Chemodiversity and α-Glucosidase Activity of Eucalyptus Species from Northwestern Himalaya,India

The aim of current work was to determine essential oils (EOs) composition from three Eucalyptus species, including E. citriodora, E. camaldulensis and E. globulus and assess their α-glucosidase inhibitory activity. The EOs were collected using the hydrodistillation technique and characterized by GC/MS, GC-FID and NMR. The isolated EOs from leaves parts of Eucalyptus species varied from 0.56 to 1.0 % on fresh weight basis. The content of the EOs was distinct according to the species. The most abundant metabolites were identified as citronellal (0–83.0 %), 1,8-cineole (0.2–44.8 %), spathulenol (0.4–16.1 %) α-pinene (0.4–15.9 %), p-cymene (3.7–11.9 %), citronellol (0–8.6 %), β-eudesmol (5.3–8.6 %) and β-pinene (0–7.1 %). The EOs obtained from targeted samples exhibited strong α-glucosidase inhibitory activity. These results are encouraging and underline that the EOs of Eucalyptus species may be a promising alternative source of natural antidiabetic.     

Chemical Characterization and Multidirectional Biological Effects of Different Solvent Extracts of Arum elongatum: in Vitro and in Silico Approaches

Arum elongatum (Araceae) is widely used traditionally for the treatment of abdominal pain, arterial hypertension, diabetes mellitus, rheumatism and hemorrhoids. This study investigated the antioxidant properties, individual phenolic compounds, total phenolic and total flavonoid contents (HPLC/MS analysis), reducing power and metal chelating effects of four extracts obtained from A. elongatum (ethyl acetate (EA), methanol (MeOH), methanol/water (MeOH/water) and infusion). The inhibitory activity of the extracts were also determined against acetylcholinesterase, butyrylcholinesterase, tyrosinase, amylase and glucosidase enzymes. The MeOH/water extracts contained the highest amount of phenolic contents (28.85 mg GAE/g) while the highest total flavonoid content was obtained with MeOH extract (36.77 mg RE/g). MeOH/water demonstrated highest antioxidant activity against DPPH⋅ radical at 38.90 mg Trolox equivalent per gram. The infusion extract was the most active against ABTS⁺⋅ (133.08 mg TE/g). MeOH/water extract showed the highest reducing abilities with the CUPRAC value of 102.22 mg TE/g and the FRAP value of 68.50 mg TE/g. A strong metal chelating effect was observed with MeOH/water extract (35.72 mg EDTAE/g). The PBD values of the extracts ranged from 1.01 to 2.17 mmol TE/g. EA extract displayed the highest inhibitory activity against AChE (2.32 mg GALAE/g), BChE (3.80 mg GALAE/g), α-amylase (0.56 mmol ACAE/g) and α-glucosidase (9.16 mmol ACAE/g) enzymes. Infusion extract was the most active against tyrosinase enzyme with a value of 83.33 mg KAE/g. A total of 28 compounds were identified from the different extracts. The compounds present in the highest concentration were chlorogenic acids, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, isoquercitrin, delphindin 3,5-diglucoside, kaempferol-3-glucoside and hyperoside. The biological activities of A. elongatum extracts could be due to the presence of compounds such as gallic acid, chlorogenic acids, ellagic acid, epicatechin, catechin, kaempferol, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, quercetin, isoquercitrin, and hyperoside. Extracts of A. elongatum showed promising biological activities which warrants further investigations in an endeavor to develop biopharmaceuticals.     

