Chemical Composition,Antioxidant and Anti‐melanogenic Activities of Essential Oils from Chrysanthemum boreale Makino at Different Harvesting Stages

In the present study, the chemical compositions and skin whitening‐related antioxidant and anti‐melanogenic effect of essential oils (EOs) extracted from Chrysanthemum borealeMakino (CBM) (CBMEOs) at vegetative, pre‐flowering and full‐flowering are investigated and contrasted among the three stages. The yields and components of the CBMEOs were different at each stage. The CBMEOs increased DPPH and ABTs scavenging activities and attenuated the α‐melanocyte stimulating hormone (α‐MSH)‐induced tyrosinase activity and melanin synthesis in B16BL6 cells. Among CBMEO components, eugenol had the highest DPPH and ABTs scavenging activities and cuminaldehyde was the strongest inhibitor of α‐MSH‐induced tyrosinase activity and melanin synthesis. The CBMEOs in each stage showed the different levels of phosphorylation of extracellular signal‐regulated kinase1/2 and p38 MAPK. These findings demonstrate that the CBMEOs have antioxidative and anti‐melanogenic activities in all the CBM harvesting stages, resulting in skin‐whitening biological activities and that the levels of their component contents and bioactivities differ among the CBM harvesting stages. The CBMEOs may have the potential for use in cosmetics and alternative medicine.     

Chemical Composition,Cytotoxic and Antibacterial Activities of Essential Oils of Cultivated Clones of Juniperus communis and Wild Juniperus Species

Needles of seven cultivated clones (C1 – C7) of Juniperus communis at lower altitude and three wild Juniperus species (J. communis, J. recurva and J. indica) at higher altitudes were investigated comparatively for their essential oils (EOs) yields, chemical composition, cytotoxic and antibacterial activities. The EOs yields varied from 0.26 to 0.56% (v/w) among samples. Sixty‐one volatile components were identified by gas chromatography‐mass spectrometry (GC/MS) and quantified using gas chromatography GC (FID) representing 82.5 – 95.7% of the total oil. Monoterpene hydrocarbons (49.1 – 82.8%) dominated in all samples (α‐pinene, limonene and sabinene as major components). Principal component analysis (PCA) of GC data revealed that wild and cultivated Juniperus species are highly distinct due to variation in chemical composition. J. communis (wild species) displayed cytotoxicity against SiHa (human cervical cancer), A549 (human lung carcinoma) and A431 (human skin carcinoma) cells (66.4 ± 2.2%, 74.4 ± 1.4% and 57.4 ± 4.0%), respectively, at 200 μg/ml. EOs exhibited better antibacterial activity against Gram‐positive bacteria than against Gram‐negative bacteria with the highest zone of inhibition against Staphylococcus aureus MTCC 96 (19.2 ± 0.7) by clone‐7. As per the conclusion of the findings, EOs of clone‐2, clone‐5 and clone‐7 can be suggested to the growers of lower altitude, as there is more possibility of uses of these EOs in food and medicinal preparations.     

Biological control of phytopathogenic bacteria Pantoea agglomerans and Erwinia chrysanthemi using 100 essential oils

Plants interact with a wide variety of pathogenic organisms by virtue of their sessile lifestyle. The Pantoea agglomerans and Erwinia chrysanthemi are major plant pathogen amongst them. They are known to cause significant losses in many crop plants. In the present study, bacteria isolated from infected Cajanus cajan and Arachis hypogaea seed are identified by 16S rDNA sequencing as P. agglomerans and E. chrysanthemi, respectively. In vitro antimicrobial properties of 100 essential oils (EOs) were evaluated against P. agglomerans and E. chrysanthemi. The chemical composition of most active EOs was investigated by gas chromatography–mass spectral analysis. The potential properties of these EOs as ecofriendly and economical biocontrol in agriculture is discussed.     

