Alkaloids from Anacyclus pyrethrum

Twelve undescribed alkaloids, including eight pyrrolo[3,2-g]isoquinoline alkaloids (+)/(−)-anacyquinoline A (1a/1b), (±)-anacyquinoline B (2), (+)/(−)-anacyquinoline C (3a/3b), (±)-anacyquinoline D (4), (±)-anacyquinoline E (5), and (±)-anacyquinoline F (6), together with four pyrrolo[2,3-g]quinoline alkaloids (+)/(−)-anacyquinoline G (7a/7b), (±)-anacyquinoline H (8), and (±)-anacyquinoline I (9), were isolated from the roots of Anacyclus pyrethrum (L.) DC. Their structures were determined via spectroscopic analyses (UV, IR, NMR), HRESIMS, quantum chemical calculations of ECD, DP4+ analysis, and single-crystal X-ray diffraction analysis (Cu Kα). Furthermore, in bioassay, (+)/(−)-anacyquinoline G (7a/7b) and (±)-anacyquinoline H (8) showed inhibition on nitric oxide production in lipopolysaccharide -induced RAW 264.7 cells with IC50 values of 41.4, 44.1, and 31.4 μM, respectively, indicating their potential anti-inflammatory bioactivity.