malek besbes - Academia.edu (original) (raw)
Papers by malek besbes
Letters in organic chemistry, Mar 14, 2024
Desalination and water treatment, 2024
Chemistry & Biodiversity, Apr 1, 2012
The essential oils isolated from three organs, i.e., fruits, stems and leaves, and flowers, of th... more The essential oils isolated from three organs, i.e., fruits, stems and leaves, and flowers, of the endemic North African plant Scabiosa arenaria Forssk. were screened for their chemical composition, as well as their possible antibacterial, anticandidal, and antifungal properties. According to the GC-FID and GC/MS analyses, 61 (99.26% of the total oil composition), 79 (98.43%), and 51 compounds (99.9%) were identified in the three oils, respectively. While α-thujone (34.39%), camphor (17.48%), and β-thujone (15.29%) constituted the major compounds of the fruit oil, chrysanthenone (23.43%), together with camphor (12.98%) and α-thujone (10.7%), were the main constituents of the stem and leaf oil. In the case of the flower oil, also chrysanthenone (38.52%), camphor (11.75%), and α-thujone (9.5%) were identified as the major compounds. Furthermore, the isolated oils were tested against 16 Gram-positive and Gram-negative bacteria, four Candida species, and nine phytopathogenic fungal strains. It was found that the oils exhibited interesting antibacterial and anticandidal activities, comparable to those of thymol, which was used as positive control, but no activity against the phytopathogenic fungal strains was observed.
Journal of Oleo Science, 2016
The chemical composition, cytotoxic and antibacterial activities of the hydrodistilled essential ... more The chemical composition, cytotoxic and antibacterial activities of the hydrodistilled essential oil of the aerial parts of Ononis angustissima from south Tunisia has been evaluated. The oil yield was 0.04% (w/w). The chemical composition, determined by GC and GC-MS is reported for the first time. Forty-five components, accounting for 93.7% of the total oil have been identified. The oil was characterized by a high proportion of oxygenated sesquiterpenes (33.2%), followed by sesquiterpene hydrocarbons (6.3%) and apocarotenoids (10.3%). The main components of the oil were α-eudesmol (22.4%), 2-tridecanone (9.3%) and acetophenone (7.4%). The essential oil was tested for its possible cytotoxic activity towards the human cervical cell line HeLa using the MTT assay and the antibacterial activity against Pseudomonas aeruginosa, Escherichia coli, Enterococcus faecalis, Staphylococcus aureus and the clinical strain Acinetobacter sp. This oil exerted a cytotoxic activity with an IC 50 of 0.53 ± 0.02 mg/mL and a significant antibacterial effect against P. aeruginosa and E. faecalis.
Plants
Catalase (CAT) is an antioxidant enzyme expressed by the CAT gene family and exists in almost all... more Catalase (CAT) is an antioxidant enzyme expressed by the CAT gene family and exists in almost all aerobic organisms. In fact, the CAT enzyme modulates the hydrogen peroxide (H2O2) contents in cells by translating this toxic compound into water (H2O) and O2− to reduce reactive oxygen species (ROS) contents in cells. ROS are produced as a result of biotic and abiotic environmental stressors. To avoid ROS toxicity, plants are armed with different enzymatic and non-enzymatic systems to decompose ROS. Among the enzymatic system, CAT proteins are well studied. CAT not only controls growth and development in plants but is also involved in plant defense against different stresses. So far, the CAT gene family has not been reported in durum wheat (Triticum turgidum ssp. durum L.). Therefore, a genome-wide comprehensive analysis was conducted to classify the CAT genes in the durum wheat genome. Here, six TdCAT genes were identified. Based on phylogenetics, the TdCAT genes belong to three group...
Plants
Pathogen-related proteins (PRs) are diversified proteins with a low molecular weight implicated i... more Pathogen-related proteins (PRs) are diversified proteins with a low molecular weight implicated in plant response to biotic and abiotic stress as well in regulating different functions in plant maturation. Interestingly, no systematical study has been conducted in durum wheat (Triticum turgidum subsp. durum). In the present study, 12 PR-1 genes encoding a CAP superfamily domain were identified in the genome of Triticum turgidum subsp. durum, which is an important cereal, using in silico approaches. Additionally, phylogenetic analysis showed that the PR-1 genes were classified into three groups based on their isoelectric point and the conserved motif domain. Moreover, our analysis showed that most of the TdPR-1 proteins presented an N-terminal signal peptide. Expression patterns analysis showed that the PR-1 gene family presented temporal and spatial specificity and was induced by different abiotic stresses. This is the first report describing the genome-scale analysis of the durum w...
