Development of New Resolvin D1 Analogues for Osteoarthritis Therapy: Acellular and Computational Approaches to Study Their Antioxidant Activities

In osteoarthritis (OA), oxidative stress plays a crucial role in maintaining and sustaining cartilage degradation. Current OA management requires a combination of pharmaceutical and non-pharmacological strategies, including intraarticular injections of hyaluronic acid (HA). However, several lines of evidence reported that HA oxidation by reactive oxygen species (ROS) is linked with HA cleavage and fragmentation, resulting in reduced HA viscosity. Resolvin D1 (RvD1) is a lipid mediator that is biosynthesized from omega-3 polyunsaturated fatty acids and is a good candidate with the potential to regulate a panoply of biological processes, including tissue repair, inflammation, oxidative stress, and cell death in OA. Herein, newly designed and synthesized imidazole-derived RvD1 analogues were introduced to compare their potential antioxidant properties with commercially available RvD1. Their antioxidant capacities were investigated by several in vitro chemical assays including oxygen radical absorbance capacity, 2,2-diphenyl-1-picrylhydrazyl radical scavenging, ferric ion reducing antioxidant power, hydroxyl radical scavenging, and HA fragmentation assay. All results proved that imidazole-derived RvD1 analogues showed excellent antioxidant performance compared to RvD1 due to their structural modifications. Interestingly, they scavenged the formed reactive oxygen species (ROS) and protected HA from degradation, as verified by agarose gel electrophoresis and gel permission chromatography. A computational study using Gaussian 09 with DFT calculations and a B3LYP/6-31 G (d, p) basis set was also employed to study the relationship between the antioxidant properties and chemical structures as well as calculation of the molecular structures, frontier orbital energy, molecular electrostatic potential, and bond length. The results showed that the antioxidant activity of our analogues was higher than that of RvD1. In conclusion, the findings suggest that imidazole-derived RvD1 analogues can be good candidates as antioxidant molecules for the treatment of oxidative stress-related diseases like OA. Therefore, they can prolong the longevity of HA in the knee and thus may improve the mobility of the articulation.

Software-assisted automated detection and identification of "unknown" fentanyl analogues

Fentanyl and its non-pharmaceutical analogues (NPFs) are potent synthetic opioids, traditionally used for pain management, with ever-increasing illicit uses. Tightening the regulation for known fentanyls leads to new synthetic analogues in the opioid market. Furthermore, the Organization for the Prohibition of Chemical Weapons (OPCW) has recently issued a decision regarding aerosolized use of central nervous system (CNS)-acting agents, such as fentanyl and its analogues, under the concern that these materials could be misused for terror or war purposes. The ever-increasing development of new fentanyl analogues makes the task of detection and identification of these new, unknown analogues crucial. In this work, we introduce an automated tool for the detection and putative identification of "unknown" fentanyl analogues, using liquid chromatography-mass spectrometry (LC-MS) (high-resolution mass spectrometry [HRMS]) analysis, subsequently followed by data processing using the "Compound Discoverer" software. This software, in our modified use, enabled the automatic detection of various fentanyl analogues, by "digging" out components and comparing them to pre-calculated theoretical molecular ions of possible modifications or transformations on the fentanyl backbone structure (no library or database used). Subsequently, structural elucidation for the proposed component of interest is carried out by automated MS/MS data interpretation, as performed by the software. This method was explored on 12 fentanyl-based "unknown" analogues used as model examples, including chemical modifications such as fluorination and methylation. In all tested compounds, automatic detection and identification were achieved, even at concentrations as low as 1 ng/mL in an environmental soil matrix extract.

Fabry disease biomarkers in patients switched from enzyme-replacement therapy to migalastat oral chaperone therapy

Background: A biomarker profile was evaluated longitudinally in patients with Fabry disease switched from enzyme-replacement therapy (ERT) to migalastat. Methods: 16 Gb3 isoforms and eight lyso-Gb3 analogues were analyzed in plasma and urine by LC-MS/MS at baseline and at three different time points in naive participants and participants switching from either agalsidase α or β to migalastat. Results: 29 adult participants were recruited internationally (seven centers). The Mainz Severity Score Index and mean biomarker levels remained stable (p ≥ 0.05) over a minimum of 12 months compared with baseline following the treatment switch. Conclusion: In this cohort of patients with Fabry disease with amenable mutations, in the short term, a switch from ERT to migalastat did not have a marked effect on the average biomarker profile.

Diflunisal and Analogue Pharmacophores Mediating Suppression of Virulence Phenotypes in Staphylococcus aureus

Invasive methicillin-resistant Staphylococcus aureus (MRSA) infections are leading causes of morbidity and mortality that are complicated by increasing resistance to conventional antibiotics. Thus, minimizing virulence and enhancing antibiotic efficacy against MRSA is a public health imperative. We originally demonstrated that diflunisal (DIF; [2-hydroxy-5-(2,4-difluorophenyl) benzoic acid]) inhibits S. aureus virulence factor expression. To investigate pharmacophores that are active in this function, we evaluated a library of structural analogues for their efficacy to modulate virulence phenotypes in a panel of clinically relevant S. aureus isolates in vitro. Overall, the positions of the phenyl, hydroxyl, and carboxylic moieties and the presence or type of halogen (F vs. Cl) influenced the efficacy of compounds in suppressing hemolysis, proteolysis, and biofilm virulence phenotypes. Analogues lacking halogens inhibited proteolysis to an extent similar to DIF but were ineffective at reducing hemolysis or biofilm production. In contrast, most analogues lacking the hydroxyl or carboxylic acid groups did not suppress proteolysis but did mitigate hemolysis and biofilm production to an extent similar to DIF. Interestingly, chirality and the substitution of fluorine with chlorine resulted in a differential reduction in virulence phenotypes. Together, this pattern of data suggests virulence-suppressing pharmacophores of DIF and structural analogues integrate halogen, hydroxyl, and carboxylic acid moiety stereochemistry. The anti-virulence effects of DIF were achieved using concentrations that are safe in humans, do not impair platelet antimicrobial functions, do not affect S. aureus growth, and do not alter the efficacy of conventional antibiotics. These results offer proof of concept for using novel anti-virulence strategies as adjuvants to antibiotic therapy to address the challenge of MRSA infection.

