Chemical composition of various Ephedra species

The medicinal significance of Ephedra is based on the sympathomimetic properties of ephedrine (E) alkaloids. Pharmacological effects depend on the phytocomposition of individual Ephedra species. The aim of this study was to measure the total alkaloids content (TAC), total phenolics content (TPC), and total flavonoids content (TFC) and determine their relationship in dry herb of Ephedra major, Ephedra distachya subsp. helvetica, Ephedra monosperma, Ephedra fragilis, Ephedra foeminea, Ephedra alata, Ephedra altissima and Ephedra foliata. Nowadays, medicinal use of Ephedrae herba is limited, but the abuse of its psychostimulants is rising. In this study, TAC, TPC and TFC were determined using spectrophotometric methods. For the first time, ultra-performance liquid chromatography with ultraviolet detection (UPLC-UV) was used for separation and quantification of E-type alkaloids of various Ephedra species. The highest TPC and TFC were found in E. alata (53.3 ± 0.1 mg Gallic acid equivalents/g dry weight, 2.8 mg quercetin equivalents/g dry weight, respectively). The total content of E and pseudoephedrine determined by UPLC-UV varied between 20.8 mg/g dry weight (E. distachya subsp. helvetica) and 34.7 mg/g dry weight (E. monosperma). The variable content and ratio between secondary metabolites determined in different Ephedra species reflects their metabolic activities. Utilization of UPLC-UV unveiled that this technique is sensitive, selective, and useful for separation and quantification of different alkaloids in complex biological matrixes. The limit of detection was 5 ng. Application of UPLC-UV can be recommended in quick analyses of E-type alkaloids in forensic medicine and quality control of pharmaceutical preparations

PERIPHERAL 8-ISO-PGF2α AS A BIOMARKER IN BOSNIAN PATIENTS WITH ALZHEIMER’S DISEASE AND VASCULAR DEMENTIA

Background: Cerebrospinal levels of isoprostanes (IsoPs) have been established as biomarkers of oxidative stress in Alzheimer’s disease (AD) and vascular dementia (VD). The value of peripheral levels in the diagnostics of these diseases is less conclusive. The aim of this study was to determine serum 8-iso-prostaglandin-F2alpha (8-iso-PGF2α) levels in Bosnian AD and VD patients and to establish whether there is an association between 8-iso-PGF2α serum concentration and cognitive impairment (CI) in patients with dementia. Subjects and methods: Serum levels of 8-iso-PGF2α were measured by enzyme immunoassay method in AD (n=30) and VD patients (n=30) and control subjects (CG, n=30). The AD and VD group were further stratified according to the level of CI. Results: The serum 8-iso-PGF2α levels were significantly higher in the AD (74.00 pg/mL) and VD groups (38.00 pg/mL) compared to the CG (17.50 pg/mL). A significant difference in serum 8-iso-PGF2α levels between patients with moderate and severe CI was not established in either AD or VD. Conclusion: Serum 8-iso-PGF2α proved to be a good biomarker in AD and VD, however it cannot be recommended for the differentiation of moderate and severe CI

The Effectiveness of Natural and Synthetic Antioxidant Additives on the Oxidation Stability of Biodiesel Synthesized from Fresh and Waste Sunflower Oilesized from fresh and waste sunflower oil

Biodiesel fuel is the realistic fuel for the future due to its environmental, economic and energetic benefits. However, the degradation and instability during biodiesel storage and application present the major disadvantages and hence a modern scientific challenge. The aim of this study was to choose optimal parameters for biodiesel synthesis from fresh and waste sunflower cooking oil and to investigate the possibilities of increasing its resistance towards oxidative degradation. Various physico-chemical characteristics essential for the quality estimation of the resulting biodiesel products were compared before testing the effectiveness of natural and synthetic antioxidants. Butylated hydroxytoluene (BHT), carvacrol and α-tocopherol were added to the biodiesel in different concentrations in order to determine their efficiency during the Schaal oven test. Results proved that both, fresh and waste oil can be valuable sources for the synthesis of biodiesel that meets European and American quality standards. Among the antioxidants, BHT was the most efficient one in both types of biodiesel and its usage would be recommended at the concentration of 1000 ppm. The findings present a cost-effective and environmentally friendly source for biodiesel production with improved properties - considerably enhanced resistance to oxidative degradation, where synthetic antioxidants are given the priority. DOI: http://dx.doi.org/10.17807/orbital.v10i7.1174  </p