Investigation of Antimicrobial and Anti-Inflammatory Efficacy of Newly Synthesized Pyrogallol-Coumarin Hybrids: In Vitro and In Silico Studies

Background: The aim of this study is to present the synthesis of two new compounds with promising antimicrobial and anti-inflammatory properties using precursors that contain pyrogallol and coumarin units. Methods: The characterization of the obtained compounds (PCHs) (E)-N′-(1-(2,4-dioxochroman-3-ylidene)ethyl)-2,3,4-trihydroxybenzohydrazide (PCH-1) and (E)-N′-(1-(2,4-dioxochroman-3-ylidene)ethyl)-3,4,5-trihydroxybenzohydrazide (PCH-2) was performed using various spectroscopic methods in combination with the DFT methods. To evaluate antimicrobial and anti-inflammatory activities, PCHs were tested against 13 different types of microorganisms and soybean lipoxygenase. To determine the specific mechanisms of anti-LOX activity, molecular docking and molecular dynamics studies were performed. Results: These compounds had the most potent antibacterial activity against the bacterium Proteus mirabilis ATCC 12453, with a MIC value of 31.125 µg/mL. In addition, three standard bacterial species were chosen to evaluate the antibiofilm activity of tested substances. The results showed that the strongest effect of PCH-2 was noticed on the biofilm formation of Staphylococcus aureus ATCC 25923 (BIC50 at 378 µg/mL). The anti-LOX results indicate that PCHs have excellent activity with the IC50 value for PCH-1 = 38.12 μM and PCH-2 = 34.12 μM. Conclusions: The obtained in vitro and in silico results confirm the strong inhibitory potential of the investigated compounds.