Chemical Diversity and Antimicrobial Activity of Salvia multicaulis Vahl Essential Oils

The chemical compositions and antimicrobial activities of the essential oils (EOs) of aerial parts of Salvia multicaulis Vahl , collected during the same week from two different Lebanese regions, were investigated. The EOs were obtained by hydrodistillation using a Clevenger‐type apparatus and characterized by GC and GC/MS analyses. The minimum inhibitory concentrations of these EOs were determined against one Gram‐negative and two Gram‐positive bacteria, one yeast, and five dermatophytes using the broth microdilution technique. One EO was notably active against Staphylococcus aureus, methicillin‐resistant S. aureus, and all of the Trichophyton species tested. Nerolidol was found to be the major compound in the active oil; nerolidol was also absent from the inactive oil. This study demonstrated that nerolidol shows antimicrobial activity and therefore significantly contributes to the antimicrobial potential of the oil. The chemical diversity of worldwide S. multicaulis EOs was analyzed, revealing that the EOs of this study belong to two different chemotypes found in the literature. The nerolidol chemotype appears to be restricted to Lebanon, and it can be used as antimicrobial agent against external bacterial and fungal infections.     

Essential Oils from Piper caldense C. DC. and Piper xylosteoides (Kunth) Steud.: Seasonal Variation of the Chemical Composition and Antimicrobial Activity

The essential oils (EOs) chemical composition can be affected by several environmental factors, impacting their desired biological activities. In this sense, this work aimed to evaluate the seasonal variation of the chemical composition and antimicrobial activity of Piper caldense and Piper xylosteoides leaves EOs. Their chemical composition was determined by GC/MS and GC-FID analyses, resulting in the identification of eighty compounds. P. caldense EOs were mainly consisted of sesquiterpene hydrocarbons, whereas in P. xylosteoides EOs, monoterpene hydrocarbons were predominant. EOs from both species strongly inhibited B. subtilis (MIC=0.25 mg mL⁻¹), while only P. caldense EOs showed strong activity against S. aureus (MIC=0.50 mg mL⁻¹). P. caldense spring EO showed the broadest spectrum of antimicrobial action amongst all samples. For each species, PCA seasonally differentiated EOs chemical composition. In addition, as expected, PCA of all samples showed a distinction between the two species. This study has successfully demonstrated the importance of evaluating the seasonal variation of EOs chemical composition and antimicrobial activity in obtaining a product with the desired properties.     

Essential Oil Variability and Biological Activities of Tetraclinis articulata (Vahl) Mast. Wood According to the Extraction Time

In the present work, the hydrodistillation (HD) and microwave‐assisted hydrodistillation (MAHD) kinetics of essential oil (EO) extracted from Tetraclinis articulata (Vahl ) Mast. wood was conducted, in order to assess the impact of extraction time and technique on chemical composition and biological activities. Gas chromatography (GC) and GC/mass spectrometry analyses showed significant differences between the extracted EOs, where each family class or component presents a specific kinetic according to extraction time, technique and especially for the major components: camphene, linalool, cedrol, carvacrol and α‐acorenol. Furthermore, our findings showed a high variability for both antioxidant and anti‐inflammatory activities, where each activity has a specific effect according to extraction time and technique. The highlighted variability reflects the high impact of extraction time and technique on chemical composition and biological activities, which led to conclude that we should select EOs to be investigated carefully depending on extraction time and technique, in order to isolate the bioactive components or to have the best quality of EO in terms of biological activities and preventive effects in food.     

