A Supramolecular Approach to Structure-Based Design with A Focus on Synthons Hierarchy in Ornithine-Derived Ligands: Review, Synthesis, Experimental and in Silico Studies

Design, synthesis, biological evaluations and in silico studies of (Z)-2-(2,4-dioxothiazolidin-5-ylidene)methyl)-2-ethoxyphenyl-alkyl/arylsulfonates as potential α-glucosidase inhibitors

Diabetes mellitus is considered one of the major worldwide health emergencies of the twenty-first century. This work described development, synthesis, and characterization of new (Z)-2-(2,4-dioxothiazolidin-5-ylidene)methyl)-2-ethoxyphenyl-alkyl/aryl-sulfonates. Compounds 7j and 7m were shown to be the most potent among the newly developed (Z)-2-(2,4-dioxothiazolidin-5-ylidene)methyl)-2-ethoxyphenyl-alkyl/aryl-sulfonates after in vitro testing for α-glucosidase inhibitory activity. Following that, an in-vivo disaccharide loading test was performed on these compounds. From the cytotoxicity studies, the most potent substance (7m) was also founded non-toxic. To investigate the binding mechanism and important interactions of α-glucosidase's amino acid residues, docking analyses were completed and binding affinities of the synthesised compounds were observed from -7.1 to 9.6 kcal/mol. To determine the binding stability of the α-glucosidase protein with chemicals 7j and 7m, molecular dynamic simulations were employed. In silico research and prediction studies for absorption, distribution, metabolism, and excretion (ADME) were used to identify the "druggable" pharmacokinetic profiles. In this instance, we developed unique (Z)-2-(2,4-dioxothiazolidin-5-ylidene)methyl)-2-ethoxyphenyl-alkyl/aryl-sulfonates as α-glucosidase inhibitors.

Computational identification of PDL1 inhibitors and their cytotoxic effects with silver and gold nanoparticles

Immunotherapy is a promising treatment for cancer that aims to boost the immune system's response to cancer cells. This can be achieved by blocking Programmed cell death protein 1/Programmed death-ligand 1 (PD1/PDL1), which activates T cells. In this work, the aim was to find high-affinity drugs against PDL1 using computational tools and conjugate nanoparticles with them. The cytotoxic activity of the nanoparticle conjugated drugs was then tested. The screening of 100,000 drugs from the ZINC database and FDA-approved drugs was done computationally. The physicochemical properties and toxicity of the drugs were analyzed using SwissADME and ProTox-II, respectively. Silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized using extracts of Catharanthus roseus flowers and Juglans regia shells, respectively. The characterization of AgNPs and AuNPs was performed using UV-Vis spectroscopy, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Their conjugation with the drugs Irinotecan, Imatinib, and Methotrexate was also confirmed using UV-Vis, FTIR, and Dynamic light scattering (DLS). The top screened drugs were ZINC1098661 and 3 FDA-approved drugs (Irinotecan, Imatinib, and Methotrexate). Docking studies revealed that Irinotecan had the highest binding affinity towards PDL1 when conjugated with silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs). The Irinotecan-PDL1 complex was confirmed as the most stable through molecular dynamics simulations. The result of the methylthiazol tetrazolium (MTT) assay showed that conjugated AgNPs and AuNPs with Irinotecan had a higher toxic effect on the A549 cancer cell line than AgNPs and AuNPs conjugated with Imatinib. This study provides a promising avenue for further investigation and development of nanoparticle-drug conjugates as a potential cancer immunotherapy strategy.

An experimental and computational investigation of the cyclopentene-containing peptide-derived compounds: focus on pseudo-cyclic motifs via intramolecular interactions

Conformational flexibility is one of the main disadvantages of peptide-based compounds. We focus on their molecular 'chameleonicity' related to forming pseudo-cyclic motifs via modulation of weak intramolecular interactions. It is an appealing strategy for controlling equilibrium between the polar open and the nonpolar closed conformations. Within this context, we report here the crystal structure of the (R)-(2-tert-butoxycarbonyl)amino-1-oxo-3-phenyl)propyl)-1-cyclopentene (1), synthesis of which in high yield was achieved by a facile multi-step protocol. Our Cambridge Structural Database (CSD) overview for the peptide-based crystals revealed the exclusivity of this compound from the viewpoint of the unusual pseudo-bicyclic system via C-H…O and C-O…π interactions, in which cyclopentene shields the amide bond. Notably, cyclopentene as a bioisostere of proline is an appealing scaffold in medicinal chemistry. An extensive combined experimental and computational study provided more profound insight into the supramolecular landscape of 1 with respect to similar derivatives deposited in the CSD, including the tendency of cyclopentene for the generation of pseudo-cyclic motifs through weak H-bonding and π-based intramolecular interactions. These weak interactions have been examined by either the quantum theory of 'atoms-in-molecules' (QTAIM) or complex Hirshfeld surface methodology, including enrichment ratios, molecular electrostatic potential surfaces and energy frameworks. In all analysed crystals, all types of H-bonded motifs involving cyclopentene are formed at all levels of supramolecular architecture. A library of cyclopentene-based H-bonding synthons is provided. A molecular docking study depicted vital interactions of cyclopentene with key amino acid residues inside the active sites of two prominent protein kinases, uncovering the therapeutic potential of 1 against breast cancer. To a large extent, dispersion forces have significance in stabilizing the supramolecular structure of both ligand and bio-complex ligand-protein. Finally, the satisfactory in silico bio-pharmacokinetic profile of 1 related to drug-likeness and blood-brain barrier permeation was also revealed.

Identification of lead inhibitors for 3CLpro of SARS-CoV-2 target using machine learning based virtual screening, ADMET analysis, molecular docking and molecular dynamics simulations

The SARS-CoV-2 3CLpro is a critical target for COVID-19 therapeutics due to its role in viral replication. We employed a screening pipeline to identify novel inhibitors by combining machine learning classification with similarity checks of approved medications. A voting classifier, integrating three machine learning classifiers, was used to filter a large database (∼10 million compounds) for potential inhibitors. This ensemble-based machine learning technique enhances overall performance and robustness compared to individual classifiers. From the screening, three compounds M1, M2 and M3 were selected for further analysis. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) analysis compared these candidates to nirmatrelvir and azvudine. Molecular docking followed by 200 ns MD simulations showed that only M1 (6-[2,4-bis(dimethylamino)-6,8-dihydro-5H-pyrido[3,4-d]pyrimidine-7-carbonyl]-1H-pyrimidine-2,4-dione) remained stable. For azvudine and M1, the estimated median lethal doses are 1000 and 550 mg kg-1, respectively, with maximum tolerated doses of 0.289 and 0.614 log mg per kg per day. The predicted inhibitory activity of M1 is 7.35, similar to that of nirmatrelvir. The binding free energy based on Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) of M1 is -18.86 ± 4.38 kcal mol-1, indicating strong binding interactions. These findings suggest that M1 merits further investigation as a potential SARS-CoV-2 treatment.