Two Medicinal Plants (Alkanna trichophila and Convolvulus galaticus) from Turkey: Chemical Characterization and Biological Perspectives

The aim of the present study was to quantify selected phenolic compounds, determine antioxidant activity and enzyme inhibitory effects of the aerial parts of Alkanna trichophylla Hub.-Mor. (A. trichophylla) and Convolvulus galaticus Rost.ex Choisy (C. galaticus) extracts prepared by homogenizer-assisted extraction (HAE), maceration (MAC) and infusion techniques. This is the first time such study has been designed to validate the phytochemical composition and bioactivity of these plants. Multivariate analysis was conducted on collected data. Rutin and caffeoylquinic acid derivatives were the most significant compounds in A. trichophylla and C. galaticus, respectively. The highest antioxidant activity of A. trichophylla was mostly exhibited by HAE/methanolic extracts as determined by DPPH, ABTS, FRAP (51.39, 112.70 and 145.73 mg TE/g, respectively) and phosphomolybdenum (2.05 mmol TE/g) assays. However, significant antioxidant activities varied within the extracts of C. galaticus. HAE/methanolic extract of A. trichophylla significantly depressed AChE (2.70 mg GALAE/g), BChE (5.53 mg GALAE/g) and tyrosinase (26.34 mg KAE/g) activities and that of C. galaticus inhibited AChE (2.04 mg GALAE/g), tyrosinase (31.25 mg KAE/g) and α-amylase (0.53 mmol ACAE/g) activities significantly. We concluded that HAE was the most efficient extraction technique as high yield of compounds and promising bioactivities were recorded from extracts prepared. Multivariate analysis showed that types of solvents influenced recovery of compounds and biological activities. This research study can be used as one methodological starting point for further investigation on these plants as all results are clearly promising and open the door to further research challenges such as cytotoxicity evaluation, molecular docking analysis, and more screening of pharmacological actions.     

Enzyme inhibition and antioxidant functionality of eleven Inula species based on chemical components and chemometric insights

The members of the genus Inula have been widely used in traditional medicinal. In the present study, 11 Inula species were investigated for their phytochemical composition, antioxidant and enzyme inhibitory effects. While quinic acid was the principal compound in I. anatolica, I. britannica, I. inuloides, I. oculus-christi, I. peacockiana, I. sechmenii, I. thapsoides and I. viscidula extracts (22.43–42.02 mg/g dry extract (DE)), I. aucheriana and I. discoidea extracts contained rutin as their most abundant compound (23.28 and 79.10 mg/g extract, respectively). Interestingly, all the Inula extracts were active inhibitors of the five key clinical enzymes (acetylcholinesterase (3.56–5.13 mg galantamine equivalent (GALAE)/g), butyrylcholinesterase (1.49–7.34 mg GALAE/g), tyrosinase (112.31–122.13 mg kojic acid equivalent (KAE)/g), α-glucosidase (0.77–2.08 mmol acarbose equivalent (ACAE)/g) and α-amylase (0.73–0.90 mmol ACAE/g)). Furthermore, the extracts were observed to exhibit substantial antioxidant capacity (1,1-diphenyl-2-picrylhydrazyl (DPPH): 58.99–188.22 mg trolox equivalent (TE)/g); 2,2-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) (ABTS): 90.51–220.97 mg TE/g; cupric reducing antioxidant capacity (CUPRAC): 169.88–460.53 mg TE/g; ferric reducing antioxidant power (FRAP): 81.57–237.99 mg TE/g; metal chelating activity: 8.31–25.39 mg ethylenediamine tetraacetate equivalent (EDTAE)/g; phosphomolybdenum: 1.55–2.49 mmol TE/g). In conclusion, the Inula species studied herein showed promising pharmacological potentials justified by the presence of a panoply of bioactive compounds.     

Antioxidant and Enzyme Inhibitory Activities of Rhoifolin Flavonoid: In Vitro and in Silico Studies

