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1 May, 2000

Dr. Bill Baker and Chemistry Question 72: What other research stations are close to Palmer Station? The L. M. Gould arrived today early in the morning and dropped off new station staff--some electricians to round out the winter construction crew and a Kiwi (New Zealander) safety inspector who is here for a few days. The LMG will take a quick (2-3 day) science cruise out into the Southern Ocean before returning to take us back to Punta Arenas. As we near the end of our field time, necessary tasks in the lab are taking up most of our days. We will be diving only a few more times. Although we all share many tasks and the research is interrelated, our research team is basically divided into two working sections. The first group (myself, Andy Mahon, Drs. Jim McClintock, Chuck Amsler, and Katrin Iken) is focused on ecological questions, looking at how chemicals affect ecological interactions in the environment, while the second group (Bruce Furrow and Dr. Bill Baker) is more interested in the chemicals themselves, their function and their production. I have been working more closely with the ecologists, so my journals have covered more of that aspect of the research. Today I am going to try to explain (in abbreviated form) what has been keeping the chemists busy. In the field, our chemists are interested in getting as wide an array of sample species as possible, both of macroalgae and invertebrates. They are looking for interesting chemicals wherever they occur in the ecosystem. Invertebrates are their main focus for the practical reason that a large sample of freshly collected macroalgae will lose around 95% of its volume as it dries, while water doesn't make up such a large portion of the initial volume of an invertebrate sample. It is easier to get the large volume of sample necessary to run chemical tests from invertebrate species. From the first moment we returned with samples from a dive, Bruce Furrow has been keeping the freeze-dryers running 24 hours a day preparing samples for travel back to the States for analyses that we have no time to complete on station. Raw material as well as refined extracts of both invertebrates and macroalgae are processed this way. Liquid extracts must first be frozen in a regular freezer so the pressure of the vacuum doesn't suck our precious chemicals into the machine! While on station, Bill and Bruce are running some simple initial surveys to find possible chemicals of interest and to identify which species we should focus on in the field. A Thin Layer Chromatography (TLCs for short) process is run on samples from each species collected. The TLC process separates the component carbon-based molecules in a sample into chemical groups. A dot of sample is placed near the base of a thin, silica gel plate, and then the entire plate is placed upright in a jar with the bottom of the plate in a solvent. The solvent runs up the plate, drawing molecules of different polarities (types) along at different rates. For someone used to looking at completed TLCs, there is a typical pattern of bands, dots and trails where expected chemical compounds show up (i.e. pigments, primary metabolites, etc.) for each type of species. Bill is looking for the unexpected spot, indicative of an unknown or unusual chemical. The chemistry group is also working on a preliminary set of the tasks that will be undertaken in earnest back in the States. Species of interest are identified by comparing TLC data and bioassay results; our group is looking for species with activity in both areas. This tells us that there is some interesting chemical present. Once we know that, then Bill and Bruce start the process of figuring out what the chemical compound of interest actually is. It is a long, complex puzzle with many steps. The extract from the species is divided into 12 different groups of chemical molecules from which the one causing the biological activity must be selected. Several techniques are then used to show the unique signature of a portion of our compound. This can be compared to signatures of known chemical structures to figure out what our compound's structure is piece by piece, until it forms a complete compound that explains all the data. We will not complete this process for any samples while in the field. Dr. Baker has worked in natural products chemistry from the end of his undergraduate work through his advanced degrees. He now has his own Natural Products (research which looks at the chemicals produced by various organisms in everything from tropical land plants to insects to antarctic marine life) and Biosynthesis (research involving isotopes and metabolic pathways) lab at Florida Institute of Technology. Bill credits an inspiring junior college teacher, a love of being outdoors and his taking advantage of some key opportunities that were presented to him for his present career in science. He especially enjoys the constant exchange of ideas in the pursuit of science, the endless discussions which he began at the University of Hawaii when working with the natural product guru, Dr. Paul Schoyer. His group had very broad interests--they were not just looking for biomedical applications for the chemicals they found but were starting to get into rudimentary chemical ecology with questions like "Why do these animals make these things?" He got involved with Antarctic research when one of Bill's first graduate students came back to the lab with an arcticle by Dr. Jim McClintock on Antarctic sea stars. Then he got a letter from Jim about working together the next season in the Antarctic... and the rest is history! Bill has spent 4 seasons at McMurdo and will spend 2 field seasons here at Palmer (this one and 2001). Answer 71: Whales have multiple-chambered stomachs, the first of which is lined with a horny material and could serve a grinding function similar to a gizzard. They also have extremely long intestines. There is a record of a 50 foot-long sperm whale with a 2,600 foot long intestine.


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