Ten years ago, a compound called dicaffeoylquinic acid has been shown to effectively inhibit HIV in vitro, and are therefore important lead compounds which may be used in AIDS therapy. However, because the compound, found in artichokes and wild chicory, is very difficult to procure, the market price (currently about �1000 per milligram) is too costly for use in routine therapy.

Researchers from the Bonn Centre of Molecular Biotechnology (CEMBIO), however, reports of an alternate, possibly cheaper, source: sunflowers.

Sunflowers which showed resistance to the fungus causing 'white stem rot' were found to produce DCQA in as a defensive response to the fungal infection. The scientists are already planning the next steps:

'We want to attempt to cultivate sunflower cells or other plant cells in a nutrient solution together with the mould Sclerotinia sclerotiorum and then obtain the enzyme from the liquid,' CEMBIO researcher Ralf Theisen says. 'If things go according to plan, we could produce DCQA at a substantially reduced cost.'

Other possible routes would be to identify the genes coding for DCQA and either over-express it, or excise and transfer it into other expression systems. The scientists also consider simply identifying the enzyme in sunflowers responsible for transferring the caffeoyl groups to quinic acid, and subsequently manufacturing DCQA synthetically.

The plants probably only have one enzyme, which acts as a catalyst for this transfer. If we can find the construction manual for this enzyme, i.e. the corresponding gene, and can smuggle it into the bacteria, the latter can produce the enzyme in large quantities. The critical step of synthesis would then be child's play and could be carried out on an industrial basis by using the fermentation technology available in J�lich.'

Source: Uni Bonn