Novel surface lipids of diapausing Manduca sexta pupae. Long chain oxoalcohol esters of acetoacetic, hydroxybutyric, and acetic acids

Ester components in the surface wax from diapausing tobacco hornworm pupae, Manduca sexta L., were separated by thin layer chromatography and gas-liquid chromatography, and characterized by infrared spectroscopy and gas-liquid chromatography-mass spectrometry. Three groups of esters were identified as natural derivatives of acetic acid, acetoacetic acid, and 3-hydroxybutyric acid. The major ester fraction was identified as a mixture of C26 (10%), C27 (5%), and C28 (85%) oxoalcohol esters of acetoacetic acid. The major homolog consisted of equal amounts of 11-oxooctacosanyl 3-oxobutanoate and 12-oxooctacosanyl 3-oxobutanoate. Lesser amounts of 11- and 12-oxooctacosanyl and n-octacosanyl esters of acetic and 3-hydroxybutyric acids were also identified. The chain length distributions of these C26, C27, and C28 oxoalcohol and n-primary alcohol ester moieties, as well as the isomeric ratios for the 11- and 12-oxoalcohol isomers, were similar to the oxoaldehydes and unesterified oxoalcohols previously identified by Buckner et al (Buckner, J. S., Nelson, D. R., Haak, H., and Pomonis, J. G. (1984) J. Biol. Chem. 259, 8452-8470) as lipid components of the surface wax of M. sexta pupae.     

The protective effect of arbutin against potassium bromate-induced oxidative damage in the rat brain

This study aimed to investigate the protective effects of arbutin (ARB) against brain injury induced in rats with potassium bromate (KBrO₃). The rats were divided into four groups as Group 1: Control (0.9% NaCl ml/kg/day p.), Group 2: KBrO₃ (100 mg/kg (gavage), Group 3: ARB (50 mg/kg/day p.), and Group 4: KBrO₃ + ARB (100 mg/kg (gavage) + 50 mg/kg/day p.). At the end of the fifth day of the study, the rats in all groups were killed, and their brain tissues were collected. In the collected brain tissues, malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) levels were measured, and routine histopathological examinations were made. The MDA levels in the group that was exposed to KBrO₃ were significantly higher than those in the control group (p ˂ 0.001). In comparison to the KBrO₃ group, the MDA levels in the KBrO₃ + ARB group were significantly lower (p ˂ 0.001). It was observed that SOD and CAT enzyme activity levels were significantly lower in the KBrO₃ group compared to the control group (p ˂ 0.001), while these levels were significantly higher in the KBrO₃ + ARB group than in the KBrO₃ group (p ˂ 0.001). Additionally, the group that was subjected to KBrO₃ toxicity, as well as ARB administration, had much lower levels of histopathologic signs than the group that was subjected to KBrO₃ toxicity only. Consequently, it was found that KBrO₃ exposure led to injury in the brain tissues of the rats, and using ARB was effective in preventing this injury.     

Photoluminescence and thermoluminescence properties of pure and rare-earth-doped ZrO2 prepared by Pechini-type sol–gel

In this article, photoluminescence (PL) and thermoluminescence (TL) properties of ZrO₂, ZrO₂:Dy³⁺, ZrO₂:Dy³⁺–Gd³⁺, ZrO₂:Dy³⁺–Yb³⁺, ZrO₂:Dy³⁺–Er³⁺, and ZrO₂:Dy³⁺–Sm³⁺ phosphors synthesized by the Pechini method were investigated. The crystal structure, thermal properties, morphology, PL and TL properties were investigated using X-ray powder diffraction (XRD), differential thermal analysis/thermogravimetric analysis (DTA/TGA), scanning electron microscopy (SEM), PL and TL, respectively. The room temperature emission bands corresponding to ⁴F_9/2 → ⁶H_J (J = 9/2, 11/2, 13/2 and 15/2) transitions of Dy³⁺ ions were measured. The phosphors were analysed using T_m–T_STOP, variable dose, and computerized glow curve fitting methods. Reusability, dose–response, and fading characteristics were investigated. The phosphors have a natural TL emission that vanished by heating treatment. Moreover, new peaks with similar properties to the natural emissions were observed after high-dose irradiation and long-term fading experiments. The glow curves of the phosphors have 13 individual peaks and many low- and high-temperature satellite peaks. The origin of the peaks is ZrO₂ host material and doping with rare-earth ions (Gd³⁺, Dy³⁺, Yb³⁺, Er³⁺ and Sm³⁺) does not lead to a new glow peak. The dopants cause drastic changes in individual peak intensities of ZrO₂.The initial fading rates of all the phosphors are relatively fast, but they slow down as time goes on.     

