Ambrosia artemisiifolia L. is an allergen species that belongs to the group of invasive weeds, and is very frequent and present in our region. The use of essential oils in the control of weeds attracts great attention of researchers. Many of them have already pointed out the ability of some oils and/or their individual components to delay seed germination of various weeds or completely inhibit it. In this paper, we present results of the efficacy of three essential oils on A. artemisiifolia seeds; the trials were carried out using two different in vitro methods, in which the percentage of seed germination was measured 7th day.  In testings with seeds soaked in essential oil solution, in Petri dishes (500 ml in 100 ml of distilled water), a significant inhibition of germination was observed in the case A. graveolens and S. officinalis oil (100 % and 97 % , respectively), while the oil of S. montana demonstrated slightly weaker inhibitory effect (86 %). When essential oils were applied in form of a vapour (an oil droplet of 25 ml applied on the inner side od Petri dish lids), A. graveolens and S. officinalis oils inhibited the seed germination 100 % and and 95 % , respectively , while the oil of S. montana again demonstrated the weakest inhibitory effect (52 %).

The aim of the presented research was to determine whether the application of the essential oils of A. graveolens, S. officinalis and S. montana in form of a solution or vapor, affects, and to what extent they are important for germination of seeds of the weed species A. artemisiifolia L.

Comparison between conventional and microwave-assisted hydrodistillation at different power levels has been applied for the extraction of essential oil from Zingiber officinale Rosc. rhizome. In addition to the collected essential oils, as the main products, hydrolats were also collected, as valuable by-products from both extraction techniques. A comparison of two applied techniques was done in terms of extraction time, extraction yield, the chemical composition of essential oils and hydrolats, and environmental impact. Microwave-assisted hydrodistillation achieved a higher extraction yield (1.70, 1.70, and 1.85 % for power levels of 180, 360, and 600 W, respectively) compared to hydrodistillation (1.50 %). Furthermore, distillation time related to the energy consumption has been reduced from 144 min and 1.44 kWh for conventional hydrodistillation to 37, 32, 27 min and 0.11, 0.19, 0.27 kWh for power levels of 180, 360, and 600 W, respectively. Content of α-zingiberene in essential oil and hydrolat obtained by hydrodistillation was 29.89 and 6.87 %, while content of α-zingiberene in essential oils and hydrolats obtained by microwave-assisted hydrodistillation was higher yielding the amounts of 34.12, 34.43, and 42.00 % and 18.70, 22.60, and 32.92 % for power levels of 180, 360, and 600 W, respectively. Microwave-assisted hydrodistillation has proven to be promising technique for the isolation of ginger’s essential oil regarding improved yield, reduced time and energy requirements, as well CO2 emissions while maintains oil quality.

This study was designed to investigate the impact of different extraction methods (ultrasound-assisted extraction, maceration, and microwave-assisted extraction) on the content of polyphenols and biological activities of leaf extract of Paeonia daurica subsp. daurica collected in Južni Kučaj (Serbia). The total polyphenol and flavonoid content were achieved by the UV-Vis spectroscopy. FTIR analysis was conducted to investigate structural properties of the extracts. In vitro methods (2,2^′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) - ABTS and 2,2-diphenyl-1-picrylhydrazyl – DPPH assays) were carried out to measure the antioxidant activity of the extracts, while their antibacterial activity was tested against three Gram-positive and three Gram-negative bacterial strains. Analyzing the results of antioxidant activity, the highest anti-DPPH potential was achieved in the extracts of LPD obtained by maceration. The extraction method proven to produce the most effective antibacterial agents is maceration. Moreover, inhibitory activity of extracts against acetyl–and butyrylcholinesterase, α-amylase, α-glucosidase, and tyrosinase was evaluated in the enzyme inhibition assays. Overall, the results of this research indicated the possible use utilization of leaf extracts of Paeonia daurica subsp. daurica Andrews in food technology and pharmacy.