Damak Mohamed

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• Professor Emerite
• Professor at University of Sfax

Objective To investigate the potential of anemonin and Clematis flammula (C. flammula) extracts against infective organisms. Methods The molluscicidal activities of anemonin and C. flammula extracts against Galba truncatula Müll. (Lymnaeidae) and Fasciola hepatica larval stages contaminating this snail in Tunisia were assessed by testing six group...

Background: The molluscicidal and larvicidal activities of the medicinal plant Citrullus colocynthis leaf extracts and its main cucurbitacins were tested against the mollusc gastropod, Galba truncatula, the intermediate host of Fasciola hepatica. Results: Our findings proved for the first time that the molluscicidal activity was correlated with...

Context: Despite some studies related to Juniperus phoenicea L. (Cupressaceae), phytochemical and biological investigations of this plant remain unexplored. Objective: This work is the first report dealing with the identification and characterization of volatile components and flavonoids in hexane and methanol extracts from J. phoenicea leaves Mate...

Context: Despite some studies related to Juniperus phoenicea L. (Cupressaceae), phytochemical and biological investigations of this plant remain unexplored. Objective: This work is the first report dealing with the identification and characterization of volatile components and flavonoids in hexane and methanol extracts from J. phoenicea leaves Mate...

The aim of the present study was to investigate the antioxidant, anti-diabetic, antiobesity and anti-bacterial activities and the chemical composition of essential oil of Zygophyllum album leaves (Zygophyllaceae) harvested from Douz (Tunisia). GC–MS analysis of essential oil of Z. album resulted in the identification of nineteen compounds represent...

The hexane extract of Echinops spinosissimus Turra subsp. spinosus flower heads was analyzed for its fatty acid and sterol composition. Its physicochemical characteristics were also studied. The saponification, iodine and peroxide values were determined as 255 mg KOH/g, 42.57 g I2 /100g and 110 mequiv.O2 /kg of oil, respectively. The oleic (C18:1;...

Renoprotective effect of Hammada scoparia extracts was evaluated in Wistar albino rats which were distributed into five groups of six animals each. Three groups were treated simultaneously with ethanol 35% (4 g/kg) and plant extracts for 4 weeks. Other animals (EtOH) were given ethanol alone, and the control received 0.9% NaCl. The results showed t...

Fasciolose é uma parasitose generalizada que ocorre em animais de fazendas em muitos países em desenvolvimento. Por esta razão, é necessária a busca de novas substâncias contra as doenças parasitárias causadas por vermes. De fato, uma grande variedade de plantas terrestres foi objeto de testes farmacológicos e químicos a fim de descobrir o seu pote...

Context: The persistence of fascioliasis in many developing countries urges the search for simple, cheap, and effective substances. In this view, plants provide interesting molluscicidal activities thanks to the secondary metabolites they produce. The genus Solanum is known for its potent effect on vector snails. Objective: The molluscicidal act...

Objective: Fascioliasis caused by Fasciola hepatica L. (Fasciolidae), a digenetic trematode, is a parasitic disease infecting many people worldwide. The present study was carried out to evaluate the molluscicidal and larvicidal activities of Capparis spinosa L. (Capparaceae) aerial parts against Galba truncatula Müll. (Lymnaeidae) and Fasciola hepa...

This paper describes the synthesis of a series of dihydroisoquinoline nitrones by isomerization of the corresponding oxaziridines. Nitrones 4a-c were obtained in excellent yields and high purity by a simple and effective method from the isomerization of oxaziridines. The synthesized compounds were also evaluated for their antibacterial activity aga...

In this study, we investigated the protective effects of Peganum harmala seeds extract (CPH) against chronic ethanol treatment. Hepatotoxicity was induced in male Wistar rats by administrating ethanol 35% (4 g/kg/day) for 6 weeks. CPH was co-administered with ethanol, by intraperitonial (IP) injection, at a dose of 10 mg/kg bw/day. Control rats wer...

