New study of the essential oil,mineral composition and antibacterial activity of Pistacia lentiscus L. from Eastern Morocco

The present study describes the chemical composition of essential oils of Pistacia lentiscus L., collected from different regions of Eastern Morocco. The essential oils were obtained by hydro-distillation of the areal parts and analyzed by gas chromatography and gas chromatography coupled to a mass spectrometry. The study was conducted to determine the phytochemistry and antibacterial activities of oil from P. lentiscus leaves against both bacteria using the disc diffusion method. For Gram-negative, Salmonella sp., Klebsiella, Escherichia coli, and Pseudomonas, and for Gram-positive, Staphylococcus aureus, and Streptococcus were used as test bacterial strains. In the end, we completed the previous study by determining the minor and major mineral contents of leaves of P. lentiscus. The yield of P. lentiscus oil ranged between 0.13 and 0.23 %, with the chemical composition changing from one region to another. The variations are important between plant populations. The major oil components of PLL oil from Taforalt and Saidia (humid climate) were limonene and α-pinene, while myrcene, β-caryophyllene were found to be the major components of Laayoune and Jerada oil (semi-arid climate). For the mineral composition of PLL, the results show that trace element profiles of leaves from different regions differed significantly; the highest levels of K, Mg, Fe, and Ca were found in leaves of all locations, while the leaves collected from the Jerada region had the highest content of mineral substrates. This work also attempts to contribute to the knowledge of the nutritional properties of this plant; the results will be investigated for the evaluation of dietary information.     

Variability of the Chemical Composition and Bioactivity between the Essential Oils Isolated from Male and Female Specimens of Hedyosmum racemosum (Ruiz & Pav.) G. Don

Hedyosmum racemosum (Ruiz & Pav.) G. is a native species of Ecuador used in traditional medicine for treatment of rheumatism, bronchitis, cold, cough, asthma, bone pain, and stomach pain. In this study, fresh H. racemosum leaves of male and female specimens were collected and subjected to hydrodistillation for the extraction of the essential oil. The chemical composition of male and female essential oil was determined by gas chromatography–gas chromatography equipped with a flame ionization detector and coupled to a mass spectrometer using a non-polar and a polar chromatographic column. The antibacterial activity was assayed against five Gram-positive and two Gram-negative bacteria, and two dermatophytes fungi. The scavenging radical properties of the essential oil were evaluated by DPPH and ABTS assays. The chemical analysis allowed us to identify forty-three compounds that represent more than 98% of the total composition. In the non-polar and polar column, α-phellandrene was the principal constituent in male (28.24 and 25.90%) and female (26.47 and 23.90%) essential oil. Other main compounds were methyl chavicol, germacrene D, methyl eugenol, and α-pinene. Female essential oil presented a strong activity against Klebsiella pneumoniae (ATCC 9997) with an minimum inhibitory concentration (MIC) of 500 μg/mL and a scavenging capacity SC₅₀ of 800 µg/mL.     

Evaluation of the antioxidant and antibacterial properties of ethanol extracts from berries,leaves and stems of Hedera pastuchovii Woron. ex Grossh

This study was designed to examine the total phenolic and flavonoid contents, radical scavenging and antibacterial activity of the ethanolic extracts from leaves, berries and stems of Hedera pastuchovii Woron. ex Grossh. The berry extract, which contained the highest phenolic and flavonoid compounds, showed an appreciable DPPH^√ scavenging ability in comparison with leaf and stem extracts. The various extracts exhibited moderate to good activity against both Gram-negative and Gram-positive bacteria, and the effectiveness of leaf extract was higher for all tested bacteria.     

