Dataset Information

Degradation of Methyl 2-Aminobenzoate (Methyl Anthranilate) by H₂O₂/UV: Effect of Inorganic Anions and Derived Radicals.

ABSTRACT: This study shows that methyl 2-aminobenzoate (also known as methyl anthranilate, hereafter MA) undergoes direct photolysis under UVC and UVB irradiation and that its photodegradation is further accelerated in the presence of H₂O₂. Hydrogen peroxide acts as a source of hydroxyl radicals (·OH) under photochemical conditions and yields MA hydroxyderivatives. The trend of MA photodegradation rate vs. H₂O₂ concentration reaches a plateau because of the combined effects of H₂O₂ absorption saturation and ·OH scavenging by H₂O₂. The addition of chloride ions causes scavenging of ·OH, yielding Cl₂·- as the most likely reactive species, and it increases the MA photodegradation rate at high H₂O₂ concentration values. The reaction between Cl₂·- and MA, which has second-order rate constant k C l 2 • - + M A = (4.0 ± 0.3) × 10⁸ M-1·s-1 (determined by laser flash photolysis), appears to be more selective than the ·OH process in the presence of H₂O₂, because Cl₂·- undergoes more limited scavenging by H₂O₂ compared to ·OH. While the addition of carbonate causes ·OH scavenging to produce CO₃·- ( k C O 3 • - + M A = (3.1 ± 0.2) × 10⁸ M-1·s-1), carbonate considerably inhibits the photodegradation of MA. A possible explanation is that the elevated pH values of the carbonate solutions make H₂O₂ to partially occur as HO₂-, which reacts very quickly with either ·OH or CO₃·- to produce O₂·-. The superoxide anion could reduce partially oxidised MA back to the initial substrate, with consequent inhibition of MA photodegradation. Fast MA photodegradation is also observed in the presence of persulphate/UV, which yields SO₄·- that reacts effectively with MA ( k S O 4 • - + M A = (5.6 ± 0.4) × 10⁸ M-1·s-1). Irradiated H₂O₂ is effective in photodegrading MA, but the resulting MA hydroxyderivatives are predicted to be about as toxic as the parent compound for aquatic organisms (most notably, fish and crustaceans).

SUBMITTER: Lanzafame GM

PROVIDER: S-EPMC6154702 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Degradation of Methyl 2-Aminobenzoate (Methyl Anthranilate) by H₂O₂/UV: Effect of Inorganic Anions and Derived Radicals.

Lanzafame Grazia Maria GM Sarakha Mohamed M Fabbri Debora D Vione Davide D

Molecules (Basel, Switzerland) 20170412 4

This study shows that methyl 2-aminobenzoate (also known as methyl anthranilate, hereafter MA) undergoes direct photolysis under UVC and UVB irradiation and that its photodegradation is further accelerated in the presence of H₂O₂. Hydrogen peroxide acts as a source of hydroxyl radicals (·OH) under photochemical conditions and yields MA hydroxyderivatives. The trend of MA photodegradation rate vs. H₂O₂ concentration reaches a plateau because of the combined effects of H₂O₂ absorption saturation a ...[more]

PMID: 28417930

Similar Datasets

Project description:BackgroundAnthranilate is a platform chemical used by the industry in the synthesis of a broad range of high-value products, such as dyes, perfumes and pharmaceutical compounds. Currently anthranilate is produced via chemical synthesis from non-renewable resources. Biological synthesis would allow the use of renewable carbon sources and avoid accumulation of toxic by-products. Microorganisms produce anthranilate as an intermediate in the tryptophan biosynthetic pathway. Several prokaryotic microorganisms have been engineered to overproduce anthranilate but attempts to engineer eukaryotic microorganisms for anthranilate production are scarce.ResultsWe subjected Saccharomyces cerevisiae, a widely used eukaryotic production host organism, to metabolic engineering for anthranilate production. A single gene knockout was sufficient to trigger anthranilate accumulation both in minimal and SCD media and the titer could be further improved by subsequent genomic alterations. The effects of the modifications on anthranilate production depended heavily on the growth medium used. By growing an engineered strain in SCD medium an anthranilate titer of 567.9 mg l-1 was obtained, which is the highest reported with an eukaryotic microorganism. Furthermore, the anthranilate biosynthetic pathway was extended by expression of anthranilic acid methyltransferase 1 from Medicago truncatula. When cultivated in YPD medium, this pathway extension enabled production of the grape flavor compound methyl anthranilate in S. cerevisiae at 414 mg l-1.ConclusionsIn this study we have engineered metabolism of S. cerevisiae for improved anthranilate production. The resulting strains may serve as a basis for development of efficient production host organisms for anthranilate-derived compounds. In order to demonstrate suitability of the engineered S. cerevisiae strains for production of such compounds, we successfully extended the anthranilate biosynthesis pathway to synthesis of methyl anthranilate.

Dataset Information

Degradation of Methyl 2-Aminobenzoate (Methyl Anthranilate) by H₂O₂/UV: Effect of Inorganic Anions and Derived Radicals.

Publications

Degradation of Methyl 2-Aminobenzoate (Methyl Anthranilate) by H₂O₂/UV: Effect of Inorganic Anions and Derived Radicals.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets