Synthesis of Antiviral Perfluoroalkyl Derivatives of Teicoplanin and Vancomycin

A Systematic Review of Second-Line Treatments in Antiviral Resistant Strains of HSV-1, HSV-2, and VZV

Drug-resistant variants of herpes simplex viruses (HSV) have been reported that are not effectively treated with first-line antiviral agents. The objective of this study was to evaluate available literature on the possible efficacy of second-line treatments in HSV and the use of second-line treatments in HSV strains that are resistant to first-line treatments. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a final search was conducted in six databases on November 5, 2021 for all relevant literature using terms related to antiviral resistance, herpes, and HSV. Eligible manuscripts were required to report the presence of an existing or proposed second-line treatment for HSV-1, HSV-2, or varicella zoster virus (VZV); have full-text English-language access; and potentially reduce the rate of antiviral resistance. Following screening, 137 articles were included in qualitative synthesis. Of the included studies, articles that examined the relationship between viral resistance to first-line treatments and potential second-line treatments in HSV were included. The Cochrane risk-of-bias tool for randomized trials was used to assess risk of bias. Due to the heterogeneity of study designs, a meta-analysis of the studies was not performed. The dates in which accepted studies were published spanned from 2015-2021. In terms of sample characteristics, the majority (72.26%) of studies used Vero cells. When looking at the viruses on which the interventions were tested, the majority (84.67%) used HSV-1, with (34.31%) of these studies reporting testing on resistant HSV strains. Regarding the effectiveness of the proposed interventions, 91.97% were effective as potential managements for resistant strains of HSV. Of the papers reviewed, nectin in 2.19% of the reviews had efficacy as a second-line treatments in HSV, amenamevir in 2.19%, methanol extract in 2.19%, monoclonal antibodies in 1.46%, arbidol in 1.46%, siRNA swarms in 1.46%, Cucumis melo sulfated pectin in 1.46%, and components from Olea europeae in 1.46%. In addition to this griffithsin in 1.46% was effective, Morus alba L. in 1.46%, using nucleosides in 1.46%, botryosphaeran in 1.46%, monoterpenes in 1.46%, almond skin extracts in 1.46%, bortezomib in 1.46%, flavonoid compounds in 1.46%, andessential oils were effective in 1.46%, but not effective in 0.73%. The available literature reviewed consistently supports the existence and potentiality of second-line treatments for HSV strains that are resistant to first-line treatments. Immunocompromised patients have been noted to be the population most often affected by drug-resistant variants of HSV. Subsequently, we found that HSV infections in this patient population are challenging to manage clinically effectively. The goal of this systematic review is to provide additional information to patients on the potentiality of second-line treatment in HSV strains resistant to first-line treatments, especially those who are immunocompromised. All patients, whether they are immunocompromised or not, deserve to have their infections clinically managed in a manner supported by comprehensive research. This review provides necessary information about treatment options for patients with resistant HSV infections and their providers.

Clinical effect of teicoplanin on pulmonary infection after chemotherapy for hematologic malignancies

OBJECTIVE

To explore the effects of teicoplanin on pulmonary infection after chemotherapy for hematologic malignancies.

METHODS

In the present retrospective study, 64 patients with pulmonary infection, who underwent chemotherapy for hematologic malignancies at Anhui No.2 Provincial People's Hospital from September 2019 to September 2021, were selected as an infection group, and their clinical data were retrospectively analyzed. Meanwhile, 30 patients without pulmonary infection after chemotherapy for hematologic malignancies were selected as a reference group. Patients in the infection group were subdivided into control and treatment groups (n=32 each) according to the different therapeutic regimens. The control group was given routine treatment with norvancomycin, while the treatment group was given teicoplanin combined with norvancomycin. The therapeutic effects, bacterial clearance rate, recovery time, clinical pulmonary infection score (CPIS), inflammatory factors and adverse reactions were compared between the two groups. The risk factors of pulmonary infection after treatment for hematologic malignancies were analyzed.

RESULTS

The treatment group exhibited higher total therapeutic effect and higher bacterial clearance rate than the control group (P < 0.05). The treatment group had shorter time to the recovery of white blood cell (WBC) count, time to the disappearance of cough and sputum, time to return to normal body temperature, and length of stay than the control group (P < 0.05). One month post-treatment, the levels of C-reactive protein, tumor necrosis factor-α, interleukin-1β, and procalcitonin in the treatment group were lower than those in the control group (P < 0.05). The CPISs at 7, 14, and 30 days after treatment were lower in the treatment group than those in the control group (P < 0.05). Compared with the reference group, the infection group had higher rate of diabetes, higher rate of glucocorticoid use, longer time of agranulocytosis, longer hospital stay and lower WBC count (P < 0.05). Multivariate Logistic regression analysis showed that agranulocytosis time, diabetes mellitus and glucocorticoid use were independent risk factors for pulmonary infection after treatment for hematologic malignancies (P < 0.05), and that higher WBC was a protective factor (P < 0.05).

CONCLUSION

Teicoplanin in the treatment of pulmonary infection after chemotherapy for hematologic malignancies can improve the therapeutic effects, effectively clear bacteria, shorten the recovery time and reduce the inflammatory response.

Semisynthetic teicoplanin derivatives with dual antimicrobial activity against SARS-CoV-2 and multiresistant bacteria

Patients infected with SARS-CoV-2 risk co-infection with Gram-positive bacteria, which severely affects their prognosis. Antimicrobial drugs with dual antiviral and antibacterial activity would be very useful in this setting. Although glycopeptide antibiotics are well-known as strong antibacterial drugs, some of them are also active against RNA viruses like SARS-CoV-2. It has been shown that the antiviral and antibacterial efficacy can be enhanced by synthetic modifications. We here report the synthesis and biological evaluation of seven derivatives of teicoplanin bearing hydrophobic or superbasic side chain. All but one teicoplanin derivatives were effective in inhibiting SARS-CoV-2 replication in VeroE6 cells. One lipophilic and three perfluoroalkyl conjugates showed activity against SARS-CoV-2 in human Calu-3 cells and against HCoV-229E, an endemic human coronavirus, in HEL cells. Pseudovirus entry and enzyme inhibition assays established that the teicoplanin derivatives efficiently prevent the cathepsin-mediated endosomal entry of SARS-CoV-2, with some compounds inhibiting also the TMPRSS2-mediated surface entry route. The teicoplanin derivatives showed good to excellent activity against Gram-positive bacteria resistant to all approved glycopeptide antibiotics, due to their ability to dually bind to the bacterial membrane and cell-wall. To conclude, we identified three perfluoralkyl and one monoguanidine analog of teicoplanin as dual inhibitors of Gram-positive bacteria and SARS-CoV-2.

Recent Advances in the Development of Semisynthetic Glycopeptide Antibiotics: 2014-2022

The accelerated appearance of drug-resistant bacteria poses an ever-growing threat to modern medicine's capacity to fight infectious diseases. Gram-positive species such as methicillin-resistant Staphylococcus aureus (MRSA) and Streptococcus pneumoniae continue to contribute significantly to the global burden of antimicrobial resistance. For decades, the treatment of serious Gram-positive infections relied upon the glycopeptide family of antibiotics, typified by vancomycin, as a last line of defense. With the emergence of vancomycin resistance, the semisynthetic glycopeptides telavancin, dalbavancin, and oritavancin were developed. The clinical use of these compounds is somewhat limited due to toxicity concerns and their unusual pharmacokinetics, highlighting the importance of developing next-generation semisynthetic glycopeptides with enhanced antibacterial activities and improved safety profiles. This Review provides an updated overview of recent advancements made in the development of novel semisynthetic glycopeptides, spanning the period from 2014 to today. A wide range of approaches are covered, encompassing innovative strategies that have delivered semisynthetic glycopeptides with potent activities against Gram-positive bacteria, including drug-resistant strains. We also address recent efforts aimed at developing targeted therapies and advances made in extending the activity of the glycopeptides toward Gram-negative organisms.

