Changes in Chemical Composition of Tagetes minuta Oil at Various Stages of Flowering and Fruiting

ABSTRACT The chemical composition of Indian Tagetes minuta L. oil was determined at different developmental stages of plant growth using GC, 1H- and 13C-NMR spectroscopy. In contrast to previous results, the characteristic components of the Indian oil were found to be (Z)-β-ocimene, (Z)-tagetenone, (E)-tagetenone, (Z)- and (E)-tagetones and dihydrotagetone. The percentage composition of these constituents changes with flower maturation. The dihydrotagetone percentage declined sharply from flower buds (48.09%) to seed shedding stage (11.90%) with a simultaneous rise in (Z)-β-ocimene (35.3%), (Z)-tagetenone and (E)-tagetenone (both 26.44%) at the time of immature fruit formation, suggesting that dihydrotagetone may biogenetically be changing into (Z)- and (E)-tagetenones.