Rhoifolin (apigenin-7-O-β-neohesperidoside) belongs to the class of flavonoids and was reported to exhibit anti-inflammatory, cytotoxic, antidiabetic, hepatoprotective, and cardioprotective activities. The current study presents the in-vitro evaluation of the antioxidative effects of rhoifolin by many assays, namely DPPH, CUPRAC, ABTS, phosphomolybdenum, and FRAP. Enzyme inhibitory potential was also evaluated for acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, amylase, and glucosidase enzymes. While results revealed weak antioxidant activities for rhoifolin, the compound demonstrated some promising enzyme inhibitory effects against BChE (4.03 mg GALAE/g) and tyrosinase (7.44 mg KAE/g) but was not active on AChE. Regarding anti-diabetic enzymes, the compound was active on amylase but did not show any inhibition effect on glucosidase. In-silico molecular docking study was performed for rhoifolin on the active site of NADPH oxidase, BChE, and amylase enzymes to verify the observed enzyme inhibitory effect. Good binding affinities were observed for rhoifolin on all the docked enzymes, revealing numerous hydrogen bonds, carbon-hydrogen, van der Waals interactions. This is the first study to evaluate the enzyme inhibition potential of rhoifolin. We concluded that the increase in the degree of glycosylation might decrease the antioxidant abilities of flavonoids and that rhoifolin had moderate enzyme inhibition abilities to be investigated in future studies.     

Chemical Variability of Moroccan Myrtle Oil

Thirty-three oil samples isolated from aerial parts of Myrtus communis L. harvested in seven localities, from Northern to Central Morocco, have been analyzed by combination of chromatographic and spectroscopic techniques. The 33 compositions have been subjected to statistical analysis, hierarchical cluster analysis (HCA) and principal component analysis (PCA). Two groups have been differentiated on the basis of their myrtenyl acetate and α-pinene contents and each one was sub-divided in two sub-groups according to the contents of 1,8-cineole and linalool. The compositions of our 33 myrtle oil samples may be named as follow by their main components: sub-group IA (13/33): α-pinene/1,8-cineole/linalool; sub-group IB (6/33): 1,8-cineole/α-pinene; sub-group IIA (10/33): 1,8-cineole/myrtenyl acetate; sub-group IIB (4/33): myrtenyl acetate.     

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.     

Chemical composition of the essential oils of circadian rhythm and of different vegetative parts from Piper mollicomum Kunth - A medicinal plant from Brazil

In this study, the chemical composition of essential oils (EOs) from different vegetative parts from P. mollicomum was evaluated. In addition, the EOs from leaves collected every 3 h in a period of 24 h, in the dry and rainy seasons were also analyzed to establish the circadian rhythm of P. mollicomum from a natural population in the Atlantic Forest. The EOs were obtained by hydrodistillation and the chemical composition and quantification were achieved by GC-MS and GC-FID, respectively. The main compounds identified in the main stems and branches were α-phellandrene, linalool and β-phellandrene. Arylpropanoids myristicin, dillapiole and apiole were identified as main compounds in the roots. Inflorescences and infructescences showed to be rich in linalool, eupatoriocromene and E-nerolidol. In the circardian rhythm study, EOs showed to be rich in 1,8-cienol and/or linalool in accordance with season and phenology. The chemometric analyzes made it possible to register sample variations in the EOs compositions, being linalool as major compound attributed to the rainy and vegetative phase periods. Monoterpene 1,8-cineole was characterized as the main compound in the dry and reproductive phase periods. The same chemometric features allowed to stablished differences considering vegetative parts as a clear grouping of the EOs by biosynthetic pathway. In summary, there are great differences in the EOs composition, considering phenology, seasonality and vegetative parts. These results are very important since P. mollicomum has been used as medicinal plant for many years.     

In vitro Antiproliferative and Antibacterial Activities of Essential Oils from Four Species of Guatteria

The essential oils (EOs) extracted from four species of the genus Guatteria, G. australis, G. ferruginea, G. latifolia, and G. sellowiana were analyzed. A total of 24, 22, 25, and 19 constituents of the oils from four species, respectively, were identified by GC/MS. These oils showed qualitative and quantitative differences. All the oils contained the oxygenated sesquiterpenes spathulenol (11.04 – 40.29%) and caryophyllene oxide (7.74 – 40.13%) as predominant constituents. Evaluation of antiproliferative activity of the EOs showed strong selectivity (1.1 – 4.1 μg/ml) against the tumor cell line OVCAR‐03 (ovarian cancer), i.e., more active than the positive control doxorubicin (11.7 μg/ml). All EOs showed strong antibacterial activity (minimum inhibitory concentrations of 0.062 – 0.25 mg/ml) against strains of Rhodococcus equi.     

Biological Insights and NMR Metabolic Profiling of Different Extracts of Spermacoce verticillata (L.) G. Mey.

Spermacoce verticillata (L.) G. Mey. is commonly used in the folk medicine by various cultures to manage common diseases. Herein, the chemical and biological profiles of S. verticillata were studied in order to provide a comprehensive characterization of bioactive compounds and also to highlight the therapeutic properties. The in vitro antioxidant activity using free-radical scavenging, phosphomolybdenum, ferrous-ion chelating and reducing power assays, and the inhibitory activity against key enzymes such as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), tyrosinase, α-amylase and α-glucosidase of S. verticillata extracts (dichloromethane, ethyl acetate, methanol and water) were investigated. The highest total phenolic and flavonoid content were observed in the methanolic and aqueous extracts. Exhaustive 2DNMR investigation has revealed the presence of rutin, ursolic and oleanoic acids. The methanolic extract, followed by aqueous extract have showed remarkable free radical quenching and reducing ability, while the dichloromethane extract was the best source of metal chelators. The tested extracts showed notable inhibitory activity against cholinesterases (AChE: 1.63–4.99 mg GALAE/g extract and BChE: 12.40–15.48 mg GALAE/g extract) and tyrosinase (60.85–159.64 mg KAE/g extract). No inhibitory activity was displayed by ethyl acetate and aqueous extracts against BChE and tyrosinase, respectively. All the tested extracts showed modest α-amylase inhibitory activity, while only the ethyl acetate and aqueous extracts were potent against α-glycosidase. This study further validates the use of S. verticillata in the traditional medicine, while advocating for further investigation for phytomedicine development.     

Composition of essential oils from turkish Salvia species

The chemical composition of the essential oils from five Salvia species from Turkey was determined by GC. The species were S. candidissima, S. cryptantha, S. fruticosa, S. officinalis and S. tomentosa. 24, 22, 20, 19, and 22 components were identified, respectively, the major ones being β-pinene (candidissima), borneol (cryptantha), 1,8-cineole (fruticosa), camphor (officinalis) and β-pinene (tomentosa). α-Pinene in candidissima, camphor in cryptantha, α-thujone in officinalis and 1,8-cineole in tomentosa were the other important components.     

Chemical Profiling of the Essential Oils of Syzygium aqueum,Syzygium samarangense and Eugenia uniflora and Their Discrimination Using Chemometric Analysis

The essential oil compositions of the leaves of three related Myrtaceae species, namely Syzygium aqueum, Syzygium samarangense and Eugenia uniflora, were investigated using GLC/MS and GLC/FID. Altogether, 125 compounds were identified: α‐Selinene (13.85%), β‐caryophyllene (12.72%) and β‐selinene constitute the most abundant constituents in S. aqueum. Germacrene D (21.62%) represents the major compound in S. samarangense whereas in E. uniflora, spathulenol (15.80%) represents the predominant component. Multivariate chemometric analyses were used to discriminate the essential oils using hierarchical cluster analysis (HCA) and principal component analysis (PCA) based on the chromatographic results. The antimicrobial activity of the popularly used E. uniflora essential oil was assessed using broth microdilution method against six Gram‐positive, three Gram‐negative bacteria and two fungi. The oil showed moderate antimicrobial activity against Bacillus licheniformis exhibiting MIC and MMC of 0.63 mg/ml. The cytotoxic activity of E. uniflora essential oil was investigated against Trypanosoma brucei brucei (T. b. brucei) and MCF‐7 cancer cell line using MTT assay. It showed moderate activity against MCF‐7 cells with an IC₅₀ value of 76.40 μg/ml. On the other hand, T. brucei was highly susceptible to E. uniflora essential oil with IC₅₀ of 11.20 μg/ml, and a selectivity index of 6.82.     