In vitro antibacterial, antibiofilm activities, and phytochemical properties of Posidonia oceanica (L.) Delile: An endemic Mediterranean seagrass

In the antibiotic resistance era, utilizing understudied sources for novel antimicrobials or antivirulence agents can provide new advances against antimicrobial resistant pathogens. In this study, we aimed to investigate antibacterial and antibiofilm activities of Posidonia oceanica (L.) Delile against Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Klebsiella pneumoniae ATCC 700603 and several S. aureus clinical isolates obtained from medical devices, including patient urinary catheters and breast implant infections, with varying antibiotic recalcitrance profiles. The ethanolic and methanolic extracts from P. oceanica rhizome exhibited significant antibacterial activity against E. faecalis and S. aureus, as well as drug resistant S. aureus clinical isolates. Furthermore, significant antibiofilm activity was observed against S. aureus and E. faecalis treated with ER, MR1, and MR2. P. oceanica extracts also exhibited synergistic antimicrobial activity with ciprofloxacin against E. faecalis, sensitizing E. faecalis to a lower ciprofloxacin concentration. Collectively, our data demonstrate the selective antibacterial and antibiofilm activity of the extracts of P. oceanica against Gram-positive bacteria and clinical isolates along with potentiation of current antibiotics, which suggests that P. oceanica can be further investigated as a potential source for novel therapeutic options in the treatment of drug resistant bacterial infections.

Unveiling the Potential of Ent-Kaurane Diterpenoids: Multifaceted Natural Products for Drug Discovery

Natural products hold immense potential for drug discovery, yet many remain unexplored in vast libraries and databases. In an attempt to fill this gap and meet the growing demand for effective drugs, this study delves into the promising world of ent-kaurane diterpenoids, a class of natural products with huge therapeutic potential. With a dataset of 570 ent-kaurane diterpenoids obtained from the literature, we conducted an in silico analysis, evaluating their physicochemical, pharmacokinetic, and toxicological properties with a focus on their therapeutic implications. Notably, these natural compounds exhibit drug-like properties, aligning closely with those of FDA-approved drugs, indicating a high potential for drug development. The ranges of the physicochemical parameters were as follows: molecular weights-288.47 to 626.82 g/mol; number of heavy atoms-21 to 44; the number of hydrogen bond donors and acceptors-0 to 8 and 1 to 11, respectively; the number of rotatable bonds-0 to 11; fraction Csp3-0.65 to 1; and TPSA-20.23 to 189.53 Ų. Additionally, the majority of these molecules display favorable safety profiles, with only 0.70%, 1.40%, 0.70%, and 46.49% exhibiting mutagenic, tumorigenic, reproduction-enhancing, and irritant properties, respectively. Importantly, ent-kaurane diterpenoids exhibit promising biopharmaceutical properties. Their average lipophilicity is optimal for drug absorption, while over 99% are water-soluble, facilitating delivery. Further, 96.5% and 28.20% of these molecules exhibited intestinal and brain bioavailability, expanding their therapeutic reach. The predicted pharmacological activities of these compounds encompass a diverse range, including anticancer, immunosuppressant, chemoprotective, anti-hepatic, hepatoprotectant, anti-inflammation, antihyperthyroidism, and anti-hepatitis activities. This multi-targeted profile highlights ent-kaurane diterpenoids as highly promising candidates for further drug discovery endeavors.

Molecular modeling of some commercially available antiviral drugs and their derivatives against SARS-CoV-2 infection

Numerous prior studies have identified therapeutic targets that could effectively combat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, including the angiotensin-converting enzyme 2 (ACE2) receptor, RNA-dependent RNA polymerase (RdRp), and Main protease (Mpro). In parallel, antiviral compounds like abacavir, acyclovir, adefovir, amantadine, amprenavir, darunavir, didanosine, oseltamivir, penciclovir, and tenofovir are under investigation for their potential in drug repurposing to address this infection. The aim of the study was to determine the effect of modifying the functional groups of the aforementioned antivirals in silico. Using the genetic optimization for ligand docking algorithm on software Maestro (version 11.1), the modified antivirals were docked onto ACE2 receptor, RdRp, and Mpro. Using QuickProp (Maestro v11.1), PASS (prediction of activity spectra for the substances), and altogether with SwissADME, the ADMET (absorption, distribution, metabolism, excretion, and toxicity) of the modified antivirals, as well as their bioavailability and the predicted activity spectra, were determined. Discovery studio software was used to undertake post-docking analysis. Among the 10 antivirals, N(CH3)2 derivative of darunavir, N(CH3)2 derivative of amprenavir and NCH3 derivative of darunavir exhibited best binding affinities with ACE2 receptor (docking scores: -10.333, -9.527 and -9.695 kJ/mol, respectively). Moreover, NCH3 derivative of abacavir (-6.506 kJ/mol), NO2 derivative of didanosine (-6.877 kJ/mol), NCH3 derivative of darunavir (-7.618 kJ/mol) exerted promising affinity to Mpro. In conclusion, the results of the in silico screenings can serve as a useful information for future experimental works.

Methyl 4-pyridyl ketone thiosemicarbazone (4-PT) as an effective and safe inhibitor of mushroom tyrosinase and antibrowning agent

Enzymatic browning is of concern as it can affect food safety and quality. In this study, an effective and safe tyrosinase inhibitor and anti-browning agent, methyl 4-pyridyl ketone thiosemicarbazone (4-PT), was synthesised and characterised using Fourier-transform infrared (FTIR) spectroscopy, CHNS elemental analysis, and proton (1H) and carbon-13 (13C) nuclear magnetic resonance (NMR) spectroscopy. The vibrational frequencies of 4-PT were studied theoretically using vibrational energy distribution analysis (VEDA). Density functional theory (DFT) was applied to elucidate its chemical properties, including the Mulliken atomic charges, molecular electrostatic potential (MEP), quantum theory of atoms in molecules (QTAIM) and reduced density gradient non-covalent interactions (RDG-NCIs). Moreover, 4-PT was compared with kojic acid in terms of its effectiveness as a tyrosinase inhibitor and anti-browning agent. The toxicity and physicochemical properties of 4-PT were predicted via ADME evaluation, which proved that 4-PT is safer than kojic acid. Experimentally, 4-PT (IC50 = 5.82 μM, browning index (10 days) = 0.292 ± 0.002) was proven to be an effective tyrosinase inhibitor and anti-browning agent compared to kojic acid (IC50 = 128.17 μM, browning index (10 days) = 0.332 ± 0.002). Furthermore, kinetic analyses indicated that the type of tyrosinase inhibition is a mixed inhibition, with Km and Vmax values of 0.85 mM and 2.78 E-09 μM/s, respectively. Finally, the mechanism of 4-PT for tyrosinase inhibition was proven by 1D, second derivative and 2D IR spectroscopy, molecular docking and molecular dynamic simulation approaches.

