of Phytolacca americana.

The glycosylation and methylation of quercetin by cultured plant cells of Phytolacca americana gave quercetin 3-Ο-β-D-glucoside and isorharnnetin 3-Ο-β-D- glucoside. Myricetin was glycosylated and methylated to syringetin 3-Ο-β-D-glucoside by cultured P. americana cells.

Synthesis of glycosides of resveratrol, pterostilbene, and piceatannol, and their anti-oxidant, anti-allergic, and neuroprotective activities.

Resveratrol was glucosylated to its 3- and 4'-β-glucosides by cultured cells of Phytolacca americana. On the other hand, cultured P. americana cells glucosylated pterostilbene to its 4'-β-glucoside.

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.

Effect of vitamin E on alloxan-induced mouse diabetes.

Objectives: Alloxan generates hydrogen peroxide in the body, and a small amount of alloxan administered to acatalasemic mice results in diabetes. D-α-Tocopherol (vitamin E) is an antioxidant which helps prevent excess oxidation in the body. In this study, we examined the effect of vitamin E on diabetes caused by alloxan administration in mice.

Glycosylation of trans-resveratrol by plant-cultured cells.

Plant-cultured cells of Catharanthus roseus converted trans-resveratrol into its 3-O-β-D-glucopyranoside, 4'-O-β-D-glucopyranoside, 3-O-(6-O-β-D-xylopyranosyl)-β-D-glucopyranoside, and 3-O-(6-O-α-L-arabinopyranosyl)-β-D-glucopyranoside. The 3-O-(6-O-β-D-xylopyranosyl)-β-D-glucopyranoside and 3-O-(6-O-α-L-arabinopyranosyl)-β-D-glucopyranoside compounds of trans-resveratrol are both new. Incubation of plant-cultured cells of Ipomoea batatas and Strophanthus gratus with trans-resveratrol gave trans-resveratrol 3-O-β-D-glucopyranoside and trans-resveratrol 4'-O-β-D-glucopyranoside.

Plant-based Paste Fermented by Lactic Acid Bacteria and Yeast: Functional Analysis and Possibility of Application to Functional Foods.

A plant-based paste fermented by lactic acid bacteria and yeast (fermented paste) was made from various plant materials. The paste was made of fermented food by applying traditional food-preservation techniques, that is, fermentation and sugaring. The fermented paste contained major nutrients (carbohydrates, proteins, and lipids), 18 kinds of amino acids, and vitamins (vitamin A, B1, B2, B6, B12, E, K, niacin, biotin, pantothenic acid, and folic acid).

One-procedure synthesis of capsiate from capsaicin by lipase-catalyzed dynamic transacylation.

Capsiate has a structure similar to capsaicin but no oral pungency. Furthermore, capsiate displayed antioxidant activity and inhibited angiogenesis and vascular permeability, and therefore, showed potential as a medicine and food supplement. Capsaicin is now commercially available, however capsiate is scarcely present in natural foods.

Enzymatic preparation of arbutin derivatives: lipase-catalyzed direct acylation without the need of vinyl ester as an acyl donor.

Direct and regioselective acylation of arbutin with aromatic or aliphatic acid using a lipase obtained from Candida antarctica in an organic solvent was investigated. We achieved the enzymatic synthesis of feruloyl arbutin and lipoyl arbutin without the need of vinyl ferulate and vinyl lipoate as acyl donors, respectively.

Low catalase activity in blood is associated with the diabetes caused by alloxan.

Background: Hydrogen peroxide is enzymatically processed by catalase, and catalase deficiency in blood is known as acatalasemia. We examined whether low catalase activity is a risk factor for diabetes mellitus.

Methods: Blood glucose, insulin and glucose tolerance test were examined in acatalasemic and normal mice under non-stress and oxidative stress conditions.

Stereoselective reduction of carbonyl compounds with Actinomycete: purification and characterization of three alpha-keto ester reductases from Streptomyces avermitilis.

We achieved the purification of three alpha-keto ester reductases (Streptomyces avermitilis keto ester reductase, SAKERs-I, -II, and -III) from Streptomyces avermitilis NBRC14893 whole cells. The molecular masses of the native SAKERs-I, -II, and -III were estimated to be 72, 38, and 36 kDa, respectively, by gel filtration chromatography. The subunit molecular masses of SAKERs-I, -II, and -III were also estimated to be 32, 32, and 34 kDa, respectively, by SDS-polyacrylamide gel electrophoresis.

Glucosylation of phenols and phenylalkyl alcohols using cultured plant cells.

Cultured plant cells of Eucalyptus perriniana can convert phenol and phenylalkyl alcohols [C(6)H(5)(CH(2))(n)OH, n=0-3] into the corresponding beta-D-glucopyranosides in a good yield. The cells preferentially glucosylated phenylmethanol (n=1, 59% yield) rather than phenol (n=0, 49%), 2-phenylethanol (n=2, 38%), and 3-phenylpropan-1-ol (n=3, 20%). On the other hand, 2-, 3-, and 4-hydroxyphenylmethanols were also glucosylated to (hydroxymethyl)phenyl beta-D-glucopyranosides and (hydroxyphenyl)methyl beta-D-glucopyranosides by cultured E.