Applications of Enzyme Technology to Enhance Transition to Plant Proteins: A Review

As the plant-based food market grows, demand for plant protein is also increasing. Proteins are a major component in foods and are key to developing desired structures and textures. Seed storage proteins are the main plant proteins in the human diet. They are abundant in, for example, legumes or defatted oilseeds, which makes them an excellent candidate to use in the development of novel plant-based foods. However, they often have low and inflexible functionalities, as in nature they are designed to remain densely packed and inert within cell walls until they are needed during germination. Enzymes are often used by the food industry, for example, in the production of cheese or beer, to modify ingredient properties. Although they currently have limited applications in plant proteins, interest in the area is exponentially increasing. The present review first considers the current state and potential of enzyme utilization related to plant proteins, including uses in protein extraction and post-extraction modifications. Then, relevant opportunities and challenges are critically discussed. The main challenges relate to the knowledge gap, the high cost of enzymes, and the complexity of plant proteins as substrates. The overall aim of this review is to increase awareness, highlight challenges, and explore ways to address them.

Calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2) inhibitors: a novel approach in small molecule discovery

The calcium/calmodulin dependent protein kinase kinase 2 (CAMKK2) plays a key role in regulation of intracellular calcium levels and signaling pathways. It is involved in activation of downstream signaling pathways that regulate various cellular processes. Dysregulation of CAMKK2 activity has been linked to various diseases including cancer, suggesting that CAMKK2 inhibitors might be beneficial in oncological, metabolic and inflammatory indications. The most pressing issues in small molecule discovery are synthesis feasibility, novel chemical structure and desired biological characteristics. To circumvent this constraint, we employed 'DrugspaceX' for rapid lead identification, followed by repositioning seven FDA-approved drugs for CAMKK2 inhibition. Further, first-level transformation (Set1 analogues) was performed in 'DrugspaceX', followed by virtual screening. The t-SNE visualization revealed that the transformations surrounding Rucaparib, Treprostinil and Canagliflozin are more promising for developing CAMKK2 inhibitors. Second, using the top-ranked Set1 analogues, Set2 analogues were generated, and virtual screening revealed the top-ranked five analogues. Among the top five Set2 analogues, DE273038_5 had the lowest docking score of -11.034 kcal/mol and SA score of 2.59, retaining the essential interactions with Hotspot residues LYS194 and VAL270 across 250 ns simulation period. When compared to the other four compounds, the ligand effectiveness score was 0.409, and the number of rotatable penalties was only three. Further, DE273038_5 after two rounds of transformations was discovered to be novel and had not been previously described in other databases. These data suggest that the new candidate DE273038_5 is likely to have inhibitory activity at the CAMKK2 active site, implying potential therapeutic use.Communicated by Ramaswamy H. Sarma.

Picamilon, a γ-aminobutyric acid (GABA) analogue and marketed nootropic, is inactive against 50 biological targets

Picamilon is an analogue of the neurotransmitter γ-aminobutyric acid (GABA), which is marketed as a nootropic claiming to enhance cognition. There is a lack of in silico, in vitro and in vivo data on the safety of picamilon. Therefore, to ascertain potential physiological effects of picamilon, it was screened against 50 safety-related biological targets (receptors, ion channels, enzymes and transporters) by in silico and in vitro methods. Using two in silico tools, picamilon was not predicted to bind to the targets. Similarly, picamilon exhibited weak or no binding to the targets when measured in vitro at 10 μM. Overall, this data shows that picamilon, although structurally similar to other GABA analogues, has a different biological target binding profile. Picamilon's lack of binding to the 50 targets fills important data gaps among GABA analogues, a group of structurally related substances found in drugs and other consumer products.

Arylnitro monocarbonyl curcumin analogues: Synthesis and in vitro antitubercular evaluation

Curcumin is a natural product that has been reported to exhibit myriad pharmacological properties, one of which is antitubercular activity. It demonstrates antitubercular activity by directly inhibiting Mycobacterium tuberculosis (M.tb) and also enhances immune responses that ultimately lead to the elimination of M.tb by macrophages. This natural product is, however, unstable, and several analogues, noticeably monocarbonyl analogues, have been synthesized to overcome this challenge. Curcumin and its monocarbonyl analogues reported so far exhibit moderate antitubercular activity in the range of 7 to 16 μM. Herein, we report a straightforward synthesis of novel monocarbonyl curcumin analogues, their antitubercular activity, and the structure-activity relationship. The hit compound from this study, 3a, exhibits potent MIC₉₀ values in the range of 0.2 to 0.9 μM in both ADC and CAS media.

Drug delivery improvements to enable a flexible care setting for monoclonal antibody medications in oncology - Analogue-based decision framework

INTRODUCTION

The substantial acceleration in healthcare spending together with the expenditures to manage the COVID19 pandemic demand drug delivery solutions that enable a flexible care setting for high-dose monoclonal antibodies (mAbs) in oncology.

AREAS COVERED

This expert opinion introduces an analogue-based framework applied to guide decision-making for associated product improvements for mAb medications that are either already authorized or in late-stage clinical development. The four pillars of this framework comprise (1) the drug delivery profile of current and emerging treatments in the market, (2) the needs and preferences of people treated with mAbs, (3) existing healthcare infrastructures, and (4) country-dependent reimbursement and procurement models. The following product optimization examples for mAb-based treatments are evaluated based on original research and review articles in the field: subcutaneous formulations, an established drug delivery modality to reduce parenteral dosing complexity, fixed-dose combinations, an emerging concept to complement combination therapy, and (connected) on-body delivery systems, an identified future opportunity to support dosing outside of a controlled healthcare institutional environment.

