Antioxidant Activity Of Essential Oil Research Articles

Chemical Composition and Antioxidant Activity of Thymus ciliatus (Desf.) Benth. Essential Oils of Algeria

The aim of this work was to study the chemical composition and antioxidant activity of essential oils of Thymus ciliatus (Desf.) Benth from middle Algeria obtained from the aerial parts by hydrodistillation using a Clevenger-type apparatus. The oil was analyzed by gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS). The antioxidant capacity values of T ciliatus extracts were determined using 2 different and complementary assays: free radical scavenging ( 2,2-diphenyl- 1-picrylhydrazyl [DPPH]) and ferric reducing antioxidant power (FRAP) assays. Six samples of T ciliatus collected in 2019 were used in the study. GC and GC-MS were used to determine the chemical composition of the essential oils. Twenty-five compounds were identified with a percentage of 89.3%–97.7%. The essential oils of T ciliatus were characterized by the presence of myrcene (9.6%-26.9%), p-cymene (7.6%-17.0%), and borneol (13.4%-30.2%) as principal components.

Chemical Composition and Antiproliferative and Antioxidant Activities of Essential Oil from Juniperus phoenicea L. Cupressaceae

Being multipurpose, relatively safe, and widely favorable for consumption, interest in the essential oils of medicinal plants has been increasing. Essential oil (EO) of Juniperus phoenicea is traditionally used for treatment of several health problems such as diabetes, rheumatism, and cancer that is the second leading cause of death in Jordan. This study aims to collect and chemically analyze EO from Juniperus phoenicea L., from Jordan and to evaluate its cytotoxic and antioxidant activity against human breast cancer cells (T47D), colorectal adenocarcinoma cells (CACO2), and normal human fibroblasts (MRC5). EO was extracted by hydro-distillation and analyzed in a gas chromatograph coupled with a mass spectrometer. Cell viability was assessed using trypan blue, neutral red, and MTT assays, and antioxidant activity was evaluated using DPPH scavenging activity assay. Chemical composition analysis revealed 23 constituents in the EO, and the amount of α- pinene was the highest (69.71%). The results also revealed that the IC50 values of the viability assays were higher among normal cells compared to the human cancer cell lines, and the viability inhibition was significant at higher concentrations compared to untreated cells. Nevertheless, low antioxidant activity was observed for the oil in the DPPH scavenging activity test. To sum up, this study indicates that Jordanian Juniperus phoenicea EO, albeit unlikely to be an effective antioxidant, is optimistically potential to be utilized in breast and colon cancers treatment due to its preferential cytotoxicity against cancer cells.

Variation in the Antibacterial and Antioxidant Activities of Essential Oils of Five New Eucalyptus urophylla S.T. Blake Clones in Thailand.

Eucalyptus oils are widely used for a variety of purposes. This study investigates the terpenoid compositions and antibacterial and antioxidant activities of eucalypt leaf oils extracted from four E. urophylla clones and one E. urophylla × E. camaldulensis hybrid clone grown in Thailand. According to GC/MS analysis, the E. urophylla oils were mainly composed of 1,8-cineole, α-terpinyl acetate, β-caryophyllene, and spathulenol, while 1,8-cineole, α-terpinyl acetate, p-cymene, and γ-terpinene were mostly identified in the hybrid oil. All eucalypt oils exhibited a significant bacteriostatic effect against Gram-positive bacteria, Streptococcus pyogenes, Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus. Only the hybrid oil had an effect on all Gram-negative bacteria tested, including Salmonella typhi, Escherichia coli, Pseudomonas aeruginosa, and Enterobacter aerogenes. These oils have antibacterial properties that vary according to their terpenoid content. Only the hybrid oil had a potent antioxidant effect, with an IC50 value of 4.21 ± 0.35 mg/mL for free radical (DPPH) scavenging. This oil’s antioxidant effect may be a result of the phenolic terpenoids, thymol and carvacrol. As a result, these oils may be a novel source of antibacterial and antioxidant agents. Additionally, the antibacterial and antioxidant capabilities of the E. urophylla × E. camaldulensis hybrid essential oil are reported for the first time.

