This work aims to elucidate the chemical composition of two essential oil (EO) samples obtained from the leaves of Thymus vulgaris L. (Lamiaceae) collected in two regions of Northwestern Algeria (Tlemcen and Mostaganem) and to assess their in vivo acute toxicity and anti-inflammatory activity. Sixty-six compounds could be identified by means of simultaneous GC-FID and GC-MS, accounting for 99.3% of total thyme oil of Mostaganem (EO.TM) and 99.0% of Tlemcen (EO.TT). In both samples, thymol was the major component, amounting to 59.5% (EO.TM) and 67.3% (EO.TT) of the total oil. EO.TT proved to be acutely toxic to mice at a dose of 4500 mg/kg p.o., whereas EO.TM did not show signs of acute toxicity, even at the highest dose tested (5000 mg/kg p.o.). Both EO samples were proven to possess anti-inflammatory activities, significantly reducing carrageenan-induced paw edema in mice (after 6 hours at a dose of 400 mg/kg p.o) at 58.4% for EO.TT and 50.4% for EO.TM, respectively. In conclusion, it could be demonstrated that EOs of T. vulgaris exhibit a considerable in vivo anti-inflammatory activity at non-toxic doses.

The essential oils (EOs) obtained by steam distillation from the leaves and the berries of Juniperus phoenicea L., harvested in northwest of Algeria were analyzed and their antimicrobial and anti-inflammatory activities were assessed. 63, 46 and 78 volatile compounds were identified by GC-FID and GC-MS from fresh leaves, dried leaves and berries representing 98.1%, 98.3% and 96.4% of the total oil, respectively. The fresh and dried leaves oils were mainly composed of β-phellandrene (43.9% / 44.9%), α-pinene (25.1% / 20.3%), myrcene (8.5% / 8.2%), α-phellandrene (4.7% / 4.5%) p-cymene (2.7%-3.0%) and limonene (2.3%-2.5%) whereas, the berries oil was mainly composed of α-pinene (43.7%), p-cymene (5.8%), β-phellandrene (4.6%), α-terpineol (4.3%) and α-campholenal (4.0%). The study of the antimicrobial activity showed that the 3 EOs were effective only on B. cereus ATCC 10876 and C. albicans ATCC 10231. No signs of acute toxicity have been noted in mice even at the highest dose tested (5000 mg/kg p.o). The fresh leaves, dried leaves and berries oils reduced the carrageenan-induced paw edema in mice by 16.8%, 15.2% and 6.4%, respectively, after 6 hours at a dose of 400 mg/kg p.o.

This study describes the chemical composition and antibacterial activities of essential oils of Moroccan Juniperus thurifera L. var. Africana (Cupressaceae). The essential oil of dried leaves was isolated by hydrodistillation, vapohydrodistillation and microwaves. Sixty-four compounds in J. thurifera L. var. Africana oils were identified (79.9%, 92.4% and 98.4% of the oil, respectively). The most abundant compound in J. thurifera L. var. Africana oils is sabinene (38%, 36.2% and 39.4%). Antibacterial activities of J. thurifera essential oils was tested against bacteria Gram ( - ) and Gram (+). The oil is very active against all bacteria tested except Pseudomonas, which turned out to be very resistant.

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The aim of this work was the examination of biological activity of three selected racemic cis-β-aryl-δ-iodo-γ-lactones. Tested iodolactones differed in the structure of the aromatic fragment of molecule, bearing isopropyl (1), methyl (2), or no substituent (3) on the para position of the benzene ring. A broad spectrum of biological activity as antimicrobial, antiviral, antitumor, cytotoxic, antioxidant, and hemolytic activity was examined. All iodolactones showed bactericidal activity against Proteus mirabilis, and lactones 1,2 were active against Bacillus cereus. The highest cytotoxic activity towards HeLa and MCF7 cancer cell lines and NHDF normal cell line was found for lactone 1. All assessed lactones significantly disrupted antioxidative/oxidative balance of the NHDF, and the most harmful effect was determined by lactone 1. Contrary to lactone 1, lactones 2 and 3 did not induce the hemolysis of erythrocytes after 48 h of incubation. The differences in activity of iodolactones 1–3 in biological tests may be explained by their different impact on physicochemical properties of membrane as the packing order in the hydrophilic area and fluidity of hydrocarbon chains. This was dependent on the presence and type of alkyl substituent. The highest effect on the membrane organization was observed for lactone 1 due to the presence of bulky isopropyl group on the benzene ring.

