Medicinal Strategies Research Articles

Small-molecule oligonucleotides as smart modality for antiviral therapy: a medicinal chemistry perspective.

Small-molecule oligonucleotides could be exploited therapeutically to silence the expression of viral infection-causing genes, and a few of them are now in clinical trials for the management of viral infections. The most challenging aspect of these oligonucleotides' therapeutic success involves their delivery. Thus medicinal chemistry strategies are inevitable to avoid degradation by serum nucleases, avoid kidney clearance and improve cellular uptake. Recently small-molecule oligonucleotide design has opened up new avenues to improve the treatment of drug-resistant viral infections, along with the development of COVID-19 medicines. This review is directed toward the recent advances in rational design, mechanism of action, structure-activity relationships and future perspective of the small-molecule oligonucleotides targeting viral infections, including COVID-19.

De Novo Design of pre-miR-21 Maturation Inhibitors: Synthesis and Activity Assessment.

Targeting RNA with small molecules is a major challenge of current medicinal chemistry, and the identification and design of original scaffolds able to selectively interact with an RNA target remains difficult. Various approaches have been developed based on classical medicinal chemistry strategies (fragment-based drug design, dynamic combinatorial chemistry, HTS or DNA-encoded libraries) as well as on advanced structural biology and biochemistry methodologies (such as X-ray, cryo-EM, NMR, or SHAPE). Here, we report the de novo design, synthesis, and biological evaluation of RNA ligands using a straightforward and sustainable chemistry combined with molecular docking and biochemical and biophysical studies that allowed us to identify a novel pharmacophore for RNA binding. Specifically, we focused on the targeting of biogenesis of microRNA-21, the re-known oncogene. This led us not only to promising inhibitors but also to a better understanding of the interactions formed between the small molecule compounds and the RNA target paving the way for the rational design of efficient inhibitors with potential anticancer activity.

Novel Medicinal Chemistry Strategies Targeting CDK5 for Drug Discovery.

Cyclin-dependent kinase 5 (CDK5) protein plays an important role not only in the central nervous system but also in the periphery, including immune response, regulation of insulin secretion, and cancer development and progression. Consequently, targeting the CDK5 protein is a potential strategy for the treatment of many diseases, especially cancer and neurodegenerative diseases. To date, numerous pan-CDK inhibitors have entered clinical trials. Nevertheless, limited clinical efficacy and severe adverse effects have prompted the application of new techniques to optimize clinical efficacy and minimize adverse events. In this Perspective, we highlight the protein properties, biofunctions, relevant signaling pathways, and associations with cancer development and proliferation of CDK5, and analyze the clinical status of pan-CDK inhibitors and the preclinical status of CDK5-specific inhibitors. In addition, CDK5-selective inhibitors, protein-protein interaction inhibitors, proteolytic-targeting chimera (PROTAC) degraders, and dual-target CDK5 inhibitors are discussed.

A MS-feature-based medicinal plant database-driven strategy for ingredient identification of Chinese medicine prescriptions

Identification of the individual herbs that constitute the Chinese medicine prescription (CMP) is a key step to control the quality and ensure the efficacy of traditional Chinese medicine (TCM), but also a challenging task for analysts from all over the world. In this study, a MS-feature-based medicinal plant database-driven strategy was proposed for quick and automatic interpretation of CMP ingredients. The single herb database consisting of stable ions of sixty-one common TCM medicinal herbs was first constructed. And then, the data of CMP was imported into a self-built searching program to achieve quick and automatic identification with four steps including level 1 candidate herb screening based on stable ions (step 1), level 2 candidate herb screening based on unique ions (step 2), difficult-to-distinguish herb differentiation (step 3) and results integration (step 4). The identification model was optimized and validated with homemade Shaoyaogancao Decoction, Mahuang Decoction, Banxiaxiexin Decoction, and their related negative prescriptions and homemade fakes. Another nine batches of homemade and commercial CMPs were applied to this new approach and most of composed herbs in the corresponding CMPs were correctly identified. This work provided a promising and universal strategy for the clarification of CMP ingredients.