Stereoselective reduction of carbonyl compounds using the cell-free extract of the earthworm, Lumbricus rubellus, as a novel source of biocatalyst.

We found the reducing activity toward carbonyl compounds in the cell-free extract of the earthworm, Lumbricus rubellus. The earthworm extract had a reducing activity for keto esters in the presence of NADH or NADPH as a coenzyme. The earthworm extract reduced ethyl 3-methyl-2-oxobutanoate to the corresponding alcohol with a high enantiomeric excess (91%, R-form) at 50 degrees C in the presence of NADH.

Enhancement of water-solubility and bioactivity of paclitaxel using modified cyclodextrins.

We investigated the aqueous solubility of paclitaxel using 11 kinds of cyclodextrins (CDs) and the bioactivity of the paclitaxel-CD inclusion complex. 2,6-Dimethyl beta-cyclodextrin was the most effective and its solubility was 2.3 mM in a 0.

Analysis of isoflavone content in tempeh, a fermented soybean, and preparation of a new isoflavone-enriched tempeh.

To produce a tempeh-like functional food containing a high level of isoflavone with a high absorptivity, we analyzed changes in the composition of isoflavone during tempeh fermentation and the difference in isoflavone content depending on the soybean variety and particular tissue. By adding soybean germ (hypocotyl) that contained a large amount of isoflavone, we prepared a new isoflavone-enriched tempeh in the form of a granular fermented soybean-based food, which can serve as a nutritious supplement for the elderly.

An isozyme of earthworm serine proteases acts on hydrolysis of triacylglycerol.

An enzyme catalyzing the hydrolysis of triacylglycerol was purified from an earthworm. The N-terminal amino acid sequence and the catalytic function of the purified enzyme were identical to those of Isozyme C, an isozyme of the earthworm-serine proteases. No other lipase proteins were found in the earthworm cells.

Stereoselective biotransformation of limonene and limonene oxide by cyanobacterium, Synechococcus sp. PCC 7942.

The biotransformation of limonene and limonene oxide by the cyanobacterium, Synechococcus sp. PCC 7942, was investigated. (S)-(+)-Limonene was hydroxylated stereo- and regioselectively at its allylic position of the endocyclic C=C double bond by the cyanobacterial cells to its corresponding alcohol.

Purification and characterization of alpha-keto amide reductase from Saccharomyces cerevisiae.

An NADPH-dependent alpha-keto amide reductase was purified from Saccharomyces cerevisiae. The molecular mass of the native enzyme was estimated to be 33 and 36 kDa by gel filtration chromatography and SDS-polyacrylamide gel electrophoresis, respectively. The purified enzyme showed a reducing activity not only for aromatic alpha-keto amides but also for aliphatic and aromatic alpha-keto esters.

A novel zinc-containing alpha-keto ester reductase from actinomycete: an approach based on protein chemistry and bioinformatics.

We have achieved the purification of an alpha-keto ester reductase (SCKER) from S. coelicolor A3(2) whole cells. SCKER proved to be a homotetramer of 132 kDa containing one equivalent of zinc ion per subunit.

Damage to cultivated Japanese pearl oysters by oxidative stress that was related to "mass mortality".

Increased blood-DNA breakage was observed in diseased pearl oysters. They showed significant formation of 8-hydroxydeoxyguanosine (8-OHdG) and malondialdehyde (MDA), whereas the oysters that had a low mortality rate from the disease had high activity of superoxide dismutase (SOD) and low amounts of 8-OHdG and MDA. These results suggest that radical damage had occurred only in the diseased pearl oysters with the cytolysis of their haemocytes, which was related to the mass mortality of the Japanese pearl oysters.

Comparison of acylated plant pigments: light-resistance and radical-scavenging ability.

The acylated plant pigments synthesized by lipase-catalyzed transesterification with aromatic acids were compared in respect of their light-resistance and radical-scavenging ability. With both the flavonols and anthocyanins, their acylated derivatives were more stable against illumination with fluorescent light than their non-acylated glucosides. Their radical-scavenging ability partially decreased or was retained by acylation to the glucoside molecules.

Further stabilization of earthworm serine protease by chemical modification and immobilization.

Earthworm serine protease is more stable and is less affected by organic solvents and detergent than other proteases. However, it is inactivated, probably by autolysis, at 60 degrees C or above under alkaline conditions. Further stabilization was managed by chemical modification of the enzyme with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and phenylglyoxal to protect the activity from the autolytic inactivation.

Purification and characterization of two alpha-keto ester reductases from Streptomyces thermocyaneoviolaceus IFO 14271.

Two NADPH-dependent alpha-keto ester reductases (Streptomyces thermocyaneoviolaceus keto ester reductase, STKER-II and -III) were purified from S. thermocyaneoviolaceus IFO 14271, one of thermophilic actinomycetes. The molecular masses of native STKER-II and -III were estimated to be 60 kDa and 70 kDa by gel filtration chromatography, respectively.