Comparison of hydrodistillation and headspace solid-phase microextraction techniques for antibacterial volatile compounds from the fruits of Seseli libanotis

The volatile compounds from the fruits of Seseli libanotis, wild-growing in Poland, were obtained by hydrodistillation (HD) and headspace solid-phase microextraction techniques (HS-SPME) and analyzed using GC-MS. A total of 58 components were identified. The most abundant compounds were sabinen and beta-phellandrene. MIC (minimal inhibitory concentration) and MBC (minimal bactericidal concentration) values for the essential oil against reference bacterial strains and clinical S. aureus isolates were determined. The essential oil showed better antibacterial activity against the Gram-positive bacteria (MICs between 0.15 to 1.25 mg/mL) when compared with Gram-negative bacteria (MICs between 1.25 to 2.5 mg/mL). The low values of the MBC/MIC ratio suggest that the examined oil behaved as a bactericidal agent.     

Antimicrobial activities of essential oil and methanol extract of Coriaria nepalensis

Plant extracts and products have been used for centuries in traditional medicine; for most of them, in addition to the scant scientific credibility, the chemical composition and spectrum of activity are yet to be explored. To put forward this effort and to identify novel antimicrobial agents, the inhibitory activities of methanolic extract and essential oil from Coriaria nepalensis against various microorganisms including pathogenic yeast, and Gram-positive and negative bacteria were evaluated. Chemical compositions of C. nepalensis methanolic extract and essential oil were analysed by gas chromatography-mass spectrometry. In vitro susceptibility tests against all the tested isolates were performed in terms of minimum inhibitory concentration (MIC), and well diffusion assay using standard protocols. All microorganisms tested were profoundly found susceptible to both the C. nepalensis extract and oil with MIC values of 1.3-2.1?mg?mL?1 (Gram-positive bacteria), 1.4-2.2?mg?mL?1 (Gram-negative bacteria) and 0.9-1.6?mg?mL?1 (yeasts). The extent of inhibition was shown more by methanolic extract than by essential oil. This study is the first to report the antimicrobial activity of extracts obtained from the C. nepalensis. It can be concluded that the observed antimicrobial characteristics of C. nepalensis indicate that it might be a promising antimicrobial agent.     

Chemical composition and antibacterial activity of the essential oil of Moroccan Juniperus phoenicea

The antibacterial activity of the essential oil from leaves of Juniperus phoenicea (Cupressaceae) and its chemical constituents were investigated in this study. The essential oil was obtained by hydro-distillation and analyzed by gas chromatography equipped with a flame ionisation detector (GC-FID), and gas chromatography coupled to a mass spectrometer (GC-MS). Sixty-three volatile compounds were identified representing 52 to 92% of the total oil compositions. The main monoterpenes were a-pinene (26.7-78.7%) and 6-3carene (7.6-15.4%). The antibacterial activity of J. phoenicea essential oil, when tested against both Gram-positive and Gram-negative bacteria, showed high activity against all bacteria tested, except Pseudomonas.     

Composition,antibacterial, antioxidant and antiproliferative activities of essential oils from three Origanum species growing wild in Lebanon and Greece

The essential oils from Origanum dictamnus, Origanum libanoticum and Origanum microphyllum were analysed by GC-MS, finding carvacrol, p-cymene, linalool, γ-terpinene and terpinen-4-ol as major components. The antioxidant activity by the DPPH and FRAP tests and the antiproliferative activity against two human cancer cell lines, LoVo and HepG2, were investigated, showing that the essential oil of O. dictamnus was statistically the most inhibitory on both the cell lines, while all the oils exerted a weak antioxidant activity. Furthermore, the samples were tested against 10 Gram-negative and Gram-positive bacteria; all the oils were active on Gram-positive bacteria but O. dictamnus essential oil was the most effective (MIC = 25–50 μg/mL), showing also a good activity against the Gram-negative Escherichia coli (MIC = 50 μg/mL). Data suggest that these essential oils and particularly O. dictamnus oil could be used as valuable new flavours with functional properties for food or nutraceutical products.     

