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28 April: Better living through Chemistry (Scotia Arc Expedition 2013)

By: Dr Nerida Wilson, Category: Science, Date: 03 May 2013

At the moment, we are sampling near the Falkland islands (or Malvinas).

28 April: Better living through Chemistry (Scotia Arc Expedition 2013) #4

Nerida Wilson & Greg Rouse © Australian Museum

Aside from our evolutionary studies, many of the animals we find are being screened for useful chemicals. Here is an explanation provided by our resident chemist, Bill Baker:

The old Dow Chemical motto still rings true in many respects. Chemistry plays an important part in the ecology of many of the animals we see on this cruise. Invertebrates that are sessile (attached to the sea floor) or slow moving (such as sea slugs), and largely composed of soft, fleshy tissues, are perfect meals for a passing fish or a hungry sea star.

But no! Chemistry comes to the rescue! Since they cannot flee their predators, these invertebrates can use chemicals that are toxic or distasteful to protect themselves. One bite of a noxious sponge can teach a fish to avoid that meal choice in the future.

The ecology of these chemicals is fascinating enough, but what is intriguing is the potential use of those natural chemicals as pharmaceutical drugs. We chemists call these kinds of chemicals ‘natural products’ to distinguish them from chemicals prepared purely in a laboratory.

Natural products have a rich history of human use, not only as pharmaceuticals but as dyes, food additives, and even perfumes. Aspirin has its origins in the bark of the willow tree and penicillin was discovered from a mould – over half of pharmaceuticals currently in use come from natural products.

So perhaps it will not surprise you that the nudibranch Nerida speaks so fondly of, Doris kergulenensis, produces a chemical to protectant itself that also turns out to inhibit a certain pathway in cancer cells.

So while much of the cruise is focused on describing the biodiversity of the region, we are also producing a collection of soft bodied, sessile or slow moving invertebrates that will go back to the States with us for chemical analysis.

Who knows, that smelly, squishy yellow sponge that came out of the trawl yesterday may well have hidden in its tissues the cure to the common cold. Here’s hoping!