title: Alkaloids and polyketides from Penicillium citrinum, an endophyte isolated from the Moroccan plant Ceratonia siliqua.
abstract: The endophytic fungus Penicillium citrinum was isolated from a fresh stem of the Moroccan plant Ceratonia siliqua. Extracts of P. citrinum grown on rice and white bean media yielded five new compounds, namely, citriquinochroman (1), tanzawaic acids G and H (2 and 3), 6-methylcurvulinic acid (4), 8-methoxy-3,5-dimethylisoquinolin-6-ol (5), and one new natural product, 1,2,3,11b-tetrahydroquinolactacide (6), which had previously been described as a synthetic compound. In addition, 13 known compounds including seven alkaloids and six polyketides were isolated. The structures of the new compounds were unambiguously determined on the basis of one- and two-dimensional NMR spectroscopy as well as by high-resolution mass spectrometry. Citriquinochroman (1) features a new skeleton, consisting of quinolactacide and (3S)-6-hydroxy-8-methoxy-3,5-dimethylisochroman linked by a C-C bond. 1,2,3,11b-Tetrahydroquinolactacide (6) may be a biogenetic precursor of quinolactacide. Citriquinochroman (1) showed cytotoxicity against the murine lymphoma L5178Y cell line with an IC50 value of 6.1 μM, while the other compounds were inactive (IC50 >10 μM) in this assay.
authors.affiliation: Institut für Pharmazeutische Biologie und Biotechnologie, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, Geb. 26.23, 40225 Düsseldorf, Germany.
authors.forename: Mona
authors.initials: M
authors.lastname: El-Neketi
authors.forename: Weaam
authors.initials: W
authors.lastname: Ebrahim
authors.forename: Wenhan
authors.initials: W
authors.lastname: Lin
authors.forename: Sahar
authors.initials: S
authors.lastname: Gedara
authors.forename: Farid
authors.initials: F
authors.lastname: Badria
authors.forename: Hassan-Elrady A
authors.initials: HE
authors.lastname: Saad
authors.forename: Daowan
authors.initials: D
authors.lastname: Lai
authors.forename: Peter
authors.initials: P
authors.lastname: Proksch
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D004926:Escherichia coli / Q000187:drug effects; D007887:Fabaceae / Q000382:microbiology*; D051379:Mice; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D009018:Morocco; D019906:Nuclear Magnetic Resonance, Biomolecular; D010407:Penicillium / Q000737:chemistry*; D061065:Polyketides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects; D013296:Streptococcus pneumoniae / Q000187:drug effects
chemical_list: D000470:Alkaloids; D000972:Antineoplastic Agents, Phytogenic; D061065:Polyketides