Cyclophane-containing peptides comprise an important group of macrocyclic peptides with unique structural properties and pharmaceutical relevance. Darobactin A is a ribosomally synthesized and post-translationally modified peptide (RiPP) antibiotic, which features an unusual biscyclophane moiety formed via the class-defining ether crosslink in addition to a carbon-carbon (C-C) crosslink. Because darobactin-like peptides (daropeptides) are widespread in nature, further exploration of these emerging RiPP natural products featuring ether crosslinked cyclophane could facilitate the discovery and development of new bioactive peptides. This perspective provides updated insights into the biosynthesis and classification of daropeptides, highlighting the potential to manipulate daropeptide maturases to access novel bioactive peptide cyclophanes.

Protein-protein interactions (PPIs) impersonate a significant role in many biological processes and are potential therapeutic targets in numerous human diseases. Stapled peptides, as the most promising therapeutic candidate for interfering with PPIs, have a higher degree of α-helicity, improved binding affinity, more resistance to proteolytic digestion, longer serum half-life, and enhanced cell permeability, which exhibits higher pharmacological activity compared with small molecule drugs and biologics. This review outlined the continuous progress of stapled peptides mainly concerning the design principle, structural stability, bioactivity, cell permeability, and potential applications in therapeutics, which is aimed at providing a broad reference for the design and exploration of stapled peptides with enhanced biological and pharmacokinetic properties as the next-generation therapeutic peptide drugs targeting various diseases.

Five families of investigational products are in clinical investigation to slow or reverse normal aging processes [longevity candidates, mesenchymal stem cells, senolytics drugs, sirtuin activators, and nicotinamide adenine dinucleotide (NAD)⁺ precursors]. The longevity candidates, vitamin D and metformin, appear to significantly reduce all-cause mortality and prolong life expectancy. This should be confirmed by interventional studies. The mesenchymal stem cell family is the most advanced in clinical trial development [phase 2b randomized controlled trial (RCT)]. An allogeneic bone marrow stem cell preparation (Lomecel-B) reduced locomotor frailty in older people. The improvement in locomotion was modest. In the future, attempts could be made to improve potency through a precondition or genetic modification of naive bone marrow stem cells. Autologous adipose stem cell-assisted fat grafting increased graft survival, facial volume, and skin quality. The association of the senolytic drugs dasatinib and quercetin was well tolerated, with low brain penetration of dasatinib and undetectable levels of quercetin. The sirtuin-1 activator resveratrol (combined with physical exercise) improved physical function in older adults with physical limitations. The NAD⁺ precursor nicotinamide riboside improved physical exercise performance. In conclusion, Lomecel-B is the most advanced agent in clinical trial development for normal aging processes (phase 2b for locomotion frailty), followed by resveratrol and nicotinamide riboside.

Pharmaceutical interventions play a vital role in managing various conditions, including weight-related issues such as obesity. In this context, lifestyle changes are often challenging to maintain, especially for individuals struggling with this condition. Obesity is strongly linked to serious health conditions like cardiovascular disease and insulin resistance, leading to a cascade of health risks. Importantly, the development of effective and safe weight loss medications has been challenging. Diabetes mellitus (DM), the incidence of which is also rising, is closely related to obesity. The annual rate of DM cases has increased significantly, mirroring trends in obesity. Pharmaceutical companies have made significant progress in developing drugs that address both diabetes and obesity. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have emerged as a promising class of medications with dual benefits in managing diabetes and aiding weight loss such as semaglutide, liraglutide, dulaglutide, exenatide, among others. However, despite their effectiveness, they can be expensive. The availability of various GLP-1RAs offers flexibility in diabetes management, but the surge in their prescription has led to a global shortage. Health authorities are working to address this issue, while pharmaceutical companies are exploring new paths to improve the quality of these drugs. In this context, tirzepatide stands out as a medication targeting key hormones involved in obesity and DM. Another potential breakthrough, retatrutide, is also being developed for these two conditions, but it requires further research. In this paper, the authors address all the GLP-1RA options developed to date, covering their mechanisms of action, efficacy, and chemical structures, among other aspects.

The search for novel therapeutic agents to combat the crisis of antimicrobial resistance has spanned from terrestrial to unique, marine environments. Currently, most of the drugs available for usage are derived from microbial metabolites, especially those belonging to the bacterial group, actinobacteria. Actinobacteria are hotspot organisms that exist in all habitats with a myriad of unique biosynthetic metabolites. Seagrasses appear to be a key ecosystem within the coastal environment worth bioprospecting for novel natural products. Unfortunately, literature about the bioactive potential of their associated prokaryotes, including actinobacteria remains limited. In this context, this review focused on actinobacteria with antibiotic-producing capabilities derived from different parts of seagrass plants (i.e. roots, rhizomes, and leaves). To date, there were no purified molecules derived from seagrass-associated actinobacteria that were subjected to structure elucidation. From the underpinning of numerous biological profiles such as antibacterial, antifungal, and algicidal activities of seagrass-derived actinobacteria reported in this review during the period from 2012–2020, it provides a continual growth of knowledge accruing overtime, providing a foundation for future research.

The influenza virus glycoprotein hemagglutinin (HA) participates in critical steps of the attachment of viral particles to the host cell membrane receptor and membrane fusion. Due to its crucial involvement in the initial phases of influenza A infections, HA emerges as a promising target in the search of novel drug-like candidates. Given its pivotal role in the early stages of influenza A infections, intense drug discovery efforts have been undertaken to target HA in the past decades. Drug discovery studies mainly rely on preventing the recognition of sialic acid units by the receptor binding site in the globular head (GH) domain, or the conformational rearrangement required for the fusion of viral and cell membranes. In this work, the aim is to summarize the progress made in HA-targeted development of small molecule fusion inhibitors. To this end, attention will primarily be focused on the analysis of the X-ray crystallographic structures of HA bound to fusion inhibitors. Furthermore, this study also aims to highlight the efforts made in exploiting the structural information in conjunction with molecular modeling techniques to discern the mechanism of action of the fusion inhibitors and to assist the design and interpretation of structure-activity relationships of novel lead compounds will be highlighted. The final section will be dedicated to elucidating novel and promising antiviral strategies proceeding from the transformation of known small molecule antivirals in proteolysis targeting chimera (PROTAC)-based targeted protein degradation. This knowledge will be valuable to assist the exploitation of classical and novel antiviral structure-based strategies, together with a deeper understanding of the mechanism of action and minimization of the impact of drug resistance.