Antioxidants
Catalase is a crucial enzyme in antioxidant defense systems protecting eukaryotes from oxidative ... more Catalase is a crucial enzyme in antioxidant defense systems protecting eukaryotes from oxidative stress. These proteins are present in almost all living organisms and play important roles in controlling plant responses to biotic and abiotic stresses by catalyzing the decomposition of H2O2. Despite their importance, little is known about their expression in the majority of monocotyledonous species. Here, we isolated and characterized two novel catalase genes from Triticum turgidum and Hordeum vulgare, designated as TtCAT1 and HvCAT1, respectively. Phylogenetic analysis revealed that TtCAT1 and HvCAT1 presented 492 aa and shared an important identity with other catalase proteins belonging to subfamily 1. Using bioinformatic analysis, we predicted the 3D structure models of TtCAT1 and HvCAT1. Interestingly, analysis showed that the novel catalases harbor a peroxisomal targeting signal (PTS1) located at their C-terminus portion, as shown for other catalase proteins. In addition, this mo...
Antioxidants
Catalase is a crucial enzyme in the antioxidant defense system protecting organisms from oxidativ... more Catalase is a crucial enzyme in the antioxidant defense system protecting organisms from oxidative stress. Proteins of this kind play important roles in controlling plant response to biotic and abiotic stresses by catalyzing the decomposition of H2O2. The durum wheat catalase 1, TdCAT1, has been previously isolated and characterized. Here, using bio-informatic analysis, we showed that durum wheat catalase 1 TdCAT1 harbors different novel conserved domains. In addition, TdCAT1 contains various phosphorylation residues and S-Nitrosylation residues located at different positions along the protein sequence. TdCAT1 activity decreased after treatment with λ−phosphatase. On the other hand, we showed that durum wheat catalase 1 (TdCAT1) exhibits a low CAT activity in vitro, whereas a deleted form of TdCAT1 has better activity compared to the full-length protein (TdCAT460), suggesting that TdCAT1 could present a putative autoinhibitory domain in its C-terminal portion. Moreover, we showed th...
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](Mediterranean Journal of Chemistry, 2014
Medicinal Chemistry Research, 2014
ABSTRACT Phosphorus-heterocycles are of great interest for the discovery of potent bioactive agen... more ABSTRACT Phosphorus-heterocycles are of great interest for the discovery of potent bioactive agents. This study reports the synthesis of a new category of oxthiazaphosphinines 3a-d + 3′a-d, oxazaphosphorines 4a-d, and azaphosphinines 5a-d incorporated with thiocoumarin by cyclocondensation reactions of Lawesson’s reagent with bifunctional compounds 2a-d containing mobile hydrogens. The newly synthesized compounds were established by spectroscopic methods (1D, 2D NMR, and HRMS) and screened for acetylcholinesterase inhibition. Among these, the mixture 3d + 3′d has shown a significant anti-AChE activity comparable to that of malathion (IC50 = 52.63 ± 0.1 µg/mL and IC50 = 49.5 ± 0.01 µg/mL), respectively.
Arabian Journal of Chemistry, 2013
New lupeol long-chain alkanoic ester 1 and lupeol b-hydroxy fatty acid esters 2c,d (laevigatins I... more New lupeol long-chain alkanoic ester 1 and lupeol b-hydroxy fatty acid esters 2c,d (laevigatins I and II) in a mixture with the previously isolated procrims a and b (2a,b) were isolated together with lupeol 3 and lupeol acetate 4 from the latex of Periploca laevigata collected in Tunisia. Their structures were elucidated by extensive spectroscopic methods including 1D (1 H, 13 C and DEPT 135), 2D-NMR experiments, (1 H-1 H COSY and NOESY), EI-MS, MALDI-TOF and GC analysis. Anti-acetylcholinesterase activity of most isolated compounds was evaluated and showed that lupeol (3) was the best inhibitor of AChE.
