Screening Q-markers for anti-MRSA activity of Amomum tsao-ko Crevost & Lemarié essential oil based on spectrum-effect relationships

To screen anti-MRSA Q-markers of Amomum tsao-ko essential oil (AEO) via spectrum-effect relationship, establish a quality evaluation system, and provide a scientific basis for the quality control and comprehensive utilization of AEO. AEO was extracted by steam distillation. GC–MS was used to construct fingerprints of 10 batches of AEO, and chemical pattern recognition methods (HCA, PCA, OPLS-DA) were combined to distinguish the quality of AEO from different producing areas. Based on VIP values, differential components (eucalyptol, linalool, α-terpineol, geraniol, trans-nerolidol) were quantitatively analyzed. The anti-MRSA activity of AEO was detected, and Q-markers were screened through GRA and monomer verification experiments . GC–MS fingerprinting of AEO revealed 22 common peaks, 5 of which were structurally identified, with average contents spanning 0.00263–0.08687 mg/g, fingerprint similarity was 0.740–0.971. HCA categorized the 10 batches into 3 clusters, PCA extracted 4 components accounting for 91.556% of cumulative variance, OPLS-DA screened 13 differential components (including eucalyptol, linalool, geraniol, and trans-nerolidol). The MIC and MBC of the 10 AEO batches against MRSA were 0.892–4.413 mg/mL and 0.982–6.354 mg/mL, respectively. GRA indicated linalool, α-terpineol, geraniol, and trans-nerolidol as potential anti-MRSA Q-markers of AEO, and verification tests confirmed consistent anti-MRSA effects for most of these compounds excluding eucalyptol. α-terpineol, geraniol, and trans-nerolidol can serve as Q-markers for the anti-MRSA activity of AEO. These findings provide a foundation for the quality control and in-depth investigation of AEO.