The Essential Oil ofPelargonium tomentosumJacq. from Reunion

Composition of the Essential Oil of a New Isomenthone-Rich Variant of Geranium Obtained from Geraniol-Rich Cultivar ofPelargoniumSpecies

“…The sesquiterpenes spathulenol and caryophyllene oxide were found in the oils of both K and K-99, whereas these compounds were not reported so far in the oils of 'Hemanti' and 'Bipuli.' Borneol and bornyl acetate were detected only in the oil of K-99 and not in the oil of K. While borneol was reported earlier in the oil of P. tomentosum (16), bornyl acetate was reported for the first time in Pelargonium species. It is interesting to note that these compounds were also not reported in the oils of isomenthone-rich clones 53 and 79 (5,6) and the cultivar 'menthe' (17).…”

“…Although there is some resemblance in the oil composition of K-99 to that of P. tomentosum (16), there are significant differences in the composition of these two oils. While the oil of P. tomentosum contained substantial amounts of menthone (1.6-33.0%) (16,(20)(21)(22)(23), the oil of K-99 contained this compound in a concentration of only 2.8%. 10-epi-γ-Eudesmol, which was found in fairly high amounts in the oil of K-99, was not reported in the oil of P. tomentosum.…”

“…It is interesting to note that these compounds were also not reported in the oils of isomenthone-rich clones 53 and 79 (5,6) and the cultivar 'menthe' (17). The mass spectral data of the tentatively identified compounds are presented in Table II. In the earlier studies, isomenthone was found as the main constituent (45.8-67.0%) in the oils of P. australe (18), P. graveolens (19), P. radens (19), their hybrids (19), P. tomentosum (16,(20)(21)(22)(23), the cultivar 'menthe' (hybrid of P. capitatum and P. radens) (17), and the clones 53 and 79 obtained from the leaf cuttings of the Indian cultivar Bourbon (5,6). Although there is some resemblance in the oil composition of K-99 to that of P. tomentosum (16), there are significant differences in the composition of these two oils.…”

“…The mass spectral data of the tentatively identified compounds are presented in Table II. In the earlier studies, isomenthone was found as the main constituent (45.8-67.0%) in the oils of P. australe (18), P. graveolens (19), P. radens (19), their hybrids (19), P. tomentosum (16,(20)(21)(22)(23), the cultivar 'menthe' (hybrid of P. capitatum and P. radens) (17), and the clones 53 and 79 obtained from the leaf cuttings of the Indian cultivar Bourbon (5,6). Although there is some resemblance in the oil composition of K-99 to that of P. tomentosum (16), there are significant differences in the composition of these two oils. While the oil of P. tomentosum contained substantial amounts of menthone (1.6-33.0%) (16,(20)(21)(22)(23), the oil of K-99 contained this compound in a concentration of only 2.8%.…”

“…The mint scented P. tomentosum oil was reported to be produced in limited quantities at the request of the perfumers (16). The oil of the genotype K-99 can be a source of natural isomenthone, which may be of interest to flavorists.…”