Variation in Essential Oil and Bioactive Compounds of Curcuma kwangsiensis Collected from Natural Habitats

The chemical compositions of essential oils (EOs) extracted from Curcuma kwangsiensis rhizomes collected from six natural habitats in P. R. China were evaluated using gas chromatography/mass spectrometry (GC/MS). Fifty‐seven components were identified from the six EOs, and their main constituents were 8,9‐dehydro‐9‐formyl‐cycloisolongifolene (2.37 – 42.59%), germacrone (6.53 – 22.20%), and l ‐camphor (0.19 – 6.12%). The six EOs exhibited different DPPH radical‐scavenging activities (IC₅₀, 2.24 – 31.03 μg/ml), with the activity of most of EOs being much higher than that of Trolox C (IC₅₀, 10.49 μg/ml) and BHT (IC₅₀, 54.13 μg/ml). Most EOs had potent antimicrobial effects against the tested bacteria and fungus. They also exhibited cytotoxicity against B16 (IC₅₀, 4.44 – 147.4 μg/ml) and LNCaP cells (IC₅₀, 73.94 – 429.25 μg/ml). The EOs showed excellent anti‐inflammatory action by significantly downregulating expression of pro‐inflammatory cytokines, cyclooxygenase‐2, and tumor necrosis factor‐α. This study provides insight into the interrelation among growth location, phytoconstituents, and bioactivities, and the results indicate the potential of C. kwangsiensis as natural nutrients, medicines, and others additives.     

Chemical Composition,Antimicrobial and Insecticidal Activities of Flowers Essential Oils of Alpinia zerumbet (Pers.) B.L.Burtt & R.M.Sm. from Martinique Island

Alpinia species, used as ornamental plants and flavoring agents, are renowned for their therapeutic properties and their subsequent use in traditional medicines throughout the world. Alpinia zerumbet (Pers .) B.L.Burtt & R.M.Sm . is the most common Alpinia species encountered in Martinique. Several essential oils (EOs) obtained by hydrodistillation of A. zerumbet flowers collected in various locations on the island at different seasons were analysed to evaluate the influence of the collection period and area on the EOs’ chemical compositions and to assess their bioactivity. A combination of GC‐FID and GC/MS techniques was used to examine the volatile constituents, leading to the identification of a total of 71 components accounting for 97.8 – 99.3% of the respective total GC‐FID areas: among them, nineteen compounds were characterized for the first time in A. zerumbet EOs. The antimicrobial activity of these EOs was assessed against eight bacterial, yeast and fungal strains and two multi‐resistant strains: some significant bacteriostatic and fungistatic activities of A. zerumbet flower oils were evidenced. Finally, an interesting insecticidal activity of the flower EO was highlighted for the first time against Aedes aegypti.     

Chemical Composition,Antibacterial, Antioxidant and in Vitro Antidiabetic Activities of Essential Oils from Eruca vesicaria

This work describes the study of the chemical composition and bioactivity of the essential oils (EOs) of the different organs (leaves, flowers, stems and roots) from Eruca vesicaria. According to the GC and GC/MS analysis, all the EOs were dominated by erucin (4‐methylthiobutyl isothiocyanate) with a percentage ranging from 17.9 % (leaves) to 98.5 % (roots). The isolated EOs were evaluated for their antioxidant (DPPH, ABTS and β‐carotene/linoleic acid), antibacterial and inhibitory property against α‐amylase and α‐glucosidase. Most EOs exhibited an interesting α‐glucosidase and α‐amylase inhibitory potential. The roots essential oil was found to be the most active with IC₅₀ values of 0.80±0.06 and 0.11±0.01 μg mL^?1, respectively. The essential oil of roots exhibited the highest antioxidant activity (DPPH, PI=92.76±0.01 %; ABTS, PI=78.87±0.19; and β‐carotene, PI=56.1±0.01 %). The isolated oils were also tested for their antibacterial activity against two Gram‐positive and three Gram‐negative bacteria. Moderate results have been noted by comparison with Gentamicin used as positive control.     

