Cytotoxic quinazoline alkaloids from the seeds of Peganum harmala.
Bioorg Med Chem Lett. 2017 Dec 5. Epub 2017 Dec 5. PMID: 29229205
Seventeen quinazoline alkaloids and derivatives, containing two pairs of new epimers, named as (S)- and (R)-1-(2-aminobenzyl)-3-hydroxypyrrolidin-2-oneβ-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside (1, 2), (S)- and (R)-vasicinone β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside (3, 4), and a new enantiomer (12b), together with six known ones (5-8, 10, and 12a), and three pairs of known enantiomers (9, 11, and 13), were isolated fromthe ethanol extracts of the seeds of Peganum harmala L.. Their structures including the absolute configuration were elucidated by using 1D and 2D NMR, and ECD calculation approaches. The cytotoxic activities of all isolated compounds were evaluated. 11 showed moderate cytotoxicity against PC-3 cellswith an IC50 value of 15.41 μM.