Environmental variables drive medicinal plant composition and distribution in various forest types of subtropical region in Pakistan

Analyzing the ecological distribution patterns of medicinal plants under the influence of environmental variables can provide important information about how these plants are affected by environmental factors. This analysis can also serve as a conceptual foundation for medicinal plant management strategies. We examined the composition and distribution of medicinal plants as well as how and which environmental factors influence the plant communities in subtropical forest types from Pakistan. 11 forest sites over the course of two years (2020−2021) were sampled, measuring 10 environmental variables and documenting medicinal plants that were present in the study area. Plants data viz.; cover, density, and frequency were recorded from randomly selected sites through quadrat method. Soil parameters i.e., pH, nitrogen, phosphorus, electrical conductance, potassium and soil organic matter were recorded from each site. After calculating importance value index for each species, the data was analyzed utilizing a multivariate ordination approach. The most prevalent family observed during present investigations were Asteraceae followed by Fabaceae and Solanaceae. The life form spectra outcomes exhibited the predominance of the therophyte species, followed by chamaephyte species. The results of the regression analysis exhibit that soil organic matter, nitrogen, potassium, and phosphorus have a positive influence on medicinal plant richness, while electrical conductance (EC) and soil pH have a negative influence. Canonical correspondence analysis revealed that the soil parameters and anthropogenic factors (grazing pressure, land degradation, over-collection) had a significant (p ≤ 0.002) effect on the distribution of medicinal plants. The seasonal pattern of the life cycle revealed its peak during the spring season (41%), followed by monsoon (32%). The leaf size spectra results showed dominance of microphylls, over nanophylls and leptophylls. The results would be significant in establishing plant conservation strategies in Pakistan, especially due to over-exploitation of medicinal plants and the negative effects of climate change make it imperative to protect them on prior basis.

Rational Design in Photopharmacology with Molecular Photoswitches.

Photopharmacology is an attractive approach for achieving targeted drug action with the use of light. In photopharmacology, molecular photoswitches are introduced into the structure of biologically active small molecules to allow for the optical control of their potency. Going beyond trial and error, photopharmacology has progressively applied rational drug design methodologies to devise light-controlled bioactive ligands. In this review, we categorize photopharmacological efforts from the standpoint of medicinal chemistry strategies, focusing on diffusible photochromic ligands modified with photoswitches that operate through E-Z bond isomerization. In the vast majority of cases, photoswitchable ligands are designed as analogs of existing compounds, through a variety of approaches. By analyzing in detail a comprehensive list of instructive examples, we describe the state of the art and discuss future opportunities for rational design in photopharmacology.

Rational Design in Photopharmacology with Molecular Photoswitches

AbstractPhotopharmacology is an attractive approach for achieving targeted drug action with the use of light. In photopharmacology, molecular photoswitches are introduced into the structure of biologically active small molecules to allow for the optical control of their potency. Going beyond trial and error, photopharmacology has progressively applied rational drug design methodologies to devise light‐controlled bioactive ligands. In this review, we categorize photopharmacological efforts from the standpoint of medicinal chemistry strategies, focusing on diffusible photochromic ligands modified with photoswitches that operate through E‐Z bond isomerization. In the vast majority of cases, photoswitchable ligands are designed as analogs of existing compounds, through a variety of approaches. By analyzing in detail a comprehensive list of instructive examples, we describe the state of the art and discuss future opportunities for rational design in photopharmacology.

Substantiated therapy of pre-dementia cognitive impairment with calcium-channel blockers

Pre-dementia cognitive impairments are a significant part of a cognitive impairment range, considered the most perspective in terms of conversion into dementia prevention. At the same time pre-dementia cognitive impairment treatment presents certain difficulties in connection with the absence of precise medicinal strategies with the high evidence level. According to current clinical recommendations, the priority in cognitive pre-dementia treatment lies in the correction of modifiable risk factors of cognitive impairment progression and non-drug therapy methods. Nevertheless, there is a great need in receiving the proofs of pathogenetically justified use of drugs with a potentially effective mechanism of action. Universal and early pathogenetical mechanism of many diseases of central nervous system, leading to the development of cognitive impairments, including Alzheimer’s disease, is Ca2+ dyshomeostasis. In this connection, the use of drugs, regulating Ca2+ metabolism in neurons in treatment of patients with pre-dementia cognitive impairments, especially high brain penetrance drugs, is potentially well-grounded. The article gives the data review of modern researches, studying the efficiency and safety of nimodipin a selective Ca+ channel blocker of the 2 class. The article provides examples of the use of nimodipin in treatment and prevention of pre-dementia syndroms of various genesis: Alzheimer’s disease, chronic brain hypoperfusion damage, post-radiation and postoperative cognitive dysfunction, etc. The article presents experimental data about nimodipin use in the prevention of postoperative delirium in elderly people and in the treatment of non-cognitive neurological disorders. Justification of the perspectives of the application area extension and directions for the further research of nimodipin are as well given in the article.