Comparative study of the chemical composition and antioxidant activities of the essential oil of Pelargonium graveoiens from the four regions of Morocco

Pelargonium graveoiens (rose-scented pelargonium) is a plant that belongs to the Geraniaceae family native to South Africa. It is recognized for its aroma and essential oil which is widely used in the cosmetic industry, aromatherapy and as a food flavoring agent. It is also known for its antifungal, antimicrobial, anti-inflammatory and antispasmodic properties. For this, it is interesting to study the chemical composition of the essential oil of Pelargonium graveolens from the four regions of Morocco (Er-Rachidia, Meknes, Rabat, Tetouan) by gas chromatography coupled with mass spectrometry (GC-MS), and determine the similarities and dissimilarities of the chemical composition of these four essential oils by carrying out an analysis on the one hand in main composition (ACP) and on the other hand, evaluating their antioxidant activities by two methods DPPH and CAT. The results showed that the essential oil of Pelargonium graveoiens (rose-scented pelargonium) from the four regions mainly contains p-Citronellol, geraniol, citronellyl formate, epi-y-eudesmol, geranyl tiglate and linalool. On the other hand, the antioxidant activity of Pelargonium graveolens essential oil by the measured DPPH method showed that the IC50 values of the Meknes region are lower than the IC50 values found in the Er-Rachidia, Tetouan and Rabat regions.

Comparative study on eucalyptol and camphor rich essential oils from rhizomes of Hedychium spicatum Sm. and their pharmacological, antioxidant and antifungal activities.

The aim of present study was to evaluate chemical composition and different biological activities viz., pharmacological and antioxidant activities of essential oils. The chemical composition of essential oils was determined by gas chromatography/mass spectrometry while biological activities were evaluated by standard protocols. Essential oils of Hedychium spicatum Sm. from two different ecological niches viz; Nainital (Site-I) and Himachal Pradesh (Site-II) of India revealed the qualitative and quantitative chemo-diversity. Both the oils were dominated by oxygenated terpenoids. Major marker compounds identified were eucalyptol, camphor, linalool, α-eudesmol, 10-epi-γ-eudesmol, and iso-borneol. Both the oils exhibited anti-inflammatory activity suppressing 17.60 % to 33.57 % inflammation at 100mg/kg b. wt. dose levels compared to ibuprofen-treated group (40.06 %). The sub-acute inflammation in oils-treated mice groups (50 and 100 mg/kg b. wt.) increased on day 2 but showed a gradual decrease from day 3 onwards and then recovered to normal by day 10. The antinociception percentage for doses (50 and 100 mg/kg b. wt.) ranged from 33.70-40.46 % in Site-I and 30.34-42.39 % in Site-II compared to standard drug, ibuprofen (43.08 %). The oils also showed a good antipyretic effect by suppressing Brewer's yeast (Saccharomyces cerevisiae) induced pyrexia after oil dose injection. The oils also exhibited good antioxidant activity.

Identification of antioxidant ingredients by GC-MS from the essential oil of Purple Eleutherococcus simonii leaves

Abstract The main objective of the current study was to investigate the components and antioxidant activity of essential oil extracted from Purple Eleutherococcus leaves (identified as Eleutherococcus simonii) (PEEO) by hydrodistillation (HD) and solid-phase microextraction (SPME). Fourteen chemical components were identified in PEEO using gas chromatography-mass spectrometry (GC-MS), accounting for 41.21% of the total essential oil extracted by SPME, including isopropyl toluene, 4-methylene-1-(1-methylethyl) cyclohexene (3.24%), fumaric-red myrrh alcohol (2.94%), farnesol acetate (2.92%), etc. Forty-three compounds were identified by HD, accounting for 73.28% of the total essential oil extracted by HD, including α-Farnesene (3.4%), Hexadecanoic acid, methyl ester (1.28%), (α-Bisabolol (0.87%), etc. The antioxidant activity of PEEO was characterized for 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, ABTS method and FRAP method, and the IC50 values were 1.125 mg/mL, 0.945 mg/mL and 0.862 mg/mL, respectively. The IC50 values for DPPH, ABTS and FRAP of essential oil were similar to those of ascorbic acid (VC; 0.853, 0.945 and 0.037 mg/mL). The results showed that the essential oil of PEEO has a high radical scavenging activity.

