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The effects of ultrasound power and frequency on the yield of total extractive substances (TES), total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity (AOA) of fresh houseleek leaves extracts obtained by direct ultrasound-assisted extraction (DUAE) were studied. Preliminary extraction of plant material was performed using methanol, acetone and 2-propanol by Soxhlet extraction. It was found that maximum TES yield could be obtained by methanol extraction (2.91±0.02), followed by acetone and 2-propanol with a TES yield of 2.32±0.01 and 2.01±0.03 g per 100 g of fresh plant material, respectively. In the fresh houseleek leaves extracts obtained by DUAE and methanol as the chosen solvent, TPC, TFC and AOA were in the ranges of: 40.5–85.9 mg gallic acid/g dry extract, 12.7–19.3 mg rutin/g dry extract and 24.6–108.2μg/ml, respectively. The results showed that the increase in the ultrasound power and extraction time have positive and significant (p < 0.05) effects on the TPC, TFC and AOA, while the increase in the ultrasound frequency leads to a decrease in the TPC, TFC and AOA of the extracts. A chromatographic analysis of crude extract identified the following: kaempferol 3-O-(6’’-O-malonylglucoside)- 7-O-glucosyde, kaempferol 3-O-glucoside-7-O-rhamnoside, luteolin 5-O-(6’’-O-malonylglucoside), kaempferol 3-O-(6’’-O-acetylglucoside)-7-O-rhamnoside, genkwanin 5-O-glucoside, luteolin 5-O-(6’’-O-malonylglucoside), kaempferol 3-O-(6’’-O-malonylglucoside), kaempferol 3-O-rhamnoside, quercetin, genkwanin 4’-O-glucoside and hyperoside. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172047]

In this study, we have examined the yield of extracted substances obtained by means of extraction using 70 % ethanol (v/v), the content of total phenols and flavonoids, as well as the antioxidant activity of the extracts obtained from the samples of the herbs dried by means of different techniques. Wild mint Mentha longifolia (L.) Hudson was dried naturally in a laboratory oven at a temperature of 45 °C and in an absorptive low temperature condensation oven at 35°C. The highest yield of extracts was obtained from the naturally dried herbs and the lowest from the herbs dried in the low temperature condensation drying oven. The content of total phenols and flavonoids was determined by spectrophotometric methods with an FC reagent and by the complexation reaction with aluminium-chloride, respectively. The extract of the naturally dried herbs had the highest overall content of phenols (113.8±2.0 mg of gallic acid/g of the dry extract) and flavonoids (106.7±0.3 mg of rutin/g of the dry extract). The highest antioxidant activity determined by the FRAP and DPPH assay was determined in the extracts obtained from naturally dried herbs (2.76±0.15 mmol Fe2+/mg of the dry extract and EC50=0.022±0.001 mg/ml), while the lowest was obtained from the extracts of herbs dried in the laboratory oven (1.13±0.11 mmol Fe2+/mg of the dry extract and EC50=0.033±0.001 mg/ml). The HPLC-DAD analysis result show that the greatest content of phenolic compounds show extract obtained from naturally dried plant material. The dominant phenolic component in the all extracts is Kaempferol 3-O-glucoside. The content of all phenolic compound strongly depend on the drying conditions.

Antioxidant and antimicrobial activities as well as total phenols and flavonoids contents of Salvia glutinosa L. (glutinous sage) and Salvia officinalis L. (sage) extracts were studied. Methanol and aqueous ethanol (70% v/v) were used for extraction of bioactive compounds, both in the presence and the absence of ultrasound, from herb and the spent plant material remaining after the essential oil hydrodistillation. The ratio of plant material to extracting solvent was 1:10 g/ml. Antioxidant and antimicrobial activities of the extracts were found to depend on the type of plant material and the extraction conditions. The plant materials from which essential oil had been recovered were proven to be valuable raw materials for making various herbal preparations.

This paper presents a comparative study of the anti-oxidant and anti-microbial activities, total phenolic compounds and total flavonoids in extracts obtained from houseleek (Sempervivum marmoreum L.) leaves by the classical (maceration), ultrasonic and Soxhlet extraction (CE, UE and SE, respectively). The extract obtained by the CE contained higher amounts of phenolic and flavonoid compounds and showed a better antioxidant activity than those obtained using other two techniques. All the extracts, independent of the extraction technique applied, showed antimicrobial activities against Aspergillus niger and Candida albicans only but not against the tested bacteria.

A sensitive, selective, precise and stability-indicating, new high-performance liquid chromatographic method for the analysis of carvedilol both as a bulk drug and in formulations was developed and validated. As the method could effectively separate the drug from its degradation products, it can be employed as a stability-indicating one. The method was validated for linearity, selectivity, precision, robustness, LOD, LOQ and accuracy. The chromatographic separation was achieved on a Chromolit RP8e, 100x4.6 mm, analytical column. The mobile phase consisted of a mixture of acetonitrile and water (45:55, V/V) (pH 2.5), pH adjusted with formic acid. The absorbance was monitored with a UV detector at 280 nm and the temperature of the analyses was 40°C. The flow rate was 0.5 mL/min. The linearity (r≥ 0.999), reproducibility (0.68-1.27 %) and recovery (99.71-101.58) were found to be satisfactory. This method enables the simultaneous determination of carvedilol and its degradation products, as well as stability. .