Inhibitory effect of Ocotea quixos (Lam.) Kosterm. and Piper aduncum L. essential oils from Ecuador on West Nile virus infection

West Nile virus (WNV) is a mosquito-borne flavivirus responsible of neuroinvasive manifestations. Natural products are well-known for their biological activities and pharmaceutical application. In this study, the inhibitory effects of essential oils (EOs) of Ocotea quixos (Lam.) Kosterm. and Piper aduncum L. on WNV replication were investigated. WNV was incubated with EOs before adsorption on Vero cells, viral replication was carried out in the absence or presence of EO. Cells were exposed to EO before the adsorption of untreated-virus. GC-MS and GC-FID were used for chemical characterization of EOs. Cell protection from infection was observed for both EOs. P. aduncum EO was characterized by dillapiole as main compound (48.21%) and O. quixos EO by 1,8-cineole (39.15%). Further investigations, such as the study of molecular and cellular mechanisms of action and in vivo evaluation, should be performed on these essential oils to derive new potential drugs against WNV.     

Phytochemical and Biological Profile of Essential Oils of Elionurus muticus (Spreng.) Growing in Northeastern Argentina

The purpose of this study was to investigate essential oils (EOs) from leaves of Elionurus muticus growing in Northeastern Argentina regarding their physicochemical profiles as well as their biological potential. Roots of a selected E. muticus population were investigated too. For this purpose, EOs of fresh materials were obtained by steam distillation and the chemical composition was characterized by gas chromatography GC/MS-FID. Antibacterial, antioxidant and eco-toxicity activities of the essential oils (EOs) were tested by in vitro assays. The EOs showed three E. muticus chemotypes: citral (neral+geranial), acorenone+bisabolone, acorenone+geranial. EO of roots of citral population contains mainly acorenone derivatives. EOs have high antibacterial effect against Staphylococcus aureus, being found minor antibacterial effect against Gram-negative bacteria. The half-maximal inhibitory concentration of EOs against DPPH⋅ were 7.1–30.0 mg/mL and the eco-toxicity was high with LD₅₀ <39 μg/mL. Based on the findings, given the high variability in their chemical composition and biological activity of E. muticus EO and the promising yields, it could be potentially chosen for industrial applications.     

Influence of Environmental Factors on Essential Oil Variability in Origanum compactum Benth. Growing Wild in Morocco

The present study aimed to evaluate the influence of environmental factors on essential oils (EOs) composition of Origanum compactum populations sampled all over the distribution area of the species in Morocco, and to determine the extent of the chemical profiles throughout the geographical distribution of the species. The chemical compositions were submitted to canonical correlation analysis and canonical discriminant analysis that indicated a significant relationship between oil components and some environmental factors. According to their chemical composition and edapho‐climatic characteristics, two major groups of populations were differentiated. The first group was composed of samples growing in regions with humid climate, clayey, sandy, and alkaline soils. These samples showed high thymol, α‐terpineol, linalool, and carvacryl methyl oxide content. The second group consisted of plants belonging to semi‐arid climate, and growing at high altitudes and silty soils. These samples were characterized by high carvacrol, α‐thujene, α‐terpinene, and myrcene content. However, populations exposed to sub‐humid climate, appeared less homogeneous and belong mainly either to the first or second group. A significant correlation between some edaphic factors (pH, K₂O content, soil texture) and the EOs yield of O. compactum plants was evidenced. In spite of the correlation obtained for the oil composition with edapho‐climatic factors and the variance explained by the environmental data set, the observed EO diversity might be also genetically determined.     

Essential Oils Composition and Antimicrobial Activity of Six Conifers Harvested in Lebanon

The chemical composition and antimicrobial activity of the essential oils (EOs) of six conifers harvested in Lebanon, Abies cilicica, Cupressus sempervirens, Juniperus excelsa, Juniperus oxycedrus, Cedrus libani and Cupressus macrocarpa gold crest, were investigated. The EOs were obtained by hydrodistillation using a Clevenger‐type apparatus and characterized by GC and GC/MS analyses. A principal components analysis based on Pearson correlation between essential oils chemical analyses was also conducted. The minimum inhibitory concentrations (MICs) of these essentials oils were determined against a range of bacteria and fungi responsible for cutaneous infections in human, using the broth microdilution technique. The EOs showed the most interesting bioactivity on the dermatophytes species (MIC values 32 – 64 μg/ml). Each of the major compounds of C. macrocarpa as well as an artificial reconstructed EO were tested on Trichophyton rubrum showing a contribution of the minor components to the overall activity.     

