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 char-acterization 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 par-ticularly,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 28.4μM.

Polyoxygenated Cembranoids from Soft Coral Lobophytum Crassum and Their Anti-tumoral Activities

Main observation and conclusion Four new cembranoids,6-oxo-cembrene-A(1),lobocrassins G-H(2-3),and 14-epi-lobophytolide B(4),along with eight known re-lated compounds(5-12),were isolated from the South China Sea soft coral Lobophytum crassum.Their structures were established by extensive spectroscopic analysis and by comparison of the spectral data with those reported in the literatures.The absolute stere-ochemistry of 14-epi-lobophytolide B(4)was established by time-dependent density functional theory electronic circular dichroism(TDDFT-ECD)calculations,whereas that of three known metabolites(6,11 and 12)was also determined,for the first time,by using modified Mosher's method and/or X-ray diffraction analyses.In bioassay,the cembranoids 6,7 and 12 showed significant an-ti-tumoral activity against A549,HT-29,SNU-398 and Capan-1 tumor cell lines with IC_(50) values ranging from 1.5 to 7.4μmol/L.A pre-liminary structure-activity relationship was also discussed.

Uncommon Bis-quinolizidine Alkaloids from the Hainan Sponge Neopetrosia chaliniformis

Main observation and conclusion Two new bis-quinolizidine alkaloids,neopetrosiasins A(1)and B(2),possessing cis-and trans-quinolizidine nuclei,one known related analogue petrosin(3)and three known xestospongins(4-6),were isolated from the South China Sea sponge Neopetrosia chaliniformis.