EXPERT OPINION

Leveraging existing synergies and learnings from other disease areas is a measure to reduce associated development and commercialization costs and thus to provide sustainable product offerings already at the initial launch of a medication.

Potent Inhibitory Activity of Natural Product Anaephene B and Analogues against Leishmania tarentolae In Vitro

In this study, a specific alkylphenol natural product, anaephene B, and its unique synthesized derivatives were tested for their inhibitory effect on the protozoan parasite Leishmania tarentolae. In a series of cell viability tests and enzyme assays, these test compounds have produced interesting results with regard to their antibiotic effect, showing similar potency against L. tarentolae as they do against drug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA). All compounds tested in this study have shown the ability to completely inhibit our model system, L. tarentolae, in vitro. This study helps increase our understanding of the structure-activity relationship (SAR) between anaephene B and its analogues for a new class of potential pharmaceuticals for the treatment of Leishmania infections.

Extending the Structure-Activity Relationship of Disorazole C1 : Exchanging the Oxazole Ring by Thiazole and Influence of Chiral Centers within the Disorazole Core on Cytotoxicity

The synthesis of novel disorazole C1 analogues is described and their biological activity as cytotoxic compounds is reported. Based on our convergent entry to the disorazole core we present a flexible and robust strategy to construct a variety of interesting new analogues. In particular, two regions of the molecules were examined for structural modification: 1. Replacement of the heterocyclic moiety by an exchange of the oxazole ring by a thiazole; and 2. Evaluation of the influence of the absolute configuration of the chiral centers of the molecule. Predicated on our flexible strategy we were able to construct all analogues in an efficient way and could perform an exciting SAR (structure-activity-relationship) study to obtain insight in the cytotoxic activity influenced by the chiral centers of the disorazole core.

Biological Effects of Modifications of the Englerin A Glycolate

Modifications at the glycolate moiety of englerin A were made to explore variations at the most sensitive site on the molecule for activity in the NCI 60 screen, wherein englerin A is highly potent and selective for renal cancer cells. Replacement of the glycolate by other functionalities as well as esterification of the glycolate hydroxyl yielded compounds which displayed excellent selectivity and potency compared with the natural product. TRPC4/5 ion channel experiments with five compounds showed delayed or reduced agonism with TRPC5, at much higher concentrations than englerin A. With TRPC4, these compounds all had no effect at 10 μM. The same compounds were not detectable in mouse serum after a single oral dose of 12.5 mg/kg. At 100 mg/kg p.o., no toxicity was observed, and blood levels were barely detectable. Intravenous administration led to toxicity but at substantially lower doses than for englerin A.

[Endocrine Treatments in Breast Cancer]

Endocrine Treatments in Breast Cancer Abstract. Breast cancer, the most common cancer in women, expresses estrogen and/or progesterone receptors in about 75% of patients. This allows for the use of endocrine treatments. Adjuvant therapy with tamoxifen for 5 years reduces the mortality by about 33%; the residual risk can be lowered by using aromatase inhibitors and by prolonging the treatment. In patients with advanced disease, the median duration of response to first-line therapy is about twelve months, and the median survival time is 20 to 40 months. The use of the various substances differs in terms of duration, sequence, and combinations, particularly with CDK4/6-inhibitors, depending on the clinical situation. Endocrine therapies are prescribed over a long period of time. Treatment adherence is improved by optimal control of side effects.

Using analogue data to substantiate long-term durability of gene therapies: a narrative review

The number of gene therapies in clinical trials and moving toward licensure is increasing. Most gene therapies are designed to achieve long-term effects, but at licensure the data to support claims of long-term durability are often limited, as long-term monitoring studies are often part of post-approval commitments by companies. Health technology assessors must therefore assess the potential for the long-term durability of a product and the potential cost-effectiveness based on the data available. The authors explored the benefit of strengthening the ability to infer durability of effect using analogue category data. Different analogue categories were assessed for the potential to substantiate claims of sustainability of effect for gene therapies by leveraging biological plausibility arguments. The authors propose a pathway for identifying potential analogues. Such a pathway should help establish plausible or theoretical long-term outcomes that can be considered in value assessments of gene therapies.

Probing O-substituted Nifuroxazide analogues against Leishmania: Synthesis, in vitro efficacy, and hit/lead identification

Leishmaniasis is a neglected tropical disease affecting millions of people worldwide, with 650 000 to 1.1 million new infections reported annually by the World Health Organization. Current antileishmanial treatments are unsatisfactory due to the development of parasitic resistance and the toxicity associated with the drugs used, and this highlights the need for the development of new antileishmanial drugs. In this study, a series of nifuroxazide analogues were synthesized in a single step reaction and investigated for their antileishmanial potential. The sulfonate 1l, bearing pyridine ring, was deemed an antileishmanial hit, targeting the amastigotes of Leishmania (L.) donovani and L. major, the pathogens of visceral and cutaneous leishmaniasis, respectively, with micromolar potencies. The benzyl analogues 2c and 2d were also confirmed as submicromolar active leads against amastigotes of L. major. These analogues stand as promising candidates for further investigation involving the evaluation of their in vivo activities and molecular targets.