Biological Synthesis of Copper Nanoparticles Using Edible Plant Allium monanthum: Characterization of Antibacterial, Antioxidant, and Anti-Inflammatory Properties Using In Silico Molecular Docking Analysis

This study prepared copper nanoparticles using an edible leaf extract from A. monanthum (AM-CuNPs) via eco-friendly green synthesis techniques. The size, shape, crystalline nature and functional groups of the synthesized AM-CuNP particles were analyzed by a UV-VIS spectrophotometer and SEM, EDX, TEM, XRD and FT-IR instrumentation. The synthesized AM-CuNPs had spherical shapes with sizes in the range of 30-80 nm and were crystalline in nature. In addition, the AM-CuNPs were synthesized using various bioactive sources, including flavonoids, phenolic acids, alkaloids and sugars that were present in an aqueous broth of A. monanthum. Furthermore, the AM-CuNPs possessed good antibacterial properties against selected major disease-causing pathogenic bacteria, such as E. coli, Salmonella typhi, Pseudomonas aeruginosa and Staphylococcus aureus. The antioxidant activity of AM-CuNPs exhibited potent free radical scavenging activities in DPPH, ABTS and H2O2 radical assays. In addition, in silico analysis of the AM-CuNPs was performed, including ADME prediction, and molecular simulation docking on the secondary metabolites identified in the edible plant extract was used to evaluate their anti-inflammatory applications. In particular, the molecular docking scores showed that alliin, apigenin, isorhamnetin, luteolin and myricetin have sufficient binding energy and top values as inhibitors of the protein target involved in the inflammation signaling cascade.

GingerenoneA overcomes dexamethasone resistance by activating apoptosis and inhibiting cell proliferation in pediatric T-ALL cells

Plant-based combination strategies have been widely considered in cancer therapy to attenuate chemotherapeutics side effects. The anti-leukemic effect of the whole ginger extract was previously portrayed by our team, and the current study is centered around the cytotoxicity and mechanism of action of a phenolic subsidiary of ginger, GingerenoneA, on pediatric acute lymphoblastic leukemia. GingernoneA imposed, dose-dependently, inhibitory effects on the viability of T and B leukemia cell lines confirmed by MTT assays. Resistance to Dexamethasone, a mostly used chemotherapeutic in acute lymphoblastic leukemia treatments, was overcome by GingernoneA. A synergistic effect of Dexamethasone and GingrenoneA on T leukemia cell lines and patient primary cells was confirmed. Annexin-V/PI and acridine orange/ethidium bromide staining illustrated dose-dependent apoptosis in CCRF-CEM cells developed by GingerenoneA. The intrinsic and extrinsic apoptosis induction and antiproliferative attribution of GingerenoneA were validated by western blot and qPCR. Despite the supposed loss of function in CCRF-CEM cells, TP53 showed increased expression levels and functional activity upon treatment with GingernoneA. Bioinformatic studies revealed the conceivable impact of GingerenoneA on the reactivity of mutant P53 through its binding to Cys124. Our findings may provide novel strategies for therapeutic intervention to ameliorate pALL outcomes.

Assessment of the Antioxidant and Antimicrobial Potential of Ptychotis verticillata Duby Essential Oil from Eastern Morocco: An In Vitro and In Silico Analysis

Ptychotis verticillata Duby, referred to as Nûnkha in the local language, is a medicinal plant that is native to Morocco. This particular plant is a member of the Apiaceae family and has a longstanding history in traditional medicine and has been utilized for therapeutic purposes by practitioners for generations. The goal of this research is to uncover the phytochemical makeup of the essential oil extracted from P. verticillata, which is indigenous to the Touissite region in Eastern Morocco. The extraction of the essential oil of P. verticillata (PVEO) was accomplished through the use of hydro-distillation via a Clevenger apparatus. The chemical profile of the essential oil was then determined through analysis utilizing gas chromatography–mass spectrometry (GC/MS). The study findings indicated that the essential oil of P. verticillata is composed primarily of Carvacrol (37.05%), D-Limonene (22.97%), γ-Terpinene (15.97%), m-Cymene (12.14%) and Thymol (8.49%). The in vitro antioxidant potential of PVEO was evaluated using two methods: the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical trapping assay and the ferric reducing antioxidant power (FRAP) method. The data demonstrated considerable radical scavenging and relative antioxidative power. Escherichia coli, Staphylococcus aureus, Listeria innocua, and Pseudomonas aeruginosa were the most susceptible bacterial strains tested, while Geotrichum candidum, Candida albicans, and Rhodotorula glutinis were the most resilient fungi strains. PVEO had broad-spectrum antifungal and antibacterial properties. To elucidate the antioxidative and antibacterial characteristics of the identified molecules, we applied the methodology of molecular docking, a computational approach that forecasts the binding of a small molecule to a protein. Additionally, we utilized the Prediction of Activity Spectra for Substances (PASS) algorithm; Absorption, Distribution, Metabolism, and Excretion (ADME); and Pro-Tox II (to predict the toxicity in silico) tests to demonstrate PVEO’s identified compounds’ drug-likeness, pharmacokinetic properties, the anticipated safety features after ingestion, and the potential pharmacological activity. Finally, our findings scientifically confirm the ethnomedicinal usage and usefulness of this plant, which may be a promising source for future pharmaceutical development.

Identification of novel C-15 fluoro isosteviol derivatives for GABA-AT inhibition by in silico investigations

CONTEXT

The treatment of epilepsy is associated with the inhibition of γ-aminobutyric acid-aminotransferase (GABA-AT), which suppresses the concentration of a key neurotransmitter GABA. Isosteviol, a natural bioactive molecule, has been reported to possess an anticonvulsant property. In this work, we first reported a series of C-15 fluoro isosteviol analogs which are bearing different functional groups at C-16 to investigate the interactions with GABA-AT by applying molecular docking and molecular dynamic simulation approach. The results revealed that all fluoro isosteviol analogs displayed a greater binding affinity than references vigabatrin, an FDA-approved GABA-AT inactivator, and CPP-115, which has Orphan Drug Designation status, and positioned at the same binding site as references. Furthermore, molecular dynamic (MD) simulation studies on minimum (A1), maximum (E1) binding energy score of fluoro isosteviol analogs, and isosteviol (G1) revealed their stable complex formation in terms of RMSD, RMSF, RG, and hydrogen bond formation. All analogs were found to have drug-like nature, non-toxic, >80% absorption, and the majority tend to penetrate brain-blood-barrier (BBB). The investigations found in this study can help in the development of isosteviol derivatives as drugs for the treatment of epilepsy.

