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| Gomes,A.J.; Lunardi,C.N.; Gonzalez,S.; Tedesco,A.C.. |
| Two natural products Polypodium leucotomos extract (PL) and kojic acid (KA) were tested for their ability to scavenge reactive oxygen species (·OH, ·O2-, H2O2, ¹O2) in phosphate buffer. Hydroxyl radicals were generated by the Fenton reaction, and the rate constants of scavenging were 1.6 x 10(9) M-1 s-1 for KA and 1.0 x 10(9) M-1 s-1 for PL, similar to that of ethanol (1.4 x 10(9) M-1 s-1). With superoxide anions generated by the xanthine/hypoxanthine system, KA and PL (0.2-1.0 mg/ml) inhibited ·O2-dependent reduction of nitroblue tetrazolium by up to 30 and 31%, respectively. In the detection of ¹O2 by rose bengal irradiation, PL at 1.0 mg/ml quenched singlet oxygen by 43% relative to azide and KA by 36%. The present study demonstrates that PL showed an... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Polypodium leucotomos extract; Kojic acid; Antioxidant; Reactive oxygen species. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001001100018 |
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| Shakibaie,Mojtaba; Ameri,Atefeh; Ghazanfarian,Roya; Adeli-Sardou,Mahboubeh; Amirpour-Rostami,Sahar; Torkzadeh-Mahani,Masoud; Imani,Mehdi; Forootanfar,Hamid. |
| ABSTRACT The ability of four Aspergillus strains for biosynthesis of kojic acid was evaluated among which Aspergillus terreus represented the highest level (2.21 g/L) of kojic acid production. Improvement kojic acid production ability of A. terreus by random mutagenesis using different exposure time to ultraviolet light (5–40 min) was then performed to obtain a suitable mutant of kojic acid production (designated as C5-10, 7.63 g/L). Thereafter, design of experiment protocol was employed to find medium components (glucose, yeast extract, KH2PO4 (NH4)2SO4, and pH) influences on kojic acid production by the C5-10 mutant. A 25-1 fractional factorial design augmented to central composite design showed that glucose, yeast extract, and KH2PO4 were the most... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Kojic acid; Aspergillus terreus; UV mutagenesis; Medium optimization. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822018000400865 |
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