Poor responses to medical care and the failure of pharmacological treatment for many high-frequency diseases, such as cancer and viral infections, have been widely documented. In this context, numerous metal-based substances, including cisplatin, auranofin, various gold metallodrugs, and ruthenium complexes, are under study as possible anticancer and antiviral agents. The two Ru(III) and Ru(II) complexes, namely, BOLD-100 and RAPTA-C, are presently being studied in a clinical trial and preclinical studies evaluation, respectively, as anticancer agents. Interestingly, BOLD-100 has also recently demonstrated antiviral activity against SARS-CoV-2, which is the virus responsible for the COVID-19 pandemic. Over the last years, much effort has been dedicated to discovering new dual anticancer–antiviral agents. Ru-based complexes could be very suitable in this respect. Thus, this review focuses on the most recent studies regarding newly synthesized Ru(II) complexes for use as anticancer and/or antiviral agents.

From Egyptian mummies to the Chanel N° 5 perfume, aldehydes have been used for a long time and continue to impact our senses in a wide range of perfumes, foods, and beverages. Aldehydes represent one of the categories of volatile organic compounds (VOCs), which are categorized as chemicals with boiling points up to 260 °C and can be found in indoor environments in the gaseous phase. Because of their potential or known hazardous properties for humans, the World Health Organization (WHO)-Europe provided some guidelines that may prevent several health risks. Indeed, some aldehydes, reported to be risky for humans, have been retired from the market, such as butylphenyl methylpropional (BMHCA). The purpose of this review is to summarize the most important aldehydes found indoors and outdoors and analyse in depth the toxicological aspects of these compounds, whose presence in perfumes is often underestimated. In addition, the ingredients’ synonyms that are reported in the literature for the same compound were unified in order to simplify their identification.

The scientific interest in the chemical modification of chitosan to increase its solubility and application has led to its conjugation with Schiff bases, which are interesting scaffolds endowed with diverse biological properties. The resultant chitosan-based Schiff bases (CSBs) are widely studied in scientific literature due to the myriad of activities exerted, both catalytic and biological, including anticancer, anti-inflammatory, antioxidant, and especially antimicrobial ones. Antimicrobial resistance (AMR) is one of the major public health challenges of the twenty-first century because it represents a threat to the prevention and treatment of a growing number of bacterial, parasitic, viral, and fungal infections that are no longer treatable with the available drugs. Thus, in this review, we present a brief outline of the biological activities of CSBs as well as their complexes with metals, with a particular focus on the recent literature regarding the antimicrobial effect of these captivating derivatives.

The strict connections/interactions between microbial infections and cancer are nowadays widely accepted. Hence, the dual (or multiple) targeting of microbial infections and cancer is an essential issue to be addressed. In this context, metal complexes have gained considerable importance and effectiveness in medicinal chemistry. Particularly, N-heterocyclic carbene (NHC) complexes with transition metals have emerged as very promising compounds. Among the myriad of NHC–metal complexes, those bearing silver will be the subject of this review. Numerous Ag(I)-NHC complexes have revealed high antibacterial and/or anticancer properties, even higher than those of reference drugs. Herein, we summarize the most recent studies while also discussing the proposed mechanism of action and offering an interesting remark about the research in this field. Literature databases (PubMed/MEDLINE, Scopus, and Google Scholar) were used as sources to search the literature, referring to the last five years.

Most of the structural studies made on the secondary structure of peptoids describe their geometric attributes in terms of the classic Ramachandran plot (based on the local analysis of ω, ψ, χ, φ dihedral angles). However, little intuitive understanding is available from internal coordinates when stereochemistry is involved. In this contribution we list all the conformationally stable cyclic peptoids reported up to the year 2017 and propose a simple method to define their geometric arrangement in terms of planar chirality. Evidence of conformational isomerism (due to the long average time of single bond rotation) and conformational chirality (induced by the absence of roto-reflection axes) in this promising class of synthetic macrocycles is provided by NMR spectroscopy (using Pirkle's alcohol as chiral solvating agent) and careful evaluation of X-ray crystallographic studies. The full understanding of the oligomeric macrocycles’ structural properties and the clear framing of their conformational isomerism in a proper conceptual scheme is fundamental for future application of peptoids in asymmetric synthesis, chiral recognition and supramolecular chemistry.

Owing of their accessibility and wide range of reactivities, alkynes make for fascinating building blocks. Either a selective alkyne carbon-carbon triple bond reaction or activation of the terminal alkyne C-H bond may be employed to functionalize them. Monocationic coinage metal complexes with a d10 electronic configuration are effective catalysts for alkyne activation. Silver(I) and gold(I) N-heterocyclic (NHC) systems are emerging as promising catalysts in multicomponent alkyne activation reactions; this review paper focuses on A³ (aldehyde-amine-alkyne)-coupling reaction and carbon dioxide fixation, furnishing a systematic overview of the scientific advances achieved during the last two decades. This study will carefully compare the corresponding silver and gold complexes employed in the two processes. The differences in reaction routes brought about by the catalyst ligand structure will be investigated with an emphasis on evaluating the benefits provided by the easily tuneable NHC backbone, in terms of chemo- and stereo-selectivity.