Ceratonia siliqua is a typical plant of the Mediterranean area, which is mainly used as animal and human food and in folk medicine for treating some diseases such as antidiarrheal and diuretic. The present study was planned to evaluate the potential of antimicrobial and antioxidant activities of C. siliqua leaves extract and the identification of b...

One new sesquiterpenoid (5R*,8R*,9R*,10R*)-cinnamolide (8), and seven known compounds, 5-hydroxy-7-methoxyflavonone (1), 8-hydroxy-3-(40-hydroxyphenyl)- 6,7-(200,200-dimethylchromene)-tetralone (2), 8-hydroxy-3-(30,40-dihydroxyphenyl)- 6,7-(200,200-dimethylchromene)-tetralone (3), 1b-E-O-p-methoxycinnamoyl-bemadienolide (4), 1b-O-(E-cinnamoyl)-6a-h...

The aim of this study was to screen various solvent extracts of seeds of Solanum elaeagnifolium to display the phytochemical composition, the total phenolic content, the total flavonoid content and the antioxidant capacity in order to find possible sources for future novel antioxidants in food and pharmaceutical formulations. Various extracts of...

Diabetes mellitus is a serious health problem worldwide that has adverse and long-lasting consequences for individuals, families, and communities. Hence, this study sought to investigate the inhibitory potential of rosemary extracts on key-enzymes related to diabetes such as α-amylase and pancreatic lipase activities, as well as to assess their ant...

Objective: To examine chemical composition and antioxidant activity as well as the in vitro α-amylase and pancreatic lipase inhibitory activities of the essential oil and various extracts of Juniperus phoenicea (J. phoenicea). Methods: Essential oil obtained by steam distillation were analyzed by mass spectrometry technique. The antioxidant activit...

The antioxidant efficacy of basil extracts was estimated in stabilization of sunflower oil. The basil essential oil was analyzed by gas chromatography–mass spectrometry. Twenty-two compounds were identified representing 93.74% of the total essential oil. Basil methanolic extract was thermally evaluated by heating at 185°C. At the 100 min heating ti...

The aim of this study was to screen various solvent extracts of seeds of Solanum elaeagnifolium to display the phytochemical composition, the total phenolic content, the total flavonoid content and the antioxidant capacity in order to find possible sources for future novel antioxidants in food and pharmaceutical formulations. Various extracts of se...

A strain of Bacillus licheniformis with high exopolysaccharide (EPS) production ability was isolated and identified. A new type of EPS was isolated from the strain fermentation and its structural characteristics were investigated and elucidated by partial and total acid hydrolysis, Fourier transform infrared, and (1)H and (13)C NMR spectroscopy inc...

The physico-chemical characteristics and the fatty acid, sterol and triacylglycerol compositions of oil extracted from Solanum elaeagnifolium seeds were determined in this study. The percentage yield of the oil was calculated as 3%. The saponification value (226.15mg KOH g-1), iodine value (149.1 g/100 g of oil), peroxide value (61.87 mequiv.O2/kg)...

The reaction of 3,3-dimethyl-7-nitro-3,4-dihydroisoquinoline 1 with m-chloroperbenzoic acid (m-CPBA) mainly yielded oxaziridine and nitrone, with their selectivities being dependent on the solvents. The reaction with 2.5 equivalents of m-CPBA gave small amounts of oxaziridines and hydroxamic acids as well as isolated O-acylhydroxamate compounds.

Purification of the ethyl acetate extract of the Olea europea stem led to the isolation and characterization of two triterpenes: the known compound oleanolic acid and the new triterpene oleanolic acid demethyl. Their structures were determined by various spectroscopic techniques (NMR 1H, 13C, DEPT, HMQC, HMBC, NOESY, COSY, MS, UV, and IR). The comp...

N-Alkyl-oxaziridines react in the presence of a nucleophile as an oxygenating agent; in the absence of a nucleophile, an isomerization reaction is observed. This study describes the synthesis of two new dihydroisoquinoline oxaziridines and their reactivity in an acid-promoted reaction in the presence and absence of sulfides.

