Export 8 results:
Sort by: Author Title Type [ Year  (Desc)]
Asolkar, RN, Singh A, Jensen PR, Aalbersberg W, Carte BK, Feussner KD, Subramani R, DiPasquale A, Rheingold AL, Fenical W.  2017.  Marinocyanins, cytotoxic bromo-phenazinone meroterpenoids from a marine bacterium from the streptomycete Glade MAR4. Tetrahedron. 73:2234-2241.   10.1016/j.tet.2017.03.003   AbstractWebsite

Six cytotoxic and antimicrobial metabolites of a new bromo-phenazinone class, the marinocyanins A-F (1-6), were isolated together with the known bacterial metabolites 2-bromo-1-hydroxyphenazine (7), lavanducyanin (8, WS-9659A) and its chlorinated analog WS-9659B (9). These metabolites were purified by bioassay-guided fractionation of the extracts of our MAR4 marine actinomycete strains CNS-284 and CNY-960. The structures of the new compounds were determined by detailed spectroscopic methods and marinocyanin A (1) was confirmed by crystallographic methods. The marinocyanins represent the first bromo-phenazinones with an N-isoprenoid substituent in the skeleton. Marinocyanins A-F show strong to weak cytotoxicity against HCT-116 human colon carcinoma and possess modest antimicrobial activities against Staphylococcus aureus and amphotericin-resistant Candida albicans. (C) 2017 Elsevier Ltd. All rights reserved.

Hughes, CC, Fenical W.  2010.  Total synthesis of the ammosamides. Journal of the American Chemical Society. 132:2528-2529.   10.1021/ja9106572   AbstractWebsite

The ammosamides A-C are chlorinated pyrrolo[4,3,2-de]quinoline metabolites isolated from the marine-derived Streptomyces strain CNR-698. The natural products, which possess a dense array of heteroatoms, were synthesized in 17-19 steps from 4-chloroisatin. That the Five nitrogen atoms were introduced at the appropriate time and in a suitable oxidation state was key to the success of the total synthesis. Compared to synthetic deschloro ammosamide B, natural ammosamide B is much less susceptible to oxidative degradation.

Hughes, CC, Prieto-Davo A, Jensen PR, Fenical W.  2008.  The marinopyrroles, antibiotics of an unprecedented structure class from a marine Streptomyces sp.. Organic Letters. 10:629-631.   10.1021/ol702952n   AbstractWebsite

Cultivation of an obligate marine Streptomyces strain has furnished the marinopyrroles A and B, densely halogenated, axially chiral metabolites that contain an uncommon bispyrrole structure. X-ray analysis of marinopyrrole B showed that the natural product exists as an atropoenantiomer with the M-configuration. Though configurationally stable at room temperature, M(-)-marinopyrrole A can be racemized at elevated temperatures to yield the non-natural P-(+)-atropo-enantiomer. The marinopyrroles possess potent antibiotic activities against methicillin-resistant Staphylococcus aureus.

Gu, W, Cueto M, Jensen PR, Fenical W, Silverman RB.  2007.  Microsporins A and B: new histone deacetylase inhibitors from the marine-derived fungus Microsporum cf. gypseum and the solid-phase synthesis of microsporin A. Tetrahedron. 63:6535-6541.   10.1016/j.tet.2007.04.025   AbstractWebsite

Two new cyclic peptides, microsporins A and B (7 and 8), were isolated from culture extracts of the marine-derived fungus Microsporum cf. gypseum obtained from a sample of the bryozoan Bugula sp. collected in the U. S. Virgin Islands. The structures of the new compounds were determined by extensive interpretation of 2D NMR data and by chemical methods. Microsporins A and B are potent inhibitors of histone deacetylase and demonstrate cytotoxic activity against human colon adenocarcinoma (HCT-116), as well as against the National Cancer Institute 60 cancer cell panel. The total synthesis of microsporin A on solid-phase is also reported. (c) 2007 Elsevier Ltd. All rights reserved.