Chemical Constituents of the Essential Oil from Ecuadorian Endemic Species Croton ferrugineus and Its Antimicrobial,Antioxidant and α-Glucosidase Inhibitory Activity

Croton ferrugineus Kunth is an endemic species of Ecuador used in traditional medicine both for wound healing and as an antiseptic. In this study, fresh Croton ferrugineus leaves were collected and subjected to hydrodistillation for extraction of the essential oil. The chemical composition of the essential oil was determined by gas chromatography equipped with a flame ionization detector and gas chromatography coupled to a mass spectrometer using a non-polar and a polar chromatographic column. The antibacterial activity was assayed against three Gram-positive bacteria, one Gram-negative bacterium and one dermatophyte fungus. The radical scavenging properties of the essential oil was evaluated by means of DPPH and ABTS assays. The chemical analysis allowed us to identify thirty-five compounds representing more than 99.95% of the total composition. Aliphatic sesquiterpene hydrocarbon trans-caryophyllene was the main constituent with 20.47 ± 1.25%. Other main compounds were myrcene (11.47 ± 1.56%), β-phellandrene (10.55 ± 0.02%), germacrene D (7.60 ± 0.60%), and α-humulene (5.49 ± 0.38%). The essential oil from Croton ferrugineus presented moderate activity against Candida albicans (ATCC 10231) with an MIC of 1000 μg/mL, a scavenging capacity SC₅₀ of 901 ± 20 µg/mL with the ABTS method, and very strong antiglucosidase activity with an IC₅₀ of 146 ± 20 µg/mL.     

Synthesis,antimicrobial activity and docking study of some novel 4-(4,4-dimethyl-2,6-dioxocyclohexylidene)methylamino derivatives carrying biologically active sulfonamide moiety

A new series of 4-((4,4-dimethyl-2,6-dioxocyclohexylidene)methylamino)-N-(substituted)benzenesulfonamide 3–17, monosubstituted 2-((4-((4-aminophenyl)sulfonyl)phenyl)amino)methylene 18, and its disubstituted derivative 19 were synthesized from the starting material 2-((dimethylamino)methylene)-5,5-dimethylcyclohexane-1,3-dione 2. The crystal structures of compounds 2, 7 and 13 were reported by us through X-ray crystallography. All the prepared compounds were evaluated for their antibacterial activity against Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, Clostridium sporogenes), Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli), and antifungal activity against Aspergillus fumigatus, Penicillium chrysogenum, Fusarium oxysporum, Candida albicans. The synthesized compounds displayed interesting antimicrobial activity. Compounds 4 and 12 were the most potent in this study and displayed higher activity compared to the reference drugs, with MIC value of 3.9–31.3 μg/mL against a panel of Gram-positive, Gram-negative bacteria and fungi. Molecular modeling was performed inside the active site of dihydropteroate synthase. The synthesized compounds showed similar orientation and binding interactions to that of the co-crystallized ligand inside the binding pocket.     

Chemical composition and antimicrobial activity of the essential oil of Anthemis altissima L. var. altissima

The essential oil obtained from the flowering parts of Anthemis altissima L. var. altissima was analysed by gas chromatography and gas chromatography mass spectroscopy. In this study, 34 compounds representing 98.76% of the essential oil were identified. The main components were α-terpineol (26.42%), β-pinene (9.23%), cis-chrysanthenyl acetate (6.30%), globulol (5.36%), n-tricosane (4.41%), terpinen-4-ol (4.08%) and 1,8 cineole (3.84%). Antibacterial activities of the essential oil and its two major components (α-terpineol and β-pinene) were determined using microdilution method against both Gram-positive (Staphylococcus aureus, Bacillus subtilis, Staphylococcus epidermidis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) bacteria. The essential oil showed a broad-spectrum antibacterial activity (MICs ranged from 3.13 to 6.25?μL?mL(-1)). It was found that α-terpineol with minimum inhibitory concentration (MIC) values of the range 0.87-1.56?μL?mL(-1) was a more potent antibacterial agent than β-pinene with MIC values of the range 1.56-6.25?μL?mL(-1). All of them, the essential oil, β-pinene and α-terpineol, were more effective against Gram-positive bacteria than Gram-negative ones.     

