Seven wild populations (hypogean and aerial parts) of Aristolochia clematitis, sampling in the North-East Italy, were studied with regard to its aristolochic acids content. Two compounds (aristolochic acids I and II) were identified and quantified by HPLC. The hypogean organs were the most productive parts. Significant quantitative variation was found among populations: two chemical types were identified.
The quantitative variability of the two secondary metabolites was correlated with seasonal and sinanthropical factors but not with the climatic variables. The compounds can play a defence role against phytophagous insects.
