RESUMEN

From the biotechnological point of view, enzymes are powerful tools that help sustain a clean environment in several ways. The enzymatic biodegradation of synthetic dyes is a promising goal since it reduces pollution caused by textile dyeing factory wastewater. Lignin peroxidase (EC 1.11.1.14, LiP) has high redox potential; thus, it is great for application in various industrial fields (e.g., paper- waste treatment and textile dyeing wastewater treatment). In the present study, a LiP from an isolated strain Pleurotus pulmonarius CPG6 (PpuLiP) was successfully purified with a specific activity of 6.59 U mg -1. The enzyme was purified by using three-step column chromatography procedures including DEAE, Sephadex G-75, and HiTrapTM Q FF columns with 17.8-fold purity. The enzyme with a molecular weight of 40 kDa exhibited enhanced pH stability in the acidic range. The activity retention was over 75% at a pH of 3.0 for more than 6 hours. Purified PpuLiP was able to oxidize a variety of substrates including veratryl alcohol, 2,4-DCP, n propanol, and guaiacol. The effect of metal ions on PpuLiP activity was analyzed. The study will provide a ground to decolorize dyes from various groups of PpuLiP. Purified PpuLiP could decolorize 35% Acid blue 25 (AB25), 50% Acid red 129 (AB129), 72% Acid blue 62 (NY3), 85% Acid blue 113 (AB113), 55% Remazol Brilliant blue R (RBBR), and 100% Reactive red 120 (RR120) for 12 hours. Most of the dyes were decolorized, but the heat-denatured enzyme used as negative control obviously did not decolorize the tested dyes. These results indicate that the PpuLiP has potential application in enzyme-based decolorization of synthetic dyes. Keywords: Decolorization; lignin peroxidase; Pleurotus pulmonarius; textile dyes.

Asunto(s)

Pleurotus , Pleurotus/metabolismo , Biodegradación Ambiental , Colorantes/análisis , Colorantes/química , Colorantes/metabolismo , Textiles , Lacasa/metabolismo

RESUMEN

BACKGROUND: Sydnone is a heterocycle that exhibits remarkable pharmacological activities, including antimicrobial, anti-inflammatory, analgesic, antipyretic and antioxidant activities. Thiosemicarbazones are of compounds that contain the -NHCSNHN=C< linkage group and are considerable interest because they exhibit important chemical properties and potentially beneficial biological activities. Similarly, thiosemicarbazones having carbohydrate moieties also exhibit various significant biological activities. RESULTS: The compounds of 3-formyl-4-phenylsydnones were obtained by Vilsmeyer-Haack's formylation reaction and were transformed into thiosemicarbazones by condensation reaction with N-(2,3,4,6-tetra-O-acetyl-ß-d-glucopyranosyl)thiosemicarbazide. Reaction were performed in the presence glacial acetic acid as catalyst using microwave-assisted heating method. Reaction yields were 43‒85 %. The antimicrobial activities of these thiosemicarbazones were screened in vitro by using agar well diffusion and MIC methods. Among these thiosemicarbazones, compounds 4k, 4l, 4m and 4n were more active against all tested bacterial strains, especially against S. epidermidis, B. subtilis and E. coli. The MIC values in these cases are 0.156, 0.156 and 0.313 µg/mL, respectively. All compounds showed weak to moderate antifungal activity against C. albicans and A. niger than nystatin (MIC = 0.156‒0.625 µg/mL vs. MIC = 0.078 µg/mL of nystatin), and thiosemicarbazones 4l, 4m and 4n exhibited significant activity with MIC = 0.156 µg/mL. These compounds also had good antifungal activity against F. oxysporum similarly to nystatin (MIC = 0.156 µg/mL). Among the tested compounds having halogen group 4k, 4l, 4m and 4n showed highest activity against three strains of fungal organisms. CONCLUSIONS: In summary, we have developed a clean and efficient methodology for the synthesis of novel thiosemicarbazone derivatives bearing sydnone ring and d-glucose moiety; the heterocyclic and monosaccharide system being connected via ‒NH‒C(=S)NH‒N=C< linker using molecular modification approach. The methodology could be further extended and used for the synthesis of other thiosemicarbazones of biological importance. 4-Formyl-3-arylsydnone N-(2,3,4,6-tetra-O-acetyl-ß-d-glucopyranosyl)thiosemicarbazones have been synthesized under microwave-assisted heating conditions. Almost all obtained compounds showed remarkable activities against the tested microorganisms. Among the tested compounds having halogen group 4k, 4l, 4m and 4n showed highest activity against all tested strains of bacterial and fungal organisms. Graphical abstract:Synthesis and antibacterial and antifungal activities of N-(tetra-O-acetyl-ß-D-glucopyranosyl)thiosemicarbazones of substituted 4-formylsydnones.