The present work was aimed at studying the antioxidative activity and hepatoprotective effects of methanolic extract (ME) of Hammada scoparia leaves against ethanol-induced liver injury in male rats. The animals were treated daily with 35 % ethanol solution (4 g kg(-1) day(-1)) during 4 weeks. This treatment led to an increase in the lipid peroxida...

Aqueous extract (AE) of Hammada scoparia leaves was chemically characterized and its hepatoprotective activities were investigated in vivo in rat model. Wistar rats were treated daily with 35% ethanol solution (3 g/kg/day) during 4 weeks and fed with basal diet or basal diet containing AE (200 mg/kg/day). Control rats were treated with saline solut...

The present study aimed to formulate and subsequently evaluate a topical skin-care cream (o/w emulsion) from virgin olive oil versus its vehicle (base). A formulation containing 3% virgin olive oil was developed by entrapping it in the oily phase of oil-in-water (o/w) emulsion. The base form did not contain natural oil. Lemon oil was incorporated t...

Given the growing interest of consumers worldwide in safe, healthy and good quality olive oil, the present study aimed to investigate a number of Tunisian virgin olive oil varieties in an attempt to procure physico-chemical characteristics of interest to the local and global olive oil industry, particularly in terms of variety and area of cultivati...

Essential oil extracted from the aerial parts of Rosmarinus officinalis by hydrodistillation was analyzed by gas chromatography/mass spectrometry and the components identified were 15. The major constituents of the essential oil were 1,8-cineole (35.32%), trans-caryophyllene (14.47%), borneol (9.37%), camphor (8.97%), α-pinene (7.9%) and α-thujone...

The antiviral activities of extracts from Daucus maritimus seeds were investigated against the reverse transcriptase of human immunodeficiency virus (HIV) type 1 and a panel of RNA-dependent RNA polymerases of dengue virus, West Nile virus (WNV) and hepatitis C virus (HCV). The extracts showed moderate to potent inhibition rates against the four vi...

A new secoiridoid, olenoside A (1a) and its known epimer olenoside B (1b), were isolated from olive mill wastewater as a mixture of two isomers. Their structures, 1-methyl-7-oxo-6,6a,8,8a-tetrahydro-1H,3H-pyrano[3,4-c]pyran-4-carboxylic acid methyl ester, were determined by spectroscopic methods including 2-D NMR. The structure of major compound 1a...

In search for compounds able to reduce cell adhesion-mediated drug resistance (CAM-DR), we studied effects of Hammada scoparia extracts on leukemic cells adherent or in suspension. We show that H. scoparia flavonoidic fraction and its compound rutin induce apoptosis specifically in adherent leukemic cells and abolish CAM-DR. Importantly, rutin inhi...

In this study, the essential oil of the aerial parts of Marrubium vulgare L. obtained by hydrodistillation was analyzed by gas chromatography coupled to mass spectrometry (GC-MS) in order to determine their chemical composition. Thirty-four (34) components in the oil of M. vulgare were identified. The results demonstrated that the major components...

The N-alkyl oxaziridines may be used as reagents for the oxidation of sulfides in acid-promoted reactions. The present work describes the behavior of two newly synthesized dihydroisoquinoline-derived oxaziridines with respect to methanesulfonic acid. An isomerization reaction was observed in the absence of sulfide.

The essential oil from the aerial parts of Ricinus communis, an aromatic member of the Euphorbiaceae family, from Tunisia, obtained by hydrodistillation, was analyzed by gas chromatography coupled to mass spectrometry (GC-MS). Seven constituents were found representing 100% of the oil. The main constituents of the essential oil were -thujone (31.71...

This study was designed to examine for the first time, the chemical composition and in vitro antioxidant activities of the essential oil obtained from the aerial parts of Thymelaea hirsuta L. The essential oil was subjected to hydrodistillation and was analyzed by GC-FID and GC-MS. The chemical composition was dominated by the presence of hydrocarb...