The alprazolam analogue 4'-chloro deschloroalprazolam identified in seized capsules

New designer benzodiazepines continue to be identified in the illicit drug market. In December 2021, eight capsules were submitted to ChemCentre for analysis. The samples were analysed by a range of analytical techniques including gas chromatography-mass spectrometry (GC-MS), ultraviolet-visible spectrophotometry, liquid chromatography-mass spectrometry (LC-MS, low and high resolution), nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography, which identified the main component of the capsules to be 4'-chloro deschloroalprazolam, a new designer benzodiazepine. Alarmingly, the mass spectral data for this alprazolam analogue were very similar to that of alprazolam, such that misidentification could be possible. A minor component of the capsules was also partially characterised, it is believed to be the synthetic precursor 4'-chloro deschloronordiazepam. The information provided in this paper includes ways to discriminate these analogues from alprazolam and nordiazepam which will enable other laboratories to identify these new drugs.

Endogenous Protective Factors and Potential Therapeutic Agents for Diabetes-Associated Atherosclerosis

The complications of macrovascular atherosclerosis are the leading cause of disability and mortality in patients with diabetes. It is generally believed that the pathogenesis of diabetic vascular complications is initiated by the imbalance between injury and endogenous protective factors. Multiple endogenous protective factors secreted by endothelium, liver, skeletal muscle and other tissues are recognized of their importance in combating injury factors and maintaining the homeostasis of vasculatures in diabetes. Among them, glucagon-like peptide-1 based drugs were clinically proven to be effective and recommended as the first-line medicine for the treatment of type 2 diabetic patients with high risks or established arteriosclerotic cardiovascular disease (CVD). Some molecules such as irisin and lipoxins have recently been perceived as new protective factors on diabetic atherosclerosis, while the protective role of HDL has been reinterpreted since the failure of several clinical trials to raise HDL therapy on cardiovascular events. The current review aims to summarize systemic endogenous protective factors for diabetes-associated atherosclerosis and discuss their mechanisms and potential therapeutic strategy or their analogues. In particular, we focus on the existing barriers or obstacles that need to be overcome in developing new therapeutic approaches for macrovascular complications of diabetes.

Insights into Structural Modifications of Valproic Acid and Their Pharmacological Profile

Valproic acid (VPA) is a well-established anticonvulsant drug discovered serendipitously and marketed for the treatment of epilepsy, migraine, bipolar disorder and neuropathic pain. Apart from this, VPA has potential therapeutic applications in other central nervous system (CNS) disorders and in various cancer types. Since the discovery of its anticonvulsant activity, substantial efforts have been made to develop structural analogues and derivatives in an attempt to increase potency and decrease adverse side effects, the most significant being teratogenicity and hepatotoxicity. Most of these compounds have shown reduced toxicity with improved potency. The simple structure of VPA offers a great advantage to its modification. This review briefly discusses the pharmacology and molecular targets of VPA. The article then elaborates on the structural modifications in VPA including amide-derivatives, acid and cyclic analogues, urea derivatives and pro-drugs, and compares their pharmacological profile with that of the parent molecule. The current challenges for the clinical use of these derivatives are also discussed. The review is expected to provide necessary knowledgebase for the further development of VPA-derived compounds.

Thiophene and its Analogs as Prospective Antioxidant Agents: A Retrospect

The field of Free Radical Chemistry has gained considerable interest in the current scenario. The formation of free radicals is attributable to different physiochemical factors, radiation exposure, pathological conditions, environmental contaminants, and as by-products of metabolized drugs. The concentration of free radicals is regulated strongly under normal conditions by physiological antioxidants. Free radicals may cause oxidative damage to proteins, lipids, sugars, and DNA when abundantly produced or when antioxidants are depleted. This imbalance of reduction-oxidation, referred to as oxidative stress, can change the body's physiological conditions and ultimately lead to tissue injury, further contributing to various disease pathologies. A proper balance between free radicals and antioxidants is required for an effective physiological process. The oxidation mechanism is chemically hindered by antioxidants; these are often called free radical scavengers. The application of an external antioxidant source is crucial in addressing the issue of oxidative stress. Plenty of naturally occurring, semi-synthetic, and synthetic antioxidants are used, and the search for an efficient, non-toxic, and safe antioxidant is stepped up over time. As an influential scaffold, thiophene and its derivatives have become a significant source of interest for researchers due to its substantial variety of biological activities. The versatility of thiophene moiety has been identified by an affluent unveiling of its derivatives with anti-inflammatory, antioxidant, anti-cancer, and antimicrobial behaviors. Thiophene activity has been influenced greatly by the nature and orientation of the substitutions. The current study aims at addressing various synthetic compounds with thiophene or condensed thiophene as a fundamental moiety or substituent as radical scavengers.

Semisynthetic Derivatives of Selected Amaryllidaceae Alkaloids as a New Class of Antimycobacterial Agents

The search for novel antimycobacterial drugs is a matter of urgency, since tuberculosis is still one of the top ten causes of death from a single infectious agent, killing more than 1.4 million people worldwide each year. Nine Amaryllidaceae alkaloids (AAs) of various structural types have been screened for their antimycobacterial activity. Unfortunately, all were considered inactive, and thus a pilot series of aromatic esters of galanthamine, 3-O-methylpancracine, vittatine and maritidine were synthesized to increase biological activity. The semisynthetic derivatives of AAs were screened for their in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Ra and two other mycobacterial strains (M. aurum, M. smegmatis) using a modified Microplate Alamar Blue Assay. The most active compounds were also studied for their in vitro hepatotoxicity on the hepatocellular carcinoma cell line HepG2. In general, the derivatization of the original AAs was associated with a significant increase in antimycobacterial activity. Several pilot derivatives were identified as compounds with micromolar MICs against M. tuberculosis H37Ra. Two derivatives of galanthamine, 1i and 1r, were selected for further structure optimalization to increase the selectivity index.

Synthesis and Bio-evaluation of 2-Alkyl Substituted Fluorinated Genistein Analogues Against Breast Cancer

BACKGROUND

Breast cancer is the leading cause of cancer death in women. The current methods of chemotherapy for breast cancer generally have strong adverse reactions and drug resistance. Therefore, the discovery of novel anti-breast cancer lead compounds is urgently needed.