Phytochemical characterisation and bioprospection for antibacterial and antioxidant activities of Lippia alba Brown ex Britton & Wilson (Verbenaceae)

Ethanol extract and fractions obtained from fresh and dry aerial parts of Lippia alba were examined in order to determine their phytochemical composition, antioxidant capacity and antibacterial activities. The ethanol extracts and fractions exhibited an antioxidant effect by the DPPH assay, especially samples of fresh plant. HPLC analysis of the ethyl acetate fractions identified the presence of phenolic acids and flavonoids. The ethanol extract and fractions showed activity against reference and multidrug-resistant strains of Staphylococcus aureus and Enterococcus faecalis (MIC range 2000–250 μg/mL). The hexane and dichloromethane fractions of fresh plant showed better activity against reference strains of Escherichia coli (MIC of 250 and 125 μg/mL, respectively), but all extracts and fractions were less active against multidrug-resistant strains of all the Gram-negative species evaluated. The results showed that the extract and fractions of L alba aerial parts showed antibacterial activity, even against multidrug-resistant Gram-positive bacteria, and antioxidant effect (DPPH assay).     

Evaluation of resazurin microtiter plate assay and HPLC- photodiode array analysis of the roots of Asparagus adscendens

Asparagus adscendens Roxb. (Asparagaceae), is native to the Himalayas. The present study, for the first time, was undertaken to explore the antimicrobial potential, to determine the minimum inhibitory concentration (MIC) values of the methanol extract of the roots of A. adscendens and its solid-phase extraction (SPE) fractions using resazurin microtitre assay against Gram-positive and negative bacterial-registered strains and to carry out HPLC-photodiode array analysis of the SPE fractions. The methanol extract and all SPE exhibited considerable level of antibacterial potential against Gram-positive bacteria (MIC: 2.5–0.009 mg/mL) than against Gram-negative bacteria (MIC: 1.25–2.5 mg/mL). The use of microtitre plates has the advantage of lower cost, fast and quantitative results. Like other Asparagus species, the presence of phenolic compounds in all SPE fractions was evident in the HPLC-PDA data.     

The Antimicrobial Activity,Mosquito Larvicidal Activity,Antioxidant Property and Tyrosinase Inhibition of Piper Betle

The essential oil and methanolic and aqueous extracts of Piper betle L. were assayed for their antimicrobial activity, mosquito larvicidal activity, antioxidant property and mushroom tyrosinase inhibition. The methanolic and aquaous extracts showed strong activity against the yeasts: C. albicans, and M. pachydermatis. The crude essential oil exhibited a broad‐spectrum strong antimicrobial activity against all test organisms. The strongest activity was observed against C. albicans, followed by S. aureus and M. pachydermatis. The chemical composition of the essential oil and its fractions was analyzed by GC/MS analysis. Eugenol (36.2%), chavibetol acetate (16.9%), 4‐allylphenyl acetate (9.4%) and 4‐allylphenol (7.2%) were the main components, comprising 69.7% of the oil. The fractionation of the essential oil gave two fractions. Fraction I was rich in eugenol (71.3%) and fraction II in eugenol (46.4%), chavibetol acetate (19.4%) and 4‐allylphenyl acetate (11.8%). The essential oil exhibited the mosquito larvicidal activity with 2 h and 24 h LD₅₀ value of 86 and 48 ppm, respectively. The methanolic extract of P. betle showed larvicidal activity with 2 h and 24 h LD₅₀ value of 153 and 125 ppm, respectively, whereas the aqueous extract showed slight active. The individual antioxidant assays such as DPPH scavenging activity, chelating effect of ferrous ions and reducing power have been used. P. betle showed remarkable antioxidant activity in DPPH and reducing power assays. The activity observed can be attributed to the presence of the phenolic compounds. The essential oil exhibited concentration‐dependent inhibition of mushroom tyrosinase, giving an IC₅₀ value of 126 ppm. The fraction I showed a strong inhibition of tyrosinase activity, giving an IC₅₀ value of 115 ppm. The presence of 4‐allylphenolic components in the essential oil may play an important role in the inhibition of tyrosinase. In conclusion, the results presented here show that Piper betle essential oil could be considered as a natural antimicrobial, mosquito larvicidal, antioxidant and tyrosinase inhibition source.     

