Enhancing 3-O-methylfunicone production by endophytic Talaromyces pinophilus J6 through culture optimization and its anti-Helicobacter pylori activity

Abstract

Endophytic fungi can produce metabolites with potential pharmaceutical applications through biosynthetic pathways strongly influenced by culture conditions. In this study, growth parameters (media composition and cultivation time) were systematically optimized to maximize 3-O-methylfunicone (3OMF) production by the endophytic fungus Talaromyces pinophilus J6. Chemical profiling by high-resolution mass spectrometry (HRMS) demonstrated that supplementation of potato dextrose agar (PDA) with 45% (w/w) ammonium sulfate and cultivation for 7 days significantly increased the accumulation of 3OMF compared to standard growth conditions. The optimized culture condition enabled the isolation of the target compound in sufficient yield for subsequent biological assays. The compound exhibited anti-Helicobacter pylori activity against one reference strain and three clinical isolates, with minimum inhibitory concentrations ranging from 0.165 to 0.660 mM and bactericidal concentrations up to 1.32 mM. In combination assays, 3OMF showed an additive effect with clarithromycin, indicating potential as an adjuvant compound in eradication therapies. Cytotoxicity assays of 3OMF demonstrated selective activity against gastric adenocarcinoma cells, with an IC50 of 0.24 mM and selectivity index of 2.37 relative to fibroblasts. Molecular docking suggested favorable interactions between 3OMF and H. pylori β-clamp protein, suggesting a possible association with interference in bacterial DNA replication. These findings demonstrate that culture optimization is an efficient biotechnological strategy to improve 3OMF production and support the further investigation of this compound as a scaffold for anti-H. pylori applications.