An elaborated phytochemical study on the fresh fruits of Terminalia chebula var. tomentella (Combretaceae) led to the isolation of five new lignans, including three tetrahydrofuran (1-3) and two furofuran (4 and 5) derivatives, namely termitomenins A-E (1-5), along with 10 known ones. All of them were obtained from the titled plant for the first time. Their structures were determined by extensive spectroscopic analysis, including 1D/2D NMR, MS, UV, IR, electronic circular dichroism (ECD), time-dependent density functional theory (TDDFT) calculation of ECD spectra, and single crystal X-ray diffraction in case of 3. Compounds 1-15 exhibited certain anti-inflammatory activities. Interestingly, compounds 6 (IC50 = 18.17 ± 0.57 μM) and 7 (IC50 = 13.66 ± 0.38 μM) which contain an aldehyde group displayed stronger NO inhibitory activity than the positive control L-NMMA (IC50 = 42.34 ± 0.66 μM).
Keywords: Anti-inflammatory activity; Calculated ECD; Combretaceae; Lignans; Terminalia chebula var. tomentella.
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