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

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.

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.

Hassan, HM, Degen D, Jang KH, Ebright RH, Fenical W.  2015.  Salinamide F, new depsipeptide antibiotic and inhibitor of bacterial RNA polymerase from a marine- derived Streptomyces sp. Journal of Antibiotics. 68:206-209.   10.1038/ja.2014.122   AbstractWebsite
Awakawa, T, Crusemann M, Munguia J, Ziemert N, Nizet V, Fenical W, Moore BS.  2015.  Salinipyrone and pacificanone are biosynthetic by-products of the rosamicin polyketide synthase. Chembiochem. 16:1443-1447.   10.1002/cbic.201500177   AbstractWebsite

Salinipyrones and pacificanones are structurally related polyketides from Salinispora pacifica CNS-237 that are proposed to arise from the same modular polyketide synthase (PKS) assembly line. Genome sequencing revealed a large macrolide PKS gene cluster that codes for the biosynthesis of rosamicin A and a series of new macrolide antibiotics. Mutagenesis experiments unexpectedly correlated salinipyrone and pacificanone biosynthesis to the rosamicin octamodule Spr PKS. Remarkably, this bifurcated polyketide pathway illuminates a series of enzymatic domain- and module-skipping reactions that give rise to natural polyketide product diversity. Our findings enlarge the growing knowledge of polyketide biochemistry and illuminate potential challenges in PKS bioengineering.