LC-ESI-MS/MS Characterization and Biological Activities of Ethyl Acetate and n-Butanol Fractions of Chrysanthemum macrocarpum From Algeria.

This study investigates the bioactivity potential of Chrysanthemum macrocarpum aerial part extracts used in traditional Algerian medicine, providing the first LC-ESI-MS/MS characterization of their phenolic composition alongside evaluation of antioxidant, enzyme inhibitory, photoprotective, cytotoxic, and antibacterial activities. LC-ESI-MS/MS analysis revealed distinct phenolic profiles, identifying 9 compounds in ethyl acetate (EAFCM) and 15 in n-butanol (BFCM), with EAFCM particularly rich in gentisic (10.428 mg/g), caffeic (3.962 mg/g), chlorogenic acids (2.731 mg/g), cynaroside (5.927 mg/g), and astragalin (3.023 mg/g). EAFCM exhibited higher total phenolic (135.25 ± 5.09 µg PEs/mg) and flavonoid contents (135.2 ± 1.23 µg QE/mg) than BFCM. Accordingly, EAFCM showed stronger antioxidant activity (DPPH: IC50 = 4.51 ± 0.22 µg/mL; ABTS: IC50 = 5.11 ± 0.60 µg/mL; CUPRAC: A0.5 = 13.51 ± 0.26 µg/mL; phenanthroline: A0.5 = 4.31 ± 0.47 µg/mL; FRAP: A0.5 = 13.30 ± 0.30 µg/mL). Enzyme inhibition assays showed weak activity against α-amylase, tyrosinase, and cholinesterase. Both extracts exhibited strong photoprotective effects (SPF > 40) and low cytotoxicity, with EAFCM selectively reducing T98G cell viability. EAFCM showed antibacterial activity against Gram-positive bacteria, while Gram-negative inhibition was weak. These results indicate that C. macrocarpum, aerial part extracts have potential as antioxidant, photoprotective, and antibacterial agents.