Food chemist associated with flavor and Maillard reaction. The research involves heavily functional components of foods and plants.Environmental chemist associated with fate of pesticides and dioxins.
A charred sample was prepared from potato starch heated with ammonium carbonate at 600 degrees C ... more A charred sample was prepared from potato starch heated with ammonium carbonate at 600 degrees C in a flask under a nitrogen stream. The water produced was collected and extracted with methylene chloride. The basic fraction obtained from the extract exhibited strong mutagenicity in Ames assays using Salmonella typhimurium strains TA98 or TA100 with metabolic activation (rat-liver S-9 mix). The basic fraction was further fractionated by silica gel column chromatography and subsequently by Sephadex column chromatography. Some of the resulting fractions exhibited strong mutagenic activities in S. typhimurium strain TA98 with S-9 mix.
Formation and inhibition of malonaldehyde (MA) from blood plasma lipids oxidized by Fenton&#3... more Formation and inhibition of malonaldehyde (MA) from blood plasma lipids oxidized by Fenton's reagent in the absence or presence of probucol [4,4'-(isopropylidenedithio)bis(2,6-di-tert-butylphenol)] and L-ascorbic acid were investigated. The amount of MA formed was quantitatively analysed by gas chromatography. L-Ascorbic acid inhibited MA formation by about 30% at the level of 4.0/micromol, but the amount of MA formed was increased by the presence of probucol. When 3.0 micromol oxidized probucol was hydrolysed at pH 1. 3 and 5, 2616.5 nmol, 287.5 nmol and 103.9 nmol MA were recovered, respectively. This is the first report of quantitative analysis of MA formed from probucol on oxidation.
Publisher Summary Essential oils are derived from various parts of the plant, including leaves, f... more Publisher Summary Essential oils are derived from various parts of the plant, including leaves, flowers, fruits, seeds, rhizomes, roots, and bark. In the plant, these constituents serve several physiological purposes for the plant—protection from pests and microorganisms, attraction of pollinating insects or birds, providing photoprotection to the plant, and allelopathy. The complex mixtures of volatile, aromatic components are secondary plant metabolites and are usually obtained by distillation. Mild techniques such as enfleurage, expression, extraction, or fermentation are also used for the isolation of more sensitive compounds. Essential oils have traditionally been used to impart flavoring or preservative effects in foods or to instill fragrances in cosmetics and aromatherapy. Since ancient times, numerous civilizations have also valued essential oils for their therapeutic qualities in disease prevention and treatment. Current interest in essential oils arises from the various bioactive effects they display, including antioxidant anti-inflammatory, antimicrobial, antiviral, and anticarcinogenic. Demand for plant essential oils has risen as a consequence of consumers searching for cheaper, more “natural” alternatives to disease-fighting medications. In food and cosmetic applications, essential oils are considered to be biodegradable, readily available, and “less toxic” than synthetic preservative agents. This optimism has raised concerns and stimulated studies to evaluate the safety and efficacy of essential oils in various systems in order to better understand their pharmacological properties and roles in health.
The attack of DNA by reactive oxygen species, such as hydroxyl radical, causes several types of d... more The attack of DNA by reactive oxygen species, such as hydroxyl radical, causes several types of damage, which subsequently promote diseases. Determination of oxidized products, such as malonaldehyde (MA), from DNA would provide theoretical and practical information on the mechanisms of DNA oxidation following DNA damage and this information could be used to prevent DNA damage caused by oxidation. In the present study, calf thymus DNA was oxidized by Fenton's reagent/EDTA with or without natural antioxidants-flavonoids and anthocyanins-and synthetic antioxidants, Trolox and 2H-pyrrole, 3,4-dihydro-2,2-dimethyl-, 1-oxide (DMPO). Amounts of MA formed, which was determined by gas chromatography, in oxidized DNA with the presence of antioxidants, ranged from 7.35+/-0.88 nmol/mg (2''-O-GIV) to 12.6+/-0.24 nmol/g (cyanidin). Except for cyanidin, all antioxidants tested inhibited MA formation. DMPO and Trolox inhibited MA formation by 12.4% and 27.3%, respectively from oxidized DNA. The decreasing order of inhibitory effect by the anthocyanins was callistephin (30.2%)>keracyanin (27.3%)>Pelargonindin (10.1%)>cyanidin (0%). The decreasing order of inhibitory effect by the flavonoids was 2''-O-GIV (42.7%)>catechin (8.8%)>quercetin (36.4%)>apigenin (34.4%). It is hypothesized that EDTA controlled formation of hydroxyl radicals via trapping Fe(II) ions reversibly.