Fenical, W.  1997.  New pharmaceuticals from marine organisms. Trends in Biotechnology. 15:339-341.   10.1016/s0167-7799(97)01081-0   AbstractWebsite

Definitions of 'marine biotechnology' often refer to the vast potential of the oceans to lead to new cures for human and animal disease; the exploitation of natural drugs has always been the most basic form of biotechnology. Although only initiated in the late 1970s, natural drug discovery from the world's oceans has been accelerated by the chemical uniqueness of marine organisms and by the need to develop drugs for contemporary, difficult to cure, diseases. Current research activities, while primarily within the academic laboratories, have generated convincing evidence that marine drug discovery has an exceedingly bright future.

Lee, NK, Fenical W, Lindquist N.  1997.  Alternatamides A-D: New bromotryptamine peptide antibiotics from the Atlantic marine bryozoan Amathia alternata. Journal of Natural Products. 60:697-699.   10.1021/np970042+   AbstractWebsite

Four new bromotryptamine peptides, alternatamides A-D (1-4), have been isolated from the Atlantic bryozoan Amathia alternata. The structures of the alternatamides were assigned primarily on the basis of 2D NMR data. The absolute stereochemistry of the N-methylleucine amino acid was shown to be L (2'S) by hydrolysis and comparison with standards. The alternatamides show modest antibacterial activities against several Gram-positive bacteria.

Montanari, AM, Fenical W, Lindquist N, Lee AY, Clardy J.  1996.  Volutamides A-E, halogenated alkaloids with antifeedant properties from the Atlantic bryozoan Amathia convoluta. Tetrahedron. 52:5371-5380.   10.1016/0040-4020(96)00188-3   AbstractWebsite

Volutamides A-E (1-5), halogenated alkaloids of amino acid origin, have been isolated from the temperate Atlantic bryozoan Amathia convoluta Lamouroux. The structures of the new compounds were determined by spectral and chemical methods. The absolute stereochemistries of volutamides B and C were established by CD measurements, while the absolute stereochemistries of volutamides D and E could not be established with confidence. Several of the volutamides deterred feeding by potential predators and were toxic toward larvae of a co-occurring hydroid, suggesting that these metabolites form the basis of an effective chemical defense. Copyright (C) 1996 Elsevier Science Ltd

Wahl, M, Jensen PR, Fenical W.  1994.  Chemical control of bacterial epibiosis on ascidians. Marine Ecology-Progress Series. 110:45-57.   10.3354/meps110045   AbstractWebsite

Two co-occurring ascidians of the Pacific subtidal, Polyclinum planum and Cystodytes lobatus, were found to exhibit remarkably different numbers of surface bacteria. On average, epibacterial densities on P. planum were 140 times greater than those on C lobatus as measured by plate-counting methods. Organic extracts of both ascidian species were tested for antimicrobial activities and effects on bacterial settlement. Bacterial settlement was measured using a new bioassay described in this paper. The results of the settlement bioassay clearly demonstrate that extracts of the little-colonized C. lobatus deter bacterial settlement while extracts of the heavily colonized P. planum induce settlement relative to the control. In addition to reducing bacterial settlement, extracts of C. lobatus colonies exhibited varying, but generally low, levels of antiraicrobial activity against, on average, one-half of the 36 strains of marine bacteria tested. On an interspecific level, including 11 ascidian species screened in a pilot study, fouling-deterring activities were correlated with epibacterial abundances while antimicrobial activity was not. It is concluded that the chemical control of bacterial settlement, possibly complemented by antimicrobial toxicity, provides an accurate model to explain the dramatically different bacterial abundance on the surfaces of the ascidian species studied. This investigation presents evidence that non-toxic metabolites influence bacterial settlement and, in this way, may function to regulate bacterial epibiosis on the surfaces of some marine invertebrates.