OBJECTIVE

Design and synthesize a series of 2-alkyl substituted fluorinated genistein analogues and evaluate their anti-breast cancer activity.

METHODS

Target compounds were obtained in a multistep reaction synthesis. The anti-tumor activity of compounds I-1~I-35 were evaluated with MCF-7, MDA-MB-231, MDA-MB-435, and MCF-10A cell lines in vitro, with tamoxifen as the positive control. Molecular docking was used to study the interaction between the synthesized compounds and PI3K-gamma.

RESULTS

A series of 2-alkyl substituted fluorinated genistein analogues were designed, synthesized and screened for their bioactivity. Most of the compounds displayed better selectivity toward breast cancer cell lines as compared with tamoxifen. Among these analogues, I-2, I-3, I-4, I-9, I-15 and I-17 have the strongest selective inhibition of breast cancer cells. Compounds I-10, I-13, I-15, I-17 and I-33 were found to have significant inhibitory effects on breast cancer cells. Molecular docking studies have shown that these compounds may act as PI3Kγ inhibitors and may further exhibit anti-breast cancer effects.

CONCLUSION

Most of the newly synthesized compounds could highly selectively inhibit breast cancer cell lines. The experimental results indicate that the synthesized analogs may also have obvious selective inhibitory effects on other malignant proliferation cancer cells.

Advancements in the Use of Platinum Complexes as Anticancer Agents

BACKGROUND

The platinum (II) complexes as anticancer agents have been well explored for the development of novel analogs. Yet, none of them achieved clinical importance in oncology. At present, anticancer compounds containing platinum (II) complexes have been employed in the treatment of colorectal, lung, and genitourinary tumors. Among the platinum-based anticancer drugs, Cisplatin (cis-diamine dichloroplatinum (II), cis-[Pt(NH3)2Cl2]) is one of the most potent components of cancer chemotherapy. The nephrotoxicity, neurotoxicity and ototoxicity, and platinum compounds associated resistant cancer are some major disadvantages.

OBJECTIVE

With the rapidly growing interest in platinum (II) complexes in tumor chemotherapy, researchers have synthesized many new platinum analogs as anticancer agents that show better cytotoxicity, and less off-target effects with less cellular resistance. This follows the introduction of oxaliplatin, water-soluble carboplatin, multinuclear platinum and newly synthesized complexes, etc. Method: This review emphasizes recent advancements in drug design and development, the mechanism of platinum (II) complexes, their stereochemistry, current updates, and biomedical applications of platinum-based anticancer agents.

CONCLUSION

In the last few decades, the popularity of platinum complexes as potent anti-cancer agents has risen as scientists have synthesized many new platinum complexes that exhibit better cytotoxicity coupled with less off-target effects.

A Brief Updated Review of Advances to Enhance Resveratrol's Bioavailability

Resveratrol (RES) has a low bioavailability. This limitation was addressed in an earlier review and several recommendations were offered. A literature search was conducted in order to determine the extent of the research that was conducted in line with these recommendations, along with new developments in this field. Most of the identified studies were pre-clinical and confirmed the heightened activity of RES analogues compared to their parent compound. Although this has provided additional scientific kudos for these compounds and has strengthened their potential to be developed into phytopharmaceutical products, clinical trials designed to confirm this increased activity remain lacking and are warranted.

Analysis of the Structural Mechanism of ATP Inhibition at the AAA1 Subunit of Cytoplasmic Dynein-1 Using a Chemical "Toolkit"

Dynein is a ~1.2 MDa cytoskeletal motor protein that carries organelles via retrograde transport in eukaryotic cells. The motor protein belongs to the ATPase family of proteins associated with diverse cellular activities and plays a critical role in transporting cargoes to the minus end of the microtubules. The motor domain of dynein possesses a hexameric head, where ATP hydrolysis occurs. The presented work analyzes the structure–activity relationship (SAR) of dynapyrazole A and B, as well as ciliobrevin A and D, in their various protonated states and their 46 analogues for their binding in the AAA1 subunit, the leading ATP hydrolytic site of the motor domain. This study exploits in silico methods to look at the analogues’ effects on the functionally essential subsites of the motor domain of dynein 1, since no similar experimental structural data are available. Ciliobrevin and its analogues bind to the ATP motifs of the AAA1, namely, the walker-A (W-A) or P-loop, the walker-B (W-B), and the sensor I and II. Ciliobrevin A shows a better binding affinity than its D analogue. Although the double bond in ciliobrevin A and D was expected to decrease the ligand potency, they show a better affinity to the AAA1 binding site than dynapyrazole A and B, lacking the bond. In addition, protonation of the nitrogen atom in ciliobrevin A and D, as well as dynapyrazole A and B, at the N9 site of ciliobrevin and the N7 of the latter increased their binding affinity. Exploring ciliobrevin A geometrical configuration suggests the E isomer has a superior binding profile over the Z due to binding at the critical ATP motifs. Utilizing the refined structure of the motor domain obtained through protein conformational search in this study exhibits that Arg1852 of the yeast cytoplasmic dynein could involve in the “glutamate switch” mechanism in cytoplasmic dynein 1 in lieu of the conserved Asn in AAA+ protein family.

Marine Alkaloid Pityriacitrin and Its Analogues: Discovery, Structures, Synthetic Methods and Biological Properties

Pityriacitrin is a natural marine alkaloid with a typical β-carboline scaffold, and which has been demonstrated to exhibit diverse biological functions. The special structural features for pityriacitrin lead to the increasing research interest and the emergence of versatile derivatives, and many pityriacitrin analogues have been isolated or synthesized over the past decades. The structural diversity and evolved biological activity of these natural alkaloids can offer opportunities for the development of highly potential novel drugs with a new mechanism of action, and therefore, the aim of this brief review is to describe the discovery, synthesis, and biological properties of natural pityriacitrin and its derivatives, as well as the isolation source.