Efecto del compuesto N-2,6-dicloro-aralquil-2-Aminoindano en la conducta estereotipada de ratas. Acción dopaminérgica selectiva central sobre los ganglios basales más que en las estructuras límbicas.

Dopamine 1 is involved in neurodegenerative disorders affect-ing the central nervous system (CNS), such as Parkinson’s disease. Despite the absence of some available drugs capable of preventing, stopping or curing the progression of such diseases, there are numerous compounds designed, synthesized, and pharmacologically tested which give rise to pharmacophoric generalizations about the dopaminergic receptor required for the search of a drug able to improve or cure those pathologies. N-aralkyl-2-aminoindane de-rivatives have shown selective activity in the central dopaminergic system. Both the N-[(2,4-dichlorophenyl)-1-methyl-ethyl]-2-aminoindane hydrochloride 2and N-[(3,4-dichlorophenyl)-1-methyl-ethyl]-2-aminoindane hydrochloride 3 showed an agonistic activity mediated by central dopaminergic mechanisms. To contribute to the search of new drugs able to re-establish homeostasis in the dopaminergic transmission in Parkinson’s disease, the compound N-2,6-dichloro-aralkyl-2-aminoindane 4 was designed through medicinal chemistry strategies that contain pharmacophoric approximations of prodrugs. The phar-macological evaluation of compound 4 in the stereotyped behavior of male Sprague Dawley rats showed agonistic activity through the activation of central dopaminergic mechanisms and a higher selectivity in the responses of stereo-typed behavior characteristic of the basal ganglia over the typical responses from limbic structures.

Systematic Analysis of Chemical Modifications of Phosphorothioate Antisense Oligonucleotides that Modulate Their Innate Immune Response.

While rare, some gapmer phosphorothioate (PS) antisense oligonucleotides (ASOs) can induce a noncanonical TLR9-dependent innate immune response. In this study, we performed systematic analyses of the roles of PS ASO backbone chemistry, 2' modifications, and sequence in PS ASO induced TLR9 signaling. We found that each of these factors can contribute to altering PS ASO induced TLR9 signaling, and in some cases the effects are quite dramatic. We also found that the positioning (5' vs. 3') of a particular backbone or 2' modification within a PS ASO can affect its TLR9 signaling. Interestingly, medicinal chemical strategies that decrease TLR9 signaling for one sequence can have opposing effects on another sequence. Our results demonstrate that TLR9 signaling is highly PS ASO sequence dependent, the mechanism of which remains unknown. Despite this, we determined that placement of two mesyl phosphoramidate linkages within the PS ASO gap is the most promising strategy to mitigate PS ASO dependent TLR9 activation to enhance the therapeutic index and, therefore, further streamline PS ASO drug development.

Synthesis and structure-activity optimization of 7-azaindoles containing aza-β-amino acids targeting the influenza PB2 subunit

