Indole diketopiperazine alkaloids from a soil-derived fungus Aspergillus sp. KYS-11
Jing Liu1, Wen-Jing Gao2, Chu-Hong Fang2
1Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250117, China; Shandong Laboratory of Yantai Drug Discovery, Bohai Rim Advanced Research Institute for Drug Discovery, Yantai, Shandong 264117, China.
Abstract:
Seven new indole diketopiperazine alkaloids (IDAs) asperdiketopoids A-G (1-7) and nine known analogues (8-16) were isolated from a Kunyu Mountain soil-derived fungus Aspergillus sp. KYS-11. Asperdiketopoid C (3) is characterized by the oxidation at C-12, a feature that is infrequently documented in the family of IDAs. Asperdiketopoids F (6) and G (7) feature an inversed C-18 configuration in the spirocyclic IDA family, marking the first time such a feature has been reported as natural products. One should be cautious that the C-18 epimers possess a nearly identical set of NMR data, making it susceptible to misidentification in the structure elucidations. A series of bioactive evaluations demonstrated that asperdiketopoids C (3) and G (7) display a certain degree of inhibition against the proliferation of B cells induced by LPS.
