(±)‐Peharmaline A: A Pair of Rare β‐Carboline–Vasicinone Hybrid Alkaloid Enantiomers from Peganum harmala. Issue 14 (11th April 2017) - Wang, Kai‐Bo
Abstract : (±)‐Peharmaline A (1 ), a pair of rare β‐carboline–vasicinone hybrid alkaloid enantiomers with the hitherto unknown hybrid dimeric system, was isolated from the seeds of Peganum harmala L. Their structures, including absolute configurations, were determined by extensive spectroscopic analyses and electronic circular dichroism (ECD) calculations. Plausible biogenetic pathways involving Mannich/Pictet–Spengler‐type and intermolecular Michael addition reactions are briefly discussed. Compound1 exhibited significant cytotoxic activities against HL‐60, PC‐3, and SGC‐7901 cancer cell lines with median inhibitory concentration values of 9.2, 21.6, and 25.4 µm, respectively. However, two biosynthetically related precursors, harmaline and vasicinone, were inactive. This cytotoxic β‐carboline–vasicinone hybrid dimeric alkaloid may give some insight into the discovery of new lead compounds for cancer therapy. Abstract : (±)‐Peharmaline A (1 ) is isolated from P. harmala L. seeds as a pair of novel hybrid dimeric alkaloid enantiomers showing significant cytotoxicity on HL‐60 cells with a median inhibitory concentration value of 9.2 µm .