Phytochemistry,antioxidant and antibacterial activities of two Moroccan Teucrium polium L. subspecies: Preventive approach against nosocomial infections

The aim of the present study was to determine the chemical composition and antioxidant activity of essential oils (EOs) from two Teucrium polium subspecies, to evaluate, also their antibacterial activities, against some nosocomial-bacteria. The phytochemical screening of essential oils was analyzed using gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry analysis (GC-MS). The antibacterial activities were assessed by disc diffusion method and minimal inhibitory concentration (MIC), against Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Citrobacter koseri and Acinetobacter baumannii) and Gram-positive bacteria Staphylococcus aureus. The antioxidant potential was evaluated in vitro by three assays, namely free radical scavenging activity against 1,1-diphenyl-2-picrylhydrzyl (DPPH), ferric reducing activity power (FRAP) and total antioxidant capacity. Twenty-six components were identified in the EO of Teucrium polium subsp. aurum representing. Its major component was Caryophyllene (19.13%) followed by γ-Muurolene (13.02%), τ-cadinol, (11.01%), α-Gurjunene (9.2%), Rosifoliol (8.79%), 3-Carene (7.04%). However, twenty two components were identified in the EO of T. polium subsp. polium. Its major components are 3-carene (16.49%), γ-Muurolene (14.03%), α-pinene (9.94%), α-phellandrene (6.93%) and Caryophyllene (7.51%). The antibacterial activity of both essential oils showed a higher activity against tested nosocomial bacteria especially against S. aureus and A. baumannii. The EO of T. polium subsp. aureum showed better antioxidant activity as measured by DPPH and FRAP assays with IC₅₀ values of 3.7 ± 0.2 mg/ml and 2.31 ± 0.11 mg/ml, respectively. The total antioxidant capacity assay showed that T. polium subsp. aureum had a significant activity with value to 3308.27 mg equivalent to ascorbic acid/g of EO. The Moroccan T. polium essential oils could be exploited as an antimicrobial agent for the treatment of several infectious diseases caused by bacteria, especially, those who have developed resistance to conventional antibiotics.     

Novel illudalane sesquiterpenes from Encephalartos villosus Lehm. antimicrobial activity

Phytochemical investigation of Encephalartos villosus Lehm. leaves afford two new illudalane sesquiterpenes namely Encephaldiene 1 and Encephaldiene 2 together with four known flavone glycosides, Luteolin-7-rutinoside, Luteolin-7-glucoside, Luteolin-7-rhamnoside and Apigenin-7-glucoside. The structures of the isolated compounds were elucidated by means of spectroscopic methods including 1D and 2D NMR experiments along with HRESIMS spectrometry. Antimicrobial activity of CHCl₃ and MeOH extracts was investigated. Both extracts showed antibacterial activity against Gram-positive bacteria Streptococcus pneumonia and Bacillus subtilis, and antifungal activity against Aspergillus fumigatus. While CHCl₃ extract showed additional activity against Gram-negative bacteria Escherichia coli.     

Essential Oil Composition and Antibacterial Activity of the Leaves of <Emphasis Type="Italic">Stachys schtschegleevii</Emphasis> from Iran

The composition of the essential oil obtained by hydrodistillation from the leaves of Stachys schtschegleevii Sosn. before the flowering stage was analyzed by GC and GC-MS. Forty-five compounds representing 98.7% of the total oil were identified, of which α-pinene (36.4%), germacrene-D (18.6%), limonene (8.2%), and piperitone (6.2%) were the major constituents. Furthermore, antibacterial activity of the entire oil and its two main monoterpenes was evaluated against six Gram-positive and Gram-negative bacteria. The oil exhibited moderate activity against the tested bacteria.__________Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 138–140, March–April, 2005.     