... 33. Affinity Chromatography: Practical and Theoretical Aspects, Peter Mohr and Klaus Pommeren... more ... 33. Affinity Chromatography: Practical and Theoretical Aspects, Peter Mohr and Klaus Pommerening 34. Reaction ... 44. Countercurrent Chromatography: Theory and Practice, edited by N. Bhu-shan Mandava and Yoichiro Ito 45. Microbore ...
Response differences by different strains of mice towards house dust mites (Dermatophagoides fari... more Response differences by different strains of mice towards house dust mites (Dermatophagoides farinae) or diesel exhaust particles (DEP) were investigated. Mouse strains BALB/c, ICR and C3H/He received 1 micro g of D. farinae or 1 microg of D. farinae + 50 microg of DEP intratracheally four times at 2-week intervals. Dermatophagoides farinae treatment caused the recruitment of eosinophils and lymphocytes. The order of magnitude of the eosinophilic airway inflammation was BALB/c < ICR < C3H/He mice. The protein levels of eotaxin and IL-5 in lung tissues correlated with the manifestations of eosinophilic airway inflammation by D. farinae administration. Diesel exhaust particles aggravated the manifestation of the eosinophilic inflammation through goblet cell proliferation in the airway and enhanced the local expression of eotaxin and IL-5 in all three strains of mice. The levels of eotaxin and IL-5 in lung tissues corresponded to the pathological changes caused by D. farinae + DEP. The increasing order of production levels of antigen-specific IgG1 by D. farinae or D. farinae + DEP was BALB/c < ICR < C3H/He mice. The significant adjuvant effect of DEP on IgG1 production was observed in the C3H/He mice (P < 0.05). These results suggest that the murine strain differences in the production of eosinophilic airway inflammation by D. farinae + DEP are related to differences in local expression of IL-5 and eotaxin. The enhancing effects of DEP may be mediated by a cytokine increase in the local expression. Antigen-specific IgG1 may be an important immunoglobulin in the pathogenesis of allergic asthma enhanced by DEP.
A charred sample was prepared from potato starch heated with ammonium carbonate at 600 degrees C ... more A charred sample was prepared from potato starch heated with ammonium carbonate at 600 degrees C in a flask under a nitrogen stream. The water produced was collected and extracted with methylene chloride. The basic fraction obtained from the extract exhibited strong mutagenicity in Ames assays using Salmonella typhimurium strains TA98 or TA100 with metabolic activation (rat-liver S-9 mix). The basic fraction was further fractionated by silica gel column chromatography and subsequently by Sephadex column chromatography. Some of the resulting fractions exhibited strong mutagenic activities in S. typhimurium strain TA98 with S-9 mix.
Formation and inhibition of malonaldehyde (MA) from blood plasma lipids oxidized by Fenton&#3... more Formation and inhibition of malonaldehyde (MA) from blood plasma lipids oxidized by Fenton's reagent in the absence or presence of probucol [4,4'-(isopropylidenedithio)bis(2,6-di-tert-butylphenol)] and L-ascorbic acid were investigated. The amount of MA formed was quantitatively analysed by gas chromatography. L-Ascorbic acid inhibited MA formation by about 30% at the level of 4.0/micromol, but the amount of MA formed was increased by the presence of probucol. When 3.0 micromol oxidized probucol was hydrolysed at pH 1. 3 and 5, 2616.5 nmol, 287.5 nmol and 103.9 nmol MA were recovered, respectively. This is the first report of quantitative analysis of MA formed from probucol on oxidation.