Essential oils and their components are becoming increasingly popular as naturally occurring antioxidant agents. In this work, the composition of essential oil in Artemisia herba-alba from southwest Tunisia, obtained by hydrodistillation was determined by GC/MS. Eighteen compounds were identified with the main constituents namely, α-thujone (24.88%...

In the present work we determined the total phenolic content of Aloe vera leaf skin (AVLS) extracts by using various solvents (hexane, chloroform-ethanol (1/1), ethyl acetate, butanol and water). We have also evaluated the antioxidant and the anti-PLA2 properties of these extracts by measuring their inhibition potency on the human pro-inflammatory...

Molluscicidal activity of Solanum nigrum var. villosum (morelle velue) extracts and their fractions were tested against the mollusca gastropoda Galba truncatula intermediate host of Fasciola hepatica. The results indicated that the hydro-methanol (MeOH-H2O) immature fruit extract possess the highest molluscicidal activity (LC50 = 3.96 mg/L) against...

The antioxidant and antimicrobial activities of various solvent extracts from Mirabilis jalapa tubers (MJT) were investigated using various in vitro assays. The total phenolic and flavonoid contents varied from 21.45 to 364.6 mg gallic acid equivalent (GAE)/g dried extract and 5.2 to 71.6 mg quercetin/g dried extract, respectively. Water extract of...

Aldehydes are converted into (E)-α,β-unsaturated methyl ketones in good yield and with a high E stereoselectivity using α,α-bis(trimethylsilyl) N-tert-butyl acetimine 3. The reaction was mediated by a catalytic amount of tetrabutylammonium fluoride (TBAF) under mild conditions. The disilylated reagent 3 is easily generated from N-tert-butylacetimin...

Antioxidant supplements have long been known to reduce the free radical-induced oxidative damage. Considering the antioxidant properties of hydroxytyrosol (Ht), this study was aimed to evaluate the effect of hydroxytyrosol and glucose on antioxidant system of rat epididymal sperm in vitro. Sperm samples were dispersed, in RPS medium (pH 6.9) and in...

This study was established that after 3 months storage, olive mill waste (OMW) was enriched with hydroxytyrosol (HT) (2,652 mg/L) and contained only phenolic monomers. It also showed that HT supplementation to surviving diabetic rats decreases considerably intestinal maltase, lactase, sucrose, and lipase activities by 49, 31, 42, and 40%, respectiv...

The aim of the present work was to evaluate the anti-inflammatory properties of Cynara cardunculus L. (Asteraceae) during its growth using various solvents such as n-hexane, dichloromethane, acetone, and methanol for air-dried leaves and stems. The anti-inflammatory activities of crude extracts were evaluated by measuring the inhibition potency of...

The molluscicidal activity of Hammada scoparia leaf extracts and the principal alkaloids isolated from them (carnegine and N-methylisosalsoline) were tested against the mollusc gastropod, Galba truncatula, the intermediate host of Fasciola hepatica in Tunisia. The results indicated that the molluscicidal activity was correlated with the presence of...

This study aimed to evaluate the effect of phenolic extract and purified hydroxytyrosol (HT) from olive mill waste (OMW) on oxidative stress and hyperglycemia in alloxan-induced diabetic rats. The OMW biophenols were extracted using ethyl acetate. The obtained extract was fractionated by solid phase extraction (SPE) experimentation to generate two...

The present study aims to investigate the effect of hydroxytyrosol in insulin secretion and the antioxidant activity in liver slices in vitro. For this, pancreas and liver slices were incubated in presence of 1g/l or 4g/l glucose (± hydroxytyrosol (HT)) during 40 minutes. We interest to evaluate the action of HT in insulin secretion, antioxidant en...

Daucus maritimus seeds were extracted successively with hexane, dichloromethane, ethyl acetate and ethanol in a soxhlet apparatus to provide four oily extracts named, respectively: HE, DM, EA and ET. The seed oils were analyzed for fatty acids, sterols, some physicochemical characteristics and antioxidant activities. The results of the analyses rev...

