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A facile methodology for the synthesis of bicyclopeptides containing isoindolone was developed by an intramolecularly photo-induced electron transfer cyclo-reaction (IPETC) with high yield and stereoselectivity. Nine bisulfide-bridged bisisodindolone–cyclopeptides were successfully prepared based on the construction of an intramolecular bis-(donor–acceptor) electron system using L -cystine as the linker. The stereostructures of the bicyclopeptides were determined by ECD and 13C-NMR spectra combined with quantum chemistry calculations. The research provided a possible solution for the preparation of multi-cyclopeptides with complex and rigid cyclic structures by introducing cysteine moieties into linear peptides. [ABSTRACT FROM AUTHOR]

Two novel Fenestin A analogs (1 and 2) containing a phthalimide moiety are prepared by photoinduced cyclization. Their absolute configurations were determined by experimental ECD with the aid of theoretical calculations. The resulting compounds are active in HeLa (IC50 = 28.2 μM for 1 and 36.5 μM for 2) and HepG-2 cell lines (IC50 = 33.5 μM for 1 and 40.3 μM for 2). [ABSTRACT FROM AUTHOR]