A comparative exploration of the phytochemical profiles and bio-pharmaceutical potential of Helichrysum stoechas subsp. barrelieri extracts obtained via five extraction techniques

We endeavoured to probe into and compare the possible effect(s) of different extraction techniques (accelerated solvent extraction (ASE), microwave-assisted extraction (MAE), ultrasonication-assisted extraction (UAE), maceration, and Soxhlet extraction (SE)) on the bioactivity (antioxidant and enzyme inhibitory activities) of the aerial parts of Helichrysum stoechas subsp. barrelieri (Ten.) Nyman. Total phenolic and flavonoid contents of the extracts obtained by different extraction methods followed the order of ASE > MAE > UAE > maceration > SE. Extract obtained by ASE was the most potent radical scavenger (219.92 and 313.12 mg Trolox equivalent [TE]/g, against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), respectively) and reducing agent (927.39 and 662.87 mg TE/g, for cupric reducing antioxidant capacity (CUPRAC) and ferric reducing antioxidant power (FRAP), respectively). Helichrysum stoechas extract obtained by UAE (18.67 mg ethylenediaminetetraacetic equivalent [EDTAE]/g) was the most active metal chelator and inhibitor of acetylcholinesterase (4.23 mg galantamine equivalent [GALAE]/g) and butyrylcholinesterase (6.05 mg GALAE/g) cholinesterase. Extract from maceration (183.32 mg kojic acid equivalent [KAE]/g) was most active against tyrosinase while ASE extract (1.66 mmol acarbose equivalent [ACAE]/g) effectively inhibited α-glucosidase. In conclusion, data amassed herein tend to advocate for the use of non-conventional extraction techniques, namely ASE and UAE, for the extraction of bioactive secondary metabolites from H. stoechas aerial parts.     

A Prospective of Multiple Biopharmaceutical Activities of Procyanidins-Rich Uapaca togoensis Pax Extracts: HPLC-ESI-TOF-MS Coupled with Bioinformatics Analysis

The article reports the chemical composition, antioxidant, six key enzymes inhibitory and antimicrobial activities of two solvent extracts (water and methanol) of leaves and stem bark of Uapaca togoensis. For chemical composition, methanol extract of stem bark exhibited significant higher total phenolic (129.86 mg GAE/g) and flavanol (10.44 mg CE/g) contents. Methanol extract of leaves and water extract of stem bark showed high flavonoids (20.94 mg RE/g) and phenolic acid (90.40 mg CAE/g) content, respectively. In addition, HPLC-ESI-TOF-MS analysis revealed that U. togoensis was rich in procyanidins. The methanol and water extracts of stem bark had overall superior antioxidant activity; however, only methanol extract of stem bark showed higher inhibition of cholinesterase (AChE: 2.57 mg GALAE/g; BChE: 4.69 mg GALAE/g), tyrosinase (69.53 mg KAE/g) and elastase (2.73 mmol CE/g). Potent metal chelating ability was showed by water extract of leaves (18.94 mg EDTAE/g), higher inhibition of amylase was detected for water extracts of leaves (0.94 mmol ACAE/g) and stem bark (0.92 mmol ACAE/g). The tested extracts have shown wide-spectrum antibacterial properties and these effects have shown to be more effective against Aspergillus ochraceus, Penicillium funiculosum, Trichoderma viride, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa. The results revealed that the antioxidant, enzyme inhibitory and antimicrobial activities depended on the extraction solvents and the parts of plant. Bioinformatics analysis on the 17 major compounds showed modulation of pathway associated with cancer. In brief, U. togoensis might be valuable as potential source of natural agents for therapeutic application.     

