Researcher profile: Lars Engman

Ideas that unite

The lines of the pencil fill up the paper, forming bonds between carbon atoms that branch out and grow into long chains, occasionally combined in ring-shaped structures. A carbon atom at a time is incorporated into a pattern, creating an organic compound of uncertain potential. However, applications are not what matters most to Lars Engman, a researcher in organic chemistry — it's the very idea.

Where it first occurs is difficult to explain, more than that it is "somewhere in here," says Lars Engman and points towards the head where he sits at the desk at the Biomedical Centre.

– It may start with a drawing of a molecule that I want to produce. Then I have to figure out how to get all these carbon atoms in place.

In recent years, his research team of synthetic chemists have tried to create more effective antioxidants.

– All organic material manufactured in society or produced in nature reacts with atmospheric oxygen and breaks down if we don't protect it. Without the addition of antioxidants, food would be wasted much faster and plastics turn into flour.

There are also diseases suspected of being caused by so-called oxidative stress - a condition where the natural antioxidant defence is overwhelmed. In such cases, artificial antioxidants could serve as pharmaceuticals, says Lars Engman.

– However, today we have a problem with all new organic compounds that come into play. Many people put an equal sign between chemicals and poison. People are afraid after historic environmental scandals with DDT and PCB.

– But if you really test things carefully before you start using them on a large scale, the benefits outweigh the harms. You can do much more good than evil with chemistry, such as curing diseases and reducing the suffering of people in the world.

He has developed several simple models to test his antioxidants. But they must first be synthetically manufactured, an often long and strenuous work. Lars Engman picks up a hefty catalogue, a veritable Bible of Chemistry, from the book shelf where thousands of substances – building blocks - in all price ranges can be ordered.

– Some chemicals are very expensive so I’ll just be able to afford five milligrams, others I can buy two kilograms of. By using fairly simple test systems, I can study how fast the organic compounds react with atmospheric oxygen.

– If the reaction time is extended from minutes to hours or days when the antioxidant is added, then it indicates that the antioxidant is doing its job.

Lars Engman is assisted by two doctoral students and a post-doc from India. Promising antioxidants are sent to various partners for additional testing, such as the Department of Engineering Sciences at the Ångström Laboratory. There the compounds undergo tests in different cell systems by a team led by Marjam Ott.

– That’s when we get a first indication whether we've produced a possible drug candidate. However, it must pass through many more needle eyes before possible usage. First of all, the compound needs to have significant effect and be able to cure a disease. Then it must be non-toxic and not involve any side effects.

Last autumn, one of the group's publications got positive reviews by the scientific journal of Chemistry. Their article showed the half-metallic substance of tellurium increasing the antioxidant properties of vitamin E nearly ten times.

– In nature, vitamin E is the best lipophilic antioxidant. What we did was to place tellurium atoms in the molecule in order to improve it, and we succeeded.

The element tellurium has long been extracted as a by-product of copper production. But the use of tellurium is increasing, and hence its price on the world market. However, there are still few groups in the world doing research on tellurium; Lars Engman himself has worked with the element since his doctoral studies in the 1970s.

– It caught my interest because it seemed to have so many uses. In addition, tellurium was a blank slate, no one had studied it in greater detail. But we still know very little about its behaviour when placed in the human body, this we would need help testing.

The dream is to have a pharmaceutical company invest in further research of the promising antioxidant. Since he came to Uppsala University in 1994, Lars Engman has tried to patent his findings from time to time.

– I have gone through the process four or five times, but so far nothing’s come out of it. One of the collaborations I had with the Astra Group was dropped because of the insufficient effects.

– But it may be that someone sees my article in fifty years and thinks, "this I can test in this system", and then suddenly it works very well.

The privilege of the scientist conducting basic research is the relative freedom to choose which project to embark on, without having to bother about its immediate practical use, says Lars Engman.

– What I'm doing is more of a curiosity-based research where I have time to wait for applications. Most important is still the very idea.

Anneli Björkman