Further C-15-acyl phragmalin derivatives from Chukrasia tabularis A. Juss. (September 2015) - Luo, Jun
Graphical abstract: Sixteen phragmalins with three types of enolic acyl substituents at C-15 were isolated from the seeds of Chukrasia tabularis A. Juss. One of these (compound1 ) had its structure determined by NMR and X-ray diffraction analysis, while the others were determined via NMR, HR-MS, and CD spectra. Highlights: Sixteen phragmalins with three kinds of enolic acyl substituents at C-15 were isolated. UV-guided separation based on the characteristic double UV absorptions (210 and 270 nm). The configuration of one of the phragmalins was confirmed by X-ray crystallographic and CD spectrum analyses. Abstract: Relying on characteristic double UV absorptions (210 and 270 nm), sixteen phragmalins with three types of enolic acyl substituents at C-15 were isolated directly from EtOH extracts of the seeds of Chukrasia tabularis A. Juss. Eight of these compounds possessed a C-15-acetyl phragmalin skeleton, and the basic carbon skeleton and absolute configuration of one of these was determined by NMR and X-ray diffraction analysis, while the structures of the other phragmalins were determined via NMR, HR-MS, and CD spectra. Additionally, all of the isolates were tested for inhibition against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 macrophages and cytotoxicity in SMMC-7721, MCF-7 and U2OS tumor cells.