Heterocyclic pharmaceuticals are emerging contaminants due to their toxic, carcinogenic nature and detrimental impact on the natural ecosystem. These compounds pose a significant environmental concern given their widespread use in medical therapy, constituting over 90% of new medications. Their unique chemical structure contributes to their persistence in various environmental matrices, necessitating urgent measures to mitigate their risks. This review comprehensively examines the sources, environmental fate, toxicity, and long-term risks associated with heterocyclic pharmaceuticals, proposing potential remediation strategies. The article commences with an overview of the diverse types of heterocyclic pharmaceuticals and their applications, focusing on compounds containing heteroatoms such as nitrogen, oxygen, and sulfur. Subsequently, it explores the sources and pathways through which these pollutants enter the environment, including wastewater discharge, agricultural runoff, improper disposal, resistance to biodegradation, and bioaccumulation. The toxic effects and long-term consequences of exposure to heterocyclic pharmaceuticals are then discussed, encompassing neurotoxicity, genotoxicity, mutagenesis, cardiovascular and metabolic toxicity, carcinogenicity, and teratogenesis. Additionally, this review summarizes various remediation strategies and treatment solutions aimed at reducing the environmental impact of these compounds, drawing insights from the literature. The research concludes by identifying critical areas for future research, emphasizing the urgent need for more effective remediation strategies to address the growing concern posed by these emerging contaminants.

The art of dyeing textiles has a long history, as natural dyes have been used since prehistoric times. With the development of synthetic dyes in the 19th century, the focus shifted from natural to synthetic dyes due to their superior properties. Recently, however, interest in natural dyes has increased again due to environmental and health concerns. Among industrial dyes, heterocyclic dyes, especially azo dyes, are of great importance due to their color brilliance and fastness. This review examines the synthesis, application, and analysis of azo dyes, especially heterocyclic dyes. It deals with monoazo, diazo, and polyazo dyes and highlights their structures, synthesis methods, and fastness properties. In addition, the ecological impact of azo dyes and practical solutions for their synthesis and application are discussed.

This article presents results on the use of a new material as a solidifying agent and/or color-fixing agent. A special polysaccharide material extracted from the prickly pear cactus (Opuntia ficus indica) was tested on historical materials and modern papers. An old book from the 18th century was chosen as historical material. From the mentioned book 42 pages were taken, on which a conservation and restoration pretreatment was performed before applying the polysaccharide material: sampling, fiber analysis, dry cleaning, ink solubility, pH test, thickness measurement and wet cleaning. The paper sheets provided for the test were divided into 4 groups, 3 of which were treated with gel and one left untreated as a reference. The division into groups is not only due to the different method of application, but also due to the process of gel extraction. The effect of the treatment was analyzed using FTIR-ATR. To test the mucilage as color-fixing agent 2 samples were prepared using watercolor papers colored with 6 different watercolors applied to 2.5 cm² samples for each color in two rows of different intensity. One of the 2 samples was treated with gel, but both were immersed for 3 times in a water-ethanol solution for approximately 20 min as is standard practice in conservation and restoration. After washing, both specimens were subjected to colorimetric analysis to assess their differences. The results provided satisfactory evidence for the protection of paints sensitive to aqueous treatments and suggest the use of mucilage as a new material in cleaning method for water-soluble media.

DFT calculations at the B3LYP/aug-cc-pVDZ level of theory on some aromatic substrates showed that in the HOMO (Highest Occupied Molecular Orbital) of nitrobenzene, the atomic coefficients are not in agreement with the meta-directing behavior of this compound. The atomic coefficients are the same in the ortho and in the meta positions. The HOMO (or NHOMO (Next Occupied Molecular Orbital) in the case of benzaldehyde) is not in agreement with the experimental results when deactivating, meta-orienting compounds are considered. Mulliken charges sometimes are not able to explain the observed reactivity. Hirshfeld charges allow us to predict the orientation of the attack of an electrophile on the aromatic ring, with the exception of nitrobenzene. Both HOMO atomic coefficients and charges are in agreement with the experimental results when deactivating, ortho-para orienting, and activating compounds are tested.

The art of dyeing fabrics is one of the oldest human activities. In order to improve the fastness properties of dyeing products, various additives are added to optimize the uniformity of fibers and surfaces and improve dye distribution. Unfortunately, these additives can be harmful and very often are not biodegradable. This article reports on the possibility of using a natural additive for dyeing textiles: a polysaccharide extracted from the prickly pear cactus (Opuntia ficus indica). One type of fabric was tested, silk, with different colors. Several samples were prepared and dyed for each color, adding the same additives but also a commercial chemical aid for one of them and the mucilage of Opuntia for another. The fastness of the applied dyes was evaluated by washing at different temperatures with a common liquid detergent. All samples were analyzed before and after washing with a colorimeter to evaluate the color changes. The results of the analyses reported and compared indicate the potential of prickly pear mucilage as an additive for dyeing silk, which is easily accessible, safe, and sustainable compared to other commonly used additives.

Background/Objectives: Biocorrosion, driven by microbial colonization and biofilm formation, poses a significant threat to the integrity of metal artifacts, particularly those composed of copper and its alloys. Pseudomonas aeruginosa, a bacterial species that reduces nitrates, plays a key role in this process. This study explores the potential of two metabolite-rich plant extracts, Aloe vera and Opuntia ficus-indica, as sustainable biobased inhibitors of microbial-induced corrosion (MICOR). Methods: The antibacterial and antibiofilm activities of the extracts were evaluated using minimal inhibitory concentration (MIC) assays, time-kill kinetics, and biofilm prevention and removal tests on copper, bronze, and brass samples. Spectrophotometric and microbiological methods were used to quantify bacterial growth and biofilm density. Results: Both extracts exhibited significant antibacterial activity, with MIC values of 8.3% (v/v). A. vera demonstrated superior bactericidal effects, achieving reductions of ≥3 log₁₀ in bacterial counts at lower concentrations. In antibiofilm assays, both extracts effectively prevented biofilm formation and reduced established biofilms, with A. vera exhibiting greater efficacy against them. The active metabolites—anthraquinones, phenolics, flavonoids, and tannins—likely contribute to these effects. Conclusions: These findings highlight the dual role of A. vera and O. ficus-indica extracts as both corrosion and biocorrosion inhibitors. The secondary metabolite profiles of these plants support their application as eco-friendly alternatives in the conservation of metal cultural heritage objects.