Chemical Composition,Antimicrobial Activity,and Mode of Action of Essential Oils against Paenibacillus larvae,Etiological Agent of American Foulbrood on Apis mellifera

This study aimed to characterize the chemical composition of Aloysia polystachia, Acantholippia seriphioides, Schinus molle, Solidago chilensis, Lippia turbinata, Minthostachys mollis, Buddleja globosa, and Baccharis latifolia essential oils (EOs), and to evaluate their antibacterial activities and their capacity to provoke membrane disruption in Paenibacillus larvae, the bacteria that causes the American Foulbrood (AFB) disease on honey bee larvae. The relationship between the composition of the EOs and these activities on P. larvae was also analyzed. Monoterpenes were the most abundant compounds in all EOs. All EOs showed antimicrobial activity against P. larvae and disrupted the cell wall and cytoplasmic membrane of P. larvae provoking the leakage of cytoplasmic constituents (with the exception of B. latifolia EO). While, the EOs’ antimicrobial activity was correlated most strongly to the content of pulegone, carvone, (Z)‐β‐ocimene, δ‐cadinene, camphene, terpinen‐4‐ol, elemol, β‐pinene, β‐elemene, γ‐cadinene, α‐terpineol, and bornyl acetate; the volatiles that better explained the membrane disruption were carvone, limonene, cis‐carvone oxide, pentadecane, trans‐carvyl acetate, trans‐carvone oxide, trans‐limonene oxide, artemisia ketone, trans‐carveol, thymol, and γ‐terpinene (positively correlated) and biciclogermacrene, δ‐2‐carene, verbenol, α‐pinene, and α‐thujene (negatively correlated). The studied EOs are proposed as natural alternative means of control for the AFB disease.     

Essential Oil of Deverra tortuosa Aerial Parts: Detailed Chemical Profile,Allelopathic, Antimicrobial,and Antioxidant Activities

Essential oils (EOs) are a promising group of natural products of the aromatic plants due to their various biological effects such as allelopathic, antioxidant, antimicrobial activities. The present study aimed to construct the detailed chemical profile of the EO derived from Deverra tortuosa aerial parts along with assessing its allelopathic, antimicrobial, and antioxidant potentialities. The EO was extracted by hydrodistillation and analyzed via gas chromatography-mass spectrometry (GC/MS). The allelopathic activity of the EO was assessed against the germination and seedling growth of the weed Chenopodium murale. Also, the EO was tested against five microbes. The antioxidant activity was determined using the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The GC/MS analysis of EO revealed the presence of 86 compounds with a preponderance of oxygenated sesquiterpenes and monoterpene hydrocarbons. Widdrol, β-phellandrene, piperitol, cubedol, α-terpinene, (E)-10-heptadecen-8-ynoic acid methyl ester, citronellyl tiglate, and m-cymene were the major compounds. A comparative profile was established between the EOs constituents of our study with the documented EOs of D. tortuosa and the other Deverra species around the world via agglomerative hierarchical clustering (AHC) and principal components analysis (PCA). The EO showed a substantial allelopathic activity against C. murale, as well as it showed considerable antimicrobial and antioxidant activities. Thereby, the EO of D. tortuosa could be considered as a promising environmental-friendly bioherbicide against weeds. Also, it could be integrated into food preservation due to its potent antimicrobial and antioxidant activities. However, further study is recommended for more characterization of the major compounds and evaluation of their activities, either singular or synergistic, and assess their efficiency and biosafety.     