The study of the biological activities of Ziziphora clinopodioides

The aim of the current study was to determine the chemical constituents of essential oil and to study the antibacterial and antioxidant activities of essential oil and the extracts obtained from the raw material of Ziziphora wild growing in the floras of Armenia and Artsakh cultivated in the hydroponic conditions. The essential oils were obtained by the method of hydro-distillation. The determination of the essential oil constituents were performed by the GC-MS method. Agar disk diffusion method was used to study the antimicrobial activity of essential oils. The antioxidant activity determination was carried out DPPH test by the spectrophotometric method, at the same time IC50 was determined. The highest values of the essential oils yield (1.25 ± 0.01%) and IC50 13.83±0.218(x10-5)g/l) were received for the plant cultivated in hydroponic conditions. For the first time in the above studied samples, by the method of GC-MS more than 70 components were revealed. The results of the study showed that essential oils of Ziziphora exhibit antimicrobial activity and the extracts revealed relatively expressed antioxidant activity. The study results show the future prospects of the use of Ziziphora not only as the source of flavonoids and essential oils, but also antimicrobial and antioxidant agents.

Chemical composition and antioxidant activities of essential oils and extracts from cones of Tetraclinis articulata (Vahl) Masters

This study was carried out to evaluate the in vitro antioxidant activity and the chemical composition of essential oils and organic extracts of Moroccan Tetraclinis articulata cones (Khemisset region). The GC–MS analysis of essential oils identified a total 23 volatile components. The major constituents of the oil were α-pinene (18.33%), cis-verbenone (10.02%), and L-pinocarveol (8. 32%). For phytosterols analysis of hexane extract, β-sitosterol constitutes the majority with a percentage of 77.74%. The amount of total phenolic and flavonoid contents was high in the methanol extract (78.54±2.8 mg GAE / g and 41.11± 4.5 mg QE/g, respectively) and the Antioxidant capacity determined by DPPH method showed a strongest radical scavenging activity exhibition by the methanol extract (IC50=0.038±0.006 mg/mL). The results indicated that T. articulata contains bioactive compounds which are responsible for its antioxidant activity. Therefore, this plant could be potential candidates for the preparation of a natural antioxidant drug or an additive preparation.

Chemical variability and antioxidant activity of Cedrus atlantica Manetti essential oils isolated from wood tar and sawdust

The present research was devoted to evaluating the effect of provenance and wood pyrolysis process on the phytochemical and antioxidant activity of essential oils extracted from sawdust and tar of Cedrus atlantica Manetti of Morocco. The essential oils were obtained by hydro-distillation from Cedar wood growing in two geographical locations of the Middle Atlas of Morocco (Senoual and Itzer forests) using a Clevenger-type apparatus and analyzed by Gas Chromatography-Mass spectrometry (GC/MS). Seventy compounds were approximately identified for each essential oil, accounting for 94% of the total oil’s composition, with the predominance of sesquiterpene hydrocarbons, where, α-himachalene (13.75%, 1.15%, 12.2%, and 16.69%) and β -himachalene (24.05%, 24.25%, 27.67%, and 44.23%) represented the major constituents in the four essential oils obtained. Multivariate analysis was used to discriminate the essential oils using principal component analysis (PCA) and Hierarchical Clustering Analysis (HCA). In addition, heatmap for dendrogram was used to investigate any correlation between the chemical profiles of each essential oil. Moreover, the antioxidant properties of the essential oils were studied using DPPH scavenging and Ferric Ion Reducing Power (FRAP). The results indicate that the essential oils from wood tar of Cedrus atlantica possess a strong antioxidant activity (IC 50 = 0.126 mg/mL and 0.143 mg/mL) in comparison with those from sawdust (IC 50 = 15.6 mg/mL and 16.3 mg/mL).

