α-Zirconium hydrogenophosphate as a nano-container of 2-aminobenzimidazole for the corrosion protection of zinc in NaCl medium

The development of a new generation of anticorrosion pigments for paints remains an important challenge to replace the usual sparingly-soluble pigments and thus avoid the dissemination of heavy metals in the environment and the formation of holes in polymer coatings. For this purpose, α-zirconium hydrogenophosphate (Zr(HPO4)2·H2O, denoted as α-ZrP) was intercalated with the corrosion inhibitor 2-aminobenzimidazole (ABIM). Various microstructural analyses have proven the insertion of ABIM in the interlayer space by an acid-base exchange reaction and allowed us to propose a structural model for the new ABIM-ZrP pigment. The anticorrosion properties on zinc of the ABIM-ZrP, characterized by electrochemical measurements in 0.1 M NaCl, are due to the release of ABIM molecules by an ion-exchange reaction and the pH-buffer effect of α-ZrP and the amine group of ABIM. Compared to the commercial aluminium tri-phosphate (ATP) pigment, an alkyd-polymer coating loaded with the ABIM-ZrP pigment shows very interesting electrochemical behaviour by avoiding the blistering of the polymer coating and the beginning of zinc corrosion. This effect may be due to both the tortuous effect brought by the platelet shape of the pigments and the release of ABIM once the water uptake of the polymer becomes significant.

Chemical composition and thermal properties of Tunisian pecan nut [Carya illinoinensis (Wangenh.) K. Koch] oils

An investigation on fatty acid, triacylglycerol, tocopherol, and xanthophyll contents and thermal properties of pecan (Carya illinoinensis) kernel oils from two cultivars was carried out. The main fatty acids were oleic acid, followed by linoleic and palmitic acids. The predominant triacylglycerols were OOL, OOO, and OLL (where O stands for oleoyl and L for linoleoyl). Pecan kernel oil is a rich source of tocopherols, mainly γ-tocopherol. Two xanthophylls (lutein and zeaxanthin) were investigated, and lutein was found to be the major one. Thermal behavior was studied by differential scanning calorimetry (DSC). Pecan nut oil displayed melting and crystallization transitions at low-temperature zones. The difference between DSC parameter values provides a path for distinguishing among cultivars. These data promote pecan kernel oil as a potential source of bioactive compounds with nutraceutical properties (monounsaturated fatty acids, tocopherols, and xanthophylls) and reveal, for the first time, the thermal properties of Carya illinoinensis oil.

Determination of phenolic compounds by MALDI-TOF and essential oil composition by GC-MS during three development stages of Origanum majorana L

This study aimed to investigate the effect of the maturation process of sweet marjoram (Origanum majorana L.) on essential oil composition, the phenolic profile of ethanolic extract and their antioxidant capacities. The essential oil composition was studied at three stages of maturity by GC-MS. Thirty compounds were detected representing 100% of the total essential oil. p-Menth-1-en-4-ol was the major compound (37.15-76.94%) followed by cyclohexanol-3,3,5 trimethyl (5.41-15.99%) and α-terpineol (0.94-11.34%). During the maturation process, an accumulation of oxygenated monoterpenes was observed. The phenolic composition was studied using matrix-assisted laser desorption/ionization time of flight. The analysis showed the presence of short flavonoid monomers at all stages of maturation. The antioxidant capacity of ethanolic extracts and essential oils was evaluated using the DPPH assay, iron chelating power and reducing power assay. The highest phenolic content and antioxidant capacity were found at flowering stage. These findings on essential oil composition, phenolic profile and antioxidant capacity of O. majorana at three different stages of development provide more information on how these secondary metabolites are accumulated.

In vitro digestion, antioxidant and antiacetylcholinesterase activities of two species of Ruta: Ruta chalepensis and Ruta montana

CONTEXT

Ruta genus (Rutaceae) is abundantly used and described in the most ancient systematic records of medical practice of the Mediterranean world. In Tunisia, this genus is represented by two medicinal and aromatic shrubs: Ruta chalepensis L. and Ruta montana L.

OBJECTIVE

This study investigates the antioxidant and acetylcholinesterase inhibition (AChE) activities before and after in vitro gastrointestinal metabolism of leaf decoction of R. chalepensis and R. montana.

MATERIALS AND METHODS

We study, in vitro, the effect of the gastrointestinal juices gastric (1.75 mL) or pancreatic (2.5 mL) juices, on the biological activity by the measurement of the antioxidant activity and AChE inhibition during 4 h of decoction extract obtained from the leaves of the two species of Ruta.

RESULTS

The results showed that the ability to inhibit the AChE enzyme was similar; being the greatest inhibitory activity exhibited by the ethanol extract (IC₅₀=12 ± 1.1 μg/mL) obtained from leaves of R. chalepensis.

CONCLUSION

In conclusion, we showed that there was no appreciable degradation and that the activity was kept constant after gastric and pancreatic juice digestion.