Computational Chemistry Study of Natural Apocarotenoids and Their Synthetic Glycopeptide Conjugates as Therapeutic Drugs

The objective of the research to be presented in the chapter is the determination of the chemical reactivity properties of some natural apocarotenoids and their synthetic glycopeptide conjugates that could have the ability to inhibit SARS-CoV-2 replication. The study will be based on the consideration of the Conceptual DFT branch of Density Functional Theory (DFT) through the consideration of particular successful model chemistry which has been demonstrated as satisfying the Janak and Ionization Energy theorems within Generalized Gradient Approximation (GGA) theory. The research will be complemented by a report of the ADMET and pharmacokinetic properties hoping that this information could be of help in the development of new pharmaceutical drugs for fighting COVID-19.

Emerging Roles of Glycopeptide Antibiotics: Moving beyond Gram-Positive Bacteria

Glycopeptides, a class of cell wall biosynthesis inhibitors, have been the antibiotics of choice against drug-resistant Gram-positive bacterial infections. Their unique mechanism of action involving binding to the substrate of cell wall biosynthesis and substantial longevity in clinics makes this class of antibiotics an attractive choice for drug repurposing and reprofiling. However, resistance to glycopeptides has been observed due to alterations in the substrate, cell wall thickening, or both. The emergence of glycopeptide resistance has resulted in the development of synthetic and semisynthetic glycopeptide analogues to target acquired resistance. Recent findings demonstrate that these derivatives, along with some of the FDA approved glycopeptides have been shown to have antimicrobial activity against Gram-negative bacteria, Mycobacteria, and viruses thus expanding their spectrum of activity across the microbial kingdom. Additional mechanisms of action and identification of novel targets have proven to be critical in broadening the spectrum of activity of glycopeptides. This review focuses on the applications of glycopeptides beyond their traditional target group of Gram-positive bacteria. This will aid in making the scientific community aware about the nontraditional activity profiles of glycopeptides, identify the existing loopholes, and further explore this antibiotic class as a potential broad-spectrum antimicrobial agent.

The Very First Modification of Pleuromutilin and Lefamulin by Photoinitiated Radical Addition Reactions-Synthesis and Antibacterial Studies

Pleuromutilin is a fungal diterpene natural product with antimicrobial properties, semisynthetic derivatives of which are used in veterinary and human medicine. The development of bacterial resistance to pleuromutilins is known to be very slow, which makes the tricyclic diterpene skeleton of pleuromutilin a very attractive starting structure for the development of new antibiotic derivatives that are unlikely to induce resistance. Here, we report the very first synthetic modifications of pleuromutilin and lefamulin at alkene position C19–C20, by two different photoinduced addition reactions, the radical thiol-ene coupling reaction, and the atom transfer radical additions (ATRAs) of perfluoroalkyl iodides. Pleuromutilin were modified with the addition of several alkyl- and aryl-thiols, thiol-containing amino acids and nucleoside and carbohydrate thiols, as well as perfluoroalkylated side chains. The antibacterial properties of the novel semisynthetic pleuromutilin derivatives were investigated on a panel of bacterial strains, including susceptible and multiresistant pathogens and normal flora members. We have identified some novel semisynthetic pleuromutilin and lefamulin derivatives with promising antimicrobial properties.

Teicoplanin-A New Use for an Old Drug in the COVID-19 Era?

Teicoplanin is an antibiotic that has been actively used in medical practice since 1986 to treat serious Gram-positive bacterial infections. Due to its efficiency and low cytotoxicity, teicoplanin has also been used for patients with complications, including pediatric and immunocompromised patients. Although teicoplanin is accepted as an antibacterial drug, its action against RNA viruses, including SARS-CoV2, has been proven in vitro. Here, we provide a thorough overview of teicoplanin usage in medicine, based on the current literature. We summarize infection sites treated with teicoplanin, concentrations of the antibiotic in different organs, and side effects. Finally, we summarize all available data about the antiviral activity of teicoplanin. We believe that, due to the extensive experience of teicoplanin usage in clinical settings to treat bacterial infections and its demonstrated activity against SARS-CoV2, teicoplanin could become a drug of choice in the treatment of COVID-19 patients. Teicoplanin stops the replication of the virus and at the same time avoids the development of Gram-positive bacterial co-infections.

