title: Merocyclophanes C and D from the Cultured Freshwater Cyanobacterium Nostoc sp. (UIC 10110).
abstract: Merocyclophanes C and D (1 and 2) were isolated from the cell extract of the cultured cyanobacterium UIC 10110. The structures were determined by one-dimensional nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry and confirmed by 2D NMR techniques. The absolute configurations were determined using electronic circular dichroism spectroscopy. Merocyclophanes C and D represent the first known analogues of the merocyclophane core structure, a recently discovered scaffold of [7,7] paracyclophanes characterized by an α-branched methyl at C-1/C-14; 1 and 2 showed antiproliferative activity against the MDA-MB-435 cell line with IC50values of 1.6 and 0.9 μM, respectively. Partial 16S analysis determined UIC 10110 to be a Nostoc sp., and it was found to clade with UIC 10062 Nostoc sp., the only other strain known to produce merocyclophanes. The genome of UIC 10110 was sequenced, and a biosynthetic gene cluster was identified that is proposed to encode type I and type III polyketide synthases that are potentially responsible for production of the merocyclophanes; however, further experiments will be required to verify the true function of the gene cluster. The gene cluster provides a genetic basis for the observed structural differences of the [7,7] paracyclophane core structures.
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: May
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States.
authors.forename: Wei-Lun
authors.identifier: 0000-0003-3703-8531
authors.initials: WL
authors.lastname: Chen
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States.
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Lantvit
authors.affiliation: Center for Biostatistics, The Ohio State University , Columbus, Ohio 43210, United States.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States.
authors.forename: Aleksej
authors.initials: A
authors.lastname: Krunic
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States.
authors.forename: Joanna E
authors.initials: JE
authors.lastname: Burdette
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Eustaquio
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States.
authors.forename: Jimmy
authors.identifier: 0000-0002-4420-2048
authors.initials: J
authors.lastname: Orjala
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry; D003120:Colorado; D005618:Fresh Water / Q000382:microbiology; D020128:Inhibitory Concentration 50; D047028:Macrocyclic Compounds / Q000737:chemistry / Q000302:isolation & purification*; D051379:Mice; D015394:Molecular Structure; D046937:Nostoc / Q000737:chemistry* / Q000235:genetics; D019906:Nuclear Magnetic Resonance, Biomolecular; D021241:Spectrometry, Mass, Electrospray Ionization; D000097566:Cyclophanes
chemical_list: D000900:Anti-Bacterial Agents; D047028:Macrocyclic Compounds; C000621337:merocyclophane C; D000097566:Cyclophanes; C000621338:merocyclophane D