Publisher Summary Essential oils are derived from various parts of the plant, including leaves, f... more Publisher Summary Essential oils are derived from various parts of the plant, including leaves, flowers, fruits, seeds, rhizomes, roots, and bark. In the plant, these constituents serve several physiological purposes for the plant—protection from pests and microorganisms, attraction of pollinating insects or birds, providing photoprotection to the plant, and allelopathy. The complex mixtures of volatile, aromatic components are secondary plant metabolites and are usually obtained by distillation. Mild techniques such as enfleurage, expression, extraction, or fermentation are also used for the isolation of more sensitive compounds. Essential oils have traditionally been used to impart flavoring or preservative effects in foods or to instill fragrances in cosmetics and aromatherapy. Since ancient times, numerous civilizations have also valued essential oils for their therapeutic qualities in disease prevention and treatment. Current interest in essential oils arises from the various bioactive effects they display, including antioxidant anti-inflammatory, antimicrobial, antiviral, and anticarcinogenic. Demand for plant essential oils has risen as a consequence of consumers searching for cheaper, more “natural” alternatives to disease-fighting medications. In food and cosmetic applications, essential oils are considered to be biodegradable, readily available, and “less toxic” than synthetic preservative agents. This optimism has raised concerns and stimulated studies to evaluate the safety and efficacy of essential oils in various systems in order to better understand their pharmacological properties and roles in health.
The attack of DNA by reactive oxygen species, such as hydroxyl radical, causes several types of d... more The attack of DNA by reactive oxygen species, such as hydroxyl radical, causes several types of damage, which subsequently promote diseases. Determination of oxidized products, such as malonaldehyde (MA), from DNA would provide theoretical and practical information on the mechanisms of DNA oxidation following DNA damage and this information could be used to prevent DNA damage caused by oxidation. In the present study, calf thymus DNA was oxidized by Fenton's reagent/EDTA with or without natural antioxidants-flavonoids and anthocyanins-and synthetic antioxidants, Trolox and 2H-pyrrole, 3,4-dihydro-2,2-dimethyl-, 1-oxide (DMPO). Amounts of MA formed, which was determined by gas chromatography, in oxidized DNA with the presence of antioxidants, ranged from 7.35+/-0.88 nmol/mg (2''-O-GIV) to 12.6+/-0.24 nmol/g (cyanidin). Except for cyanidin, all antioxidants tested inhibited MA formation. DMPO and Trolox inhibited MA formation by 12.4% and 27.3%, respectively from oxidized DNA. The decreasing order of inhibitory effect by the anthocyanins was callistephin (30.2%)>keracyanin (27.3%)>Pelargonindin (10.1%)>cyanidin (0%). The decreasing order of inhibitory effect by the flavonoids was 2''-O-GIV (42.7%)>catechin (8.8%)>quercetin (36.4%)>apigenin (34.4%). It is hypothesized that EDTA controlled formation of hydroxyl radicals via trapping Fe(II) ions reversibly.
... 33. Affinity Chromatography: Practical and Theoretical Aspects, Peter Mohr and Klaus Pommeren... more ... 33. Affinity Chromatography: Practical and Theoretical Aspects, Peter Mohr and Klaus Pommerening 34. Reaction ... 44. Countercurrent Chromatography: Theory and Practice, edited by N. Bhu-shan Mandava and Yoichiro Ito 45. Microbore ...
Response differences by different strains of mice towards house dust mites (Dermatophagoides fari... more Response differences by different strains of mice towards house dust mites (Dermatophagoides farinae) or diesel exhaust particles (DEP) were investigated. Mouse strains BALB/c, ICR and C3H/He received 1 micro g of D. farinae or 1 microg of D. farinae + 50 microg of DEP intratracheally four times at 2-week intervals. Dermatophagoides farinae treatment caused the recruitment of eosinophils and lymphocytes. The order of magnitude of the eosinophilic airway inflammation was BALB/c < ICR < C3H/He mice. The protein levels of eotaxin and IL-5 in lung tissues correlated with the manifestations of eosinophilic airway inflammation by D. farinae administration. Diesel exhaust particles aggravated the manifestation of the eosinophilic inflammation through goblet cell proliferation in the airway and enhanced the local expression of eotaxin and IL-5 in all three strains of mice. The levels of eotaxin and IL-5 in lung tissues corresponded to the pathological changes caused by D. farinae + DEP. The increasing order of production levels of antigen-specific IgG1 by D. farinae or D. farinae + DEP was BALB/c < ICR < C3H/He mice. The significant adjuvant effect of DEP on IgG1 production was observed in the C3H/He mice (P < 0.05). These results suggest that the murine strain differences in the production of eosinophilic airway inflammation by D. farinae + DEP are related to differences in local expression of IL-5 and eotaxin. The enhancing effects of DEP may be mediated by a cytokine increase in the local expression. Antigen-specific IgG1 may be an important immunoglobulin in the pathogenesis of allergic asthma enhanced by DEP.
Uploads