Composition of the essential oils of two isomenthone-rich variants of geranium (Pelargonium sp.)

Two clones of geranium (nos 53 and 79) obtained from leaf cuttings of a geranium cultivar (Pelargonium sp.) and later multiplied by stem cuttings were found to be rich in isomenthone (64.4 and 67.7%) in their essential oils. The detailed composition of the oils of these two clones was investigated by capillary GC and GC–MS and compared with that of the oil of the parent cultivar. Linalol, citronellol, geraniol and citronellyl formate, which are the major constituents of the parent cultivar, were found only as minor constituents in the oils of the two clones. These two isomenthone-rich clones differed from each other in their α-pinene content (1.1% and 8.5%) although both have 10-epi-γ-eudesmol (6.8% and 8.4%) comparable with the parent cultivar (7.6%).