Increase of Chamazulene and α-Bisabolol Contents of the Essential Oil of German Chamomile (Matricaria chamomilla L.) Using Salicylic Acid Treatments under Normal and Heat Stress Conditions.

Mojtaba Ghasemi,Nadali Bagheri,Abbas Jamali,Mohammad Modarresi,Nadali Babaeian Jelodar

doi:10.3390/foods5030056

Abstract

The chamazulene and α-(−)-bisabolol contents and quality of the chamomile oil are affected by genetic background and environmental conditions. Salicylic acid (SA), as a signaling molecule, plays a significant role in the plant physiological processes. The aim of this study was to evaluate the chemical profile, quantity, and improve the essential oil quality as a consequence of the increase of chamazulene and α-(−)-bisabol using salicylic acid under normal and heat stress conditions by the gas chromatography-mass spectrometry (GC-MS) technique. The factorial experiments were carried out during the 2011–2012 hot season using a randomized complete block design with three replications. The factors include four salicylic acid concentrations (0 (control), 10, 25 and 100 mg·L−1), and three chamomile cultivars (Bushehr, Bona, Bodegold) were sown on two different planting dates under field conditions. Fourteen compounds were identified from the extracted oil of the samples treated with salicylic acid under normal and heat stress conditions. The major identified oil compositions from chamomile cultivars treated with salicylic acid were chamazulene, α-(−)-bisabolol, bisabolone oxide, β-farnesene, en-yn-dicycloether, and bisabolol oxide A and B. Analysis of variance showed that the simple effects (environmental conditions, cultivar and salicylic acid) and their interaction were significant on all identified compounds, but the environmental conditions had no significant effect on bisabolol oxide A. The greatest amount of chamazulene obtained was 6.66% at the concentration of 10 mg·L−1 SA for the Bona cultivar under heat stress conditions, whereas the highest α-(−)-bisabolol amount attained was 3.41% at the concentration of 100 mg·L−1 SA for the Bona cultivar under normal conditions. The results demonstrated that the application of exogenous salicylic acid increases the quantity and essential oil quality as a consequence of the increase of chamazulene and α-(−)-bisabolol under normal and heat stress conditions.

Highlights

Chamomile is an annual plant, belonging to Asteraceae family, indigenous to Iran and grows as a wild plant in Europe [1]
Fourteen components were identified in three cultivar of chamomile treated with salicylic acid under normal and stress conditions
The application of exogenous salicylic acid at the specific concentration under heat stress and normal conditions was made increasing in the chamazulene and α-(−)-bisabolol contents, respectively

Summary

Introduction

Chamomile is an annual plant, belonging to Asteraceae family, indigenous to Iran and grows as a wild plant in Europe [1]. The chamomile essential oil is extensively served in food, cosmetics, and pharmaceutical industries [5]. It is a popular treatment for numerous ailments, including sleep disorders, anxiety, digestion/intestinal conditions, skin infections/inflammation (including eczema), wound healing, infantile colic, teething pains, and diaper rash [6]. Over 120 constituents have been recognized in chamomile essential oil, where α-(−)-bisabolol, chamazulene, β-farnesene, bisabolol oxides A and B, and α-bisabolone oxide A are the most important ones [4,7]. Active principles of German chamomile are terpenoids: α-bisabolol, α-bisabolol oxide A and B, chamazulene, and sesquiterpenes; coumarins: umbelliferone; flavonoids: luteolin, apigenin, and quercetin; spiroethers: en-yn dicycloether and other components such as tannins, anthemic acid, choline, polysaccharides, and phytoestrogens [8].

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