Antimetastatic Potential of Quercetin Analogues with Improved Pharmacokinetic Profile: Pharmacoinformatic Preliminary Study

BACKGROUND

Urokinase-type plasminogen activator (uPA) system is a crucial pathway for tumor invasion and metastasis. Recently, multiple anticancer effects of quercetin have been described, including inhibitory activity against uPA. However, the clinical use of this flavonoid has been limited due to its low oral bioavailability.

OBJECTIVE

The objectives of the study were to assess the antimetastatic potential of quercetin analogues by analyzing their binding affinity for uPA and to select the compounds with improved pharmacological profiles.

METHODS

Binding affinities of structural analogues of quercetin to uPA receptor were determined by molecular docking analysis using Molegro Virtual Docker software, and molecular descriptors relevant for estimating pharmacological profile were calculated from ligand structures using computational models.

RESULTS

Among 44 quercetin analogues, only one quercetin analogue (3,6,2',4',5'-pentahydroxyflavone) was found to possess both higher aqueous solubility and membrane permeability, and a stronger affinity for uPA than quercetin, which makes it the potential lead compound for anticancer drug development. Like quercetin, this compound has five hydroxyl groups but is arranged differently, which contributes to the higher aqueous solubility and higher amphiphilic moment compared to quercetin. Since membrane permeability is not recognized as the limiting factor for quercetin absorption, analogues with higher aqueous solubility and retained or stronger uPA inhibitory activity should also be further experimentally validated for potential therapeutic use.

CONCLUSION

Identified quercetin analogues with better physicochemical and pharmacological properties have a high potential to succeed in later stages of research in biological systems as potential anticancer agents with antimetastatic activity.

Establishing an Analogue Based In Silico Pipeline in the Pursuit of Novel Inhibitory Scaffolds against the SARS Coronavirus 2 Papain-Like Protease

The ongoing coronavirus pandemic has been a burden on the worldwide population, with mass fatalities and devastating socioeconomic consequences. It has particularly drawn attention to the lack of approved small-molecule drugs to inhibit SARS coronaviruses. Importantly, lessons learned from the SARS outbreak of 2002-2004, caused by severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1), can be applied to current drug discovery ventures. SARS-CoV-1 and SARS-CoV-2 both possess two cysteine proteases, the main protease (Mpro) and the papain-like protease (PLpro), which play a significant role in facilitating viral replication, and are important drug targets. The non-covalent inhibitor, GRL-0617, which was found to inhibit replication of SARS-CoV-1, and more recently SARS-CoV-2, is the only PLpro inhibitor co-crystallised with the recently solved SARS-CoV-2 PLpro crystal structure. Therefore, the GRL-0617 structural template and pharmacophore features are instrumental in the design and development of more potent PLpro inhibitors. In this work, we conducted scaffold hopping using GRL-0617 as a reference to screen over 339,000 ligands in the chemical space using the ChemDiv, MayBridge, and Enamine screening libraries. Twenty-four distinct scaffolds with structural and electrostatic similarity to GRL-0617 were obtained. These proceeded to molecular docking against PLpro using the AutoDock tools. Of two compounds that showed the most favourable predicted binding affinities to the target site, as well as comparable protein-ligand interactions to GRL-0617, one was chosen for further analogue-based work. Twenty-seven analogues of this compound were further docked against the PLpro, which resulted in two additional hits with promising docking profiles. Our in silico pipeline consisted of an integrative four-step approach: (1) ligand-based virtual screening (scaffold-hopping), (2) molecular docking, (3) an analogue search, and, (4) evaluation of scaffold drug-likeness, to identify promising scaffolds and eliminate those with undesirable properties. Overall, we present four novel, and lipophilic, scaffolds obtained from an exhaustive search of diverse and uncharted regions of chemical space, which may be further explored in vitro through structure-activity relationship (SAR) studies in the search for more potent inhibitors. Furthermore, these scaffolds were predicted to have fewer off-target interactions than GRL-0617. Lastly, to our knowledge, this work contains the largest ligand-based virtual screen performed against GRL-0617.

Coenzyme Q10 Analogues: Benefits and Challenges for Therapeutics

Coenzyme Q₁₀ (CoQ₁₀ or ubiquinone) is a mobile proton and electron carrier of the mitochondrial respiratory chain with antioxidant properties widely used as an antiaging health supplement and to relieve the symptoms of many pathological conditions associated with mitochondrial dysfunction. Even though the hegemony of CoQ₁₀ in the context of antioxidant-based treatments is undeniable, the future primacy of this quinone is hindered by the promising features of its numerous analogues. Despite the unimpeachable performance of CoQ₁₀ therapies, problems associated with their administration and intraorganismal delivery has led clinicians and scientists to search for alternative derivative molecules. Over the past few years, a wide variety of CoQ₁₀ analogues with improved properties have been developed. These analogues conserve the antioxidant features of CoQ₁₀ but present upgraded characteristics such as water solubility or enhanced mitochondrial accumulation. Moreover, recent studies have proven that some of these analogues might even outperform CoQ₁₀ in the treatment of certain specific diseases. The aim of this review is to provide detailed information about these Coenzyme Q₁₀ analogues, as well as their functionality and medical applications.

Molecular docking of potential inhibitors with the mTOR protein

The mTOR (mammalian or mechanistic Target of Rapamycin) is linked with oral cancer. Therefore, it is of interest to study the molecular docking-based binding of paclitaxel (a FDA approved drug for oral cancer) and its analogues with mTOR. Hence, we report the binding features of 10-Deacetyltaxol, 7-Epi-10-deacetyltaxol, 7-Epi-Taxol and 6alpha-Hydroxypaclitaxel with mTOR for further consideration.

