title: Cytotoxic and Antihaptotactic beauvericin analogues from precursor-directed biosynthesis with the insect pathogen Beauveria bassiana ATCC 7159.
abstract: Precursor-directed biosynthesis was used to produce analogues of the cyclic depsipeptide mycotoxin beauvericin (1) using the filamentous fungus Beauveria bassiana ATCC 7159. Feeding 30 analogues of D-2-hydroxyisovalerate and L-phenylalanine, the natural 2-hydroxycarboxylic acid and amino acid precursors of beauvericin, led to the biosynthesis of novel beauvericins. Six of these were isolated and characterized, and their cytotoxicity and directional cell migration (haptotaxis) inhibitory activity against the metastatic prostate cancer cell line PC-3M were evaluated. Replacement of one, two, or all three of the D-2-hydroxyisovalerate constituents in beauvericin (1) with 2-hydroxybutyrate moieties (beauvericins G(1-3), compounds 2-4) caused a parallel decline of cell migration inhibitory activity and cytotoxicity, suggesting a requirement for a branched side chain for both of these biological activities at the corresponding positions of beauvericins. Replacement of one, two, or all three N-methyl-L-phenylalanine residues of beauvericin with N-methyl-L-3-fluorophenylalanine moieties (beauvericins H(1-3), compounds 5-7) increased cytotoxicity without affecting antihaptotactic activity.
authors.affiliation: SW Center for Natural Products Research and Commercialization, Office of Arid Lands Studies, College of Agriculture and Life Sciences, The University of Arizona, Tucson, Arizona 85706-6800, USA.
authors.forename: Yuquan
authors.initials: Y
authors.lastname: Xu
authors.forename: Jixun
authors.initials: J
authors.lastname: Zhan
authors.forename: E M Kithsiri
authors.initials: EM
authors.lastname: Wijeratne
authors.forename: Anna M
authors.initials: AM
authors.lastname: Burns
authors.forename: A A Leslie
authors.initials: AA
authors.lastname: Gunatilaka
authors.forename: István
authors.initials: I
authors.lastname: Molnár
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D052982:Beauveria / Q000737:chemistry / Q000378:metabolism*; D012831:Bombyx / Q000382:microbiology; D047630:Depsipeptides / Q000096:biosynthesis* / Q000737:chemistry / Q000494:pharmacology*; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D008297:Male; D015394:Molecular Structure; D009361:Neoplasm Invasiveness; D011471:Prostatic Neoplasms; D013329:Structure-Activity Relationship; D013778:Tetrazolium Salts / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014945:Wound Healing / Q000187:drug effects