A novel benzimidazole and other constituents with antiproliferative and antioxidant properties from Thymelaea microphylla Coss. et Dur.

A new compound (microphybenzimidazole, 7) along with the six known compounds matairesinol (1), prestegane B (2), umbelliferone (3), daphnoretin (4), microphynolide A (5) and microphynolide B (6) were isolated from Thymelaea microphylla. The structures of the pure compounds were elucidated by spectroscopic and mass-spectrometric analyses, including 1D-, 2D-NMR, and HPLC-TOF/MS. Compounds 2 and 4, as well as three fractions (F6, F6-C5, and F6-W42) obtained from a 50% (v:v) CH2Cl2:MeOH extract exhibited a selective activity against rat brain glioma cells (C6). Moreover, compound 1 and other fractions obtained from 50% (v:v) CH2Cl2:MeOH and 70% (v:v) MeOH:H2O extracts exhibited dose- and time-dependent effects on human cervical cancer cell (HeLa), as measured by xCELLigence assay. Compound 2 (IC50 = 14.0 ± 0.2 μg/mL) and fraction F5 (IC50 = 12.4 ± 0.1 μg/mL) showed higher radical scavenging ability than the synthetic agent butylated hydroxytoluene (BHT, IC50 = 22.7 ± 0.6 μg/mL).