Žika Lepojević

Chromatography in our investigations of camomile (Matricaria chamomilla L.)

SummaryChromatographic methods for qualitative and quantitative analysis of non-volatile and volatile compounds of camomile (Matricaria chamomilla L.) are described. For determination of flavonoids of the apigenin series HPTLC and HPLC were used. To obtain standard samples of components of camomile oil semi-preparative TLC was used. Mass spectra of these standards were obtained to provide a data base. Qualitative and quantitative analysis of camomile oil compounds by GC-MS was then possible.

MODELING OF THE THYME-SUPERCRITICAL CARBON DIOXIDE EXTRACTION SYSTEM. I. THE INFLUENCE OF CARBON DIOXIDE FLOW RATE AND GRINDING DEGREE OF THYME

The influence of carbon dioxide flow rate and grinding degree of thyme on supercritical fluid extraction of thyme was investigated. The extraction rate of the pharmacologically important compound of thyme-thymol can be successfully expressed by analogy to first-order reaction kinetics. To model extraction of the thyme–supercritical carbon dioxide system, we used the Reverchon-Sesti Osseo equation as well as our modified equation.

Modeling of the Thyme–Supercritical Carbon-Dioxide Extraction System. II. The Influence of Extraction Time and Carbon Dioxide Pressure

The influence of extraction time and carbon dioxide pressure (i.e., carbon dioxide density) on supercritical fluid extraction of thyme was investigated. For determination of obtained extracts, HPLC and GC-MS methods were used. To model extraction of the thyme–supercritical carbon dioxide system, we used the Reverchon-Sesti Osseo equation as well as our modified equation.

Composition of Essential Oil Obtained From Tubular, Head and Ligulate Flowers of Calendula officinalis L. by Steam Distillation of Plant Material and CO2 Extracts

Abstract Essential oil content of tubular, head and ligulate flowers of Calendula officinalis L. were determined using official steam distillation procedure. It was found that the ligulate flower sample had the highest oil content (0.16%). Applying SFE by means of CO2 (200 bar, 40°C, 3 h extraction time), the highest extraction yield was found in tubular and ligulate flower samples (3.67% and 3.64%). Head flower had a lower extraction yield (2.60%) as the result of relatively small content of fatty oil, waxes and resins present in plant material. Steam distillation procedure was applied to obtain essential oils from the CO2 extracts devoid from cuticular waxes and resins. The compositions of oils were determined by GC and GC/MS. The main compounds of all investigated oils were α-cadinol (11.7–29.1%), δ-cadinene (3.2–20.3%), γ-cadinene (1.5–11.4%) and cadina-3,9-diene (0.4–11.2%). The oil samples obtained from the CO2 extracts were found to be more complex containing α-gurjunene, β-caryophyllene, β-gurjunene, cis-muurola-4(14)-5-diene and α-humulene.

High-performance liquid chromatographic determination of glaucine inGlaucium flavum crantz

SummaryA method has been developed for the extraction and rapid analysis of D-glaucine inGlaucium flavum Crantz. Simple extraction of the drug with diethyl ether was followed by high-performance liquid chromatography on a μBondapak C18 column using a mixture of acetonitrile, methanol and phosphate buffer as the mobile phase. Data on selectivity, sensitivity and precision demonstrate the reliability of this method.

The antioxidant properties of polypore mushroom Daedaleopsis confragosa

Daedaleopsis confragosa belong to a large and remarkable group of mushrooms called polypores. This type of mushroom could be easily said to be quite unexplored and unused when it comes to its antioxidant properties. Thus, in order to evaluate its antioxidant activity, the investigation had to include the total phenolics and flavonoide content, the content of Selenium, the content of Zinc, the scavenging capacity on DPPH· and OH· radicals, reducing power and capacity to remove lipid peroxidation. The investigated mushroom extract contained 54.17 mg GAE/g of total phenols and 48.46 mg CE/g of total flavonoides. Zinc and Selenium were detected and quantified by using inductively coupled plasma mass spectroscopy. The scavenging activity of the radicals was found to exhibit 50% of the inhibition value (IC50 value) at the extract concentration of 0.015±0.007 mg/ml for the investigated D. confragosa extract. By using electron paramagnetic resonant spectroscopy it was found that the investigated extract does not have a significant role in the prevention of lipid peroxidation. It was effective in scavenging on ·OH radical, RI was 56±2%.