Tamio Maitani

The Composition of Metals Bound to Class III Metallothionein (Phytochelatin and Its Desglycyl Peptide) Induced by Various Metals in Root Cultures of Rubia tinctorum.

The induction of phytochelatins (PCs) and their desglycyl peptides (both are referred to as class III metallothionein [CIIIMT]) by exposure to various metals (Ag+, As3+, As5+, Cd2+, Cu2+, Ga3+, Hg2+, In3+, Ni2+, Pb2+, Pd2+, Se4+, and Zn2+) and the metal composition in the CIIIMTs were investigated in root cultures of Rubia tinctorum L. All of these metal species induced PCs to various degrees when analyzed by the postcolumn derivatization high-performance liquid chromatography method. The desglycyl peptides of PCs often were also present. However, only Ag, Cd, and Cu were bound to the CIIIMTs that they induced when analyzed by the high-performance liquid chromatography-inductively coupled plasma-atomic emission spectrometry method. Cu was also bound to the CIIIMTs induced by Ag+, As3+, and Cd2+. After Ag+ exposure, an Fe peak that may be of Fe-CIIIMT was also observed. However, most of the metal species studied were not bound to the CIIIMTs that they induced.

Two acylated anthocyanins from purple sweet potato

Two new acylated anthocyanins were isolated from the storage root of Ipomoea batatas. On the basis of spectroscopic analyses, these compounds were identified as the 3-O-(6-O-trans-caffeyl-2-O-beta-glucopyranosyl-beta-glucopyranoside)-5-O - beta-glucoside of cyanidin and peonidin.

Phytochelatin homologs induced in hairy roots of horseradish

When exposed to excess heavy metals, plants induce phytochelatins and related peptides (all designated as PCAs). Thus, when hairy roots of horseradish (Armoracia rusticana) were exposed for 3 days to cadmium (1 mM) along with reduced glutathione (2 mM), PCA induction occurred. Moreover, a new family of thiol peptides was detected as well as the previously known PCAs, as revealed by postcolumn-derivatization HPLC. Two were isolated and their structures were identified as (gamma-Glu-Cys)n-Gln (n = 3 and 4) by electrospray ionization-mass spectrometer spectra, this being confirmed by chemical synthesis of the peptides. These new analogs constitute the sixth PCA family identified to date.

Hydride generation-flame atomic-absorption spectrometry as an arsenic detector for high-performance liquid chromatography.

Hydride generation-flame atomic-absorption spectrometry (HG-FAAS) was used as a continuous detection system for arsenic in the eluate from high-performance liquid chromatography (HPLC). Four arsenic species (arsenite, arsenate, monomethylarsonate and dimethylarsinate) were detected separately with the HPLC-HG-FAAS system equipped with an anion-exchange column. When hijiki (Hizikia fusiforme) extract was examined, arsenate was found predominantly and arsenite and dimethylarsinate were also detected. Liver supernatant fraction obtained from mice administered orally with arsenite was also studied with the HPLC-HG-FAAS system equipped with a gel permeation column. In addition to free or low-molecular-weight ligand-bound arsenic, high-molecular-weight protein-bound arsenic fractions were also detected.

Induction of metallothionein after lead administration by three injection routes in mice

The amount of induced hepatic metallothionein (MT) and the alterations of calcium (Ca) and lead (Pb) concentrations in plasma, liver, kidney, and spleen were compared in male mice after iv, ip, and sc injections of lead acetate at a dose of 30 mg Pb/kg body wt. The amount of hepatic MT at 1 day was in the order of ip greater than iv greater than sc injection approximately 0, despite the hepatic Pb concentration in the order of iv greater than ip greater than sc injection. Heat-stable Pb-binding MT was not detected following any injection route. After the iv injection, a transitory hypercalcemia with hyperphosphatemia was observed. As for the tissue Pb concentration after the iv and ip injections, liver and spleen showed a high concentration, while kidney concentration was relatively low. The high tissue Pb was accompanied by an increase of tissue Ca in most cases. Only 10 to 15% of the total Pb accumulated in the liver at 1 day was recovered from the supernatant fraction after ultracentrifugation. The increase of hepatic Ca was ascribed to that in the sediment fraction. After the sc injection, the tissue Pb concentration was very low and no alterations were observed in tissue Ca concentrations.