METHODS

The two-dimensional (2D) ligand structures were drawn using ChembioDraw Ultra 14.0. Molecular docking with Autodock4 and molecular dynamic simulation with GROMACS version 2020.1 were performed. The CHARMM27 all-atom force field was applied for writing the topology. Biovia Discovery Studio DS2021 was used for viewing and analyzing the protein-ligand complexes. The data generated from molecular dynamic simulation trajectories were plotted using the Origin® 8 software. The Open Babel software was utilized for extracting SMILEs files of all the fluoro isosteviol analogs. The drug-likeness and ADMET of the molecules were evaluated by SwissADME and ADMETlab 2.0 web tools.

Network pharmacology and bioinformatics approach reveals the therapeutic mechanism of action of curcumin in Alzheimer disease

Curcumin is a natural anti-inflammatory and antioxidant substance which plays a major role in reducing the amyloid plaques formation, which is the major cause of Alzheimer's disease (AD). Consequently, a methodical approach was used to select the potential protein targets of curcumin in AD through network pharmacology. In this study, through integrative methods, AD targets of curcumin through SwissTargetPrediction database, STITCH database, BindingDB, PharmMapper, Therapeutic Target Database (TTD), Online Mendelian Inheritance in Man (OMIM) database were predicted followed by gene enrichment analysis, network construction, network topology, and docking studies. Gene ontology analysis facilitated identification of a list of possible AD targets of curcumin (74 targets genes). The correlation of the obtained targets with AD was analysed by using gene ontology (GO) pathway enrichment analyses and Kyoto Encyclopaedia of Genes and Genomes (KEGG). We have incorporated the applied network pharmacological approach to identify key genes. Furthermore, we have performed molecular docking for analysing the mechanism of curcumin. In order to validate the temporospatial expression of key genes in human central nervous system (CNS), we searched the Human Brain Transcriptome (HBT) dataset. We identified top five key genes namely, PPARγ, MAPK1, STAT3, KDR and APP. Further validated the expression profiling of these key genes in publicly available brain data expression profile databases. In context to a valuable addition in the treatment of AD, this study is concluded with novel insights into the therapeutic mechanisms of curcumin, will ease the treatment of AD with the clinical application of curcumin.

Phytochemical, Antimicrobial, Antioxidant, and In Vitro Cytotoxicity Evaluation of Echinops erinaceus Kit Tan

Wild plants are used by many cultures for the treatment of diverse ailments. However, they are formed from mixtures of many wanted and unwanted phytochemicals. Thus, there is a necessity to separate the bioactive compounds responsible for their biological activity. In this study, the chemical composition as well as antimicrobial and cytotoxic activities of Echinops erinaceus Kit Tan (Asteraceae) were investigated. This led to the isolation and identification of seven compounds, two of which are new (erinaceosin C3 and erinaceol C5), in addition to methyl oleate (C1) and ethyl oleate (C2), loliolide (C4), (E)-p-coumaric acid (C6), and 5,7,3`,5`-tetrahydroxy flavanone (C7). The structures of the isolated compounds were elucidated by 1D, 2D NMR, and HR-ESI-MS. The methanol extract showed the highest antimicrobial activity among the tested extracts and fractions. The n-hexane and EtOAc extracts showed remarkable antimicrobial activity against B. subtilus, P. aeruginosa, E. coli, and C. albicans. A cytotoxicity-guided fractionation of the most bioactive chloroform extract resulted in the isolation of bioactive compounds C1/C2, which showed significant cytotoxicity against HCT-116 and CACO2 cell lines (IC50 24.95 and 19.74 µg/mL, respectively), followed by compounds C3 (IC50 82.82 and 76.70 µg/mL) and C5 (IC50 99.09 and 87.27 µg/mL), respectively. The antioxidant activity of the bioactive chloroform fractions was screened. Molecular docking was used to explain the results of the antimicrobial and anticancer activities against five protein targets, including DNA gyrase topoisomerase II, enoyl-acyl carrier protein reductase of S. aureus (FabI), dihydrofolate reductase (DHFR), β-catenin, and human P-glycoprotein (P-gp).

Microwave assisted synthesis of 2-amino-4-chloro-pyrimidine derivatives: Anticancer and computational study on potential inhibitory action against COVID-19

We report microwave synthesis of seven unique pyrimidine anchored derivatives (1–7) incorporating multifunctional amino derivatives along with their in vitro anticancer activity and their activity against COVID-19 in silico. 1–7 were characterized by different analytical and spectroscopic techniques. Cytotoxic activity of 1–7 was tested against HCT116 and MCF7 cell lines, whereby 6 exhibited highest anticancer activity on HCT116 and MCF7 with EC₅₀ values of 89.24 ± 1.36 µM and 89.37 ± 1.17 µM, respectively.

Molecular docking was performed for derivatives (1–7) on main protease for SARS-CoV-2 (PDB ID: 6LU7). Results revealed that most of the derivatives had superior or equivalent affinity for the 3CLpro, as determined by docking and binding energy scores. 6 topped the rest with highest binding energy score of −8.12 kcal/mol with inhibition constant reported as 1.11 µM. ADME, drug-likeness, and pharmacokinetics properties of 1–7 were tested using Swiss ADME tool. Toxicity analysis was done with pkCSM online server.

All derivatives showed high GI absorption. Except 1 and 3, all derivatives showed blood brain barrier permeability. Most derivatives showed negative logKp values suggesting derivatives are less skin permeable and bioavailability score of all derivatives was 0.55. The toxicity analysis demonstrated that all derivatives have no skin sensitization properties. 6 and 7 showed maximum tolerated dose (Human) values of −0.03 and −0.018, respectively and absence of AMES toxicity.

The use of machine learning modeling, virtual screening, molecular docking, and molecular dynamics simulations to identify potential VEGFR2 kinase inhibitors

Targeting the signaling pathway of the Vascular endothelial growth factor receptor-2 is a promising approach that has drawn attention in the quest to develop novel anti-cancer drugs and cardiovascular disease treatments. We construct a screening pipeline using machine learning classification integrated with similarity checks of approved drugs to find new inhibitors. The statistical metrics reveal that the random forest approach has slightly better performance. By further similarity screening against several approved drugs, two candidates are selected. Analysis of absorption, distribution, metabolism, excretion, and toxicity, along with molecular docking and dynamics are performed for the two candidates with regorafenib as a reference. The binding energies of molecule1, molecule2, and regorafenib are - 89.1, - 95.3, and - 87.4 (kJ/mol), respectively which suggest candidate compounds have strong binding to the target. Meanwhile, the median lethal dose and maximum tolerated dose for regorafenib, molecule1, and molecule2 are predicted to be 800, 1600, and 393 mg/kg, and 0.257, 0.527, and 0.428 log mg/kg/day, respectively. Also, the inhibitory activity of these compounds is predicted to be 7.23 and 7.31, which is comparable with the activity of pazopanib and sorafenib drugs. In light of these findings, the two compounds could be further investigated as potential candidates for anti-angiogenesis therapy.