Chemical Composition, Antibacterial Activity using Micro-broth Dilution Method and Antioxidant Activity of Essential Oil and Water Extract from Aerial Part of Tunisian Thymus algeriensis Boiss. & Reut.

In this study, we investigated the chemical composition, antioxidant and antibacterial activities of essential oil and aqueous extract from Thymus algeriensis Boiss. & Reut growing in Tunisia. GC/MS analysis of essential oil from the aerial part of the plant led to identifying 54 constituents representing 96.87 % of the total oil composition. Monoterpenes represented the major components of the essential oil. On the other hand, the aqueous extract and the essential oil were screened for their antioxidant and antibacterial activities. The latter was assessed against Gram-negative and Gram-positive bacterial strains using the broth dilution micro method for the determination of antibacterial activity. The antioxidant activity was evaluated using the DPPH scavenging activity and Ferric Reducing/Antioxidant Power (FRAP) assays. The essential oil was found to be more active in antibacterial screening (MIC = 0.54 μg/mL). Whereas the aqueous extract exhibited the most potent antioxidant activity with (IC50 = 0.04 μg/mL). UHPLC ESI(-)-HRMS/MS analysis of the aqueous extract allowed tentative identification of its constituents and showed that it is rich in phenolic compounds. Luteolin-glucuronide was found to be the most abundant compound followed by Vicenin-2 and Apigenin-diglucuronide.

Influence of Different Drying Methods on Extraction Yield, Chemical Compositions, Total Phenolic and Flavonoid Contents and Antioxidant Activity of Essential Oil from Aerial Parts of Ferulago angulata Boiss.

Influence of Different Drying Methods on Extraction Yield, Chemical Compositions, Total Phenolic and Flavonoid Contents and Antioxidant Activity of Essential Oil from Aerial Parts of Ferulago angulata Boiss.

GC-MS analyses and bioactivities of essential oil obtained from the roots of Chrysopogon zizanioides (L.) Roberty cultivated in Giresun, Turkey

The essential oils (EOs) constituents have trade importance due to their bioactivities. In this research, the essential oil of the roots of Chrysopogon zizanioides (L.) Roberty cultivated in Giresun was obtained by hydrodistillation. Then, the chemical composition and biological activities of Chrysopogon zizanioides root essential oil (CEO) were studied. Thirty compounds were identified by gas chromatography-mass spectrometry (GC-MS) and the major compounds were determined as isobutyl-angelate (11.15%), α-muurolene (10.56%), α-cedrene (8.42%), α-patchoulene (8.10%), and ethylene brassylate (7.49%). The antimicrobial effect of CEO was investigated against pathogenic bacteria and fungus. Minimal inhibition concentration (MIC) was determined 31.25 μg/mL against C. albicans and between 62.5 and 125 μg/mL against the rest of the microorganisms. According to the antioxidant assays, the total phenolic content of CEO was found to be 13.70 ± 2.10 μg/mL gallic acid equivalent (GAE) and 24.67 ± 3.79 μg/mL catechin equivalent (CE). Ferric reducing/antioxidant power (FRAP) of CEO was found to be 356.44 ± 2.34 μM Trolox equivalent antioxidant capacity (TEAC). 2,2-diphenyl-1-picrylhydrazyl (DPPH?) was determined as IC50 to be 7.124 ± 0.076 μg/mL. According to the obtained results, CEO has significant antimicrobial and antioxidant activities. This study is the first report determining the chemical composition, antimicrobial and antioxidant activities of essential oil obtained from vetiver grown in the Black Sea Region of Turkey.

