Office: BSF 308
Lab: BSF 358,362
Ph.D., University of Hawaii, 1986
Postdoctoral Fellow, Rice University, 1987-88
Stanford University, 1988-89
Natural product isolation and characterization from marine invertebrates; biosynthesis and synthesis of secondary metabolites from marine invertebrates; chemical ecology.
Marine invertebrates such as sponges, corals and mollusks have evolved a variety of defenses to protect themselves in the hostile environment of the ocean. Some of these defense mechanisms are physical. More common in these organisms is chemical defense, production of toxic secondary metabolites that deter predation, fouling, infection or otherwise promote the welfare of the organism.
The study of secondary metabolites in marine invertebrates is a multifaceted endeavor. Our major emphasis is the isolation and identification of new secondary metabolites using the techniques of organic structure determination: high-field 1H and 13C NMR in one- and two-dimensions (COSY, RCT, HETCOR, HMBC, etc.); mass spectrometry (electron impact, fast atom bombardment, etc.); IR; and UV; as well as traditional wet chemistry (derivatization, hydrolysis, ozonolysis, Baeyer-Villiger oxidation, etc.). Once we have identified a new metabolite, we can broaden the scope of our investigation to biosynthetic and ecological aspects and investigate its biological activity.
Biosynthesis addresses the fundamentals of metabolism in an organism. Our investigation of how an organism makes secondary metabolites from primary metabolites (amino acids, carbohydrates, etc.) involves the synthesis of stable- and/or radioactively labeled precursors that are either fed to a live organism or treated with an enzyme preparation from that organism. The location of the label in the product is identified by spectroscopy or chemical degradation. An accumulation of precursor/product data allows the elucidation of the mechanism.
In collaboration with biologists, we study the role of new metabolites both in the organism (i.e., feeding deterrents) and in the environment that the organism is found (i.e., allelopathy). Other biological and ecological aspects of interest include the distribution of a metabolite in the food chain (some nudibranchs, for example, sequester defensive agents from the sponge they prey on) and chemotaxonomy.
Nature is an important source of new pharmaceuticals. Compounds that an organism has developed for its own defense can be used for man's defense as antiviral agents (AIDS, Herpes), antineoplastic agents (cancer), or other pharmaceuticals. In collaboration with pharmacologists, we screen our new isolates in assays that will identify their potential as drugs.
View our currently funded projects here.
Laurent Calcul, Carrie Waterman
Thesis Undergraduate Students
Samantha Landolfa, Morgan Pyne, Jacqueline Salm, Michelle Summerville
Kristin Costelow, Danielle Demers, Jacqueline Fries, Daniel Utic, Michael Veri, Christopher Witowski
Marine Chemical Ecology - James B. McClintock (Editor), Bill J. Baker (Editor)
- Jeffrey R. Jones, Matthew Lebar, Umesh K. Jinwal, Jose F. Abisambra, John Koren III, Laura Blair, John C. O’Leary, Zachary Davey, Justin Trotter, Amelia G. Johnson, Edwin Weeber, Christopher B. Eckman, Bill J. Baker and Chad A. Dickey. The diarylheptanoid (+)-aR,11S-myricanol and two flavones from Bayberry (Myrica cerifera)destabilize the microtubule associated protein tau. J. Nat. Prod., in press.
- Philip Bucolo, Charles D. Amsler, James B. McClintock and Bill J. Baker. Palatability of the Antarctic rhodophyte Palmaria decipiens (Reinsch) R.W. Ricker and its endo/epiphyte Elachista antarctica Skottsberg to sympatric amphipods. J. Exp. Biol. Ecol., in press.
- Jill P. Zamzow, Craig F. Aumack, Charles D. Amsler, James B. McClintock, and Bill J. Baker. Gut contents and stable isotope analyses of the Antarctic fish, Notothenia coriiceps Richardson, from two macroalgal communities. Antarctic Sci., in press.
- Rob W. M. van Soest and Bill J. Baker. A new carnivorous shallow-water sponge from McMurdo Sound, Antarctica (Porifera, Poecilosclerida). Mar. Biodiversity, in press.
- Matthew D. Lebar, Lisha Luttenton, James B. McClintock, Charles D. Amsler and Bill J. Baker. Accumulation of vanadium, manganese, and nickel in Antarctic tunicates. Polar Biol., in press.