Mediterranean Journal of Chemistry, 2011
acetylcholinesterase properties of the aerial parts and roots essential oils from Crithmum mariti... more acetylcholinesterase properties of the aerial parts and roots essential oils from Crithmum maritimum L., Apiaceae, gathered in the area of Monastir (Tunisia). The essential oils have been analysed by GC and GC-MS. Remarkable differences were found between the constituent percentages of the different studied organs. The most important compounds from the aerial parts were: γ-terpinene (39.3%), methylcarvacrol (21.6%) and p-cymene (11.8%). In the roots oil, the main components were terpinolene (36.9%), dillapiole (26.8%) and γ-terpinene (21.9%). The antioxidant activity of the two oils was evaluated by employing 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging tests. The results showed that the antioxidant capacity assessed by different in vitro tests were moderate, the ABTS assay after 20 min (IC 50 = 0.051 mg/mL) of aerial parts and (IC 50 = 0.643 mg/mL) of the roots, appeared to be more potent than that for the DPPH assay (IC 50 = 0.92 mg/mL) of aerial parts and (IC 50 = 0.048 mg/mL) of roots. In addition, the examined oils showed the highest AchE inhibitory 1 mg/mL activity (31.16% and 26.35%, for the aerial parts and roots, respectively).
Industrial Crops and Products
tThe essential oil (EO) from leaves of Eugenia calycina Cambess. was analysed by Gas Chromatograp... more tThe essential oil (EO) from leaves of Eugenia calycina Cambess. was analysed by Gas Chromatography cou-pled to Mass Spectrometry (GC–MS). Thirty-nine compounds accounting for 88.09% of the EO compositionwere identified. The EO was rich in sesquiterpene hydrocarbons and oxygenated sesquiterpenes, and themajor components were spathulenol (21.36%), bicyclogermacrene (19.30%), �-caryophyllene (8.57%),viridiflorol (3.43%), allo-aromadendrene (3.34%), and a mixture of the caryophyllene oxide, gleenol,and globulol (7.71%). The EO was fractioned in four fractions and the first fraction (F1) contained onlysesquiterpene hydrocarbons; the second one (F2) contained one sesquiterpene hydrocarbon (1.95%) and96.98% of oxygenated sesquiterpenes; and the other fractions (F3 and F4) contained mostly oxygenatedsesquiterpenes. The antimicrobial activity of the EO and its fractions were evaluated against aerobic andanaerobic oral bacteria by microdilution method. The EO showed strong antimicrobial acti...
Asian Pacific Journal of Tropical Medicine
Letters in organic chemistry, Mar 14, 2024
Desalination and water treatment, 2024
Chemistry & Biodiversity, Apr 1, 2012
The essential oils isolated from three organs, i.e., fruits, stems and leaves, and flowers, of th... more The essential oils isolated from three organs, i.e., fruits, stems and leaves, and flowers, of the endemic North African plant Scabiosa arenaria Forssk. were screened for their chemical composition, as well as their possible antibacterial, anticandidal, and antifungal properties. According to the GC-FID and GC/MS analyses, 61 (99.26% of the total oil composition), 79 (98.43%), and 51 compounds (99.9%) were identified in the three oils, respectively. While α-thujone (34.39%), camphor (17.48%), and β-thujone (15.29%) constituted the major compounds of the fruit oil, chrysanthenone (23.43%), together with camphor (12.98%) and α-thujone (10.7%), were the main constituents of the stem and leaf oil. In the case of the flower oil, also chrysanthenone (38.52%), camphor (11.75%), and α-thujone (9.5%) were identified as the major compounds. Furthermore, the isolated oils were tested against 16 Gram-positive and Gram-negative bacteria, four Candida species, and nine phytopathogenic fungal strains. It was found that the oils exhibited interesting antibacterial and anticandidal activities, comparable to those of thymol, which was used as positive control, but no activity against the phytopathogenic fungal strains was observed.
Journal of Oleo Science, 2016
The chemical composition, cytotoxic and antibacterial activities of the hydrodistilled essential ... more The chemical composition, cytotoxic and antibacterial activities of the hydrodistilled essential oil of the aerial parts of Ononis angustissima from south Tunisia has been evaluated. The oil yield was 0.04% (w/w). The chemical composition, determined by GC and GC-MS is reported for the first time. Forty-five components, accounting for 93.7% of the total oil have been identified. The oil was characterized by a high proportion of oxygenated sesquiterpenes (33.2%), followed by sesquiterpene hydrocarbons (6.3%) and apocarotenoids (10.3%). The main components of the oil were α-eudesmol (22.4%), 2-tridecanone (9.3%) and acetophenone (7.4%). The essential oil was tested for its possible cytotoxic activity towards the human cervical cell line HeLa using the MTT assay and the antibacterial activity against Pseudomonas aeruginosa, Escherichia coli, Enterococcus faecalis, Staphylococcus aureus and the clinical strain Acinetobacter sp. This oil exerted a cytotoxic activity with an IC 50 of 0.53 ± 0.02 mg/mL and a significant antibacterial effect against P. aeruginosa and E. faecalis.