Peptide-Drug Conjugates: A New Hope for Cancer Management

Cancer remains the leading cause of death worldwide despite advances in treatment options for patients. As such, safe and effective therapeutics are required. Short peptides provide advantages to be used in cancer management due to their unique properties, amazing versatility, and progress in biotechnology to overcome peptide limitations. Several appealing peptide-based therapeutic strategies have been developed. Here, we provide an overview of peptide conjugates, the better equivalents of antibody-drug conjugates, as the next generation of drugs for required precise targeting, enhanced cellular permeability, improved drug selectivity, and reduced toxicity for the efficient treatment of cancers. We discuss the basic components of drug conjugates and their release action, including the release of cytotoxins from the linker. We also present peptide-drug conjugates under different stages of clinical development as well as regulatory and other challenges.

Modeling Polyzwitterion-Based Drug Delivery Platforms: A Perspective of the Current State-of-the-Art and Beyond

Drug delivery platforms are anticipated to have biocompatible and bioinert surfaces. PEGylation of drug carriers is the most approved method since it improves water solubility and colloid stability and decreases the drug vehicles' interactions with blood components. Although this approach extends their biocompatibility, biorecognition mechanisms prevent them from biodistribution and thus efficient drug transfer. Recent studies have shown (poly)zwitterions to be alternatives for PEG with superior biocompatibility. (Poly)zwitterions are super hydrophilic, mainly stimuli-responsive, easy to functionalize and they display an extremely low protein adsorption and long biodistribution time. These unique characteristics make them already promising candidates as drug delivery carriers. Furthermore, since they have highly dense charged groups with opposite signs, (poly)zwitterions are intensely hydrated under physiological conditions. This exceptional hydration potential makes them ideal for the design of therapeutic vehicles with antifouling capability, i.e., preventing undesired sorption of biologics from the human body in the drug delivery vehicle. Therefore, (poly)zwitterionic materials have been broadly applied in stimuli-responsive "intelligent" drug delivery systems as well as tumor-targeting carriers because of their excellent biocompatibility, low cytotoxicity, insignificant immunogenicity, high stability, and long circulation time. To tailor (poly)zwitterionic drug vehicles, an interpretation of the structural and stimuli-responsive behavior of this type of polymer is essential. To this end, a direct study of molecular-level interactions, orientations, configurations, and physicochemical properties of (poly)zwitterions is required, which can be achieved via molecular modeling, which has become an influential tool for discovering new materials and understanding diverse material phenomena. As the essential bridge between science and engineering, molecular simulations enable the fundamental understanding of the encapsulation and release behavior of intelligent drug-loaded (poly)zwitterion nanoparticles and can help us to systematically design their next generations. When combined with experiments, modeling can make quantitative predictions. This perspective article aims to illustrate key recent developments in (poly)zwitterion-based drug delivery systems. We summarize how to use predictive multiscale molecular modeling techniques to successfully boost the development of intelligent multifunctional (poly)zwitterions-based systems.

In Silico Interactions of the Components from the Schinus terebinthifolius Extract with Human Tyrosinase

The anti-tyrosinase activity of the leaf extract of Schinus terebinthifolius, also known as Brazilian peppertree, was evaluated using multiple in silico approaches, such as molecular homology, molecular docking, MM-GBSA, molecular dynamics, MM-PBSA, QSAR, and skin permeability predictions. With these computational tools, the compounds that downregulate tyrosinase enzyme activity could be evaluated, and more potent molecules could be identified. The results indicated that various compounds, especially luteolin, are accountable for the anti-tyrosinase activity of S. terebinthifolius. For cosmetic application, further studies with luteolin are especially recommended, for having presented a good performance both in theoretical inhibition (30.92 kJ mol^-1 ) and skin permeability (LogKp=-6.62 cm^-1 ).

Evaluation of antiplasmodial activity in silico and in vitro of N-acylhydrazone derivatives

N-acylhydrazones are considered privileged structures in medicinal chemistry, being part of antimicrobial compounds (for example). In this study we show the activity of N-acylhydrazone compounds, namely AH1, AH2, AH4, AH5 in in vitro tests against the chloroquine-resistant strain of Plasmodium falciparum (W2) and against WI26 VA-4 human cell lines. All compounds showed low cytotoxicity (LC₅₀ > 100 µM). The AH5 compound was the most active against Plasmodium falciparum, with an IC₅₀ value of 0.07 μM. AH4 and AH5 were selected among the tested compounds for molecular docking calculations to elucidate possible targets involved in their mechanism of action and the SwissADME analysis to predict their pharmacokinetic profile. The AH5 compound showed affinity for 12 targets with low selectivity, while the AH4 compound had greater affinity for only one target (3PHC). These compounds met Lipinski's standards in the ADME in silico tests, indicating good bioavailability results. These results demonstrate that these N-acylhydrazone compounds are good candidates for future preclinical studies against malaria.

Structural and Biofunctional Insights into the Cyclo(Pro-Pro-Phe-Phe-) Scaffold from Experimental and In Silico Studies: Melanoma and Beyond

Short peptides have great potential as safe and effective anticancer drug leads. Herein, the influence of short cyclic peptides containing the Pro-Pro-Phe-Phe sequence on patient-derived melanoma cells was investigated. Cyclic peptides such as cyclo(Leu-Ile-Ile-Leu-Val-Pro-Pro-Phe-Phe-), called CLA, and cyclo(Pro-homoPro-β3homoPhe-Phe-), called P11, exert the cytotoxic and the cytostatic effects in melanoma cells, respectively. CLA was the most active peptide as it reduced the viability of melanoma cells to 50% of control at about 10 µM, whereas P11 at about 40 µM after 48 h incubation. Interestingly, a linear derivative of P11 did not induce any effect in melanoma cells confirming previous studies showing that cyclic peptides exert better biological activity compared to their linear counterparts. According to in silico predictions, cyclic tetrapeptides show a better pharmacokinetic and toxic profile to humans than CLA. Notably, the spatial structure of those peptides containing synthetic amino acids has not been explored yet. In the Cambridge Structural Database, there is only one such cyclic tetrapeptide, cyclo((R)-β2homoPhe-D-Pro-Lys-Phe-), while in the Protein Data Bank—none. Therefore, we report the first crystal structure of cyclo(Pro-Pro-β3homoPhe-Phe-), denoted as 4B8M, a close analog of P11, which is crucial for drug discovery. Comparative molecular and supramolecular analysis of both structures was performed. The DFT findings revealed that 4B8M is well interpreted in the water solution. The results of complex Hirshfeld surface investigations on the cooperativity of interatomic contacts in terms of electrostatic and energetic features are provided. In short, the enrichment ratio revealed O…H/H…O and C…H/H…C as privileged intercontacts in the crystals in relation to basic and large supramolecular H-bonding synthon patterns. Furthermore, the ability of self-assemble 4B8M leading to a nanotubular structure is also discussed.

