An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Two new azaphilone derivatives, chaephilones A (1) and B (2), were isolated from the fungus Chaetomium globosum, together with four structurally related analogs 3 - 6. The structures of 1 and 2 were elucidated by comprehensive spectroscopic analyses including HR-ESI-MS and NMR. The known compounds were identified as chaetomugilin Q (3), chaetomugilin D (4), 11-epichaetomugilin A (5), and chaetomugilin S (6) by comparing their NMR data and optical rotation values with those reported. Compound 2 represents the first example of azaphilone with an open furan ring. Compounds 1 and 2 were evaluated for cytotoxic activities against five human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7, and SW480) by the MTS method.
The flavoprotein monooxygenase (FPMO) TerC is encoded by all known cyclopentene biosynthetic gene clusters. It can catalyze oxidative dearomatization toward a series of 6-HM analogues and further induces different skeletal distortions to form either benzoquinone or pyrone by bimodal reaction cascades, which is only governed by the C7 substitutions. Beyond our study demonstrated bimodal reaction cascades and advanced the biosynthetic knowledge of fungal cyclopentenes, this work also sets the stage for the bioengineering of 6-HM polyketides.
Abstract Asperflavipines A ( 1 ) and B ( 2 ), two structurally complex merocytochalasans, were isolated from Aspergillus flavipes . Asperflavipine A ( 1 ), which contains two cytochalasan moieties and two epicoccine moieties, is the first cytochalasan heterotetramer to be discovered. It is uniquely defined by 5/6/11/5/6/5/6/5/6/5/5/11/6/5 fused tetradecacyclic rings with three continuous bridged ring systems. Asperflavipine B ( 2 ) is a cytochalasan heterotrimer containing a cytochalasan and two epicoccine moieties with a 5/6/11/5/5/6/5/6/5 nonacyclic ring system. The hypothetical biosynthesis of 1 and 2 is proposed to involve Diels–Alder and [3+2] cycloaddition reactions as key steps and reveals unparalleled plasticity in the biosynthesis of merocytochalasans. The existence of 1 adds a new dimension to the diversity of the cytochalasan family. Compound 1 showed moderate cytotoxicity and induced apoptosis in Jurkat, NB4, and HL60 cells through the activation of caspase‐3 and degradation of poly(ADP‐ribose) polymerase (PARP).
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.