Fungus offers a new mould of antibiotics: Annual Chemical Congress of the Royal Society of Chemistry

AN ANTIBIOTIC found in an Indian fungus could help doctors combat diseases that are increasingly resistant to drugs.

The medical world is becoming alarmed at the growing list of bacteria that are showing resistance to traditional antibiotics. Some strains are resistant to almost all known drugs. Scientists fear it is only a matter of time before a bacterium appears against which even the strongest drugs will be useless.

The problem of drug resistance is now so severe that doctors are trying to keep some antibiotics in reserve. One recently introduced group, called fluoroquinolones, are now largely reserved for use against super-resistant hospital bacteria.

Richard Taylor, Professor of Organic Chemistry at York University, leads a team that has beaten the world in a race to synthesise the antibiotic, called aranorosin, in the laboratory. 'At the moment we have this list of antibiotics and we can work our way through it, but resistance is now a serious problem,' he said at the Annual Chemical Congress of the Royal Society of Chemistry in Liverpool yesterday.

He said the new antibiotic was particularly promising because it comes from a newly-identified family of antibiotics called epoxycyclohexanes. These have different chemical structures to existing drugs, so behave in a new way when they attack bacteria.

'Just now, in this past six months, a whole group of compounds has been isolated and published with this similar structure - and nobody knows their mode of action,' Professor Taylor said. Antibiotics usually work either by interfering with the bacteria's cell walls or with the production of proteins vital to the bacteria's function.

The team is working in conjunction with Smithkline Beecham, the drugs company, which has found the antibiotic effective against so-called 'gram-negative' bacteria. These include the salmonella bacteria. Simplified versions of the compound have yet to be tested against diseases such as tuberculosis.

'What we've done is develop a synthesis that in addition to making the natural product will also be able to be used to make very simple products. We are trying to identify the bit of the molecule that is crucial for biological activity,' Professor Taylor said.

'There is now a world-wide programme to scour nature, testing chemists' ingenuity to make every kind of antibiotic they can. It is important to stay one step ahead. This work shows how important it is that we continue to look to nature for leads.'

Shrubs used by Chinese herbalists to make a tea for fevers have provided a compound from which Reading University scientists have made a series of promising anti-malaria drugs.