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Structure Effect on Antioxidant Activity of Catecholamines toward Singlet Oxygen and Other Reactive Oxygen Species in vitro.

Shimizu T, Nakanishi Y, Nakahara M, Wada N, Moro-Oka Y, Hirano T, Konishi T, Matsugo S - J Clin Biochem Nutr (2010)

Bottom Line: The results revealed that reactivity of catecholamines was markedly higher than that of sodium azide, and catechin as catechol reference.DMPO-OH signal of epinephrine was significantly small compared to other catecholamines, catechin, and 4-methylcatechol as a reference compound and was as small as that of tyrosine.These results indicated that epinephrine is the most potent singlet oxygen quencher than other catecholamines, and the secondary amino group in its alkyl side chain could play a role in unique singlet oxygen quenching property of epinephrine.

View Article: PubMed Central - PubMed

Affiliation: School of Natural System, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.

ABSTRACT
The reactivity of catecholamine neurotransmitters and the related metabolites were precisely investigated toward 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and reactive oxygen species. Catecholamines reacted immediately with DPPH radicals, their reactivity being stronger than that of ascorbic acid as a reference. Superoxide scavenging activities of catecholamines determined by WST-1 and electron spin resonance (ESR) spin trapping methods were also high. Whereas tyrosine, the dopamine precursor showed no reactivity toward superoxide. The reactivity toward singlet oxygen was evaluated by observing specific photon emission from singlet oxygen. The results revealed that reactivity of catecholamines was markedly higher than that of sodium azide, and catechin as catechol reference. The reaction of catecholamines and singlet oxygen was further studied by ESR using 55-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trapping reagent and rose bengal as photosensitizer. DMPO-OH signal of epinephrine was significantly small compared to other catecholamines, catechin, and 4-methylcatechol as a reference compound and was as small as that of tyrosine. The signal formation was totally dependent on singlet oxygen, and the presence of catechol compounds. These results indicated that epinephrine is the most potent singlet oxygen quencher than other catecholamines, and the secondary amino group in its alkyl side chain could play a role in unique singlet oxygen quenching property of epinephrine.

No MeSH data available.


Dose effect of catecholamines on singlet oxygen quenching reaction. Singlet oxygen quenching activity was measured as in Fig. 4. Precise reaction condition is given experimental section. (a) dopamine, (b) norepinephrine, (c) epinephrine, (d) L-DOPA, (e) sodium azide, (f) catechin.
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Figure 5: Dose effect of catecholamines on singlet oxygen quenching reaction. Singlet oxygen quenching activity was measured as in Fig. 4. Precise reaction condition is given experimental section. (a) dopamine, (b) norepinephrine, (c) epinephrine, (d) L-DOPA, (e) sodium azide, (f) catechin.

Mentions: The peak height of the emission spectra of singlet oxygen decreased in the presence of dopamine in a concentration dependent manner as shown in Fig. 4. The dose dependence of the quenching profile shown in Fig. 5 revealed that both epinephrine and norepinephrine have stronger quenching ability than dopamine and L-DOPA. The IC50 values of test samples are summarized in Table 5. The scavenging activities of catecholamines were significantly higher than those of catechin and sodium azide as typical singlet oxygen quencher. The reactivity was in the following order: epinephrine > norepinephrine > L-DOPA > dopamine >> catechin > sodium azide.


Structure Effect on Antioxidant Activity of Catecholamines toward Singlet Oxygen and Other Reactive Oxygen Species in vitro.

Shimizu T, Nakanishi Y, Nakahara M, Wada N, Moro-Oka Y, Hirano T, Konishi T, Matsugo S - J Clin Biochem Nutr (2010)

Dose effect of catecholamines on singlet oxygen quenching reaction. Singlet oxygen quenching activity was measured as in Fig. 4. Precise reaction condition is given experimental section. (a) dopamine, (b) norepinephrine, (c) epinephrine, (d) L-DOPA, (e) sodium azide, (f) catechin.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2966927&req=5

Figure 5: Dose effect of catecholamines on singlet oxygen quenching reaction. Singlet oxygen quenching activity was measured as in Fig. 4. Precise reaction condition is given experimental section. (a) dopamine, (b) norepinephrine, (c) epinephrine, (d) L-DOPA, (e) sodium azide, (f) catechin.
Mentions: The peak height of the emission spectra of singlet oxygen decreased in the presence of dopamine in a concentration dependent manner as shown in Fig. 4. The dose dependence of the quenching profile shown in Fig. 5 revealed that both epinephrine and norepinephrine have stronger quenching ability than dopamine and L-DOPA. The IC50 values of test samples are summarized in Table 5. The scavenging activities of catecholamines were significantly higher than those of catechin and sodium azide as typical singlet oxygen quencher. The reactivity was in the following order: epinephrine > norepinephrine > L-DOPA > dopamine >> catechin > sodium azide.

Bottom Line: The results revealed that reactivity of catecholamines was markedly higher than that of sodium azide, and catechin as catechol reference.DMPO-OH signal of epinephrine was significantly small compared to other catecholamines, catechin, and 4-methylcatechol as a reference compound and was as small as that of tyrosine.These results indicated that epinephrine is the most potent singlet oxygen quencher than other catecholamines, and the secondary amino group in its alkyl side chain could play a role in unique singlet oxygen quenching property of epinephrine.

View Article: PubMed Central - PubMed

Affiliation: School of Natural System, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.

ABSTRACT
The reactivity of catecholamine neurotransmitters and the related metabolites were precisely investigated toward 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and reactive oxygen species. Catecholamines reacted immediately with DPPH radicals, their reactivity being stronger than that of ascorbic acid as a reference. Superoxide scavenging activities of catecholamines determined by WST-1 and electron spin resonance (ESR) spin trapping methods were also high. Whereas tyrosine, the dopamine precursor showed no reactivity toward superoxide. The reactivity toward singlet oxygen was evaluated by observing specific photon emission from singlet oxygen. The results revealed that reactivity of catecholamines was markedly higher than that of sodium azide, and catechin as catechol reference. The reaction of catecholamines and singlet oxygen was further studied by ESR using 55-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trapping reagent and rose bengal as photosensitizer. DMPO-OH signal of epinephrine was significantly small compared to other catecholamines, catechin, and 4-methylcatechol as a reference compound and was as small as that of tyrosine. The signal formation was totally dependent on singlet oxygen, and the presence of catechol compounds. These results indicated that epinephrine is the most potent singlet oxygen quencher than other catecholamines, and the secondary amino group in its alkyl side chain could play a role in unique singlet oxygen quenching property of epinephrine.

No MeSH data available.