New Potent DPPH Radical Scavengers from a Marine-Derived Actinomycete Strain USF-TC31

Abstract

Six compounds were isolated as radical scavengers from the culture broth of a marine-derived actinomycete strain USF-TC31. The structures of two novel compounds were determined to be those of N-carbamoyl-2,3-dihydroxybenzamide (5) and 2-acetamido-3-(2,3-dihydroxybenzoylthio)propanoic acid (6), and four known compounds were identified to be anthranilic acid (1), 2,3-dihydroxybenzoic acid (2), 2,3-dihydroxybenzamide (3) and benadrostin (4) on the basis of spectroscopic data. Compound 6 was characterized as a racemate by its specific rotation. Each of the obtained compounds was evaluated for DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, and compounds 2, 3, 5 and 6 each exhibited potent activity in comparison with the butylhydroxytoluene (BHT) positive control.

Clicked Cinnamic/Caffeic Esters and Amides as Radical Scavengers and 5-Lipoxygenase Inhibitors

“…That the esters as a whole were slightly more potent radical scavengers than the corresponding amides could indicate a long distance influence of the amide/ester group on the electron accepting ability of the catechol ring, transmitted through the extend π system of the conjugated caffeoyl moiety. Similar effects have been noted in DPPH assays with dihydroxybenzamide and dihydroxybenzoic acid, with the benzamide being slightly less potent than the corresponding benzoic acid [ 42 ]. That being said, no large differences in radical scavenging capacity were found between triazole esters or amides, with most falling in the IC 50 range of 8–10 μ M and 10–18 μ M, respectively.…”

Biodiversity, Anti-Trypanosomal Activity Screening, and Metabolomic Profiling of Actinomycetes Isolated from Mediterranean Sponges

“…MS 2 data obtained by source fragmentation gave an ion peak at m/z 123.008 [M-CH 3 O] - for C 6 H 6 O 3 which indicated the presence of a similar substituent found in (−)-phyllostine ( Fig 4A ). Outlying mass ion peak at m/z 152.035 [M−H] − , for the predicted molecular formula C 7 H 7 NO 3 , was dereplicated as maleimycin [ 54 , 55 ], 3-amino-4-hydroxybenzoic acid [ 56 ], or 2,3-dihydroxybenzamide [ 57 ], all of which were previously reported as actinomycete metabolites ( Fig 4B ). While outlying mass ion peaks at m/z 178.015, and 195.041, both [M−H] − , were tentatively identified as benadrostin [ 58 , 59 ] and N-carbamoyl-2,3-dihydroxybenzamide [ 57 ], respectively, both isolated from Streptomyces sp.…”

Potential of rare actinomycetes in the production of metabolites against multiple oxidant agents

“…The compound 5-(2,4-dimethylbenzyl) pyrrolidin-2-one (DMBPO) from a Streptomyces strain was exhibited DPPH scavenging activity with 44.1% inhibition at the concentration of 5 μg/mL (Saurav and Kannabiran 2012 ). In another study, four compounds, 2,3-dihydroxybenzoic acid, 2,3-dihydroxybenzamide, N -carbamoyl-2,3-dihydroxybenzamide and 2-acetamido-3-(2,3-dihydroxybenzoylthio) propanoic acid were isolated from a marine-derived actinobacterium which exhibited DPPH radical scavenging activity with ED 50 value of 10.3, 14.6, 14.4, and 13.0 μM, respectively, in comparison with the BHT (34.7 μM) (Sugiyama and Hirota 2009 ). The compound dermacozine C from the rare actinobacterium, Dermacoccus sp.…”

“…Among the bacterial biologically active compounds, almost 45% are produced by Gram-positive, often Actinobacteria, that are known as remarkable producers of secondary metabolites. A variety of actinobacterial antioxidants such as dihydroherbimycin A (Chang and Kim 2007 ), N -carbamoyl-2,3-dihydroxybenzamide, 2-acetamido-3-(2,3-dihydroxybenzoylthio) propanoic acid (Sugiyama and Hirota 2009 ), 2-allyloxyphenol (Arumugam et al. 2010 ), and phenazines (Abdel-Mageed et al.…”