Plants
Catalase (CAT) is an antioxidant enzyme expressed by the CAT gene family and exists in almost all... more Catalase (CAT) is an antioxidant enzyme expressed by the CAT gene family and exists in almost all aerobic organisms. In fact, the CAT enzyme modulates the hydrogen peroxide (H2O2) contents in cells by translating this toxic compound into water (H2O) and O2− to reduce reactive oxygen species (ROS) contents in cells. ROS are produced as a result of biotic and abiotic environmental stressors. To avoid ROS toxicity, plants are armed with different enzymatic and non-enzymatic systems to decompose ROS. Among the enzymatic system, CAT proteins are well studied. CAT not only controls growth and development in plants but is also involved in plant defense against different stresses. So far, the CAT gene family has not been reported in durum wheat (Triticum turgidum ssp. durum L.). Therefore, a genome-wide comprehensive analysis was conducted to classify the CAT genes in the durum wheat genome. Here, six TdCAT genes were identified. Based on phylogenetics, the TdCAT genes belong to three group...
Plants
Pathogen-related proteins (PRs) are diversified proteins with a low molecular weight implicated i... more Pathogen-related proteins (PRs) are diversified proteins with a low molecular weight implicated in plant response to biotic and abiotic stress as well in regulating different functions in plant maturation. Interestingly, no systematical study has been conducted in durum wheat (Triticum turgidum subsp. durum). In the present study, 12 PR-1 genes encoding a CAP superfamily domain were identified in the genome of Triticum turgidum subsp. durum, which is an important cereal, using in silico approaches. Additionally, phylogenetic analysis showed that the PR-1 genes were classified into three groups based on their isoelectric point and the conserved motif domain. Moreover, our analysis showed that most of the TdPR-1 proteins presented an N-terminal signal peptide. Expression patterns analysis showed that the PR-1 gene family presented temporal and spatial specificity and was induced by different abiotic stresses. This is the first report describing the genome-scale analysis of the durum w...
Antioxidants
Catalase is a crucial enzyme in antioxidant defense systems protecting eukaryotes from oxidative ... more Catalase is a crucial enzyme in antioxidant defense systems protecting eukaryotes from oxidative stress. These proteins are present in almost all living organisms and play important roles in controlling plant responses to biotic and abiotic stresses by catalyzing the decomposition of H2O2. Despite their importance, little is known about their expression in the majority of monocotyledonous species. Here, we isolated and characterized two novel catalase genes from Triticum turgidum and Hordeum vulgare, designated as TtCAT1 and HvCAT1, respectively. Phylogenetic analysis revealed that TtCAT1 and HvCAT1 presented 492 aa and shared an important identity with other catalase proteins belonging to subfamily 1. Using bioinformatic analysis, we predicted the 3D structure models of TtCAT1 and HvCAT1. Interestingly, analysis showed that the novel catalases harbor a peroxisomal targeting signal (PTS1) located at their C-terminus portion, as shown for other catalase proteins. In addition, this mo...
Antioxidants
Catalase is a crucial enzyme in the antioxidant defense system protecting organisms from oxidativ... more Catalase is a crucial enzyme in the antioxidant defense system protecting organisms from oxidative stress. Proteins of this kind play important roles in controlling plant response to biotic and abiotic stresses by catalyzing the decomposition of H2O2. The durum wheat catalase 1, TdCAT1, has been previously isolated and characterized. Here, using bio-informatic analysis, we showed that durum wheat catalase 1 TdCAT1 harbors different novel conserved domains. In addition, TdCAT1 contains various phosphorylation residues and S-Nitrosylation residues located at different positions along the protein sequence. TdCAT1 activity decreased after treatment with λ−phosphatase. On the other hand, we showed that durum wheat catalase 1 (TdCAT1) exhibits a low CAT activity in vitro, whereas a deleted form of TdCAT1 has better activity compared to the full-length protein (TdCAT460), suggesting that TdCAT1 could present a putative autoinhibitory domain in its C-terminal portion. Moreover, we showed th...