Synthesis and biological analysis of anti-addiction effect and hepatotoxicity of tow baclofen analogues complexed with β-Cyclodextrin

AIM AND OBJECTIVE

The excessive consumption of alcohol and the installation of a dependence is, in most cases, facilitated by favorable psychological factors which trigger and maintain the behavior of consumption. Examples more frequently encountered in individuals having difficulty with alcohol are in particular: one or more anxiety disorders, deficits in the capacities to manage stress and anxiety. The main objective of this work was study in vivo the anti-addiction effect and hepatotoxicity of tow baclofen analogues complexed with β-Cyclodextrin (βCD) on an alcohol-dependent rat model.

MATERIALS AND METHODS

The synthesis of two analogues ABF1 and ABF2 close to baclofen was reported. The structural determination of the two compounds was confirmed by NMR and IR analysis. The complexation of analogues with βCyclodextrin (βCD) was performed in water at room temperature (25 °C). The interactions of ABF with β-Cyclodextrin, and the stability constant (Ka) of the inclusion complex formed between them were investigated by using UV-visible spectroscopy. The biological effects of baclofen and the two analogues on alcohol dependence were studied in wistar rats. The anti-addiction effect of the analogues was tested by measuring the alcohol intake and the variation of the animal behaviour. The toxicity of the compounds was also analysed on liver injury markers.

RESULTS

The amino-3-phenylbutanoic acid (ABF1) and 3,4,5-trihydroxy-N-(methyl-2-acetate) benzamide (ABF2) were synthesized. The complexation of both analogues of baclofen (BF) with β-cyclodextrin (βCD) (ABF- βCD) was realized and confirmed by the stability constant of the inclusion complex (Ka) and Job's method. The evaluation of anti-addiction activity in vivo showed that ABF1-βCD inhibits the consumption of alcohol at the doses equivalent to those of baclofen. Both baclofen analogues have shown an anxiolytic effect. Regarding the toxicity of the two compounds, our results showed that ABF1-βCD has less toxic effect than baclofen, it reduces the activity of ALT and AST enzymes. Histologically ABF1-βCD has no effect on structure of the liver in addition and has a protective effect against lesions alcohol-induced liver disease.

CONCLUSION

Therefore, it can be suggested that ABF1 analogue combined with β-Cyclodextrin can be used as a treatment for alcohol dependence. Further clinical works are needed to confirm its effectiveness.

Synthesis, aphicidal activity and conformation of novel insect kinin analogues as potential eco-friendly insecticides

BACKGROUND

The discovery of ecofriendly insecticides through a new strategy for aphid control is important because of the substantial resistance and unexpected eco-toxicity to honeybees caused by traditional insecticides. The insect kinins, a class of multifunctional insect neuropeptides, are considered for potential application in pest control. In our previous work we developed several series of insect kinin analogues and found a promising lead II-1 with good aphicidal activity. To seek further eco-friendly aphicides, the optimization of II-1 is carried out in this study.

RESULTS

Fifteen novel Yaa³ modified analogues based on the lead II-1 were synthesized. The aphicidal tests indicated that IV-3, IV-5 and IV-10 exhibited significant activity against the soybean aphid Aphis glycines with LC₅₀ values of 0.0029, 0.0072 and 0.0086 mmol L^-1 , respectively, higher than that of lead II-1 and the commercial Pymetrozine. The molecular modeling results showed that analogues II-1, IV-3, IV-5, IV-7 and IV-10 formed a β-turn-like conformation, while the conformation of analogues IV-1, IV-2 and IV-9 seemed to be linear. Some structural elements favorable for the activity were proposed based on the conformation-activity relationship of the analogues.

CONCLUSION

Insect kinin analogues derived from lead II-1 by modifying the hydrolysis site Yaa³ with natural, sterically hindered α- and β-amino acids showed great potential as eco-friendly insecticides. Inspiringly, the most active analogue IV-3 can be a candidate for further development. The β-turn-like conformation and the orientation of the aromatic rings of the side chain of Phe² and Trp⁴ may be critical factors beneficial to activity. © 2019 Society of Chemical Industry.

Molecular docking analysis of docetaxel analogues as duel lipocalin 2 inhibitors

Lipocalin 2 (Lcn2, also called as neutrophil gelatinase-associated lipocalin) is a member of the lipocalin family and a known target for breast cancer. Therefore, it is of interest to use Docetaxel as a scaffold to design molecules with improved efficiency from naturally derived phytochemicals. We document 10 analogues (4Deacetyltaxol, 7Acetyltaxol, Cabazitaxel, Cephalomannine, Docetaxal, Deacetyltaxol, Docetaxeltrihydrate, Ortataxel, Paclitaxel, Taxoline) having optimal binding with Lipocalin 2 in comparison with Docetaxel. This data is highly useful for consideration in the design and development of drugs for breast cancer.

Bioluminescent Properties of Semi-Synthetic Obelin and Aequorin Activated by Coelenterazine Analogues with Modifications of C-2, C-6, and C-8 Substituents

Ca2+-regulated photoproteins responsible for bioluminescence of a variety of marine organisms are single-chain globular proteins within the inner cavity of which the oxygenated coelenterazine, 2-hydroperoxycoelenterazine, is tightly bound. Alongside with native coelenterazine, photoproteins can also use its synthetic analogues as substrates to produce flash-type bioluminescence. However, information on the effect of modifications of various groups of coelenterazine and amino acid environment of the protein active site on the bioluminescent properties of the corresponding semi-synthetic photoproteins is fragmentary and often controversial. In this paper, we investigated the specific bioluminescence activity, light emission spectra, stopped-flow kinetics and sensitivity to calcium of the semi-synthetic aequorins and obelins activated by novel coelenterazine analogues and the recently reported coelenterazine derivatives. Several semi-synthetic photoproteins activated by the studied coelenterazine analogues displayed sufficient bioluminescence activities accompanied by various changes in the spectral and kinetic properties as well as in calcium sensitivity. The poor activity of certain semi-synthetic photoproteins might be attributed to instability of some coelenterazine analogues in solution and low efficiency of 2-hydroperoxy adduct formation. In most cases, semi-synthetic obelins and aequorins displayed different properties upon being activated by the same coelenterazine analogue. The results indicated that the OH-group at the C-6 phenyl ring of coelenterazine is important for the photoprotein bioluminescence and that the hydrogen-bond network around the substituent in position 6 of the imidazopyrazinone core could be the reason of different bioluminescence activities of aequorin and obelin with certain coelenterazine analogues.

