Seasonal variation in chemical composition of Cistus albidus L. from Spain

The chemical composition of the oils of two samples of the same population of Cistus albidus gathered in Spain during winter and spring, have been analyzed by GG and GUMS. All the samples were characterized by a high percentage of sesquiterpenes while monoterpenes were totally absent. Most of the differences detected in the flower oils (SF) were quantitative, although small qualitative ones were also found. The principal compounds of the winter leaf oils (WL) were identified as zingiberene (14.8%), aromadendrene (10.6%), ar-curcumene (10.6%) and guaiol (6.5%), whereas the oil from the spring leaves (SL) contained as main constituents aromadendrene (9.2%), ar-curcumene (8.8%), zingiberene (8.0%) and guaiol (7.0%). The flower oils also contained these components but the major ones were found to be alpha-cadinol (8.4%) and zingiberene (8.1%). The seeds of this species were the part of the plant with less yield oil. As far as we know, this is the first report about the seasonal variation on the chemical composition of the oil of this species isolated by hydrodistillation mid analyzed by GC and GC/MS.