Chemotaxonomic value of essential oil compounds in Citrus species

Several Citrus species are cultivated in Tachira, an Andean State of Venezuela. Fresh fruits are sold as such, or processed to produce juice, marmalade, sauce and as additive in children's food. The purpose of this work was to determine and compare the composition of the essential oils from the pericarp of Citrus paradisi (red and white varieties), C grandis, C limon and C reticulata. Fruits were collected at plantations around San Joaquin de Navay (Tachira State) at harvest time (October-December 2000). The main component of the essential oil of all species (and varieties), except Citrus grandis, was limonene. In Citrus grandis the main constituent was linalool (50.31 %). Some chemical markers were detected and quantified. In Citrus paradisi (red and white) octanal (3.58 % and 2.22 %) as well as octyl formate (0.78 % and 0.95 %) were detected. Citrus grandis contained delta-3-carene (2.37 %). In contrast, Citrus limon contained alpha-thujene (0.56 %), alpha-terpinene (0.54 %) and 1-isopropyl-2-methoxy-4-methyl-bencene(2.28 %). The biological activity against Escherichia coli, Staphylococcus aureus and Pseudomonas was determined. These results are a contribution to normalise quality control criteria of the industrial essential oil production in Tachira State, Venezuela.