2-Hydroxy-4-(3′-oxo-3′H-benzofuran-2′-yliden)but-2-enoic acid biosynthesis from dibenzofuran using lateral dioxygenation in a Pseudomonas putida strain B6-2 (DSM 28064)

Abstract Background Benzofuran and its derivatives contain central pharmacophores and are important structures in medicinal chemistry. Chemical synthesis of benzofuran rings often requires expensive catalysts and stringent operational conditions. Biosynthesis is recognized as a promising way to save energy and produce valuable compounds. Dioxin biodegradation pathways can form several benzofuran derivatives, and these pathways may be a better choice for further synthesis of important biological compounds. 2-Hydroxy-4-(3′-oxo-3′H-benzofuran-2′-yliden)but-2-enoic acid (HOBB), a benzofuran derivative, can be biosynthesized from dibenzofuran (DBF) through co-metabolic degradation in a lateral dioxygenation pathway. Results Efficient biosynthesis of HOBB was observed using whole cells of Pseudomonas putida strain B6-2. After cultivation in LB medium containing biphenyl, the cells were suspended to an OD600 of 5 to conduct biosynthesis in the presence of 0.5-mM DBF at pH 7 for 8 h. The bacterial cells were used twice to degrade approximately 0.70-mM DBF, and in batch process, accumulated about 0.29-mM HOBB. HOBB could be easily purified from the reaction with ethyl acetate using the neutral-acid extraction method, and 13.58 ± 0.31 mg of HOBB was obtained from 22.49 ± 0.74-mg DBF with an overall production yield of 60.4% (w/w). The product HOBB, which is a yellow powder, could be detected and identified by LC–MS, GC–MS, and NMR. Conclusions In this study, a new biological route was developed to produce HOBB from DBF using whole cells of P. putida B6-2 (DSM 28064). The biosynthesis of HOBB may contribute to studies of the DBF lateral pathway and provide a new green route for synthesizing benzofuran derivatives with pharmacological activities