title: Diketopiperazine alkaloids from a mangrove rhizosphere soil derived fungus Aspergillus effuses H1-1.
abstract: Effusin A (1), a spirobicyclic N,O-acetal derivative with an unprecedented 3',3a',5',6'-tetrahydrospiro[piperazine-2,2'-pyrano[2,3,4-de]chromene] ring system, and a spiro-polyketide-diketopiperazine hybrid dihydrocryptoechinulin D (2) were isolated from a mangrove rhizosphere soil derived fungus, Aspergillus effuses H1-1. Their structures were determined by detailed spectroscopic analysis. Effusin A (1) and dihydrocryptoechinulin D (2) occurred as racemates, the enantiomers of which were separated and characterized by online HPLC-ECD analysis and their absolute configurations were determined by the solution TDDFT ECD calculation approach. The cytotoxic effects of 1 and 2 were preliminarily evaluated and 2 showed potent activity on P388 cells with an IC(50) value of 1.83 μM. The target of racemic 2 was also investigated and the (12R,28S,31S)-2 enantiomer showed selectivity against topoisomerase I.
authors.affiliation: Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
authors.forename: Huquan
authors.initials: H
authors.lastname: Gao
authors.forename: Weizhong
authors.initials: W
authors.lastname: Liu
authors.forename: Tianjiao
authors.initials: T
authors.lastname: Zhu
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Mo
authors.forename: Attila
authors.initials: A
authors.lastname: Mándi
authors.forename: Tibor
authors.initials: T
authors.lastname: Kurtán
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Jing
authors.initials: J
authors.lastname: Ai
authors.forename: Qianqun
authors.initials: Q
authors.lastname: Gu
authors.forename: Dehai
authors.initials: D
authors.lastname: Li
mesh_terms: D001230:Aspergillus / Q000737:chemistry*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D054659:Diketopiperazines / Q000737:chemistry* / Q000493:pharmacokinetics / Q000627:therapeutic use; D006801:Humans; D020128:Inhibitory Concentration 50; D009682:Magnetic Resonance Spectroscopy; D058441:Rhizosphere; D012987:Soil / Q000737:chemistry; D053833:Wetlands
chemical_list: D054659:Diketopiperazines; D012987:Soil; C580727:dihydrocryptoechinuline D; C580728:effusin A