Articolele autorului Grigore DAMIAN
Link la profilul stiintific al lui Grigore DAMIAN

Oxidative protection of hemoglobin and hemerythrin by cross-linking with a nonheme iron peroxidase: Potentially improved oxygen carriers for use in blood substitutes

The nonheme peroxidase, rubrerythrin, shows the ability to reduce hydrogen peroxide to water without involving strongly oxidizing and free-radical creating powerful oxidants such as compounds I and II [formally Fe(IV)] formed in peroxidases and catalases. Rubrerythrin could, therefore, be a useful ingredient in protein-based artificial oxygen carriers. Here, we report that the oxygen-carrying proteins, hemoglobin (Hb) and hemerythrin (Hr), can each

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Evaluation of Antioxidant and Antimicrobial Activities and Phenolic Profile for Hyssopus officinalis, Ocimum basilicum and Teucrium chamaedrys

This study was designed to examine the in vitro antioxidant and antimicrobial activities and to characterize the polyphenolic composition of the ethanolic extracts of Hyssopus officinalis, Ocimum basilicum and Teucrium chamaedrys. Qualitative and quantitative analysis of the major phenolic compounds were conducted using high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). The total polyphenols, caffeic acid derivatives and

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EPR investigation of libration motion of spin labeled hemerythrin

Reported here are room-temperature continuous wave X-band Electron Paramagnetic Resonance (EPR) spectra of the non-heme di-iron protein hemerythrin (Hr), spin labeled at position 51C in different viscous media, illustrating the mobility and oligomeric recombination tendency of the Phascolopsis gouldii Hr. The mobility of a spin labeled Hr depends on the local viscosity and its connectivity to the nature of the molecular environment (glycerol, PEG4000

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Microwave assisted synthesis, photophysical and redox properties of (phenothiazinyl)vinyl-pyridinium dyes

New cationic cyanine dyes, containing electron donor 10-alkyl-phenothiazine and electron acceptor pyridinium units connected through a vinylene bridge were conveniently synthesized by microwaves assisted condensation of phenothiazine carbaldehyde with methylpyridinium salts in dry media. Their photophysical properties revealing strong absorption bands in 440-470 nm region (É ≈ 104-105) and large Stokes shifts of fluorescence emission (610-750

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Photoprotective effects of Romanian propolis on skin of mice exposed to UVB irradiation

We aimed at investigating the antioxidant, antiinflamatory, antiapoptotic and antigenotoxic effects of a Romanian Propolis (RP) extract in two concentrations (RP1 3 mg, respectively RP2 1.5mg polyphenols/cm2), topically administered, either prior to or after UVB exposure, in a Swiss mouse model. Our results showed that both concentrations of RP extract, independent of the time of administration, significantly attenuated the malondialdehyde (MDA)

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Gamma radiation effects on seed germination, growth and pigment content, and ESR study of induced free radicals in maize (Zea mays)

The effects of gamma radiation are investigated by studying plant germination, growth and development, and biochemical characteristics of maize. Maize dry seeds are exposed to a gamma source at doses ranging from 0.1 to 1 kGy. Our results show that the germination potential, expressed through the final germination percentage and the germination index, as well as the physiological parameters of maize seedlings (root and shoot lengths) decreased by

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Polyphenolic composition, antioxidant and antibacterial activities for two Romanian subspecies of Achillea distans Waldst. et Kit. ex Willd.

The aim of this work was to study the chemical composition, antioxidant and antibacterial properties of Achillea distans Waldst. et Kit. subsp. distans and Achillea distans Waldst. et Kit. subsp. alpina Rochel, from the Rodna Mountains (Romania). The identification and quantification of major phenolic compounds was performed by a HPLC-MS method. The total polyphenolic and flavonoid content was determined spectrophotometrically. The antioxidant activity

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An assay for pro-oxidant reactivity based on phenoxyl radicals generated by laccase

A transient species may be detected with UV-vis and EPR spectroscopy during turnover of a laccase with quercetin; this species is assigned as a quercetin-derived radical, based on EPR spectra as well the observed UV-vis similarities (a 540. nm centred band) with previously reported data. The rates of formation and decay of this species correlate well (. r=. 0.9946) with the pro-oxidant reactivity manifested by flavonoids in the presence of laccase.

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Site directed spin labeling Hemerythrin and hemoglobin

Site directed spin labeling in combination with electron paramagnetic resonance spectroscopy has become a very effective tool for studying the dynamics and structure of biomolecules in their native environment. This work presents the basics of site directed spin labeling and provides our results obtained in spin labeling hemerythrin and hemoglobin using methanethiosulfonate spin label. Best fit magnetic and libration parameters are obtained by simulation

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Anticancer and Antimicrobial Activities of Some Antioxidant-Rich Cameroonian Medicinal Plants

Traditional remedies have a long-standing history in Cameroon and continue to provide useful and applicable tools for treating ailments. Here, the anticancer, antimicrobial and antioxidant activities of ten antioxidant-rich Cameroonian medicinal plants and of some of their isolated compounds are evaluated.The plant extracts were prepared by maceration in organic solvents. Fractionation of plant extract was performed by column chromatography and the

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