Inhibition of Mycobacterium tuberculosis InhA (Enoyl-acyl carrier protein reductase) by synthetic Chalcones: a molecular modelling analysis and in-vitro evidence

Tuberculosis (TB) is a serious infectious disease caused by the bacillus Mycobacterium tuberculosis (Mtb). The World Health Organization (WHO) estimates that 1.8 million people die each year from TB, with 10 million new cases being registered each year. In this study, 50 Chalcones were developed, five of which were synthesized, and their inhibitory effects against Mtb were studied. The discovery of new powerful inhibitors with IC₅₀ values in the sub-micro molar range resulted from the development of structure-activity relationships (SAR). The goal of the molecular modelling studies was to uncover the most important structural criteria underpinning the binding affinity and selectivity of this class of inhibitors as possible anti-TB drugs. Because of their great efficacy and selectivity, our developed nitro and benzyloxy substituted Chalcones compounds appear to be promising anti-TB therapies.Communicated by Ramaswamy H. Sarma.

1-Mesityl-3-(3-Sulfonatopropyl) Imidazolium Protects Against Oxidative Stress and Delays Proteotoxicity in C. elegans

Due to the increase in life expectancy worldwide, age-related disorders such as neurodegenerative diseases (NDs) have become more prevalent. Conventional treatments comprise drugs that only attenuate some of the symptoms, but fail to arrest or delay neuronal proteotoxicity that characterizes these diseases. Due to their diverse biological activities, imidazole rings are intensively explored as powerful scaffolds for the development of new bioactive molecules. By using C. elegans, our work aims to explore novel biological roles for these compounds. To this end, we have tested the in vivo anti-proteotoxic effects of imidazolium salts. Since NDs have been largely linked to impaired antioxidant defense mechanisms, we focused on 1-Mesityl-3-(3-sulfonatopropyl) imidazolium (MSI), one of the imidazolium salts that we identified as capable of improving iron-induced oxidative stress resistance in wild-type animals. By combining mutant and gene expression analysis we have determined that this protective effect depends on the activation of the Heat Shock Transcription Factor (HSF-1), whereas it is independent of other canonical cytoprotective molecules such as abnormal Dauer Formation-16 (DAF-16/FOXO) and Skinhead-1 (SKN-1/Nrf2). To delve deeper into the biological roles of MSI, we analyzed the impact of this compound on previously established C. elegans models of protein aggregation. We found that MSI ameliorates β-amyloid-induced paralysis in worms expressing the pathological protein involved in Alzheimer’s Disease. Moreover, this compound also delays age-related locomotion decline in other proteotoxic C. elegans models, suggesting a broad protective effect. Taken together, our results point to MSI as a promising anti-proteotoxic compound and provide proof of concept of the potential of imidazole derivatives in the development of novel therapies to retard age-related proteotoxic diseases.

Insights into the inhibitory mechanism of skullcapflavone II against α-synuclein aggregation and its mediated cytotoxicity

The dangerous self-assembled and infectious seeds of α-synuclein (αSN) play primary roles in Parkinson's disease. Accordingly, the inhibition of αSN fibrillation and elimination of toxic aggregates are the main therapeutic strategies. Skullcapflavone II (S.FII), a compound isolated from S. pinnatifida, has shown multiple neuroprotective features. Herein, we demonstrated that S.FII inhibited αSN aggregation with IC50 of 7.2 μM. It increased nucleation time and decreased fibril elongation rate and the species formed in the presence of S.FII were unable to act as seeds. Additionally, S.FII inhibited both secondary nucleation and seeding of αSN and disaggregated the mature preformed fibrils as well. The species formed in the presence of S.FII showed less toxicity. It also preserved neurite length and dopamine content of SH-SY5Y cells and attenuated the inflammatory responses in mixed glial cells. The Localized Surface Plasmon Resonance (LSPR) analysis indicated that S.FII interacts with αSN. Docking simulation studies on αSN fibrils revealed that S.FII could interact with the key residues of the salt bridges and glutamine ladder, which might lead to the destruction of fibril's structures. We also showed that S.FII passes through the blood-brain barrier in vitro and in vivo. Overall, these findings elucidate the neuroprotective roles of S.FII in reducing αSN pathogenicity.

In vitro biological and in silico molecular docking and ADME studies of a substituted triazine-coordinated cadmium(II) ion: efficient cytotoxicity, apoptosis, genotoxicity, and nuclease-like activity plus binding affinity towards apoptosis-related proteins

A cadmium(II) complex containing dppt ligand with the formula [CdCl₂(dppt)₂], where dppt is 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine was synthesized, elucidated and submitted to in vitro cytotoxicity studies against human breast (MCF-7), glioblastoma (U-87), and lung (A549) cancer cell lines as well as mouse embryo normal cell line (NIH/3T3), in comparison with cisplatin employing MTT assay over 24 and 48 h. The complex exhibited the highest cytotoxic effect against MCF-7 cells among the other three cell lines with IC₅₀ values of 8.7 ± 0.5 (24 h) and 1.2 ± 0.7 µM (48 h). Significantly, flow cytometric assessment of the complex-treated MCF-7 and U-87 cells demonstrated a dose-dependent induced apoptotic cell death. The cellular morphological changes were in concord with cytotoxicity and flow cytometric results. The results of comet assay showed that the complex is able to induce DNA damage in MCF-7 cells. These observations are of importance, as sustained damage to cellular DNA could lead to apoptotic cell death. The results of DNA-binding studies indicated that the complex fits into the DNA minor groove and interacts with DNA via a partial intercalation. Moreover, the complex was able to efficiently cleave pUC19 DNA through a hydrolytic mechanism. The binding affinity between the complex and apoptosis-relevant protein targets including APAF1, Bax, Bcl-2, Cas3, Cas7, and Cas9 was evaluated through molecular docking studies. In silico virtual studies revealed the complex's strong affinity towards apoptosis-related proteins; therefore the complex can act as a potential apoptosis inducer. Physicochemical, pharmacokinetics, lipophilicity, drug-likeness, and medicinal chemistry properties of the complex were also predicted through in silico absorption, distribution, metabolism and excretion studies.