The PB2 subunit of influenza virus polymerase has been demonstrated as a promising drug target for anti-influenza therapy. In this work, 7-azaindoles containing aza-β3- or β2,3 -amino acids were synthesized possessing a good binding affinity of PB2. The aza-β-amino acid moieties with diverse size, shape, steric hindrance and configuration were investigated. Then a lead HAA-09 was validated, and the attached aza-β3-amino acid moiety with acyclic tertiary carbon side chain well occupied in the key hydrophobic cavity of PB2_cap binding domain. Importantly, HAA-09 displays potent polymerase inhibition capacity, low cytotoxicity (selectivity index up to 2915) as well as robust anti-viral activity against A/WSN/33 (H1N1) virus and oseltamivir-resistant H275Y variant. Moreover, HAA-09 exhibited druggability with high plasma stability (t1/2 ≥ 12 h) and no obvious hERG inhibition (IC50 > 10 μM). Also, HAA-09 demonstrated a favorable safety profile when orally administrated in healthy mice at a high dose of 40 mg/kg QD for consecutive 3 days. Besides, in vivo therapeutic efficacy (85.7% survival observed at the day 15 post infection) was demonstrated when HAA-09 was administrated orally at 12.5 mg/kg BID starting 48 h post infection for 9 days. These data support that exploring the interactions between side chains on aza-β3- or β2,3 -amino acid moieties and hydrophobic pocket of PB2_cap binding domain is a potential medicinal chemistry strategy for developing potent PB2 inhibitors.

Discovery of carboxyl-containing heteroaryldihydropyrimidine derivatives as novel HBV capsid assembly modulators with significantly improved metabolic stability.

Interfering with the assembly of hepatitis B virus (HBV) capsid is a promising approach for treating chronic hepatitis B (CHB). In order to enhance the metabolic stability and reduce the strong hERG inhibitory effect of HBV capsid assembly modulator (CAM) GLS4, we rationally designed a series of carboxyl-containing heteroaryldihydropyrimidine (HAP) derivatives based on structural biology information combined with medicinal chemistry strategies. The results from biological evaluation demonstrated that compound 6a-25 (EC50 = 0.020 μM) exhibited greater potency than the positive drug lamivudine (EC50 = 0.09 μM), and was comparable to the lead compound GLS4 (EC50 = 0.007 μM). Furthermore, it was observed that 6a-25 reduced levels of core protein (Cp) and capsid in cells. Preliminary assessment of drug-likeness revealed that 6a-25 exhibited superior water solubility (pH 2.0: 374.81 μg mL-1; pH 7.0: 6.85 μg mL-1; pH 7.4: 25.48 μg mL-1), liver microsomal metabolic stability (t1/2 = 108.2 min), and lower hERG toxicity (10 μM inhibition rate was 72.66%) compared to the lead compound GLS4. Overall, compound 6a-25 holds promise for further investigation.

Substitution mode of rare and endangered Chinese medicinal materials and research strategy of multi-component replacement

Rare and endangered Chinese medicinal materials are the material basis for innovation and development of Chinese medicinal materials and their curative effects are remarkable. However, the resources are in shortage due to various man-made or natural factors such as rising demand, overexploitation and environmental degradation. Therefore, finding alternatives is a feasible and effective solution. This study systematically sorted out the list of rare and endangered Chinese medicinal materials, and combed relevant policies and regulations. According to existing research, the substitution model of rare and endangered Chinese medicinal materials was constructed from the theoretical level. In view of the slow search for substitutes, the failure to follow the basic theory of traditional Chinese medicine in the process of research and development, the difficulty in breaking through technologies and the incomplete guarantee of the clinical efficacy of substitutes, a multi-component replacement was proposed to replace the originals with more effective components from a wide range of sources. This study was expected to promote the study on the substitutes of rare and endangered Chinese medicinal materials to step into a new stage.

Medicinal Chemistry Strategies for the Development of Inhibitors Disrupting β-Catenin's Interactions with Its Nuclear Partners.

Dysregulation of the Wnt/β-catenin signaling pathway is strongly associated with various aspects of cancer, including tumor initiation, proliferation, and metastasis as well as antitumor immunity, and presents a promising opportunity for cancer therapy. Wnt/β-catenin signaling activation increases nuclear dephosphorylated β-catenin levels, resulting in β-catenin binding to TCF and additional cotranscription factors, such as BCL9, CBP, and p300. Therefore, directly disrupting β-catenin's interactions with these nuclear partners holds promise for the effective and selective suppression of the aberrant activation of Wnt/β-catenin signaling. Herein, we summarize recent advances in biochemical techniques and medicinal chemistry strategies used to identify potent peptide-based and small-molecule inhibitors that directly disrupt β-catenin's interactions with its nuclear binding partners. We discuss the challenges involved in developing drug-like inhibitors that target the interactions of β-catenin and its nuclear binding partner into therapeutic agents.