Chemical Composition and Antimicrobial Activity of the Essential Oil of Juniperus excelsa M.Bieb. Growing Wild in Lebanon

The essential oils (EOs) isolated from the leaves and twigs of Juniperus excelsa M.Bieb . growing wild in Lebanon were characterized, and their antimicrobial activity and antiradical capacity were evaluated. The EOs were obtained by hydrodistillation using a Clevenger‐type apparatus and characterized by GC and GC/MS analyses. The antimicrobial activity was evaluated by determining minimal inhibitory concentrations (MICs) against a Gram‐positive and a Gram‐negative bacterium, a yeast, and a dermatophyte with the broth microdilution technique. A total of 28 constituents was identified and accounted for 90.1 and 95.6% of the twig and leaf EO composition, respectively. Both EOs were essentially composed of monoterpene hydrocarbons (46.7 and 59.6% for twig and leaf EOs, resp.) and sesquiterpenes (39.4 and 32.1%, resp.). The main components were α‐pinene, α‐cedrol, and δ‐car‐3‐ene. The J. excelsa EOs did not show any antiradical potential, but revealed interesting in vitro antimicrobial activities against Staphylococcus aureus and Trichophyton rubrum (MICs of 64 and 128 μg/ml, resp.). The three major compounds were tested separately and in combination according to their respective amounts in the oil. δ‐Car‐3‐ene was the most active component and is undoubtedly one of the constituents driving the antifungal activity of J. excelsa essential oil, even though synergies are probably involved.     

GC/MS Profiling,In Vitro and In Silico Pharmacological Screening and Principal Component Analysis of Essential Oils from Three Exotic and Two Endemic Plants from Mauritius

The chemical and pharmacological profiles of essential oils (EOs) hydrodistilled in yields of 0.03–0.77 % (w/w) from three exotic (Cinnamomum camphora, Petroselinum crispum, and Syzygium samarangense) and two endemic (Pittosporum senacia subsp. senacia and Syzygium coriaceum) medicinal plants were studied. GC-MS/GC-FID analysis of the EOs identified the most dominant components to be myristicin (40.3 %), myrcene (62.2 %), 1,8-cineole (54.0 %), β-pinene (21.3 %) and (E)-β-ocimene (24.4 %) in P. crispum, P. senacia and C. camphora, S. samarangense and S. coriaceum EOs, respectively. All EOs were found to possess anti-amylase (0.70–1.50 mM ACAE/g EO) and anti-tyrosinase (109.35–158.23 mg KAE/g) properties, whereas no glucosidase inhibition was displayed. Only Syzygium EOs acted as dual inhibitors of both acetyl- and butyryl-cholinesterases, while P. senacia and C. camphora EOs inhibited acetylcholinesterase selectively and P. crispum EO was inactive (AChE: 4.64–4.96 mg GALAE/g; BChE: 5.96 and 7.10 mg GALAE/g). Molecular docking revealed 1,8-cineole to present the best binding affinities with butyrylcholinesterase, amylase and tyrosinase, while both myristicin and β-pinene with acetylcholinesterase and finally β-pinene with glucosidase. In vitro antioxidant potency was also demonstrated in different assays (DPPH: 13.52–53.91 mg TE/g, ABTS: 5.49–75.62 mg TE/g; CUPRAC: 45.38–243.21 mg TE/g, FRAP: 42.49–110.64 mg TE/g; and phosphomolybdenum assay: 82.61–160.93 mM TE/g). Principal component analysis revealed the EOs to differ greatly in their bioactivities due to their chemodiversity. This study has unveiled some interesting preliminary pharmacological profiles of the EOs that could be explored for their potential applications as phytotherapeutics.     