Comparative study of chemical composition, antibacterial and antioxidant activity of essential oils isolated from the seeds of Amomum subulatum by using microwave extraction and hydro-distillation methods

Microwave assisted hydro-distillation (MAHD) and conventional hydro-distillation (HD) techniques were compared in the extraction of essential oils from Amomum subulatum seeds. The time required for MAHD method (70 ​min) is lesser than that for HD method (4 ​h). There is a slight increase in the yield of extracted oil in MAHD method (3.35%) compared to HD (3%). Gas chromatography–mass spectrometry GC-MS results show that MAHD extracted essential oil was wealthier in oxygenated compounds. 1, 8-Cineole was found to be a major compound in case of both the essential oil, followed by α-pinene. In MAHD the percentage of the major oxygenated monoterpene (1, 8- cineol) slightly increases from 88% to 89% as compared to hydrodistillation. Contrarily to this, the percentage of monoterpene hydrocarbon was decreased in MAHD than HD extracted oil. MAHD and HD extracted oils show good antibacterial activities against gram-negative and gram-positive bacteria. MAHD extracted oil shows better antibacterial activity than HD extracted against both gram positive and gram-negative bacteria. 2, 2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging antioxidant activities show that MAHD extract has better inhibition percentage than HD extract, and the half-maximal inhibitory concentration IC50 value of MAHD was less than HD extracted oil.

Promising Antioxidant and Anticorrosion Activities of Mild Steel in 1.0 M Hydrochloric Acid Solution by Withania frutescens L. Essential Oil.

The present study was conducted to evaluate the anticorrosive and antioxidant activities of essential oil from Withania frutescens L. In the present study, the extraction of Withania frutescens L. essential oil (Wf-EO) was conducted using hydrodistillation before being characterized by gas chromatographic analysis (GC/MS) and flame ionization detector (GC/FID). Four bioassays were used for antioxidant testing including 2,2-diphenyl-1-picrylhydrazyl (DPPH), total antioxidant capacity (TAC), ferric reducing antioxidant power (FRAP), and β-carotene bleaching. The inhibiting effect of Wf-EO on the corrosion behavior of mild steel in 1.0 M HCl was conducted by using polarization curves and electrochemical impedance spectroscopy techniques. The yield of Wf-EO was 0.46% including 175 compounds identified by GC-MS. The oil was mostly constituted of camphor (37.86%), followed by thujone (26.47%), carvacrol (6.84%), eucalyptol (3.18%), and linalool (2.20%). The anti–free radical activity of Wf-EO was 34.41 ± 0.91 μg/ml (DPPH), 9.67 ± 0.15 mg/ml (FRAP), 3.78 ± 0.41 mg AAE/g (TAC), and 89.94 ± 1.44% (β-carotene). The Wf-EO showed potent antioxidant activity in all bioassays used for testing. The anticorrosion activity, polarization curves as well as EIS diagrams indicated that the Wf-EO exhibited anticorrosive properties and reacted as a suitable corrosion inhibitor in an acidic medium.

Chemical Composition and Antioxidant Activity of Essential Oils from Leaves of Two Specimens of Eugenia florida DC.

Eugenia florida DC. belongs to the Myrtaceae family, which is present in almost all of Brazil. This species is popularly known as pitanga-preta or guamirim and is used in folk medicine to treat gastrointestinal problems. In this study, two specimens of Eugenia florida (Efl) were collected in different areas of the same region. Specimen A (EflA) was collected in an area of secondary forest (capoeira), while specimen B (EflB) was collected in a floodplain area. The essential oils (EOs) were extracted from both specimens of Eugenia florida by means of hydrodistillation. Gas chromatography coupled to mass spectrometry (GC/MS) was used to identify the volatile compounds present, and the antioxidant capacity of the EOs was determined by antioxidant capacity (AC-DPPH) and the Trolox equivalent antioxidant (TEAC) assay. For E. florida, limonene (11.98%), spathulenol (10.94%) and α-pinene (5.21%) were identified as the main compounds of the EO extracted from sample A, while sample B comprised selina-3,11-dien-6α-ol (12.03%), eremoligenol (11.0%) and γ-elemene (10.70%). This difference in chemical composition impacted the antioxidant activity of the EOs between the studied samples, especially in sample B of E. florida. This study is the first to report on the antioxidant activity of Eugenia florida DC. essential oils.

