Phytochemicals from Tetraclinis articulata wood tar: HPLC-DAD-ESI-MS analysis, biological activities and in silico studies

Wood tar is a natural substance rich in bioactive compounds that has traditionally been used as a therapeutic and preservative agent. This study aims to explore the chemical profile of Tetraclinis articulata wood tar as well as its biological activities using experimental and in silico approaches. Phytochemical screening and quantitative analysis revealed high contents of polyphenols and tannins, while HPLC-DAD-ESI-MS profiling tentatively identified nine compounds, with syringic acid, epicatechin, and p-coumaroyl-glucoside as dominant constituents. The wood tar yield was 1.5% (w/w). The extract showed strong antioxidant activity in the DPPH assay (IC₅₀ = 20.24 ± 1.03 µg/mL), whereas weaker activities were observed in the FRAP assay (IC₅₀ = 111.50 ± 12.38 µg/mL), ABTS assay (IC₅₀ = 155.46 ± 3.23 µg/mL), and iron-chelating assay (IC₅₀ = 2808.94 ± 27.57 µg/mL). Furthermore, it exhibited moderate antimicrobial properties, particularly against Escherichia coli ATCC (MIC = 1.56 mg/mL), with bactericidal effects against Pseudomonas aeruginosa , Staphylococcus aureus , and methicillin-resistant S. aureus . Regarding repellent effect, wood tar exhibited the greatest percentage repellency (PR), recording 100% against Tribolium castaneum and 84% against Sitophilus oryzae at a concentration of 8 mg/mL after 2 h. After 24 h, the repellent effect remained high for T. castaneum (96%) but decreased for S. oryzae (58%). In terms of antifeedant effect, wood tar displayed a low effect against both insect species, with 32.8% as the highest feeding deterrent index (FDI) observed in the case of T. castaneum compared to 13.5% for S. oryzae at the highest concentration tested (2%). Molecular docking results suggested potential interactions, with quercetin aglycone showed the strongest interaction with DHFR (− 9.8 kcal/mol), DNA gyrase (− 8.7 kcal/mol), and MurA (− 8.6 kcal/mol), followed by catechin with slightly lower affinities of − 9.1, − 8.0, and − 8.3 kcal/mol, respectively. As for the odorant-binding protein C12 (TcOBP C12), quercetin aglycone and epicatechin exhibited strong binding affinities with docking scores of − 8.2 and − 8.4 kcal/mol, respectively. Overall, this study suggests for the first time the potential of T. articulata wood tar may represent a potential source of antioxidant, antimicrobial, repellent, and antifeedant agents, warranting further investigation.