Yield, Phytochemical Constituents, and Antibacterial Activity of Essential Oils from the Leaves/Twigs, Branches, Branch Wood, and Branch Bark of Sour Orange (Citrus aurantium L.)

Abstract

In the present work, essential oils (EOs) extracted from different parts of sour orange Citrus aurantium (green leaves/twigs, small branches, wooden branches, and branch bark) were studied through gas chromatography coupled with mass spectrometry (GC/MS). Furthermore, the EOs in the amounts of 5, 10, 15, 20, and 25 µL were studied for their antibacterial activity against three pathogenic bacteria, Agrobacterium tumefaciens, Dickeya solani, and Erwinia amylovora. The main EO compounds in the leaves/twigs were 4-terpineol (22.59%), D-limonene (16.67%), 4-carvomenthenol (12.84%), and linalool (7.82%). In small green branches, they were D-limonene (71.57%), dodecane (4.80%), oleic acid (2.72%), and trans-palmitoleic acid (2.62%), while in branch bark were D-limonene (54.61%), γ-terpinene (6.68%), dodecane (5.73%), and dimethyl anthranilate (3.13%), and in branch wood were D-limonene (38.13%), dimethyl anthranilate (8.13%), (-)-β-fenchol (6.83%), and dodecane (5.31%). At 25 µL, the EO from branches showed the highest activity against A. tumefaciens (IZ value of 17.66 mm), and leaves/twigs EO against D. solani and E. amylovora had an IZ value of 17.33 mm. It could be concluded for the first time that the wood and branch bark of C. aurantium are a source of phytochemicals, with D-limonene being the predominant compound in the EO, with potential antibacterial activities. The compounds identified in all the studied parts might be appropriate for many applications, such as antimicrobial agents, cosmetics, and pharmaceuticals.

Impact of Three Natural Oily Extracts as Pulp Additives on the Mechanical, Optical, and Antifungal Properties of Paper Sheets Made from Eucalyptus camaldulensis and Meryta sinclairii Wood Branches

“…GC/MS analysis was used to analyze the oils with a Focus GC-DSQ Mass Spectrometer (Thermo Scientific, Austin, TX, USA) with a TG-5MS direct capillary column (30 m × 0.25 mm × 0.25 µm film thickness) as reported in the previous work [18]. The Xcalibur 3.0 data system of the GC/MS with threshold values was used to confirm that all MS were attached to the library by measuring the standard index (SI) and reverse standard index (RSI), where a value ≥ 650 was acceptable to confirm the compounds [11,[49][50][51].…”

Toxicological Activity of Some Plant Essential Oils Against Tribolium castaneum and Culex pipiens Larvae

“…Freshly collected samples (200 g) of ripe and unripe Schinus terebinthifolius fruits, S. terebinthifolius leaves, Origanum majorana air-dried aerial parts, and Psidium guajava leaves were cut into small pieces using scissors and hydro-distilled for 3 h using a Clevenger-type apparatus [40]. The collected essential oils (EOs) were dried over anhydrous sodium sulphate (Sigma-Aldrich, Darmstadt, Germany).…”

Assessment of the Toxicity of Natural Oils from Mentha piperita, Pinus roxburghii, and Rosa spp. Against Three Stored Product Insects

“…The components were identified by comparing their retention times and mass spectra with those of the WILEY 09 and NIST 14 mass spectral databases. The Xcalibur data system (3.0, Thermo Fisher Scientific Inc., Austin, TX, USA, 2014) of GC/MS with threshold values was used to confirm that all of the mass spectra (MS) were attached to the library by measuring the standard index (SI) and reverse standard index (RSI), where a value of ≥650 was acceptable to confirm the compounds [42][43][44][45].…”