Composition and biovariability of Deverra scoparia volatile oil and its potential use as a source of bioactive phthalide components

Chemical biodiversity of essential oils of natural populations of Deverra scoparia growing in different regions in Algeria, and spreading from of semiarid to Saharan territories, was assessed. More than 60 compounds were identified by GC and GC-MS. Both phenylpropanoids and phathalids classes of bioactive components in leaves part were exhibiting drastic variations: (0.77–59.46%) and (0.04–28.55%), respectively. More specifically, the following bioactive components reached a very high level for this plant species: myristicin “up to 58.19%”, dill apiole “up to 25.52%” and (Z)-ligustilide “up to 27.5%”. Seven major compounds identified for the flowers part were varying from very low to very high percentages: α-pinene (2.49–42.32%), sabinene + β-pinene (1.11–30.31%), α-phellandrene (0.99–20.63%), p-cymene (0.0–44.22%), limonene (0.0–42.99%), myristicin (0.03–58.19%) and dill apiole (0.4–25.52%). Similarly, for the stems part, larges variations of both major and minor components were also registered: α-pinene (17.97–53.25%), sabinene + β-pinene (3.44–24.99%), α-phellandrene (0.75–10.32%), limonene (1.35–59.68%), terpinen-4-ol (0.29–15.85%) and spathulenol (0.46–11.29%). Agglomerative Hierarchical Cluster analysis was conducted, showing the existence of two main groups. Obtained data for volatile components in each plant part gave an insight of the existence of simultaneous clear and large biodiversity of the chemical profiles of the studied plant parts.     

Chemical Compositions,Antioxidant and Antimicrobial Activities of Essential Oils of Psidium guajava L. Leaves from Different Geographic Regions in China

Hydrodistilled essential oils (EO) of Psidium guajava L. leaves from different regions in China were analyzed by GC and GC/MS. The samples from Guangdong Province displayed high EO yields (0.61 – 0.75%, v/w). A total of 50 components, representing over 98.00% of the EOs, were identified and semi‐quantitatived. The major constituents of EOs included β‐caryophyllene (17.17 – 31.38%), γ‐gurjunene (9.17 – 15.22%), τ‐cadinol (1.35 – 10.02%) and calamenene (2.13 – 7.80%). The terpenoids in all sample oils were dominated by sesquiterpenes hydrocarbons (70.18 – 84.35%), followed by oxygenated sesquiterpenes (9.89 – 22.19%). The similarities and differences among EOs from different samples were evaluated by hierarchical cluster analysis and principal component analysis methods. The IC₅₀ values of EOs from different regions were between 18.52 – 33.72 mg/ml (DPPH) and 13.12 – 25.15 mg/ml (ABTS⁺). The FRAP value of EO from Guangdong Province was 7.34 – 9.13 mmol Vc/g DM, while the FRAP value of EO from Taiwan Province was 2.29 – 2.36 mmol Vc/g DM. The antimicrobial tests revealed that EO had a higher antimicrobial activity against all Gram‐positive bacteria and two fungi. Moreover, EO from P. guajava leaves of Guangdong Province showed the highest antimicrobial activity. These properties can be considered in the design of industrial products and for further application in the food, pharmaceutical and cosmetic industries.     

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.     

Insecticidal Activity of the Leaf Essential Oil of Peperomia borbonensis Miq. (Piperaceae) and Its Major Components against the Melon Fly Bactrocera cucurbitae (Diptera: Tephritidae)

The essential oil from the leaves of Peperomia borbonensis from Réunion Island was obtained by hydrodistillation and characterized using GC‐FID, GC/MS and NMR. The main components were myristicin (39.5%) and elemicin (26.6%). The essential oil (EO) of Peperomia borbonensis and its major compounds (myristicin and elemicin), pure or in a mixture, were evaluated for their insecticidal activity against Bactrocera cucurbitae (Diptera: Tephritidae) using a filter paper impregnated bioassay. The concentrations necessary to kill 50% (LC₅₀) and 90% (LC₉₀) of the flies in three hours were determined. The LC₅₀ value was 0.23 ± 0.009 mg/cm² and the LC₉₀ value was 0.34 ± 0.015 mg/cm² for the EO. The median lethal time (LT₅₀) was determined to compare the toxicity of EO and the major constituents. The EO was the most potent insecticide (LT₅₀ = 98 ± 2 min), followed by the mixture of myristicin and elemicin (1.4:1) (LT₅₀ = 127 ± 2 min) indicating that the efficiency of the EO is potentiated by minor compounds and emphasizing one of the major assets of EOs against pure molecules.     