Anthocyanin production of Glehnia littoralis callus cultures

A stable callus line that produces anthocyanins was established from callus derived from a petiole of a Glehnia littoralis seedling and subcultured in the dark. The major anthocyanin which made up about 60% of the total anthocyanins was determined as cyanidin 3-O-(6-O-(6-O-(E)-feruloyl-beta-D-glucopyranosyl) -2-O-beta-D-xylopyranosyl-beta-D-glucopyranoside) by chemical and spectroscopic analyses. Anthocyanin contents in the cells cultured on B5 basal medium containing NAA (1 mg l-1), kinetin (0.01 mg l-1) and 3% sucrose reached 14% (dry wt basis) and the productivity has been sustained for 5 years.

Molecular weight distribution of carrageenans studied by a combined gel permeation/inductively coupled plasma (GPC/ICP) method

Degraded carrageenan (known as poligeenan, molecular weight: 20kDa to 30kDa) causes ulcerative colitis in experimental animals. In this paper, the molecular weight distributions of 29 samples of food-grade refined carrageenans were studied by high performance liquid gel permeation chromatography (GPC) directly connected to vacuum-ultraviolet inductively coupled plasma-atomic emission spectrometry (ICP) (GPC/ICP) as well as GPC/refractive index (RI) detection. All samples of food-grade carrageenan had a major broad peak of high molecular weight which eluted at around 6.5min in both RI and ICP mode (sulphur and carbon), and each sample of them had no obvious peak of poligeenan (the detection limit was about 5%). The number average molecular weights of these carrageenans ranged from 193 kDa to 324kDa, and the weight average molecular weights ranged from 453kDa to 652kDa based on RI data. Some samples had a few minor peaks which eluted around 10–12min. These peaks came from ionic sulphate, sucrose or glucose. It was considered that if the data-sampling programme was improved, the GPC/ICP system would become a more powerful technique for evaluation of carrageenan samples containing ionic substances and sugar.

Acute renal dysfunction by cadmium injected with cysteine in relation to renal critical concentration of cadmium.

In order to study the critical concentration of cadmium (Cd) in acute renal dysfunction following Cd, male mice were injected IV with Cd complexed with cysteine. The critical concentration was 10 μg Cd/g wet weight in whole kidney and it was the same as that for Cdthionein (Cd-Th), which may suggest that the toxicity of Cd-Th is due to Cd ions liberated from Cd-Th in the kidneys. Renal Cd concentration was at first higher than the critical concentration, but decreased to the critical concentration by 24 h after administration. As an index for renal dysfunction, the uptake of p-aminohippurate (PAH) by renal cortical slices in vitro was sensitive, and showed the different time-course from those of urinary protein and glucose levels. The results suggest the usefulness of PAH uptake as an index. Incidental to the renal dysfunction, renal calcium levels exhibited a marked increase.

Analysis of enzymatically glucosylated flavonoids by capillary electrophoresis.

HPCE with UV detection was applied to the analyses of enzymatically glucosylated flavonoids, which are used as natural food additives in Japan. Four items, which have flavonol or flavanone as aglycone, were analyzed. Each of these items is a mixture of glycosides with various lengths of maltooligosaccharide chain. On capillary zone electrophoresis with an untreated fused-silica capillary at alkaline pH, glycosides with longer sugar chains migrated more rapidly. Flavonol glycosides with 1-13 glucose units were distinguished with the borate buffer (pH 10.0). Flavanone glycosides needed higher pH values for good separation than flavonol glycosides.

Essential metal contents and metallothionein-like protein in testes of mice after cadmium administration

To study the testicular injury by Cd from the viewpoint of essential element levels, male mice were injected with Cd subcutaneously at a dose of 30 mumol/kg body weight singly and the concentrations of 8 elements (Na, Mg, P, K, Ca, Fe, Zn, and Cd) in the testis were measured for 6 weeks. The most pronounced alteration was an increase of Ca content with time after the injection; the experimental group had 270 times more Ca than the control despite a decrease of the testis weight to one-third of the control at 4 weeks. K content decreased markedly and Fe remained at an elevated level throughout the experimental period. Decreased Mg, P, and Zn levels started to be restored after 2 weeks. Metallothionein (MT)-like Zn-binding proteins were studied in the cytosol fraction with a high performance liquid chromatograph-atomic absorption spectrophotometer. MT-like proteins were observed at a higher concentration in the control than in the Cd-injected group. No indications of new induction of MTs or MT-like proteins could be detected.