Alaninyl variants of the marine natural product halocyamine A and their antibacterial properties

In an effort to explore the antibacterial potential of the marine natural product halocyamine A, a series of analogues including desbromo and alanine-substituted variants were synthesised and evaluated for biological activity against a panel of Gram-positive and –negative bacteria. The analogues were synthesised by a combination of solid-phase peptide synthesis and ruthenium complex/ytterbium triflate catalysed hydroamidation chemistry. Single alanine substitutions ([Ala¹]-halocyamine A and [Ala²]-halocyamine A) gave only modest increases in activity towards Gram-positive bacteria, while di-alaninyl variants exhibited more potent activity with MIC values of 12.5–50?μM towards the Gram-positive bacteria Staphylococcus aureus and Enterococcus faecalis. A lipophilic trityl-protected intermediate of [Ala²]-halocyamine was the most active against the Gram-negative bacterium Escherichia coli.     

Activity of Several Plant Extracts Against Drug-sensitive and Drug-resistant Microbes

The misused antimicrobial agents can lead to the emergence of antibiotic-resistant pathogens, fueling an ever-increasing need for new drugs. Chemical compounds in plants can act as a source of new antimicrobial. The activity of six plants had been studied on ten microbes by broth microdillution method. Time-kill test of ethanolic extract of Anredera cordifolia was performed against Bacillus subtilis, Escherichia coli, MRCNS, dan Pseudomonas aeruginosa. Time-kill test of ethanolic extract of Tinospora tuberculata was performed against MRCNS. The results showed that the minimum inhibitory concentrations (MIC) of ethanolic extracts were different for each microbe. Killing curve determination showed that ethanolic extract of A. cordifolia leaves and T. tuberculata stem could inhibit the growth of tested bacteria. The greatest inhibitory action was produced by Tinospora tuberculata and Zingiber officinale against Pseudomonas aeruginosa. Killing curve determination showed that ethanolic extract of A. cordifolia leaves and T. tuberculata stem had bacteriostatic effect against tested bacteria. T. tuberculata and A. cordifolia are potential to be developed as an antibacterial drug.     

Synthesis, characterization and antimicrobial activity of some new 1-(fluorobenzoyl)-3-(fluorophenyl)thioureas

Synthesis of a variety of new 1-(isomeric fluorobenzoyl)-3-(isomeric fluorophenyl)thioureas (1a-t) was accomplished in two steps. The synthetic route involves the reaction of equimolar quantities of isomeric fluorobenzoyl chlorides with potassium thiocyanate in anhydrous acetone to afford the corresponding isothiocyantes in situ, followed by treatment with equimolar quantities of isomeric fluoroanilines. All of the synthesized compounds (1a-t) were screened for their in vitro antibacterial activity using Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aureginosa). The minimum inhibitory concentration (MIC) was also determined for the most active compounds. In vitro antifungal activity was also determined against the five fungal species (Rhizopus oryzae, Aspergillus tereus, Fusarium oxysporum, Aspergillus niger, Aspergillus fumigatus). In general, the antifungal activity of compounds was better than their antibacterial activity.     

Synthesis of water soluble quaternary chitosan derivative via protection-deprotection strategy and investigation of its antibacterial effect

New water-soluble trimethyl quaternary derivative of chitosan was synthesized by a multi step processes through protection-deprotection strategy. This derivative was characterized using FTIR and ¹H NMR spectroscopy. Finally, the antibacterial effect of this derivative against Gram-negative (Escherichia coli and Salmonella typhimurium) and Gram-positive (Staphylococcus aureus and Staphylococcus epidermidis) bacteria in acidic and nutral medium was invetigated. The results of this study demonstrated that this chitosan derivative did not have antibacterial activity against Gram-negative bacteria; however, it showed a relatively good antibacterical effect against Gram-positive bacteria in both acidic and neutral mediums.