The title compound (systematic name: 1,2-dimethyl-6-meth­oxy-1,2,3,4-tetra­hydro­isoquinolin-7-ol), C12H17NO2, is a major alkaloid isolated from Hammada scoparia leaves. It belongs to the isoquinoline family and it was characterized by NMR spectroscopy and X-ray crystallographic techniques. The absolute configuration could not be reliably determine...

The title compound (systematic name: 16-hydroxy­methyl-12-methoxy­ibogamine), C21H28N2O2, was prepared by reaction of ibogaine with a formaldehyde–acetic acid solution (pH = 4). The crystal structure of this new product, belonging to the iboga indole family, is stabilized by an inter­molecular O—H⋯N hydrogen bond. The identity of the compound was c...

In the title compound, C11H12N2O4, a new hydroxamic acid which belonging to the isoquinole family, the heterocyclic ring adopts a half-chair conformation. The nitro group is essentially coplanar with the aromatic ring. Intermolecular O—H� � �O hydrogen bonds assemble the molecules around inversion centres to form pseudo-dimers.

In the title compound, C11H12N2O4, a new hydroxamic acid which belonging to the isoquinole family, the heterocyclic ring adopts a half-chair conformation. The nitro group is essentially coplanar with the aromatic ring. Inter­molecular O—H⋯O hydrogen bonds assemble the mol­ecules around inversion centres to form pseudo-dimers.

Maturity is one of the most important factors associated with the quality evaluation of fruit and vegetables. This work aims to investigate the effect of the maturation process of the olive fruit on the phenolic fraction and fatty acid of irrigated Chétoui cultivar. The phenolic composition was studied by using reverse-phase high-performance liquid...

The ethanolic extract of Aloe vera leaf skin was fractionated by liquid-liquid partition using hexane, ethyl acetate, chloroform-ethanol and butanol. The total phenolic content of the four different fractions were determined by Folin-Ciocalteu method and their antioxidant activity was essayed through some in vitro models such as the antioxidant cap...

The title compound (systematic name: 1,2-dimethyl-6-methoxy-1,2,3,4-tetrahydroisoquinolin-7-ol), C12H17NO2, is a major alkaloid isolated from Hammada scoparia leaves. It belongs to the isoquinoline family and it was characterized by NMR spectroscopy and X-ray crystallographic techniques. The absolute configuration could not be reliably determined....

The title compound (systematic name: 16-hydroxymethyl-12-methoxyibogamine), C21H28N2O2, was prepared by reaction of ibogaine with a formaldehyde–acetic acid solution (pH = 4). The crystal structure of this new product, belonging to the iboga indole family, is stabilized by an intermolecular O—H...N hydrogen bond. The identity of the compound was co...

Two new sesquineolignans, Furfuraceol A (1) and Furfuraceol B (2), have been isolated from the flowers of Centaurea furfuracea as a mixture of two isomers. Their structures have been determined by spectroscopic methods including 2D NMR spectroscopy COSY, HMQC, HMBC and NOESY.

Pressure is a non-invasive physical parameter that can be used to control and influence protein crystallization. It is also found that protein crystals of superior quality can be produced in gel. Here, a novel crystallization strategy combining hydrostatic pressure and agarose gel is described. Comparative experiments were conducted on hen and turk...

Increasing interest in phenolic compounds in olives is due to their antioxidant and health-enhancing properties. In this study the phenolics in fruits of the Tunisian olive cultivar Chemlali were extracted by methanol-water and fractionated using Sephadex LH-20 column chromatography. The identification of phenolic monomers and flavonoids was based...

Two new alkaloids have been obtained from Peschiera echinata: 10-methoxyeglandine (21) and 10-hydroxyheyneanine (22). Twenty known alkaloids were also isolated.

