Dagne Ermias (PhD)Mulugeta Afework2018-06-122023-11-092018-06-122023-11-091995-06http://etd.aau.edu.et/handle/12345678/544The chemical compositions of the essential oils of the leaves and flowers of Tagetes minuta L. were determined by chromatographic and spectroscopic methods. The characteristic components of the essential oils produced from the leaves of T. minuta 'were found to contain (Z)-Ocimenone (41%) and (E)Ocimenone (18%) as the major components, while the oils from the flowers of T. minuta contained cis-p-ocimene (46%), (Z)-and (E)-Ocimenones (22% and 10%, respectively). The volatile oil constituents of the aerial parts of Artemisia rehan plants purchased at different times were investigated using gas chromatographic and spectroscopic techniques. Differences in the camphor (5%, 30%, 31%), chamazulene (7.6%, 1.9%, 1%) composition and yield (0.3%, 0.4%, 0.8%) of these oils was observed. Such differences in the essential oil composition and yield may be ascribed to the existence of different A. rehan chemotypes, seasonal variation or difference in stages of development of the plant materialenTagetes minuta and Artemisia rehanThesis