Antibacterial activity against drug-resistant microbial pathogens of cytochalasan alkaloids from the arthropod-associated fungus Chaetomium globosum TW1-1

作者：Gao, Weixi; He, Yan; Li, Fengli; Chai, Chenwei; Zhang, Jinwen; Guo, Jieru; Chen, Chunmei; Wang, Jianping; Zhu, Hucheng; Hu, Zhengxi^*; Zhang, Yonghui^*

来源：Bioorganic Chemistry, 2019, 83: 98-104.

DOI：10.1016/j.bioorg.2018.10.020

• Chaetomium globosum TW1-1
• Feeding experiment
• Cytochalasan alkaloids
• Antibacterial activity

By feeding 1-methyl-L-tryptophan (1-MT) into cultures of the arthropod-associated fungus Chaetomium globosum TW1-1, three novel cytochalasan alkaloids, termed as armochaetoglosins A-C (1-3), together with five known analogues, namely prochaetoglobosin I (4), chaetoglobosin T (5), chaetoglobosin C (6), armochaetoglobin Y (7), and chaetoglobosin V-b (8), were isolated and characterized. Their structures including absolute configurations were elucidated by means of NMR spectroscopy, single-crystal X-ray crystallography, and comparison of the experimental electronic circular dichroism (ECD) spectra. Structurally, compounds 1-3 represented the first examples of 1'-N-methyl-chaetoglobosins, which were possibly biosynthesized from the additive 1-MT rather than tryptophan. Additionally, compound 3 showed the highest antibacterial activity against K. pneumoniae and ESBL-E. coli with MIC values of 4.0 mu g/mL and 16.0 mu g/mL, respectively, wherein the inhibitory effect of 3 against K. pneumoniae was stronger than that of the clinically used antibiotic meropenem, with an MIC value of 8 mu g/mL. Our findings may provide new chemical templates for the development of new antibacterial agents against drug-resistant microbial pathogens.

• 出版日期2019-3
• 单位华中科技大学