An Irish scientist, Sean O'Sullivan, who helped develop one of the world's most important anti-leprosy drugs has died at the age of 75.
Dr John F (Séan) O'Sullivan was a member of a team working in the former Medical Research Council of Ireland laboratory at Trinity College Dublin in the years immediately following the second World War. With J.G. Belton, M.L. Conalty and Dermot Twomey he was part of a group led by Vincent Barry, whose actual goal was the discovery of new drugs for use in the fight against TB.
The disease was rife and drug therapies had only a limited effect. The then Taoiseach, Mr de Valera, set up the Medical Research Council hoping to spur new research into controlling TB.
A screening programme was initiated whereby plant products were isolated and tested and this produced a promising lead, a natural product extracted from lichen. Other scientists identified the substance and then serendipity came into play as it so often does in scientific research. A solution containing the substance was left exposed to the air and unexpectedly turned pink.
The research team decided to study why this happened and identified an unusual compound that had a powerful activity against TB in mice. Initially this raised hopes that a promising new drug had been found for use against TB but, alas, it had very little effect in humans.
However, the researchers recognised similarities between the progress of TB in mice and leprosy in humans and the team decided to test the substance against this disease. It had an immediate and dramatic effect, in the process delivering a powerful new drug for controlling a disease endemic at the time in many developing countries.
Called Clofazimine, the drug is now one of the three drugs used by the World Health Organisation together in a cocktail with rifampicin and dapsone to control leprosy.
It is the only drug completely developed in Ireland to be found in the standard Pharmacopeia, a book containing an official list of medicinal drugs together with articles on their preparation and use.
It also probably ranks as the single most important high-tech compound developed in Ireland up to now.
In 1980, the United Nations Education, Science and Cultural Organisation's science prize was presented to the four MRCI researchers for their discovery of Clofazimine and its activity. The award citation reads: "For an outstanding contribution to scientific and technical development in developing countries."
O'Sullivan was an organic chemist specialising in medicinal chemistry. He was born in Dublin and graduated with a BSc (Hons) in 1950 from the National University of Ireland. In 1951 he completed an MSc in Physical Chemistry and in 1954 his PhD in organic chemistry, both from University College Dublin. He worked in the MCRI at Trinity through to 1990, further developing this new drug family and unearthing an entirely new series of drugs, riminophenazines. This opened up the possibility of tackling other diseases with the substances he helped discover.
When MRCI research was discontinued he moved in 1990 to UCD on the invitation of Prof Dervilla Donnelly and remained there until his death.
He continued his work as an emeritus research associate, assessing these drugs for use in a number of areas.
They are being assessed for use in the treatment of multi-drug-resistant cancers and also for the treatment of opportunistic infections in AIDS patients.
O'Sullivan was a member of the Institute of Chemistry of Ireland and of the Irish Association for Cancer Research, serving as its secretary/treasurer from 1970-78 and as president from 1980-82.
He was also a member of the International Leprosy Association and a council member of the Irish Federation of University Teachers. More recently he was awarded the Boyle Higgins medal of the Institute of Chemistry of Ireland. Sadly, he was to have been presented with this important research award next month at a lecture he was to give on the history of medicinal chemistry in Ireland. The medal will now be presented to his family.
He had been co-nominated for this medal by Dr Raphael Darcy of UCD and Dr Mary Meegan of TCD, in recognition of his major research contribution to both institutions.
O'Sullivan and the MRCI team made a groundbreaking discovery that helped reduce the suffering caused by the scourge of leprosy. It represents his legacy to the Irish research community and also to world science.
He is survived by his wife Maire, daughter Cliona, sons Huw and Cian, granddaughter Sorcha and her mother Dominique Le Goff, his brother Donnchadh and sister Máirin.
Séan O'Sullivan: born April 1927; died, September 29th, 2002.