Distinguished Professor of Oceanography

Research Interests

  • Chemistry of marine plants, microorganisms and invertebrate animals.
  • Utilization of marine-derived compounds for the treatment of various human diseases, in particular cancer and infectious diseases.


  • B.S., California State Polytechnic University
  • M.S., San Jose State University
  • Ph.D., University of California, Riverside

Recent Publications

Kumar, A, Borgen M, Aluwihare LI, Fenical W.  2017.  Ozone-activated halogenation of mono- and dimethylbipyrrole in seawater. Environmental Science & Technology. 51:589-595.   10.1021/acs.est.6b03601   AbstractWebsite

Polyhalogenated N-methylbipyrroles of two different structure classes have been detected worldwide in over 100 environmental samples including seawater, bird eggs, fish, dolphin blubber, and in the breast milk of humans that consume seafood. These molecules are concentrated in the fatty tissues in comparable abundance to some of the most important anthropogenic contaminants, such as the halogenated flame-retardants and pesticides. Although the origin of these compounds is still unknown, we present evidence that the production of these materials can involve the direct ozone activated seawater halogenation of N-methylbipyrrole precursors. This observation shows that environmental polyhalogenated bipyrroles can be produced via an abiotic process, and implies that the ozone activated halogenation of a variety of natural and anthropogenic seawater organics may be a significant process occurring in surface ocean waters.

Lee, J, Han C, Lee TG, Chin J, Choi H, Lee W, Paik MJ, Won DH, Jeong G, Ko J, Yoong YJ, Nam SJ, Fenical W, Kang H.  2016.  Marinopyrones A-D, alpha-pyrones from marine-derived actinomycetes of the family Nocardiopsaceae. Tetrahedron Letters. 57:1997-2000.   10.1016/j.tetlet.2016.03.084   AbstractWebsite

Two actinomycetes, a member of the rare halophilic genus Streptomonospora and a Nocardiopsis sp. (Nocardiopsaceae), strains CNQ-082 and CNQ-675, respectively, were isolated from marine sediments collected off shore near La Jolla, California. HPLC-UV guided fractionations of the extracts of these strains yielded marinopyrones A-D (1-4), the structures of which were elucidated by interpretation of 1D and 2D NMR and HRMS spectroscopic data. Oxidative ozonation, followed by conversion of the acid product to an alpha-naphthyl amide, provided the absolute configuration at the chiral center on the side-chain. Marinopyrones A-D were examined for the inhibitory activity on nitric oxide production in LPS-activated mouse macrophage cells (RAW 264.7); marinopyrone D (4) was inhibitory with an IC50 value of 13 mu M. To our knowledge, marinopyrones A-C are only the second reported natural products from the rare halophilic genus Streptomonospora. (C) 2016 Elsevier Ltd. All rights reserved.

Le, TC, Yang I, Yoon YJ, Nam SJ, Fenical W.  2016.  Ansalactams B-D illustrate further biosynthetic plasticity within the ansamycin pathway. Organic Letters. 18:2256-2259.   10.1021/acs.orglett.6b00892   AbstractWebsite

Further chemical investigation of a marine-derived bacterium of the genus Streptomyces has led to the isolation of ansalactams B-D (1-3) along with the previously reported metabolite ansalactam A (4). Ansalactams B-D are significantly modified ansamycins, representing three new carbon skeletons and further illustrating the biosynthetic plasticity of the ansalactam class. Unlike ansalactam A, ansalactams B and D are penta- and hexacyclic metabolites, while ansalactam C illustrates an open polyene chain with a terminal carboxylic acid.

Hassan, HM, Boonlarppradab C, Fenical W.  2016.  Actinoquinolines A and B, anti-inflammatory quinoline alkaloids from a marine-derived Streptomyces sp., strain CNP975. Journal of Antibiotics. 69:511-514.   10.1038/ja.2016.56   AbstractWebsite

Actinomycete bacteria of the common genus Streptomyces can be routinely isolated from shallow and deep ocean sediments. Although commonly considered a terrestrial genus, and most abundantly found in soil, Streptomyces strains are found that have distinct requirements for seawater and routinely do not show significant similarity, with terrestrial strains by 16S ribosomal DNA phylogenetic sequence comparisons. Our examination of the culture broth of a Streptomyces sp., strain CNP975, isolated from a local La Jolla, California sediment sample, resulted in the isolation of actinoquinolines A and B (1, 2), which show significant inhibition of the arachidonic acid pathway enzymes cyclooxygenases-1 and -2. The new compounds contain the 3-hydroxyquinaldic acid (3HQA) motif found in numerous peptide antibiotics. In the actinoquinolines, 3HQA forms an amide linkage with a linear six-carbon fragment, formally a 2, 6-diamino-1, 5-dihydroxyhexane unit, a component of likely amino acid reductive off-loading origin. Actinoquinoline A illustrated amide rotational isomerism leading to complex NMR spectral data. Actinoquinoline B was assigned as the C-13 aldehyde analog isolated as an intramolecular hemiacetal. Reduction of 2 with NaBH4 yielded actinoquinoline A thus confirming the relative configurations of all centers in the actinoquinolines.

Zhou, XF, Fenical W.  2016.  The unique chemistry and biology of the piericidins. Journal of Antibiotics. 69:582-593.   10.1038/ja.2016.7   AbstractWebsite

The piericidin family of microbial metabolites features a 4-pyridinol core linked with a methylated polyketide side chain. Piericidins are exclusively produced by actinomycetes, especially members of the genus Streptomyces. The close structural similarity with coenzyme Q renders the piericidins important NADH-ubiquinone oxidoreductase (complex I) inhibitors in the mitochondria! electron transport chain. Because of the significant activities of the piericidins, which include insecticidal, antimicrobial and antitumor effects, total syntheses of the piericidins were developed using various synthetic strategies. The biosynthetic origin of this class has also been the subject of investigation. This review covers the isolation and structure determination of the natural piericidins, their chemical modification, the total syntheses of natural and unnatural analogs, their biosynthesis, and reported biological activities together with structure-activity relationships. Given the fundamental biology of this class of metabolites, the piericidin family will likely continue to attract attention as biological probes of important biosynthetic processes.