Antimicrobial drugs are highly popular in the treatment of infectious diseases and particularly nosocomial infections. However, excessive microbial exposure to drugs has become the most important factor triggering the emergence and spread of multidrug resistance (MDR) of microorganisms (1). This phenomenon has become a pressing global problem for two reasons. Firstly, it increases morbidity and mortality rates and treatment costs. Secondly, it limits the effectiveness of existing drugs and enhances the number of treatment failures (2). Furthermore, in the last few decades, cancer has become one of the most fiercely combated diseases around the world (3). Synthetic drugs are often the only option for cancer chemotherapy (4). However, most of them kill not only tumor cells but also the normal ones (5). Therefore, there is an urgent need for new treatments with few side effects. The use of medicinal plants and especially their secondary metabolites, essential oils (EOs), may pose a viable alternative. Thymus vulgaris L., known as common thyme (Lamiaceae family), is a perennial herb indigenous to the Mediterranean region, Asia, Southern Europe and North Africa (6). It is widely used in folk medicine and also in the food industry as a spice and natural preservative. Its oil is among the top 10 EOs exhibiting various biological activities (7) mainly due to phenols, e.g. thymol and carvacrol (8). This considerable potential of thyme oil encouraged us to analyze its chemical structure by GC-FID and GC-MS and verify its antimicrobial activity against seven reference strains responsible for nosocomial infections. We also assessed its cyto

The essential oils of Juniperus phoenicea L. from Algeria were obtained by hydrodistillation and analyzed by GC-FID and GC-MS. Concerning their chemical composition, 74, 61 and 72 volatile compounds were identified from fresh leaves, dried leaves and berries, representing 88.8%, 91.3% and 94.7% of the total composition, respectively. The main monoterpene in the oils of fresh leaves, dried leaves and berries was α-pinene (29.6% / 55.9% / 56.6%), accompanied by lesser amounts of the sesquiterpenes β-caryophyllene (2.6% / 1.6% /1.2%) and germacrene D (2.01% / 1.7% / 1.5%), respectively. Antibacterial activity of J. phoenicea essential oils was tested against one Gram-negative and four Gram-positive bacterial strains and the yeast Candida albicans, responsible for nosocomial infections. As references, 14 antibiotics and 5 antifungal agents were evaluated. The berry essential oil was ineffective against all but two of the strains tested, whereas the essential oil of dried leaves significantly inhibited all strains but Pseudomonas aeruginosa, which turned out to be the most resistant strain overall. However, Escherichia coli was the most susceptible to the essential oils tested. The essential oil of dry leaves was highly active against Candida albicans, outclassing even the standard antifungal substances. These promising results could substantiate the use of essential oils in the treatment of hospital-acquired infections.

Starting from 1-acetyl-1-cyclohexene, three enantiomeric pairs (ee ≥ 99%) of bicyclic δ-halo-γ-lactones with cyclohexane ring were obtained in five-step synthesis. The key stereochemical steps were lipase-catalyzed kinetic resolution of racemic 1-(cyclohex-1-en-1-yl) ethanol followed by transfer of chirality to ethyl 2-(2-ethylidenecyclohexyl) acetate in the Johnson–Claisen rearrangement. Synthesized halolactones exhibited antiproliferative activity towards canine B-cell leukemia cells (GL-1) and canine B-cell chronic leukemia cells (CLB70) and the most potent (IC50 18.43 ± 1.46 μg/mL against GL-1, IC50 11.40 ± 0.40 μg/mL against CLB70) comparable with the control etoposide, was (1R,6R,1′S)-1-(1′-chloroethyl)-9-oxabicyclo[4.3.0]nonan-8-one (8b). All halolactones did not have a toxic effect on erythrocytes and did not change the fluidity of membranes in the hydrophobic region of the lipid bilayer. Only weak changes in the hydrophilic area were observed, like the degree of lipid packing and associated hydration. The racemic halolactones were also tested for their antimicrobial properties and found to exhibit selectivity towards bacteria, in particular, towards Proteus mirabilis ATCC 35659.