Three new alkaloids have been obtained from Anartia cf. meyeri. They are 11-hydroxycoronaridine (14), 11-hydroxyheyneanine (15) and 10-hydroxyheyneanine (16). Thirteen other known alkaloids were also isolated; traces of four other alkaloids, one of which is a bis-indole, were also observed.

For the first time, a soil bacterium, designated Pseudomonas aeruginosa, was isolated based on its ability to grow on tyrosol as a sole source of carbon and energy. During growth on tyrosol, this strain was capable of promoting the formation of a significant amount of hydroxytyrosol and trace quantities of parahydroxyphenyl acetic acid and 3,4-dihy...

The effect of hydrostatic pressure and pH on the crystallization of tetragonal hen lysozyme crystals (HeL, M r 14,300) and hexagonal turkey lysozyme crystals (TeL, M r 14,200) in agarose gel was studied. Samples (adjusted to a pH in the range 4–6) were pressurized at 0.1–100 MPa for nine days at 293 K. The morphology and number of crystals as well...

Hydrostatic pressure in the 0.1–75 MPa range has been used as a non-invasive tool to study the crystallization process of the tetragonal crystal form of the protein thaumatin (Mr 22 200). Crystals were prepared within agarose gel and at temperatures in the range from 283 to 303 K. The solubility, i.e. the concentration of soluble macromolecules re...

The combined effect of both pressure and pH on the crystallization in agarose gel of thaumatin (0.1–230MPa and pH 5.7–8.0) and the lysozymes from turkey (0.1–100MPa and pH 4.0–6.0) and hen egg-white (0.1–75MPa and pH 4.0–6.0) was investigated. For each condition, crystal morphology was examined and four crystal growth parameters determined (crystal...

A new dilignan, 7,8-trans-7',8'-trans-7",8"-cis-7"',8"'-cis-8,8'-trans-4",4"',7',9,9",9"'-hexahydroxy-3,3',3",3"'-tetramethoxy-4,8":4',8"':5,7":5',7"'-tetraoxy-7,9'-epoxy-8,8'-dilignan-7'-ol, named cynarinine (2), was isolated together with the known tracheloside (1) from the seeds of Cynara cardunculus.

Six products have been isolated for the first time from the leaves and flowers of Hyparrhenia hirta (L.) Stapf (Andropogon hirtus) : tricosane; vanillin; 4-hydroxybenzaldehyde; 12,14-tritriacontandione; β-sitosterol and 3-O-β-D-glucoside sitosterol. Their structures were determined by spectroscopic methods.

A new flavonol triglycoside, isorhamnetin 3-O-beta-D-xylopyranosyl-(1"-->3)-alpha-L-rhamnopyranosyl-(1'''-->6")-beta-D-galactopyranoside, has been isolated from the leaves of Hammada scoparia together with two known compounds, isorhamnetin 3-O-beta-D-apiofuranosyl-(1'''-->2")[alpha-L-rhamnopyranosyl-(1"-->6")]-beta-D-galactopyranoside and isorhamne...

Leaves of Hyparrhenia hirta yielded the rare diastereoisomeric flavonolignans tricin 4'-O-(erythro-beta-guaiacylglyceryl) ether and tricin 4'-O-(threo-beta-guaiacylglyceryl) ether together with their 7-O-glucosides, which are the first flavonolignan glycosides to be isolated as natural products. A complete set of (1)H and (13)C NMR resonance assign...

The isolation of (−)-arctigenin (1) and (−)-arctigenin 4′-glucoside from the seeds of Cynara cardunculus, and of hentriacontane and eicosyldocosanoate from the leaves is reported, along with 1H- and 13C-NMR spectra of 1.

This is the first report of Alkaloid Screening of Tunisian flora and their reputation in popular medecine. A total of 492 plant extracts of 145 species belonging to 41 botanic families were tested with Meyer reactant, for the presence of alkaloids. Only 35 species were found to contain alkaloids and within them 8 species were not previously studied...

Die Titelverbindungen (I) und (II) wurden aus den Blättern von Bonafousia tetrastachya extrahiert.