Flavonoids were analyzed in the extracts of garden (Salvia officinalis L.) and glutinous (Salvia glutinosa L.) sage. Ultrasonic extraction (20 minutes at 40°C) and classical maceration (6 h at room temperature) of the extractable substances from dried herbs and dried residual plant materials from which the essential oil had previously been removed by hydrodistillation were performed with petroleum ether, 70 % aqueous solution of ethanol and water. It was found that the extracts from both plants contained flavonoids, but their compositions were dependent of the plant species, the polarity of the extracting solvent and the extraction technique applied. Apigenin and its derivatives (e.g., apigenin 4'-methyl ether), scutellarein 6-methyl ether, isoscutellarein 8-methyl ether, luteolin and 6-OH-luteolin-6-methyl ether where distinctive for S. officinalis. Apigenin, luteolin, 6-OH-luteolin-6-methyl ether, kaempherol 3-methyl ether, kaempherol 3,7-dimethyl ether, quercetin 3,7,3'-trimethyl ether and quercetin 3,7,3',4'-tetramethyl ether were distinctive for S. glutinosa. The flavonoids were also detected in considerable quantities in the plant material from which the essential oils had been already removed. Hence, this industrial waste plant material might be further used as a source of the flavonoids. .

The paper presents the equations for the determination of the neutral axis position, when it is on the face, that is, on the bearing plate, and for the highest normal tensile stress in the fastener, as well as for the determination of highest and lowest normal compressive stress occurring on the face, that is bearing plate when the neutral axis is outside the face that is, the bearing plate. Which of these three possible cases will occur depends solely on the force field occurring in the given cross-section for the dimensioning of the joint. The connection is effected by the face or bearing plate, depending on the task being solved and the bolt fasteners. The expressions for the calculation of the said connections are derived for the general case when all three forces intersecting, M, T and N, in the cross section given for their dimensioning, are other than zero or any one of them is other than zero. The paper also presents a tabular presentation of the results for all of the three possible cases of the force fields, that is, the stress fields most frequently occurring in the civil engineering building practice at these joints.

In this paper a comparison of the chemical composition and antimicrobial action of the ethanol extracts from the flower, leaf and stem of the herbal species Salvia officinalis L. (Lamiaceae), originating from the southeast region of Serbia was carried out. The chemical composition of the extracts was determined by GC-FID and GC-MS analyses. Manool has the highest level of all the components (9.0–11.1 %). Antimicrobial activity was determined by the diffusion and dilution method, whereby the latter one was modified by use of cellulose discs, and it was applied for the determination of the minimal inhibitory (MIC) and minimal lethal concentrations (MLC). The leaf extract has a stronger antimicrobial activity than those of the flower and stem.

The chemical composition of four essential oils of four species of sage (Salvia officinalis L., Salvia pratensis L., Salvia glutinosa L. and Salvia aethiopis L) are examined by GC-FID and GC-MS analysis. The presence of some components in the essential oil (mono- and sesquiterpene) determines the pharmacological effects and therapeutical application of a plant species. Salvia officinalis L. gives the highest yield of oil (1.1 %), while the lowest is in Salvia pratensis L. (0.1 %). The investigations included the determination of the antimicrobic activities of the essential oils by the diffusion method and the oil of Salvia pratensis L. proved to have the highest activity.

The kinetics of the extraction of the overall extracted materials (resinoids), total hypericine, hypericine and pseudohypericine from amber (Hypericum perforatum L) was investigated by the procedure of maceration both with and without ultra-sound, using methanol as the extractant. It was found that the period of fast extraction with intensification of the extraction of resinoid by ultra-sound was significantly shorter (about 20 minutes) than was needed for the extraction without ultra-sound (about 5 h). Similar results were also obtained for the extraction of the other tested substances. It can be concluded that better drug exploitation can be achieved in a much shorter extraction time by intensification of the extraction using ultra-sound. By preparation of herbal material through pulverization, a significant grade of herbal tissue structure disintegration was achieved, so that turbulent mass transfer plays a dominant role in the extraction. The results show that the coefficient values of fast extraction (b) are approximately the same for all the investigated kinetics.

In this paper the chemical composition and antimicrobial action of the extracts from the flower, leaf and stem of Salvia pratensis L., Salvia glutinosa L. and Salvia aethiopis L. were investigated. The investigated extracts mostly contain monoterpenes to a high degree, except the flower extract of S. pratensis and the leaf extract of S. glutinosa where sesquiterpenes were found in great amounts. Diterpenes were found only in the extracts of S. aethiopis. All these extracts contained 1,8-cineole (to the highest degree (19.1%) in the stem extract of S. glutinosa) and beta-caryophyllene (to the highest degree (7.0%) in the flower extract of S. pratensis). The antimicrobial activities of the extracts were determined by the diffusion and dilution method.

The subject of this study is the chemical composition of volatile fractions from the fruit and leaf of quince (Cydonia oblonga Mill.). Dominant components were ethyl 2-methylbutanoate, (E,E)--farnesene, ethyl- (2E,4Z)-decadienoate, pentadecanol, -acoradienol, ethyl decanoate, ethyl octanoate, (E)-nerolidol, ethyl dodecanoate, 14-hydroxy-9-epi-(E)-caryophyllene, (2Z,6E)-farnesol, -cedrene. Volatile fraction of the fruit was also characterized by ethyl-(4Z)-decenoate, ethyl 9-dodecenoate, ethyl hexanoate, ethyl nonanoate and - cyclocitral, where in the leaf n-octanal, n-hexanol, n-nonanal and benzaldehyde were present. [ABSTRACT FROM AUTHOR]