Introduction: The aim of this study was to assess the antioxidant activity of cinnamon extracts obtained using different solvents (ethanol, methanol, acetone, water) and their mixtures with water. Additionally, the phenolic and flavonoid contents were analyzed to investigate their correlation with antioxidant activity. Materials and Methods: Cinnamon extracts were prepared using pure solvents (ethanol, methanol, acetone, water) and their mixture with water in different proportions. The total phenolic and flavonoid contents, as well as the antioxidant activity of the obtained extracts, were analyzed. Results and Discussion: The results showed that the extracts obtained from mixtures of ethanol and water had a high content of phenols and flavonoids, with the 40:10 ethanol-to-water mixture yielding the highest phenolic (240.69 mg/g) and flavonoid (0.275 mg/g) contents. Similarly, methanol and its mixtures with water showed variations in the content of these components, with pure methanol providing the highest values (252.12 mg/g for phenols and 0.2212 mg/g for flavonoids). Regarding antioxidant activity, ethanol extracts and their mixtures with water achieved the best results, with the 20:30 ethanol-to-water mixture displaying the highest antioxidant potential (937.775 µmol TE/g). Methanol-water mixtures, particularly in the 40:10 ratio, also exhibited high activity (928.675 µmol TE/g). Acetone extracts and their mixtures with water had somewhat lower values, while water-based extracts showed the lowest antioxidant activity (192.9 µmol TE/g). Conclusion: These results indicate a significant potential of solvent mixtures, particularly acetone-water mixtures, in enhancing bioactivity and antioxidant effects.

2-acetoxybenzoic acid, also known as aspirin, is one of the most widespread and important pharmaceutical compound used in the treatment of pain, inflammation, and febrile conditions. In addition to its well-known therapeutic properties, 2-acetoxybenzoic acid is increasingly being investigated in the context of its interactions with metals, leading to new insights into potential applications in medicine, chemistry, and biotechnology. Among the metals that form complex compounds with 2-acetoxybenzoic acid, nickel is one of the most interesting due to its specific electrochemical properties and biological activity. The study of the 2-acetoxybenzoic acid-nickel complex plays a significant role in understanding the molecular mechanisms of interaction between drugs and metal ions, as well as the potential therapeutic benefits of these compounds. This research thoroughly examines the structural, chemical, and biological aspects of the 2-acetoxybenzoic acid-nickel complex, with particular emphasis on its potential application in the pharmaceutical industry and medicine. The structure of this complex was determined by various spectroscopic and analytical techniques, including Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV), mass spectrometry (MS), melting point methods, and optical microscopy. These methods contributed to the understanding of the interaction mechanisms between the ligand and the nickel ion center, opening the possibility for further investigation of the pharmacological properties and potential therapeutic applications of this complex. The antibacterial and antifungal activity of the synthesized Ni(II) complex with 2-acetoxybenzoic acid was investigated, and it was found that the metal complex exhibits varying degrees of inhibitory effects on bacteria.

Bitter and sweet wormwoods are traditional plant species in the Asteraceae (Compositae). Their use in traditional medicine has long been known. Numerous preparations of bitter and sweet wormwood (teas, tinctures) are used in the treatment of diseases of the digestive system. The content of bioactive components (polyphenols and flavonoids) and antioxidant activity of Artemisia absinthium L. (bitter wormwood) and Artemisia annua L. (sweet wormwood) were examined in this paper. Extract's series were prepared by mixing selected organic solvents (methanol, ethanol and acetone) and water in different volume ratios for both analyzed species. Antioxidant activity was tested using FRAP and DPPH methods. Extracts of sweet wormwood contain more bioactive components and have a higher antioxidant capacity compared to extracts of bitter wormwood. In terms of extraction efficiency, the mixture of acetone and water (20:30 v/v) proved to be the most efficient. Regarding pure organic solvents, the most effective for the bioactive components isolation is ethanol, while acetone showed the weakest extraction power.

The UV-VIS method is an effective, non-destructive method that enables a better understanding of the electrolyte during corrosion. The aim of the study presented in this paper is to determine the existence of an organometallic complex in a 0.5 M NaCl solution with the addition of Rubus fruticosus L. leaf extract (RFLE). The experiments were conducted in a 0.5 M NaCl solution with the addition of RFLE (5 g/L and 10 g/L) with and without the immersion of a copper coupon. The results show that after the copper coupon standing in the electrolyte, there is a change in the absorbance maximum in the solution with 5 g/L RFLE, while no change is observed in the solution with 10 g/L RFLE. Such a change indicates the existence of a copper-RFLE complex in the solution with lower inhibitor concentration. In the case of RFLE, forming a copper complex with caffeic acid, isoquercetin and astragalin is possible. The absence of the complex at a concentration of 10 g/L RFLE can be attributed to a change in the mechanism and the lack of copper ions in the solution due to adequate corrosion protection.

Tussilago farfara L., also known as coltsfoot, is a plant that has been used since ancient times to relieve coughs. Subsequently, the effectiveness of coltsfoot in the treatment of bronchial asthma, pneumonia and other respiratory diseases was established. In this research, the antioxidant and antimicrobial activity of different coltsfoot extracts was analyzed. The antioxidant activity was monitored through the DPPH radical inhibition efficiency and the extract's reducing ability. Antibacterial activity was tested using the diffusion technique. Tussilago farfara L. extracts showed extremely high antioxidant activity in in vitro conditions. The highest antioxidant capacity was found in extracts prepared by mixing water and organic solvents. High antibacterial activity was found for ethanolic, acetone and aqueous-ethanolic extracts of coltsfoot.

Capsella bursa-pastoris (L.) Medik. (known as shepherd's purse) is a plant whose parts are used as medicine in herbal medicine. It is applicable as a medicine in the treatment of all forms of internal bleeding, for the treatment of hemorrhoids, excessive menstruation, but also for the usual stopping of nosebleeds. Through this research, the influence of organic solvents and their aqueous mixtures on the efficiency of polyphenol extraction and antioxidant activity was compared. The inhibition of free radicals was tested by the DPPH method, while the FRAP method was used to test the reduction potential. Analyzes have shown that water is the most effective solvent in the isolation of polyphenols from the aerial parts of shepherd's purse. Mixtures of organic solvents with water also showed high efficiency in the extraction of bioactive components, while the weakest results were obtained for extracts prepared in pure organic solvents.