Chemical Profiles and Cytotoxic Activities of Essential Oils from Six Species of Baccharis Subgenus Coridifoliae (Asteraceae)

Several Baccharis species are popularly known in traditional medicine as “carquejas”, “vassouras”, “ervas-santas” and “mio-mios”, and are used as anti-inflammatories, digestives, and diuretics. This study aimed to investigate the chemical compositions and cytotoxic activities of essential oils (EOs) of six Baccharis species belonging to subgenus Coridifoliae, namely B. albilanosa, B. coridifolia, B. erigeroides, B. napaea, B. ochracea, and B. pluricapitulata. GC/MS analyses of the EOs showed that the oxygenated sesquiterpenes spathulenol (7.32–38.22 %) and caryophyllene oxide (10.83–16.75 %) were the major components for all the species. The EOs of almost all species were cytotoxic against cancer (BT-549, KB, SK-MEL and SK-OV-3) and normal kidney (VERO and LLC-PK1) cell lines, whereas B. erigeroides EO showed cytotoxicity only against LLC-PK1. This article augments the current knowledge about the chemical-biological properties of Baccharis subgenus Coridifoliae and discusses the therapeutic potentials of these economically unexploited plants.     

Chemical Characterization of Euphorbia heterophylla L. Essential Oils and Their Antioxidant Activity and Allelopathic Potential on Cenchrus echinatus L.

The genus Euphorbia attracted the attention of many researchers worldwide from natural products, bioactivity, and ecological perspective. The essential oils (EOs) of Euphorbia heterophylla are poorly studied. Therefore, the present study aimed to provide a detailed profile of the E. heterophylla EOs as well as to determine their antioxidant and allelopathic activities. The EOs from aerial parts of E. heterophylla were extracted using hydrodistillation and analyzed via GC/MS. The antioxidant activity was determined based on scavenging of the free radical, 1,1‐diphenyl‐2‐picrylhydrazyl and H₂O₂. Various concentrations of the EOs were tested against the noxious weed, Cenchrus echinatus. Thirty‐five compounds were identified representing 100 % of the total mass. Four classes of components were characterized, among which terpenoids were the main components (88.70 %). Monoterpenes represented the main class (69.48 %), followed by sesquiterpenes (18.63 %), and only one diterpenoid, kaur‐16‐ene, was identified. 1,8‐Cineole (32.03 %), camphor (16.54 %), β‐elemene (5.92 %), endo‐borneol (4.94 %), limonene (4.27 %), pentatriacontane (3.91 %), and α‐pinene (3.89 %) were the major compounds. The EOs composition of Egyptian E. heterophylla ecospecies was comparable to that of other reported Euphorbia species, although it showed no correlation with Nigerian E. heterophylla ecospecies. The EOs from E. heterophylla aerial parts exhibited significant antioxidant activity. Moreover, a concentration of 100 μL L^?1 of the EOs reduced the germination, root, and shoot growth of C. echinatus by about 93.95 %, 84.6 %, and 57.8 %, respectively. Therefore, the EOs from E. heterophylla could be integrated into the control of this weed, as eco‐friendly biocontrol method. Further study is needed to characterize their allelopathic activity under field conditions as well as to evaluate their durability and biosafety.     

Casearia sylvestris Essential Oil Degradation Products Generated by Leaf Processing

Casearia sylvestris is an endemic tree of the Latin America that the essential oil (EO) has anti-inflammatory and gastroprotective actions. This study evaluates the chemical composition of the EO from the volatile fractions of in natura, fresh, and dried C. sylvestris var. sylvestris and var. lingua leaves. For both varieties, the dried leaves presented higher EO yield as compared to fresh leaves. The major EO chemical components were (E)-caryophyllene, α-humulene, germacrene D, bicyclogermacrene, spathulenol, caryophyllene oxide, and humulene epoxide II. In both varieties, the content of sesquiterpene hydrocarbons decreased and oxygenated sesquiterpenes increased on going from in natura to fresh and dried leaves, which indicated that leaf drying and hydrodistillation modified the volatile composition. The results also suggested that bicyclogermacrene and (E)-caryophyllene were oxidized during processing, to generate spathulenol and caryophyllene oxide, respectively. C. sylvestris varieties and in natura, fresh, and dried leaves differed in terms of the chemical composition of volatiles, which could affect the EO biological activities.