Chemical Compositions and Antioxidant Activities of Indonesian Citrus Essential Oils and Their Elucidation Using Principal Component Analysis

Abstract

Citrus essential oils (EOs) have various bioactivities like antioxidants, with many applications. Antioxidant activities depend on the chemical compositions of the EOs, which are affected by climate, soil, and geographical region. Thus, investigations on chemical compositions and antioxidant activities of Citrus EOs in different countries are valuable. In this study, we distilled EOs from peels of Indonesian-grown Citrus, including C. nobilis, C. limon, C. aurantifolia, C. amblycarpa, and Citrus spp.Chemical compositions of EOs were analyzed using Gas Chromatography-Mass Spectrometer (GC-MS), whereas the antioxidant activities were determined by employing 2,2-diphenyl-2-picrylhydrazyl (DPPH) method. Furthermore, principal component analysis (PCA) was applied to elucidate the main contributing compounds for antioxidant activity. The results show that all EOs possess unique chemical characteristics, with limonene as the majority constituent. For antioxidant activities, C. limon and C. amblycarpa EOs are the two strongest, IC50 values below 7.00 μL/mL. PCA approach suggests that -terpinene mainly contributes to the high antioxidant activities of C. limon and C. amblycarpa. Moreover, o-cymene, thymol, p-cymene, and α-pharnesene may also be responsible for the antioxidant activity of C. limon EO. These results are valuable information for the applications of Citrus EOs as antioxidant sources.

Secondary metabolites of Java cardamom leaves extract function under shading and nitrogen doses

“…Oliveira et al (2015) reported that p-Cymene has antioxidant potential and can act as a neuroprotective agent in the brain. This is also supported by Julaeha et al (2020), who reported that p-Cymene and o-Cymene are responsible for the antioxidant activity of C. limon EO. At RT 6.284, cis-p-Menth-2,8-dienol, which has anticancer, antimicrobial, and antitumor potential (Nayak et al, 2014), was found after treatment with T1 (4.74%), T11 (5.28%), and T12 (5.36%).…”

Physiochemical properties, antibacterial, antifungal, and antioxidant activities of essential oils from orange (Citrus nobilis) peel

“…This result was in a comparable range with previously reported studies. The extraction yield of orange peel EOs was 3.15% in the study of Gursoy, Tepe, and Sokmen (2010), whereas another study obtained the higher extraction efficiency of 3.7% (Julaeha et al, 2020). The variation of EOs in the orange peel could be ascribed to the differences in genetic (Farhat et al, 2011;Julaeha et al, 2020;Okunowo et al, 2013;Singh et al, 2010).…”

“…The extraction yield of orange peel EOs was 3.15% in the study of Gursoy, Tepe, and Sokmen (2010), whereas another study obtained the higher extraction efficiency of 3.7% (Julaeha et al, 2020). The variation of EOs in the orange peel could be ascribed to the differences in genetic (Farhat et al, 2011;Julaeha et al, 2020;Okunowo et al, 2013;Singh et al, 2010). This result indicated that the orange peels could be a feasible and applicable source for EOs production due to higher extraction yield compared to others.…”

Phytochemical Profile, Preliminary Toxicity, and Antioxidant Capacity of the Essential Oils of Myrciaria floribunda (H. West ex Willd.) O. Berg. and Myrcia sylvatica (G. Mey) DC. (Myrtaceae)

“…Other compounds at lower concentrations in the EO of M. floribunda, such as o -cymene, γ-terpinene, α-terpineol, myrcene, and α-pinene, also have antioxidant potential [ 147 , 148 , 149 , 150 , 151 ]. The synergistic and/or antagonistic effects of the constituents of this EO may explain its high capture of free radicals considering that the volatile components in the sample are known for their excellent antioxidant properties [ 152 , 153 ].…”