Browsing by Author "Asfaw Nigist"

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    Chemical Investigation on the Essential Oils of Endemic Wild and Cultivated Lippia Adoensis:a Comparative Study
    (1992-06) Asfaw Nigist; Abegaz Berhanu (PhD)
    study on the essential oil of endemic L. adoensis Hochst. ex. Walp. was undertaken. The 'search work was conducted on samples from four areas where the ethnic groups claim a lfference in the flavour of the wild and cultivated L. adoensis. The chemical investigation Idicated that the essential oils obtained from the wild and cultivated L. adoensis are markedly ifferent in their physical characteristics and chemical composition. The eSsential oils froM~ese NO types were differentiated from each other by the Presence of l-linaloo las a major component 1 the cultivated and its absence in the wild; and by the presence of d-limonene, peri1laldehyde, .iperitenone, and citral a in the wild and their absence in the cultivated L. adoensis. The oils listilled from cultivated L. adoensis show a laevo rotation while those from the wild are dextro otatory. Morphological differences of the leaves were also observed. There are no published eports on the morphological or chemical differences between the wild and cultivated L. adoensis erior to this work.ourteen components comprising 88.1 - 94.8% of the oil from the cultivated, and 16 components ;onstituting 68.4 - 86.5 % of the oil from the wild were identified. These include ipsdienone, 1- inalool, germacrene D, d-limonene, d-perillaldehyde, piperitenone, citral a and b, ocimene, Ci; opaene, Ci- and Jl-caryophyllene, Ci-farnesene, Ci- and Jl-cadinene. To the best of our knowledge, this is the first time that ipsdienone is reported from a natural source. All the other compounds are known. However, piperitenone, perillaldehyde, germacrene D, citral a and b, have not been reported before in L. adoensis. The elucidations of the structures are based on spectroscopic techniques and by comparison of these data with those reported in the literature.