A New Approach to Supramolecular Structure Determination in Pharmaceutical Preparation of Self-Assembling Peptides: A Case Study of Lanreotide Autogel

The supramolecular structure in peptides’ prolonged-released gel formulations is the most critical parameter for the determination of the pharmaceutical profile of the drug. Here, we report our investigation on lanreotide Autogel as a case study. For the first time, we describe the use of the pulsed field gradient (PFG) diffusion-ordered spectroscopy (DOSY) magic-angle spinning NMR to characterize the supramolecular self-assembly and molecular mobility of different samples of lanreotide Autogel formulations prepared according to different formulation protocols. The diffusion coefficient was used to calculate the hydrodynamic radii of supramolecular assemblies and build relative molecular models. DOSY data were integrated with NMR imaging (MRI) measurements and atomic force microscopy (AFM) imaging.

Phytochemical Screening, In Vitro and In Silico Studies of Volatile Compounds from Petroselinum crispum (Mill) Leaves Grown in Saudi Arabia

The herbal plant Petroselinum crispum (P. crispum) (Mill) is commonly available around the world. In this study, the leaves of the herbal plant P. crispum were collected from the central region of Al-Kharj, Saudi Arabia, to explore their in vitro pharmacological activity. Essential oil from the leaves of P. crispum was isolated using the hydrodistillation method. The composition of P. crispum essential oil (PCEO) was determined using Gas chromatography-mass spectrometry (GC-MS). A total of 67 components were identified, representing approximately 96.02% of the total volatile composition. Myristicin was identified as the principal constituent (41.45%). The in vitro biological activity was assessed to evaluate the antioxidant, antimicrobial, and anti-inflammatory potential of PCEO. PCEO showed the highest antimicrobial activity against Candida albicans and Staphylococcus aureus among all the evaluated microbial species. In vitro anti-inflammatory evaluation using albumin and trypsin assays showed the excellent anti-inflammatory potential of PCEO compared to the standard drugs. An in silico study of the primary PCEO compound was conducted using online tools such as PASS, Swiss ADME, and Molecular docking. In silico PASS prediction results supported our in vitro findings. Swiss ADME revealed the drug likeness and safety properties of the major metabolites present in PCEO. Molecular docking results were obtained by studying the interaction of Myristicin with an antifungal (PDB: 1IYL and 3LD6), antibacterial (PDB: 1AJ6 and 1JIJ), antioxidant (PDB: 3NM8 and 1HD2), and anti-inflammatory (3N8Y and 3LN1) receptors supported the in vitro results. Therefore, PCEO or Myristicin might be valuable for developing anti-inflammatory and antimicrobial drugs.

Antidepressant-like effect of rosmarinic acid during LPS-induced neuroinflammatory model: The potential role of cannabinoid receptors/PPAR-γ signaling pathway

Rosmarinic acid (RA), an ester of caffeic acid and 3, 4-dihydroxyphenyllactic acid, has anti-inflammatory and neuroprotective activities. Herein, this study investigated in silico the drug-likeness and the potential molecular targets to RA. Moreover, it tested the antidepressant-like potential of RA in the lipopolysaccharide (LPS)-induced depression model. RA (MW = 360.31 g/mol) meets the criteria of both Lipinski's rule of five and the Ghose filter. It also attends to relevant pharmacokinetic parameters. Target prediction analysis identified RA's potential targets and biological activities, including the peroxisome proliferator-activated receptor (PPAR) and the cannabinoid receptors CB1 and CB2 . In vivo, RA's acute, repetitive, and therapeutic administration showed antidepressant-like effect since it significantly reduced the immobility time in the tail suspension test and increased grooming time in the splash test. Further, the pretreatment with antagonists of CB1 , CB2 , and PPAR-γ receptors significantly blocked the antidepressant-like effect of RA. Altogether, our findings suggest that cannabinoid receptors/PPAR-γ signaling pathways are involved with the antidepressant-like effect of RA. Moreover, this molecule meets important physicochemical and pharmacokinetic parameters that favor its bioavailability. RA constitutes a promising, innovative, and safe molecule for the pharmacotherapy of major depressive disorder.

Impact of aliphatic acyl and aromatic thioamide substituents on the anticancer activity of Ru(II)-p-cymene complexes with acylthiourea ligands-in vitro and in vivo studies

Six different acylthiourea ligands (L1-L6) and their corresponding Ru(II)-p-cymene complexes (P1-P6) were designed to explore the structure-activity relationship of the complexes upon aliphatic chain and aromatic conjugation on the C- and N-terminals, respectively. The compounds were synthesized and adequately characterized using various analytical and spectroscopic techniques. The structures of P2-P6, solved using single crystal X-ray diffraction (XRD), confirmed the neutral monodentate coordination of the S atoms of the acylthiourea ligands to Ru(II) ions. In silico studies showed an increase of lipophilicity for the ligands with an increase in alkyl chain length or aromatic conjugation at the C- or N-terminal, respectively. Subsequently, mitogen-activated protein kinases (MAPK) were predicted as one of the primary targets for the complexes, which showed good binding affinity towards extracellular signal-regulated kinases (ERK1, ERK2 and ERK5), c-Jun N-terminal kinase (JNK) and p38 of the MAPK pathway. Henceforth, the complexes were tested for their anticancer activity in lung carcinoma (A549) and cisplatin-resistant lung carcinoma (cisA549R) cells and human umbilical vein epithelial normal cells (HUVEC). Interestingly, an increase in chain length or aromatic conjugation led to an increase in the activity of the complexes, with P5 (7.73 and 13.04 μM) and P6 (6.52 and 14.45 μM) showing the highest activity in A549 and cisA549R cells, which is better than the positive control, cisplatin (8.72 and 44.28 μM). Remarkably, we report the highest activity yet observed for complexes of the type [(η6-p-cymene)RuIICl2(S-acylthiourea)] in the tested cell lines. Aqueous solution studies showed that complexes P5 and P6 are rapidly hydrolyzed to produce solely aquated species that remained stable for 24 h. Staining assays and flow cytometric analyses of P5 and P6 in A549 cells revealed that the complexes induced apoptosis and arrested the cell cycle predominantly in the S phase. In vivo studies demonstrated the higher toxicity of cisplatin and a comparatively higher survival rate of mice injected with the most active complex P6. Histological analyses revealed that treatment with P6 at high doses of up to 8 mg kg-1 did not cause any palpable damage to the tested organs.