Natural Apocarotenoids and Their Synthetic Glycopeptide Conjugates Inhibit SARS-CoV-2 Replication

The protracted global COVID-19 pandemic urges the development of new drugs against the causative agent SARS-CoV-2. The clinically used glycopeptide antibiotic, teicoplanin, emerged as a potential antiviral, and its efficacy was improved with lipophilic modifications. This prompted us to prepare new lipophilic apocarotenoid conjugates of teicoplanin, its pseudoaglycone and the related ristocetin aglycone. Their antiviral effect was tested against SARS-CoV-2 in Vero E6 cells, using a cell viability assay and quantitative PCR of the viral RNA, confirming their micromolar inhibitory activity against viral replication. Interestingly, two of the parent apocarotenoids, bixin and β-apo-8′carotenoic acid, exerted remarkable anti-SARS-CoV-2 activity. Mechanistic studies involved cathepsin L and B, as well as the main protease 3CLPro, and the results were rationalized by computational studies. Glycopeptide conjugates show dual inhibitory action, while apocarotenoids have mostly cathepsin B and L affinity. Since teicoplanin is a marketed antibiotic and the natural bixin is an approved, cheap and widely used red colorant food additive, these readily available compounds and their conjugates as potential antivirals are worthy of further exploration.

Antiviral Activity of Peptide-Based Assemblies

The COVID-19 pandemic highlighted the importance of developing surfaces and coatings with antiviral activity. Here, we present, for the first time, peptide-based assemblies that can kill viruses. The minimal inhibitory concentration (MIC) of the assemblies is in the range tens of micrograms per milliliter. This value is 2 orders of magnitude smaller than the MIC of metal nanoparticles. When applied on a surface, by drop casting, the peptide spherical assemblies adhere to the surface and form an antiviral coating against both RNA- and DNA-based viruses including coronavirus. Our results show that the coating reduced the number of T4 bacteriophages (DNA-based virus) by 3 log, compared with an untreated surface and 6 log, when compared with a stock solution. Importantly, we showed that this coating completely inactivated canine coronavirus (RNA-based virus). This peptide-based coating can be useful wherever sterile surfaces are needed to reduce the risk of viral transmission.

Repurposing Approved Drugs for Guiding COVID-19 Prophylaxis: A Systematic Review

The SARS-CoV-2 outbreak originally appeared in China in December 2019 and became a global pandemic in March 2020. This infectious disease has directly affected public health and the world economy. Several palliative therapeutic treatments and prophylaxis strategies have been used to control the progress of this viral infection, including pre-(PrEP) and post-exposure prophylaxis. On the other hand, research groups around the world are still studying novel drug prophylaxis and treatment using repurposing approaches, as well as vaccination options, which are in different pre-clinical and clinical testing phases. This systematic review evaluated 1,228 articles from the PubMed and Scopus indexing databases, following the Kitchenham bibliographic searching protocol, with the aim to list drug candidates, potentially approved to be used as new options for SARS-CoV-2 prophylaxis clinical trials and medical protocols. In searching protocol, we used the following keywords: "Covid-19 or SARS-CoV-2" or "Coronavirus or 2019 nCoV," "prophylaxis," "prophylactic," "pre-exposure," "COVID-19 or SARS-CoV-2 Chemoprophylaxis," "repurposed," "strategies," "clinical," "trials," "anti-SARS-CoV-2," "anti-covid-19," "Antiviral," "Therapy prevention in vitro," in cells "and" human testing. After all protocol steps, we selected 60 articles that included: 15 studies with clinical data, 22 studies that used in vitro experiments, seven studies using animal models, and 18 studies performed with in silico experiments. Additionally, we included more 22 compounds between FDA approved drugs and drug-like like molecules, which were tested in large-scale screenings, as well as those repurposed approved drugs with new mechanism of actions. The drugs selected in this review can assist clinical studies and medical guidelines on the rational repurposing of known antiviral drugs for COVID-19 prophylaxis.