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 outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in December 2019 quickly escalated to pandemic levels and had a severe impact on public health. There are 761 million confirmed coronavirus disease 2019 (COVID-19) cases, with over 6.88 million deaths worldwide till March 2023. Severe cases of the disease caused critical respiratory failure followed by multiorgan involvement. Clinical escalation of COVID-19 has been correlated with markedly increased plasma inflammatory markers [e.g., C-reactive protein (CRP)] and pro-inflammatory cytokine levels [e.g., interleukin (IL)-6, tumor necrosis factor-α (TNF-α)]. Therapeutic options have mostly utilized corticosteroids, antivirals (e.g., remdesivir), and monoclonal antibody-based immunomodulation (e.g., tocilizumab). These existing treatments have adverse side effects, inadequate efficacy, and limitations in administering to patients with comorbidities and other underlying diseases. Monoclonal antibody-based therapies and some of the antivirals are very costly. Many phytochemicals have previously reported anti-inflammatory, antiviral, and antioxidant properties. Studying the effectiveness of such phytochemicals against COVID-19 and identifying new plant-derived molecules with antiviral properties have been a focus since the SARS-CoV-2 outbreak. This review article has documented in vitro, in vivo, and clinical studies encompassing 28 different phytochemicals belonging to various chemical groups (e.g., polyphenols, alkaloids, terpenes) that show anti-COVID-19 activity. These findings suggest that multiple phytochemicals can interfere with virus entry and replication inside the host cell. Many of them can protect from cytokine storm by acting on intracellular signalling pathways in addition to inhibiting virus multiplication. Phytochemicals may prove useful in alleviating post-COVID complications associated with kidney injury, and central nervous system complications, as well. Plant-derived compounds are usually cheaper and have fewer side effects. But, developing new formulations with better absorption and bioavailability remains a priority. This review informs the readers of the current status and indicates the ongoing research in this highly relevant field.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), known to cause the coronavirus disease 2019 (COVID-19), was declared a pandemic in early 2020. During the past time, several infections control methods have been developed. Nevertheless, all of them have certain limitations: uncertainty in duration, limited efficacy of vaccines, and lack of effective drugs for COVID-19 treatment. So, the issue of creating drugs for symptomatic and etiotropic therapy is still relevant. This review summarizes the current knowledge of using natural compounds as anti-SARS-CoV-2 agents by analysing the results of in vitro studies and completed clinical trials (CTs). Also, this work highlighted the most active molecules and discussed the possibility of using some compounds in clinical practice.

Bacterial infections constitute one of the major cases of primary medical incidences worldwide. Historically, the fight against bacterial infections in humans has been an ongoing battle, due to the ability of bacteria to adapt and to survive. Indeed, bacteria have developed various mechanisms of resistance against several therapeutic agents. Consequently, the scientific community is always interested in search of new therapeutic agents, which are able to efficiently kill resistant-bacterial strains. This article covers the most recent antibacterial molecules approved by the Food and Drugs Administration (FDA) and European Medicines Agency (EMA) from 2012 to 2022 and intends to focus on synthetic derivatives to give a pedagogical view, with the goal of highlighting the importance of organic synthesis to obtain greater efficacy. A focus will be made on studies describing the structure and activity of the organic molecules and their interactions with their respective biological targets.

Peptides constitute an important component of Nature’s pharmacy and they play a significant role in several signaling pathways acting as natural biological messengers. While nature has mastered the cycle of creation, application, and destruction of large and short peptides to the benefit of the host organism, organic and medicinal chemists have in their capacity and small steps, made big developments in the field of peptide synthesis as well as in developing them as therapeutics. In comparison to their big counterparts, i.e. proteins, short peptides encompass several advantages, from the ease of synthesis to their physico-chemical properties. However, the real challenge for in vivo application of therapeutic peptides is to overcome their low plasma availability and their fast enzymatic degradation. This review briefly covers the relevant areas of medicinally important short peptides and the recent developments made to turn these peptides into therapeutics. Also presented in this article are important efforts and strategies used to overcome some of the inherent limitations of peptidic molecules and thereby facilitate their progression in the clinical phases towards approved drugs.