Anti-Inflammatory Activity-Guided Isolation and In Silico Validation of Turmeric (Curcuma longa L.) Phytochemicals

Turmeric (Curcuma longa L., Zingiberaceae) is a widely consumed spice and functional food valued for its bioactive constituents. Using an activity-guided strategy, this study identified the dichloromethane fraction as the most potent anti-inflammatory fraction, exhibiting markedly stronger inhibition of reactive oxygen species (ROS) production than ibuprofen (IC₅₀ ≤ 0.4 vs. 11.2 μg/mL). Bioassay-guided purification yielded bisacurone (1), didemethoxycurcumin (2), and β-turmerone (3), with compounds 1 and 2 reported here for the first time in this fraction. Among them, β-turmerone displayed the strongest anti-inflammatory activity (IC₅₀ = 4.7 μg/mL), consistent with in silico docking and molecular dynamics analyses, revealing greater binding affinity and complex stability with myeloperoxidase (ΔG_bind = -20.90 vs. -18.89 kcal/mol for ibuprofen). Gas chromatography-mass spectrometry (GC-MS) profiling revealed a phytochemical profile dominated by turmerones and curlone, correlating with the observed bioactivity. None of the fractions exhibited acute toxicity in brine shrimp lethality assays, indicating a favorable preliminary safety profile. Our findings demonstrate the value of activity-guided isolation combined with computational validation for identifying turmeric-derived bioactives with promising nutraceutical potential, warranting further in vivo evaluation.