Chemical characterization and thermal properties of kernel oils from Tunisian peach and nectarine varieties of

A comparative study was conducted to determine the fatty acids, triacylglycerol compositions and thermal properties of Tunisian kernel oils from the Prunus persica varieties, peach and nectarine, grown in two areas of Tunisia, Gabes and Morneg. Qualitatively, the fatty acids composition and triacylglycerol species were identical for all samples. Oleic acid (67.7-75.0%) was the main fatty acid, followed by linoleic (15.7-22.1%) and palmitic (5.6-6.3%) acids. The major triacylglycerol species were triolein, OOO (38.4-50.5%), followed by OOL (18.2-23.2%), POO (8.3-9.7%) and OLL (6.3-10.1%). The thermal profiles were highly influenced by the high content of triolein due to the importance of oleic acid in these oils. Moreover, the fatty acids distribution in TAG external positions was determined as corresponding to an α asymmetry coefficient that was between 0.10 and 0.12, indicating a high asymmetry in the distribution of saturated fatty acids in the position sn-1 and sn-3 in the TAG species of all samples.

Analysis of pecan nut (Carya illinoinensis) unsaponifiable fraction. Effect of ripening stage on phytosterols and phytostanols composition

Changes in 4-desmethylsterol, 4-monomethylsterol, 4,4-dimethylsterol and phytostanol composition were quantitatively and qualitatively investigated during the ripening of three varieties of Tunisian-grown pecan nuts (Mahan, Moore and Burkett). These components have many health benefits, especially in lowering LDL-cholesterol and preventing heart disease. The phytosterol composition of whole pecan kernel was quantified by Gas Chromatography-Flame Ionisation Detection (GC-FID) and identified by Gas Chromatography-Mass Spectrometry (GC-MS). Fifteen phytosterols and one phytostanol were quantified. The greatest amount of phytosterols (2852.5mg/100g of oil) was detected in Mahan variety at 20 weeks after the flowering date (WAFD). Moore had the highest level of phytostanols (7.3mg/100g of oil) at 20 WAFD. Phytosterol and phytostanol contents showed a steep decrease during pecan nut development. Results from the quantitative characterisation of pecan nut oils revealed that β-sitosterol, Δ5-avenasterol, and campesterol were the most abundant phytosterol compounds at all ripening stages.

Changes in phospholipid composition, protein content and chemical properties of flaxseed oil during development

The aim of the present research is to investigate the effect of harvest date on the composition of flaxseed. Samples were collected at regular intervals from 7 to 56 days after flowering (DAF) and analyzed for phospholipid composition, storage protein content and chemical properties. Phospholipid (PL) percentage of the total lipid decreased from 32.72% on the 7th DAF to 2.55% on the 56th DAF. The most phospholipids present in flaxseed were phosphatidylinositol (PI), phosphatidylethanolamine (PE) and lysophosphatidylcholine (LPC) which were highly unsaturated and rich in linolenic and linoleic acids, comprising together 60% of the total fatty acids. Chemical investigation of flaxseed oil showed overall a decrease in UV absorbance (K(232) and K(270)), acid value, free fatty acid content and an increase in peroxide value and storage protein content with development. At full maturity, flaxseed contained 29% proteins on a dry weight basis (DW %).

[Intracranial abscess and empyema: neurosurgical management]

Brain abscesses and empyemas are severe infections with lethal outcomes in the case of inappropriate treatment. The files of 34 patients with brain abscesses, and nine with intracranial empyemas treated over eight years (1990-1997) were analyzed retrospectively. Cases were evaluated for treatment and compared with data from the literature. Patients with brain abscess underwent either aspiration of the lesion through a burr hole (79.5% of the cases), or craniotomy and excision (8.8% of the cases); 11.7% were treated only with antibiotics. The operative mortality was 2.9% and the outcome was satisfactory in 85% of patients. These results are in agreement with data from the literature. Prognosis is strongly related to the initial clinical status. Current methods of treatment include surgical aspiration of large abscesses with a mass effect, and are usually associated with a poor clinical status. Excision is suggested whenever aspiration procedures have failed, or in the presence of foreign material or fungal abscess. Medical treatment is indicated for small and deeply located abscesses in patients with satisfactory clinical states. Empyemas in our series were treated with burr hole and pus aspiration. The mortality rate was 11%, and 62.5% of the patients made a good recovery. In agreement with other reported studies, the method of treating subdural empyema is much less significant than an aggressive early drainage of the infection. Although brain abscesses and empyema remain a significant neurosurgical concern, aggressive treatment can result in an excellent outcome in the majority of patients.

[Neurosurgical aspects of Rendu-Osler disease. Apropos of 6 recent cases and review of the literature]

Six patients with neurological complications in Rendu-Osler-Weber disease were reviewed. There were 4 patients (3 int the same family) with a brain abscess, one patient with a brain abscess and a spinal cord subarachnoid hemorrhage, one patient with a recurrent intracerebral hemorrhage due to a vascular malformation. The infectious complications are related to the presence of pulmonary arterio-venous fistula, which should be treated, whenever diagnosed. Because of the potentially severe outcome of these neurological complications of the Rendu-Osler-Weber disease, screening of the patient's relatives is highly recommended.

[Lumbar intradural disk herniation. X-ray computed tomographic diagnosis]

Intradural disk herniation is a rare condition. Most of reported cases involve the lumbar spine and have histories of chronic low back pain followed by an acute episode of radicular pain with neurologic deficit. The authors report the myelographic and lopamidol-CT findings in a case of a L4-5 intradural disk herniation. These two examinations demonstrated an intradural multilobular mass associated with an extradural component at the level of the disk space and with a same density as it. Anatomic adherences between dura-mater and posterior longitudinal ligament could explain the primary mechanism of these intradural disk herniations; but operative or traumatic antecedents are often noted. Most often operation discloses only the intradural component with a small anterior dural cleft, without extradural abnormalities. Postoperative follow up is usually good.