Recent advances on cyclodepsipeptides: biologically active compounds for drug research.

Cyclodepsipeptides are a large family of peptide-related natural products consisting of hydroxy and amino acids linked by amide and ester bonds. A number of cyclodepsipeptides have been isolated and characterized from fungi and bacteria. Most of them showed antitumor, antifungal, antiviral, antimalarial, and antitrypanosomal properties. Herein, this review summarizes the recent literatures (2010-2022) on the progress of cyclodepsipeptides from fungi and bacteria except for those of marine origin, in order to enrich our knowledge about their structural features and biological sources.

Cytotoxic Cyclodepsipeptides and Cyclopentane Derivatives from a Plant-Associated Fungus Fusarium sp.

In this work, four new cyclodepsipeptides, fusarihexins C-E (1-3) and enniatin Q (4), four new cyclopentane derivatives, fusarilins A-D (5-8), together with eight known compounds (9-16), were isolated from cultures of the endophytic fungus Fusarium sp. The structures of the isolated compounds were elucidated by analysis of HRMS and NMR spectroscopic data. The absolute configurations were determined using Marfey's method, a modified Mosher's method, single-crystal X-ray diffraction analysis, and ECD analysis. The antitumor activities of the isolated compounds in vitro were evaluated. Cyclodepsipeptides displayed cytotoxicities against the Huh-7, MRMT-1, and HepG-2 cell lines. Compounds 4, 9, 10, and 12 with IC50 values of 1.0-9.1 µM exhibited the most potent cytotoxicities against the three cell lines as compared to the positive control-5-fluorouracil. Compounds 1-3 and 11 exhibited moderate cytotoxic activities (IC50 values of 10.7-20.1 µM).

Structure Elucidation and Anti-Tumor Activities of Trichothecenes from Endophytic Fungus Fusariumsporotrichioides.

The secondary metabolites of Fusarium sporotrichioides, an endophytic fungus with anti-tumor activity isolated from Rauvolfia yunnanensis Tsiang, were investigated. Five trichothecenes, including one previously undescribed metabolite, were isolated and identified. Their structures were elucidated by means of extensive spectroscopic methods; the absolute configuration of compound 1 was determined by the ECD method. Surprisingly, 8-n-butyrylneosolaniol (3) exhibited stronger anti-tumor activity than T-2 toxin against Huh-7 cell line, with an IC50 value of 265.9 nM. 8-n-butyrylneosolaniol (3) promoted apoptosis induction in Huh-7 cells. Moreover, cell cycle analysis showed that cell cycle arrest caused by 8-n-butyrylneosolaniol (3) at the G2/M phase resulted in cell proliferation inhibition and pro-apoptotic activity. Further studies showed a significant decrease in mitochondrial membrane permeabilization and a significant increase in ROS generation, which led to the activation of caspase cascades and subsequent cleavage of PARP fragments. In conclusion, 8-n-butyrylneosolaniol (3) induced cell apoptosis in Huh-7 cells via the mitochondria-mediated apoptotic signaling pathway, which could be a leading compound for anti-tumor agents.