title: Entonalactams A-C: Isoindolinone derivatives from an Australian rainforest fungus belonging to the genus Entonaema.
abstract: Bioassay-guided fractionation of an antimalarial DCM/MeOH extract derived from the Australian rainforest fungus Entonaema sp. resulted in the isolation of three new isoindolinone derivatives, entonalactams A-C (1-3), along with the known natural products 3-methoxy-5-methylbenzene-1,2-diol (4), daldinal B (5), and ergosta-4,6,8(14),22-tetraen-3-one (6). The chemical structures of the new secondary metabolites were determined following extensive 1D/2D NMR and MS data analysis. A single crystal X-ray structure for entonalactam A (1) confirmed the NMR-based structure assignment. Entonalactams A-C (1-3) were all determined to be racemic based on chiro-optical data. All secondary metabolites were tested in vitro against Plasmodium falciparum malaria parasites, and ergosta-4,6,8(14),22-tetraen-3-one (6) was identified as the most active compound with 66% inhibition at 50 μM.
authors.affiliation: Eskitis Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111, Australia.
authors.forename: Vanida
authors.initials: V
authors.lastname: Choomuenwai
authors.affiliation: Eskitis Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111, Australia.
authors.forename: Karren D
authors.initials: KD
authors.lastname: Beattie
authors.affiliation: Eskitis Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111, Australia.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Healy
authors.affiliation: Eskitis Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111, Australia.
authors.forename: Katherine T
authors.initials: KT
authors.lastname: Andrews
authors.affiliation: Queensland Herbarium, Brisbane Botanic Gardens Mt Coot-tha, Brisbane, QLD 4066, Australia.
authors.forename: Nigel
authors.initials: N
authors.lastname: Fechner
authors.affiliation: Eskitis Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111, Australia. Electronic address: r.davis@griffith.edu.au.
authors.forename: Rohan A
authors.initials: RA
authors.lastname: Davis
mesh_terms: D000962:Antimalarials / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001315:Australia; D018360:Crystallography, X-Ray; D054833:Isoindoles / Q000737:chemistry / Q000302:isolation & purification*; D007769:Lactams / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010963:Plasmodium falciparum / Q000187:drug effects; D065947:Rainforest; D013098:Xylariales / Q000737:chemistry*
chemical_list: D000962:Antimalarials; D054833:Isoindoles; D007769:Lactams; C000606052:entonalactam A; C000606053:entonalactam B; C000606054:entonalactam C
keywords: Entonaema; Entonalactam; Fungi; Isoindolinone; Lactam; Malaria; Natural product; Rainforest