A new perspective for psoriasis: Dithranol nanosponge loaded hydrogels

We developed dithranol nanosponge integrated Carbopol hydrogel (DTHNS-HG) as a novel perspective for psoriasis management. Dithranol was chosen as antipsoriatic moiety for this system. In this study, our objective was to fabricate and evaluate DTHNS-HG for in vivo anti-psoriatic activity using mouse tail model. Nanosponges (NSs) were synthesized using diphenyl carbonate and β-cyclodextrin employing melt method and appropriately characterized. The selected nanosponges were then embedded into Carbopol hydrogels and assessed for viscosity, spreadability and texture analysis. The developed formulations were further evaluated in vivo for antipsoriatic potential (% drug activity,% orthokeratosis and relative changes in epidermal thickness). Additionally, oxidative stress markers were also checked in mouse tail samples. DTH loaded cyclodextrin nanosponges were successfully fabricated and displayed acceptable mean particle size (274.6 ± 43.54 nm with 0.545 PDI) and zeta potential (-28.3 ± 6.34 mV). Further, DTHNS amalgamated hydrogel showed satisfactory results in terms of spreadability, viscosity and texture profiles. The degree of orthokeratosis was significantly (p < 0.05) increased with DTHNS-HG (0.5 and 1.0% w/v) and marketed ointment, as compared to the untreated group (control). Similarly, the drug activity and changes in epidermal thickness were found significant. Our findings from present investigations suggested a new cargo for delivery of DTH in topical medicinal strategies for psoriasis. Hence, this novel hydrogel showed promising outcomes for psoriasis.

Recent Advances and Therapeutic Journey of Schiff Base Complexes with Selected Metals (Pt, Pd, Ag, Au) as Potent Anticancer Agents: A Review.

Schiff bases and their transition metal complexes play an important role in the field of medicine, in particular in the treatment of cancer. Since the discovery of the cisplatin anticancer activity, great efforts have focused on the rational design of metal-based anticancer drugs that can be potentially used for the treatment of cancer. However, drug resistance and significant side effects greatly limit its clinical application. This has inspired medicinal chemists to employ various strategies in the development of novel and effective anticancer drugs. Recently, a greater number of transition metal complexes have been designed and evaluated for their anticancer activities, and some of them were at different stages of clinical studies. Amongst these, platinum, palladium, gold and silver complexes have an important place within medicinal and inorganic chemistry. This review article discusses Schiff bases and their complexes with selected transition metals (Pd, Pt, Ag, Au) for anticancer activity against different cancer cell lines.

Medicinal plant microbiome: advances and prospects

Medicinal plants are the main source of clinical medication in traditional Chinese medicine(TCM). China has achieved large-scale cultivation and production of medicinal plants. As an important resource for the sustainable development of agriculture in the future, microorganisms can also promote the green, ecological and high-quality development of Chinese medicine agriculture. However, research on the medicinal plant microbiome is still limited. Therefore, based on the development timeline of microbiome research, the present study reviewed the origin, technology, and hotspots of microbiome research and proposed some suggestions for future research according to the advances in medicinal plant microbiome.(1)Systematic investigation of medicinal plant microbiome on the species, genus, and family levels should be carried out on the medicinal plants of different chemotypes in order to reveal the coevolution of the microorganisms and their host plants.(2)Spatial and temporal research on medicinal plant microbiome should be performed to reveal the effects of microorganisms on the growth, development, and secondary metabolite accumulation of medicinal plants, as well as the underlying mechanisms.(3)Model medicinal plant species should be selected and microorganism-plant interaction research models should be established.(4)Core microbiome of medicinal plants should be explored for the future application of crucial microbes in the sustaina-ble agriculture of Chinese medicine.(5)Breeding of medicinal plant-associated microbes should be carried out to lay the foundation for novel medicinal plant breeding strategies.(6)High-throughput sequencing, traditional incubation, and isolation of microbes should be combined to study medicinal plant microbiome, thereby promoting the exploitation and application of uncultured microbial strains.(7)Platforms for the preservation of medicinal plant-associated microbe strains and data of their metabolites should be established and the exchange of information and cooperation between these platforms should be subsequently enhanced. With these suggestions, the efficient and rapid development of medicinal plant microbiome research is expected to be promoted.

