title: Metabolites from carnivorous fungus Arthrobotrys entomopaga and their functional roles in fungal predatory ability.
abstract: The carnivorous fungus Arthrobotrys entomopaga (Drechsler) can develop adhesive knobs to capture nematodes. Chemical study on the culture medium of A. entomopaga producing adhesive knobs led to isolation of six trace amounts of metabolites, including two new metabolites, paganins A and B (1 and 2), blumenol A (3), talathermophilins A and B (4 and 5), and cyclo(glycyltryptophyl) (6). Compounds 3-6 were reported for the first time from carnivorous fungi. Compounds 1 and 2 promoted the formation of the predatory adhesive knobs with an increasing rate up to 118% at a concentration of 50 μM but showed moderate inhibitory activity at a concentration of 5 μM. Moreover, compounds 1 and 2 displayed strong inhibitory activities toward the formation of A. entomopaga conidiophores with inhibitory rates of 40-75%. Growth experiments suggested that compounds 1 and 2 could be involved in the regulation of the fungal predatory and reproductive abilities. Nematode chemotaxis bioassay indicated that compounds 1 and 3 displayed strong nematode-attracting abilities. These findings provided a new type of regulatory metabolite and support for the hypothesis that predators often evolve to respond to their metazoan prey.
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University , Kunming 650091, People's Republic of China.
authors.forename: De-Kai
authors.initials: DK
authors.lastname: Wu
authors.forename: Chuan-Ping
authors.initials: CP
authors.lastname: Zhang
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Zhu
authors.forename: Yan-Li
authors.initials: YL
authors.lastname: Wang
authors.forename: Li-Lei
authors.initials: LL
authors.lastname: Guo
authors.forename: Ke-Qin
authors.initials: KQ
authors.lastname: Zhang
authors.forename: Xue-Mei
authors.initials: XM
authors.lastname: Niu
mesh_terms: D000818:Animals; D000969:Antinematodal Agents / Q000737:chemistry / Q000494:pharmacology; D001203:Ascomycota / Q000737:chemistry*; D061046:Biological Control Agents; D002633:Chemotaxis; D003470:Culture Media; D004151:Dipeptides / Q000737:chemistry / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D009348:Nematoda / Q000382:microbiology*; D010456:Peptides, Cyclic / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000969:Antinematodal Agents; D061046:Biological Control Agents; D003470:Culture Media; D004151:Dipeptides; D010456:Peptides, Cyclic; C569085:cyclo(glycyltryptophyl)