Effect of Axial Ligand Length on Biological and Anticancer Properties of Axially Disubstituted Silicon Phthalocyanines

In this study, three new axially disubstituted silicon phthalocyanines ( SiPc1–3 ) and their quaternized phthalocyanine derivatives ( QSiPc1–3 ) were prepared and characterized. The biological properties (antioxidant, antimicrobial, antibiofilm, and microbial cell viability activities) of the water-soluble silicon phthalocyanines were examined, as well. A 1 % DMSO diluted with pure water was used as a solvent in biological activity studies. All the compounds exhibited high antioxidant activity. They displayed efficient antimicrobial and antimicrobial photodynamic therapeutic properties against various microorganisms, especially Gram (+) bacteria. Additionally, they demonstrated high antibiofilm activities against S. aureus and P. aeruginosa. In addition, 100 % bacterial reduction was obtained for all the studied phthalocyanines against E. coli viable cells. Besides, the DNA cleavage and binding features of compounds ( QSiPc1–3 ) were studied using pBR322 DNA and CT-DNA, respectively. Furthermore, the human topoisomerase I enzyme inhibition activities of compounds QSiPc1 – 3 were studied. Anticancer properties of the water-soluble compounds were investigated using cell proliferation MTT assay. They exhibited anticarcinogenic activity against the human colon cancer cell line (DLD-1). Compounds QSiPc1 and QSiPc3 displayed a high anticarcinogenic effect on the DLD-1 cell line. The obtained results indicated that all the studied compounds may be effective biological agents and anticancer drugs after further investigations.     

Synthesis,Biological Evaluation,and Molecular Modeling Studies of New 1,3,4-Thiadiazole Derivatives as Potent Antimicrobial Agents

In this work, the synthesis, characterization, and biological activities of a new series of 1,3,4-thiadiazole derivatives were investigated. The structures of final compounds were identified using ¹H-NMR, ¹³C-NMR, elemental analysis, and HRMS. All the new synthesized compounds were then screened for their antimicrobial activity against four types of pathogenic bacteria and one fungal strain, by application of the MIC assays, using Ampicilin, Gentamycin, Vancomycin, and Fluconazole as standards. Among the compounds, the MIC values of 4 and 8 μg/mL of the compounds 3f and 3g , respectively, are remarkable and indicate that these compounds are good candidates for antifungal activity. The docking experiments were used to identify the binding forms of produced ligands with sterol 14-demethylase to acquire insight into relevant proteins. The MD performed about 100 ns simulations to validate selected compounds’ theoretical studies. Finally, using density functional theory (DFT) to predict reactivity, the chemical characteristics and quantum factors of synthesized compounds were computed. These results were then correlated with the experimental data. Furthermore, computational estimation was performed to predict the ADME properties of the most active compound 3f .     

Effect of taurine on wound healing

Summary Taurine which has antioxidant effects is also known to have effects on cell proliferation, inflammation and collagenogenesis. The aim of this study was to investigate the effect of taurine on incisional skin wounds.The mice incised on the dorsal area were divided into control and experimental groups. Saline was injected intraperitoneally to half of the animals in the control group and locally applied to the other half. Fifty mM taurine solution was given intraperitoneally to the first half of the experimental animals and locally to the second half of the experimental group.After four days of treatment, malondialdehyde (MDA) and histamine levels as well as the tensile strength of the wound tissue were measured. Structural alterations in epidermis and dermis were histologically evaluated.The locally administreated taurine significantly increased wound tensile strength by decreasing the MDA and histamine levels and prevented the degranulation of the mast cells. These observations suggest that taurine may be useful on wound healing.     

Elemental composition of seston and nutrient dynamics in the Sea of Marmara

The Sea of Marmara, an intercontinental basin with shallow and narrowstraits, connects the Black and Mediterranean Seas. Data obtained during1991–1996 have permitted the determination of the elementalcomposition of seston in the euphotic zone and the N:P ratio of thesubhalocline waters of the Marmara Sea. Since primary production is alwayslimited to the less saline upper layer (15–20 m), of the Marmara Sea,the subhalocline waters of Mediteranean origin are always rich in nutrients(NO₃ + NO₂ = 8–10 μm, PO₄ = 0.8–1.2 μm) but depleted in dissolvedoxygen (30–50 μm) throughout the basin, yielding an -O_{_2} : N : P ratio of 178 : 9 : 1. Pollution of the surfacewaters since the 60s has modified the subhalocline nutrient chemistryslightly. In the euphotic zone, the N : P ratio of the seston changes from5.9 to 9.5 between the less and more productive periods. Though the biologyof the Marmara has changed significantly during the previous two decades,the close relationship observed between the elemental composition of thesurface seston and the NO₃ : PO₄ ratio of thesubhalocline waters strongly suggests that during the whole year primaryproduction throughout the basin and POM export to the lower layer remainnitrogen-limited. This suggestion needs to be confirmed by bio-assays,biological studies and sediment trap data from the upper subhaloclinedepths. Nonetheless, the counterflows in the Marmara basin possessrelatively low N : P ratios in both dissolved and particulate nutrients andextend as far as the adjacent seas. This revised version was published online in July 2006 with corrections to the Cover Date.     

Recherches Cytotaxonomiques et Cytogéographiques surMinuartia sect.Sabulina en Turquie (Caryophyllaceae)

25 populations from Turkey and one of Syria belonging to theSabulina section of the genusMinuartia have been karyologically examined. New chromosome numbers have been recorded forM. mesogitana andM. hybrida subsp.turcica, and a new variety was found in theM. hybrida complex. The origin of the taxa with n = 23 and n = 35 is discussed.