Study of Chemical Composition, Antibacterial and Antioxidant Activity of Thyme Leaves and Stems Essential Oil

Given the increase in drug resistance of microorganisms and the tendency in using medicinal plants, the present study was carried out to investigate the chemical compounds of Thymol as a constituent of essential oil and antimicrobial activity against several pathogenic bacteria and its antioxidant activity. In this study, the chemical compounds of Thymol extracted from the two parts of the plant together (the leaves and stems) were performed by making use of gas chromatography and the other gas chromatography linked to the mass spectrograph and its antibacterial activity against Ecoli, Klebsiella, Pseudomonas, Staphylococcus, Salmonella Paratyphi B, Salmonella Typhi typhus and enterococci through Microdilution and the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) were investigated. The antioxidant activity of essential oils was measured through the ability of essential oil compounds in decolorizing diphenyl picrilhydrazyl (DPPH) free radicals. Chemical analysis of thyme essential oil resulted in the identification of 23 (83.68%) compounds, which Thymol with 25.30% was considered as the main part of the essential oil compound. The highest inhibitory effect was imposed on Klebsiella, Escherichia coli, and Staphylococcus aureus, and the largest inhibitory zone diameter of essential oil appeared against growth Salmonella paratyphi B. Concerning the results, total phenol was equal to 114.3 mg of gallic acid.g and IC50 of thyme was considered to be 49.94 μM/ml. The achieved results from this study declared that thyme essential oil had a suitable inhibitory effect against pathogenic bacteria and also possessed antioxidant properties. In other words, thyme was considered as an alternative to synthetic drugs and food additives.

Antioxidant and anti-inflammatory properties of essential oils from three Eucalyptus species

Abstract Eucalyptus essential oils are used as traditional medicines in many countries. The objective of this study was to evaluate the antioxidant and anti-inflammatory activities of leaf essential oils extracted from three different Eucalyptus species on HepG2 and RAW264.7 cells. Essential oils were distilled from fresh leaf samples, and the chemical constituents were analyzed using gas chromatography–mass spectrometry. The antioxidant activities of essential oils were determined using ABTS and hydroxyl radical scavenging assays, and hydrogen peroxide (H2O2)-induced oxidative stress in HepG2 cells. Additionally, lipopolysaccharide (LPS)-activated RAW264.7 macrophages were used to evaluate the anti-inflammatory properties. The results revealed that Eucalyptus citriodora and Eucalyptus urophylla leaf essential oils had a high content of oxygenated monoterpenes, whereas Eucalyptus deglupta contained a high amount of monoterpene hydrocarbons. Essential oils extracted from the three Eucalyptus species showed antioxidant and anti-inflammatory activities. E. citriodora and E. urophylla leaf essential oils had strong antioxidant activity against H2O2-induced oxidative stress in human HepG2 cells. Additionally, E. citriodora leaf essential oil, which contains a high amount of citronellal, exhibited the most potent anti-inflammatory activity in LPS-activated RAW264.7 macrophages. The antioxidant and anti-inflammatory effects of essential oils depended on their chemical composition. A principal component analysis explained 100% of the variance was performed to construct three groups based on the chemical components and antioxidant and anti-inflammatory activities. This study suggests that E. citriodora leaf essential oil, which represents a good source of oxygenated monoterpenes, could be considered a potential phytochemical agent for the prevention of oxidative stress and inflammation. Keywords: Antioxidant, Anti-inflammatory effect, Eucalyptus essential oils, Gas chromatography–mass spectrometry, Principal component analysis

