title: Bioactive Polycyclic Tetramate Macrolactams from Lysobacter enzymogenes and Their Absolute Configurations by Theoretical ECD Calculations.
abstract: Two new polycyclic tetramate macrolactams, lysobacteramides A (1) and B (2), together with HSAF (heat-stable antifungal factor, 3), 3-dehydroxy HSAF (4), and alteramide A (5) were isolated from a culture of Lysobacter enzymogenes C3 in nutrient yeast glycerol medium. Their structures were determined by MS and extensive NMR analysis. The absolute configurations of 1-5 were assigned by theoretical calculations of their ECD spectra. Although HSAF and analogues were reported from several microorganisms, their absolute configurations had not been established. The isolation and the absolute configurations of these compounds revealed new insights into the biosynthetic mechanism for formation of the polycycles. Compounds 1-4 exhibited cytotoxic activity against human carcinoma A549, HepG2, and MCF-7 cells with IC50 values ranging from 0.26 to 10.3 μM. Compounds 2 and 3 showed antifungal activity against Fusarium verticillioides with IC50 value of 47.9 and 6.90 μg/mL, respectively.
authors.affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences , Guangzhou 510650, People's Republic of China.|Department of Chemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States.
authors.forename: Liangxiong
authors.initials: L
authors.lastname: Xu
authors.affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences , Guangzhou 510650, People's Republic of China.
authors.forename: Ping
authors.initials: P
authors.lastname: Wu
authors.affiliation: Department of Chemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Wright
authors.affiliation: Department of Chemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States.
authors.forename: Liangcheng
authors.initials: L
authors.lastname: Du
authors.affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences , Guangzhou 510650, People's Republic of China.
authors.forename: Xiaoyi
authors.initials: X
authors.lastname: Wei
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry; D004354:Drug Screening Assays, Antitumor; D005670:Fusarium / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D047029:Lactams, Macrocyclic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D053528:Lysobacter / Q000737:chemistry*; D061986:MCF-7 Cells; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D048630:Polyketide Synthases / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; C557945:HSAF compound; D047029:Lactams, Macrocyclic; C000602696:lysobacteramide A; C000602697:lysobacteramide B; D048630:Polyketide Synthases