Effect of Some Bioregulators on the Chemical Composition of Essential Oil and its Antioxidant Activity of Egyptian Carnation (<i>Dianthus caryophyllus</i>L.)

Abstract

Pot experiments were conducted in the screen of the National Research Center during two successive growth seasons 2002–2003 and 2003–2004 to study the effect of foliar application of the bioregulators, stigmasterol and/or putrescine on the chemical composition and the growth of carnation (Dianthuus caryophylus L.) plants. Essential oil production is highly integrated with the physiology of the whole plant and so depends on the metabolic state and present development differentiation programme of the synthesizing. The chemical composition and the essential oil and its antioxidant activity of the carnation flowers (Dianthus caryophyllus) was studied. Twelve volatiles were identified by gas chromatography-mass spectrometry (GC-MS) as the main components of carnation flower fragrance signature. The major components of the volatiles found were phenyl ethyl alcohol, eugenol, hexyl benzoate, hexenyl benzoate (z), benzyl benzoate, benzoin, nootkatone, benzyl salyicylate, m-cresyl phenyl acetate, hexadecanoic acid and eicosene. The marked increase in benzyl benzoate from 12.62 to 45.04 % was obtained as a result of treating with 200 ppm stigmasterol, where as the application of 100 ppm stigmasterol together with 200 ppm putrescine reduced its amount to 3.85 % compared to untreated plants 12.62 %. The most significant variation of eugenol from (21.48 to 33.54 %) was obtained as a result of treating with 50 ppm stigmasterol and 400 ppm of putrescine, while application of other concentrations of stigmasterol and putrescine caused reduction in eugenol in comparison with untreated plants. The scavenging effect of volatile oil of carnation flowers was studied by using DPPH assay. Treating the plants with 400 ppm stigmasterol gave the highest scavenging of the oil compared to other treatments.