Advances in AR-targeting chimeras: a case study of proteolysis-targeting chimeras from bench to bedside.

Proteolysis-targeting chimera (PROTAC) is an emerging revolutionary technology that promotes degradation of target proteins by proteolysis. AR-targeting PROTACs marked many milestones in the history of PROTAC development. In this review, the author discusses the development of AR-targeting PROTACs over the last two decades. Also included in this focused review are medicinal chemistry strategies, pharmacokinetic profiles and clinical development. Taking AR targeting PROTACs forcase study, this review provides atarget specific overview of how PROTAC technologyhas advanced from a revolutionary concept and achieved proof of concept leadingto drug candidatesthatbenefitpatients.

Light-Activating PROTACs in Cancer: Chemical Design, Challenges, and Applications

Nonselective cell damage remains a significant limitation of radiation therapies in cancer. Decades of successful integration of radiation therapies with other medicinal chemistry strategies significantly improved therapeutic benefits in cancer. Advancing in such technologies also led to the development of specific photopharmcology-based approaches that improved the cancer cell selectivity and provided researchers with spatiotemporal control over the degradation of highly expressed proteins in cancer (proteolysis targeting chimeras, PROTACs) using a monochrome wavelength light source. Two specific strategies that have achieved notable successes are photocage and photoswitchable PROTACs. Photocaged PROTACs require a photolabile protecting group (PPG) that, when radiated with a specific wavelength of light, irreversibly release PPG and induce protein degradation. Thus far, diethylamino coumarin for estrogen-related receptor α (ERRα), nitropiperonyloxymethyl (BRD4 bromodomain protein), and 4,5-dimethoxy-2-nitrobenzyl for (BRD4 bromodomain protein, as well as BTK kinase protein) were successfully incorporated in photocaged PROTACs. On the other hand, photoswitches of photoswitchable PROTACs act as an actual ON/OFF switch to target specific protein degradation in cancer. The ON/OFF function of photoswitches in PROTACs (as photoswitchable PROTACs) provide spatiotemporal control over protein degradation, and to an extent are correlated with their photoisomeric state (cis/trans-configuration), showcasing an application of the photochemistry concept in precision medicine. This study compiles the photoswitchable PROTACs targeted to bromodomain proteins: BRD 2, 3, and 4; kinases (BCR-ABL fusion protein, ABL); and the immunophilin FKBP12. Photocaging of PROTACs found successes in selective light-controlled degradation of kinase proteins, bromodomain-containing proteins, and estrogen receptors in cancer cells.

Protective Effect of Natural Medicinal Plants on Cardiomyocyte Injury in Heart Failure: Targeting the Dysregulation of Mitochondrial Homeostasis and Mitophagy.

Heart failure occurs because of various cardiovascular pathologies, such as coronary artery disease or cardiorenal syndrome, eventually reaching end-stage disease. Various factors contribute to cardiac structural or functional changes that result in systolic or diastolic dysfunction. Several studies have confirmed that the key factor in heart failure progression is myocardial cell death, and mitophagy is the major mechanism regulating myocardial cell death in heart failure. The clinical mechanisms of heart failure are well understood in practice. However, the essential role of mitophagic regulation in heart failure has only recently received widespread attention. Receptor-mediated mitophagy is involved in various mitochondrial processes like oxidative stress injury, energy metabolism disorders, and calcium homeostasis, which are also the main causes of heart failure. Understanding of the diverse regulatory mechanisms in mitophagy and the complexity of its pathophysiology in heart failure remains incomplete. Related studies have found that various natural medicinal plants and active ingredients, such as flavonoids and saponins, can regulate mitophagy to a certain extent, improve myocardial function, and protect myocardial cells. This review comprehensively covers the relevant mechanisms of different types of mitophagy in regulating heart failure pathology and controlling mitochondrial adaptability to stress injury. Further, it explores the relationship between mitophagy and cardiac ejection dysfunction. Natural medicinal plant-targeted regulation strategies and scientific evidence on mitophagy were provided to elucidate current and potential strategies to apply mitophagy-targeted therapy for heart failure.