Screening of β1- and β2-Adrenergic Receptor Modulators through Advanced Pharmacoinformatics and Machine Learning Approaches

Cardiovascular diseases (CDs) are a major concern in the human race and one of the leading causes of death worldwide. β-Adrenergic receptors (β1-AR and β2-AR) play a crucial role in the overall regulation of cardiac function. In the present study, structure-based virtual screening, machine learning (ML), and a ligand-based similarity search were conducted for the PubChem database against both β1- and β2-AR. Initially, all docked molecules were screened using the threshold binding energy value. Molecules with a better binding affinity were further used for segregation as active and inactive through ML. The pharmacokinetic assessment was carried out on molecules retained in the above step. Further, similarity searching of the ChEMBL and DrugBank databases was performed. From detailed analysis of the above data, four compounds for each of β1- and β2-AR were found to be promising in nature. A number of critical ligand-binding amino acids formed potential hydrogen bonds and hydrophobic interactions. Finally, a molecular dynamics (MD) simulation study of each molecule bound with the respective target was performed. A number of parameters obtained from the MD simulation trajectories were calculated and substantiated the stability between the protein-ligand complex. Hence, it can be postulated that the final molecules might be crucial for CDs subjected to experimental validation.

Cyclic Dipeptides: The Biological and Structural Landscape with Special Focus on the Anti-Cancer Proline-Based Scaffold

Cyclic dipeptides, also know as diketopiperazines (DKP), the simplest cyclic forms of peptides widespread in nature, are unsurpassed in their structural and bio-functional diversity. DKPs, especially those containing proline, due to their unique features such as, inter alia, extra-rigid conformation, high resistance to enzyme degradation, increased cell permeability, and expandable ability to bind a diverse of targets with better affinity, have emerged in the last years as biologically pre-validated platforms for the drug discovery. Recent advances have revealed their enormous potential in the development of next-generation theranostics, smart delivery systems, and biomaterials. Here, we present an updated review on the biological and structural profile of these appealing biomolecules, with a particular emphasis on those with anticancer properties, since cancers are the main cause of death all over the world. Additionally, we provide a consideration on supramolecular structuring and synthons, based on the proline-based DKP privileged scaffold, for inspiration in the design of compound libraries in search of ideal ligands, innovative self-assembled nanomaterials, and bio-functional architectures.

The First Insight Into the Supramolecular System of D,L-α-Difluoromethylornithine: A New Antiviral Perspective

Targeting the polyamine biosynthetic pathway by inhibiting ornithine decarboxylase (ODC) is a powerful approach in the fight against diverse viruses, including SARS-CoV-2. Difluoromethylornithine (DFMO, eflornithine) is the best-known inhibitor of ODC and a broad-spectrum, unique therapeutical agent. Nevertheless, its pharmacokinetic profile is not perfect, especially when large doses are required in antiviral treatment. This article presents a holistic study focusing on the molecular and supramolecular structure of DFMO and the design of its analogues toward the development of safer and more effective formulations. In this context, we provide the first deep insight into the supramolecular system of DFMO supplemented by a comprehensive, qualitative and quantitative survey of non-covalent interactions via Hirshfeld surface, molecular electrostatic potential, enrichment ratio and energy frameworks analysis visualizing 3-D topology of interactions in order to understand the differences in the cooperativity of interactions involved in the formation of either basic or large synthons (Long-range Synthon Aufbau Modules, LSAM) at the subsequent levels of well-organized supramolecular self-assembly, in comparison with the ornithine structure. In the light of the drug discovery, supramolecular studies of amino acids, essential constituents of proteins, are of prime importance. In brief, the same amino-carboxy synthons are observed in the bio-system containing DFMO. DFT calculations revealed that the biological environment changes the molecular structure of DFMO only slightly. The ADMET profile of structural modifications of DFMO and optimization of its analogue as a new promising drug via molecular docking are discussed in detail.

A Global Review on Short Peptides: Frontiers and Perspectives

Peptides are fragments of proteins that carry out biological functions. They act as signaling entities via all domains of life and interfere with protein-protein interactions, which are indispensable in bio-processes. Short peptides include fundamental molecular information for a prelude to the symphony of life. They have aroused considerable interest due to their unique features and great promise in innovative bio-therapies. This work focusing on the current state-of-the-art short peptide-based therapeutical developments is the first global review written by researchers from all continents, as a celebration of 100 years of peptide therapeutics since the commencement of insulin therapy in the 1920s. Peptide "drugs" initially played only the role of hormone analogs to balance disorders. Nowadays, they achieve numerous biomedical tasks, can cross membranes, or reach intracellular targets. The role of peptides in bio-processes can hardly be mimicked by other chemical substances. The article is divided into independent sections, which are related to either the progress in short peptide-based theranostics or the problems posing challenge to bio-medicine. In particular, the SWOT analysis of short peptides, their relevance in therapies of diverse diseases, improvements in (bio)synthesis platforms, advanced nano-supramolecular technologies, aptamers, altered peptide ligands and in silico methodologies to overcome peptide limitations, modern smart bio-functional materials, vaccines, and drug/gene-targeted delivery systems are discussed.

Cocrystal engineering of pharmaceutical solids: therapeutic potential and challenges

This highlight presents an overview of pharmaceutical cocrystal production and its potential in reviving problematic properties of drugs in different dosage forms. The challenges and future outlook of its translational development are discussed.

A Proline-Based Tectons and Supramolecular Synthons for Drug Design 2.0: A Case Study of ACEI

Proline is a unique, endogenous amino acid, prevalent in proteins and essential for living organisms. It is appreciated as a tecton for the rational design of new bio-active substances. Herein, we present a short overview of the subject. We analyzed 2366 proline-derived structures deposited in the Cambridge Structure Database, with emphasis on the angiotensin-converting enzyme inhibitors. The latter are the first-line antihypertensive and cardiological drugs. Their side effects prompt a search for improved pharmaceuticals. Characterization of tectons (molecular building blocks) and the resulting supramolecular synthons (patterns of intermolecular interactions) involving proline derivatives, as presented in this study, may be useful for in silico molecular docking and macromolecular modeling studies. The DFT, Hirshfeld surface and energy framework methods gave considerable insight into the nature of close inter-contacts and supramolecular topology. Substituents of proline entity are important for the formation and cooperation of synthons. Tectonic subunits contain proline moieties characterized by diverse ionization states: -N and -COOH(-COO-), -N+ and -COOH(-COO-), -NH and -COOH(-COO-), -NH+ and -COOH(-COO-), and -NH2+ and -COOH(-COO-). Furthermore, pharmacological profiles of ACE inhibitors and their impurities were determined via an in silico approach. The above data were used to develop comprehensive classification, which may be useful in further drug design studies.