- Craig F. Aumack, Charles D. Amsler, James B. McClintock and Bill J. Baker. Impacts of mesograzers on epiphyte and endophyte growth associated with chemically defended macroalgae along the Western Antarctic Peninsula. J. Phycol., in press.
- James B. McClintock, Charles D. Amsler and Bill J. Baker. Overview of the chemical ecology of benthic marine invertebrates along the Western Antarctic Peninsula. Integ. Comp. Biol. 2010, 50, 967-980.
- Hiroki Asao, Yoko Nakamura, Yukito Furuya, Shigefumi Kuwahara, Bill J. Baker and Hiromasa Kiyota. Synthesis of pteroenone and its stereoisomers, a defensive metabolite of the abducted Antarctic pteropod Clione antarctica. Helv. Chem. Acta 2010, 93, 1933-1944.
- Matt D. Lebar and Bill J. Baker. Synthesis and structure reassessment of psammopemmin A. Aust. J. Chem. 2010, 63, 862-866.
- J. Alan Maschek, Cindy Bucher, Alberto van Olphen, Charles D. Amsler, James B. McClintock and Bill J. Baker. The pursuit of potent anti-influenza activity from the Antarctic red marine alga Gigartina skottsbergii. In: The Biological Activity of Phytochemicals, Recent Adv. Phytochem. Vol 41, Gang, D. R., ed., Springer, 2011, in press.
- Thushara Diyabalanage, Katrin B. Iken, Charles D. Amsler, James B. McClintock and Bill J. Baker. Palmadorins A-C, sesquiterpene glycerides from the Antarctic nudibranch Austrodoris kerguelenensis. J. Nat. Prod. 2010, 73, 416-421.
- Matt D. Lebar and Bill J. Baker. Synthesis of the C3-14 fragment of palmerolide A using a chiral pool based strategy. Tetrahedron 2010, 66, 1557-1562.
- Jill P. Zamzow, Charles D. Amsler, James B. McClintock and Bill J. Baker. Habitat choice and predator avoidance by Antarctic amphipods: the roles of algal chemistry and morphology. Mar. Ecol. Prog. Ser. 2010, 400, 155-163.
- Kevin J. Peters, Charles D. Amsler, James B. McClintock, and Bill J. Baker. Potential chemical defenses of Antarctic sponges against sympatric microorganisms. Polar Biol. 2010, 33, 649-658.
- Craig F. Aumack, Charles D. Amsler, James B. McClintock and Bill J. Baker. Chemically mediated resistance to mesoherbivory in finely branched macroalgae along the western Antarctic Peninsula. Euro. J. Phycol. 2010, 45, 19-26.
- Wai S. Ma, Tina Mutka, Brian Vesley, Margaret O. Amsler, James B. McClintock, Charles D. Amsler, Jason A. Perman, Maya P. Singh, William M. Maiese, Michael J. Zaworotko, Dennis E. Kyle and Bill J. Baker. Norselic acids A-E, highly oxidized anti-infective steroids that deter mesograzer predation, from the Antarctic sponge Crella sp. J. Nat. Prod. 2009, 72, 1842-1846.
- Gil Koplovitz, James B. McClintock, Charles D. Amsler and Bill J. Baker. Palatability and chemical anti-predatory defenses in common ascidians from the Antarctic peninsula. Aquatic Biol. 2009, 7, 81-92.
- Margaret O. Amsler, James B. McClintock, Charles D. Amsler, Robert A. Angus and Bill J. Baker. An evaluation of sponge-associated amphipods from the Antarctic Peninsula. Antarctic Sci. 2009, 21, 579-589.
- James B. McClintock, Margaret O. Amsler, Gil Koplovitz, Charles D. Amsler and Bill J. Baker. Observations on an Association between the dexaminid amphipod Polycheria antarctica F. acanthopoda and its ascidian host Distaplia cylindrica. J. Crustacean Biol. 2009, 29, 605-608.
- Kevin J. Peters, Charles D. Amsler, James B. McClintock, Rob W. M. van Soest, Bill J. Baker. Palatability and chemical defenses of sponges from the western Antarctic Peninsula. Mar. Ecol. Prog. Ser. 2009, 385, 77-85.