Mediterranean Journal of Chemistry, 2014
Medicinal Chemistry Research, 2014
ABSTRACT Phosphorus-heterocycles are of great interest for the discovery of potent bioactive agen... more ABSTRACT Phosphorus-heterocycles are of great interest for the discovery of potent bioactive agents. This study reports the synthesis of a new category of oxthiazaphosphinines 3a-d + 3′a-d, oxazaphosphorines 4a-d, and azaphosphinines 5a-d incorporated with thiocoumarin by cyclocondensation reactions of Lawesson’s reagent with bifunctional compounds 2a-d containing mobile hydrogens. The newly synthesized compounds were established by spectroscopic methods (1D, 2D NMR, and HRMS) and screened for acetylcholinesterase inhibition. Among these, the mixture 3d + 3′d has shown a significant anti-AChE activity comparable to that of malathion (IC50 = 52.63 ± 0.1 µg/mL and IC50 = 49.5 ± 0.01 µg/mL), respectively.
Arabian Journal of Chemistry, 2013
New lupeol long-chain alkanoic ester 1 and lupeol b-hydroxy fatty acid esters 2c,d (laevigatins I... more New lupeol long-chain alkanoic ester 1 and lupeol b-hydroxy fatty acid esters 2c,d (laevigatins I and II) in a mixture with the previously isolated procrims a and b (2a,b) were isolated together with lupeol 3 and lupeol acetate 4 from the latex of Periploca laevigata collected in Tunisia. Their structures were elucidated by extensive spectroscopic methods including 1D (1 H, 13 C and DEPT 135), 2D-NMR experiments, (1 H-1 H COSY and NOESY), EI-MS, MALDI-TOF and GC analysis. Anti-acetylcholinesterase activity of most isolated compounds was evaluated and showed that lupeol (3) was the best inhibitor of AChE.
Mediterranean Journal of Chemistry, 2011
acetylcholinesterase properties of the aerial parts and roots essential oils from Crithmum mariti... more acetylcholinesterase properties of the aerial parts and roots essential oils from Crithmum maritimum L., Apiaceae, gathered in the area of Monastir (Tunisia). The essential oils have been analysed by GC and GC-MS. Remarkable differences were found between the constituent percentages of the different studied organs. The most important compounds from the aerial parts were: γ-terpinene (39.3%), methylcarvacrol (21.6%) and p-cymene (11.8%). In the roots oil, the main components were terpinolene (36.9%), dillapiole (26.8%) and γ-terpinene (21.9%). The antioxidant activity of the two oils was evaluated by employing 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging tests. The results showed that the antioxidant capacity assessed by different in vitro tests were moderate, the ABTS assay after 20 min (IC 50 = 0.051 mg/mL) of aerial parts and (IC 50 = 0.643 mg/mL) of the roots, appeared to be more potent than that for the DPPH assay (IC 50 = 0.92 mg/mL) of aerial parts and (IC 50 = 0.048 mg/mL) of roots. In addition, the examined oils showed the highest AchE inhibitory 1 mg/mL activity (31.16% and 26.35%, for the aerial parts and roots, respectively).
Industrial Crops and Products
tThe essential oil (EO) from leaves of Eugenia calycina Cambess. was analysed by Gas Chromatograp... more tThe essential oil (EO) from leaves of Eugenia calycina Cambess. was analysed by Gas Chromatography cou-pled to Mass Spectrometry (GC–MS). Thirty-nine compounds accounting for 88.09% of the EO compositionwere identified. The EO was rich in sesquiterpene hydrocarbons and oxygenated sesquiterpenes, and themajor components were spathulenol (21.36%), bicyclogermacrene (19.30%), �-caryophyllene (8.57%),viridiflorol (3.43%), allo-aromadendrene (3.34%), and a mixture of the caryophyllene oxide, gleenol,and globulol (7.71%). The EO was fractioned in four fractions and the first fraction (F1) contained onlysesquiterpene hydrocarbons; the second one (F2) contained one sesquiterpene hydrocarbon (1.95%) and96.98% of oxygenated sesquiterpenes; and the other fractions (F3 and F4) contained mostly oxygenatedsesquiterpenes. The antimicrobial activity of the EO and its fractions were evaluated against aerobic andanaerobic oral bacteria by microdilution method. The EO showed strong antimicrobial acti...
Asian Pacific Journal of Tropical Medicine