Phytochemical Variation within Aerial Parts of Ferula cupularis Populations,an Endangered Medicinal Plant from Iran

Ferula cupularis (Boiss.) Spalik et S. R. Downie is an endangered endemic Iranian medicinal plant with occurrence restricted to Fars and Kohkilooyeh Boyerahmad provinces, Iran. F. cupularis is cited for strong antibacterial activity, usages in foodstuffs preservation, and has long been used by local peoples for ulcer treatment. In this research, the aerial parts of F. cupularis wild populations were collected from three natural habitats: Eqlid-Kaftar (FC1), Kakan (FC2), and Sepidan-Komohr (FC3), to assess phytochemical diversity and antioxidant activity. The quantity of essential oil (EO) ranged remarkably from 0.42 to 0.72 % v/w among the populations. Results obtained from the EO analysis by GC-FID and GC/MS detected up to 56 compounds. α-Pinene (21.65–31.53 %), sabinene (4.74–11.39 %), phellandrene (1.78–5.1 %), δ-3-carene (1.85–7.18 %), limonene (4.12–7.45 %), (Z)-β-ocimene (9.08–17.64 %), and elemicin (0.23–5.74 %) were the major compounds of EOs varied significantly among the populations. Moreover, total phenol content (250.54 to 387.45 mg gallic acid/100 g dry weight (DW)) and flavonoids (34.38 to 41.12 mg quercetin/100 g DW) of methanolic extracts varied substantially among the populations. Antioxidant activities of F. cupularis EOs and extracts were assessed by DPPH (2,2,1-diphenyl-1-picrylhydrazyl) radical scavenging method. EOs exhibited EC₅₀ values ranging from 8.88 to 9.67 μg mL⁻¹ and the EC₅₀ values for the extract ranged from 941.36 to 1335.96 μg mL⁻¹ within the populations. Results demonstrated significantly different levels of antioxidant capacities among the studied populations. Monitoring the data, the population collected from Eqlid-Kaftar (FC1) was selected as the most potent population concerning the highest EO content and antioxidant activity level. The obtained data provided new insights for an initial source of breeding plans and ultimately massive production for food and pharmaceutical industries.     

Acaricidal and repellent effects of myrtacean essential oils and their major constituents against Tetranychus urticae (Tetranychidae)

Nineteen plant essential oils (EOs) extracted from the family Myrtaceae growing in Australia were screened for their acaricidal and repellent activities against two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), in the laboratory by dipping method and choice- and no-choice tests. Acaricidal bioassays showed that five EOs of Callistemon viminalis, Eucalyptus bicostata, Eucalyptus maidenii, Eucalyptus sideroxylm and Eucalyptus approximans significantly increased the mortality of female adult mites and decreased the total number of eggs. In a choice test, Callistemon sieberi, E. bicostata, Eucalyptus ovata, E. sideroxylm, Eucalyptus mannifera, Eucalyptus dives, Eucalyptus elata, Eucalyptus condonocarpa, Kunzea ericoides, Melaleuca armillaris and Melaleuca fulgens demonstrated good repellency to the mite. In another test, C. sieberi, E. bicostata, E. mannifera, E. condonocarpa, K. ericoides, M. armillaris, and M. fulgens EOs decreased the egg production of the females significantly. In the acaricidal and repellent tests, E. bicostata and E. sideroxylon EOs showed both acaricidal and repellent effects (choice test) and decreased the number of eggs on treated bean leaves. The gas chromatograph/mass spectroscopy analyses revealed that the major components of E. bicostata and E. sideroxylon were 1,8-cineole, limonene, and α-pinene. The 1,8-cineole and limonene showed significant repellent effects on the mites, resulting in reduced numbers of eggs in the choice test. Hence, EOs of E. bicostata and E. sideroxylon and limonene and 1,8-cineole may be potential agents to be used in the sustainable management of T. urticae.