Composition and Anti-Inflammatory and Antioxidant Activity of Essential Oil from Aucuba japonica var. variegata

Composition and Anti-Inflammatory and Antioxidant Activity of Essential Oil from Aucuba japonica var. variegata

Assessment of phytochemical screening, total phenolic content, antioxidant activity of leaves and stems extract from Adenocarpus bacquei and its essential oil antioxidant activity

The researchers’ focus has recently been directed towards finding new natural antioxidants especially those originated from plants. This work is about the screening of phytochemical constituents and the variation of total phenolic and flavonoid content for different parts of Adenocarpus bacquei (leaves and stems) harvested from Morocco. It regards also extracting its essential oil , analyzing its chemical composition by gas chromatography-mass spectrometry (GC/MS) which reveals the presence of 25 compounds where the major one is the (+)-2-Bornanone (38.26%) followed by Eucalyptol (27.74%).Yet, this essential oil proved great antioxidant capacities measured with TAC and DPPH assays. On the other hand, the phytochemical analysis of Adenocarpus bacquei‘s leaves and stems showed the existence of principal groups of secondary metabolites (tannins, flavonoids, mucilage, oses and holosides sterols and triterpenes and combined antraquinons). Quantifying total phenolic and flavonoid content of different crudes extracts of leaves and stems of Adenocarpus bacquei was done using solvents with different polarity (hexane, dichloromethane, ethyl-acetate, ethanol and water). These crude extracts’ total antioxidant activity and radical scavenging activity were respectively evaluated with the phosphomolybdenum and DPPH assays. Therefore, the results showed a simultaneous increasing in total phenolic content of crude extract and the solvent polarity. Yet, the aqueous leaves extract indicates the highest TPC. Also, the results show a significant positive correlation between TAC and DPPH assay in relation with the total phenolic and flavonoid content. These results revealed the powerful capacity of Adenocarpus bacquei’s essential oil and crudes extracts which comes to conclude that Adenocarpus bacquei can be a natural resource of antioxidants.

The variation in essential oils composition, phenolic acids and flavonoids is correlated with changes in antioxidant activity during Cinnamomum loureirii bark growth

Cinnamomum loureirii is one of the most important medicinal and aromatic plants. It is used by the food, perfumery, cosmetic, and pharmaceutical industries. The objective of this study was to examine the relationships between the chemical composition and antioxidant activity of essential oil (EOs) and ethanol extracts from 10 samples of the bark from C. loureirii trees (6–15 years old). Obtained results showed that C. loureirii bark EO content at 12–15 years old had high oil yields (4.52–5.48%). The major components in the EOs were trans-cinnamaldehyde (50.2–92.9%) and α-copaene (0.5–21.3%). The highest content of trans-cinnamaldehyde in bark EOs was obtained from 10 to 12-year-old trees, while the highest content of α-copaene was obtained at 13–15 years. The highest total phenolic (429.85 and 474.45 mg TAE /g DW) and total flavonoid contents (85.54 and 102.80 mg RE /g e DW) were obtained from the 13- to 14-year-old trees. Our results indicated that the EO and ethanol extract of 13- to 14-year-old bark showed the strongest antioxidant properties. Moreover, GC–MS, PCA and correlation analysis indicated that the changes in α-copaene, beta-caryophyllene, τ-muurolene, γ-muurolene, δ-cadinene and τ-muurolol were positively correlated with the changes in antioxidant activity in oils. Meanwhile, procyanidin B2 and hyperoside were the main contributors to the antioxidant activity of the ethanol extract from C. loureirii bark. This study is the first one that report the antioxidant potential and phenolic profile of C. loureirii plant. These results provide reference information for the rational utilization of C. loureirii resources and the harvest of C. loureirii bark as medicinal materials during the optimal period.