Lagerindicine, a New Pyrrole Alkaloid Isolated from the Flowers of Lagerstroemia indica Linnaeus

A phytochemical investigation of the EtOH extract of the flowers of Lagerstroemia indica L. led to the isolation and characterization of a new pyrrole alkaloid, named lagerindicine (1), along with four known compounds (2-5). Their structures were elucidated by the detailed spectroscopic analysis and comparison with literature data, whereas the structure, in particularly, the absolute configuration (AC) of 1, was firmly determined by total synthesis. All the isolates were evaluated for their cytotoxic effects against human colon cancer cell (HCT-116), and compound 3 exhibited weak cytotoxicity with IC₅₀ value of 28.4 μM.