In Vitro Interaction of Organophosphono- and Organophosphorothioates with Human Acetylcholinesterase

The implementation of the Chemical Weapons Convention (CWC) in 1997 was a milestone in the prohibition of chemical warfare agents (CWA). Yet, the repeated use of CWA underlines the ongoing threat to the population. Organophosphorus (OP) nerve agents still represent the most toxic CWA subgroup. Defensive research on nerve agents is mainly focused on the "classical five", namely tabun, sarin, soman, cyclosarin and VX, although Schedule 1 of the CWC covers an unforeseeable number of homologues. Likewise, an uncounted number of OP pesticides have been produced in previous decades. Our aim was to determine the in vitro inhibition kinetics of selected organophosphono- and organophosphorothioates with human AChE, as well as hydrolysis of the agents in human plasma and reactivation of inhibited AChE, in order to derive potential structure-activity relationships. The investigation of the interactions of selected OP compounds belonging to schedule 1 (V-agents) and schedule 2 (amiton) of the CWC with human AChE revealed distinct structural effects of the P-alkyl, P-O-alkyl and N,N-dialkyl residues on the inhibitory potency of the agents. Irrespective of structural modifications, all tested V-agents presented as highly potent AChE inhibitors. The high stability of the tested agents in human plasma will most likely result in long-lasting poisoning in vivo, having relevant consequences for the treatment regimen. In conclusion, the results of this study emphasize the need to investigate the biological effects of nerve agent analogues in order to assess the efficacy of available medical countermeasures.

Bengamide Analogues Show A Potent Antitumor Activity against Colon Cancer Cells: A Preliminary Study

The limited success and side effects of the current chemotherapeutic strategies against colorectal cancer (CRC), the third most common cancer worldwide, demand an assay with new drugs. The prominent antitumor activities displayed by the bengamides (Ben), a family of natural products isolated from marine sponges of the Jaspidae family, were explored and investigated as a new option to improve CRC treatment. To this end, two potent bengamide analogues, Ben I (5) and Ben V (10), were selected for this study, for which they were synthesized according to a new synthetic strategy recently developed in our laboratories. Their antitumor effects were analyzed in human and mouse colon cell lines, using cell cycle analysis and antiproliferative assays. In addition, the toxicity of the selected analogues was tested in human blood cells. These biological studies revealed that Ben I and V produced a significant decrease in CRC cell proliferation and induced a significant cell cycle alteration with a greater antiproliferative effect on tumor cell lines than normal cells. Interestingly, no toxicity effects were detected in blood cells for both compounds. All these biological results render the bengamide analogues Ben I and Ben V as promising antitumoral agents for the treatment of CRC.

Diversity-Oriented Library Synthesis from Steviol and Isosteviol-Derived Scaffolds

The readily available natural product stevioside provides a unique diterpene core structure that can be explored for small molecule library development by diversity-oriented synthesis and functional group transformations. Validation arrays were prepared from steviol, isosteviol, and related analogues, derived from stevioside, to produce over 90 compounds. These compounds were submitted to the NIH Molecular Libraries Small Molecule Repository for screening in the Molecular Libraries Screening Center Network. Micromolar hits were identified in multiple high-throughput assays for several library members. A cheminformatics analysis of the compounds was performed that verified the expected diversity and complexity of this set of compounds. The screening results indicate that scaffolds-derived natural products can provide screening hits against multiple target proteins.

Synthesis and Structural Determination of New Brassinosteroid 24-Nor-5α-Cholane Type Analogs

Natural brassinosteroids possess a 22R, 23R configuration that appears essential for biological activity. It is, therefore, interesting to elucidate if the activity of brassinosteroids with a short side chain depends on the C22 configuration. Herein, we describe the synthesis of new brassinosteroids analogs with 24-norcholane type of side chain and R configuration at C22. The initial reaction is the dihydroxylation of a terminal olefin that leads to S/R epimers. Three different methods were tested in order to evaluate the obtained S/R ratio and the reaction yields. The results indicate that Upjohn dihydroxylation is the most selective reaction giving a 1.0:0.24 S/R ratio, whereas a Sharpless reaction leads to a mixture of 1.0:0.90 S/R with 95% yield. Using the latter mixture and following a previous reported method, benzoylated derivatives and both S and R brassinosteroids analogs were synthesized. All synthesized compounds were completely characterized by NMR spectroscopy, and HRMS of new compounds are also given. In conclusion, a synthetic route for preparation of new analogs of brassinosteroids of 24-norcholane type and R configuration at C22 were described. It is expected that this will help to elucidate if a configuration at C22 is a structural requirement for hormonal growth activity in plants.

Fastidious Anatomization of Biota Procured Compounds on Cancer Drug Discovery

BACKGROUND

Natural products are the rootstock for identifying new drugs since ancient times. In comparison with synthetic drugs, they have abounding beneficial effects in bestowing protection against many diseases, including cancer. Cancer has been observed as a major threat in recent decades, and its prevalence is expected to increase over the next decades. Also, current treatment methods in cancer therapy such as radiation therapy and chemotherapy cause severe adverse side effects among the cancer population. Therefore, it is exigent to find a remedy without any side effects.

METHODS

In recent years, research has focused on obtaining naturally derived products to encounter this complication. The current pace of investigations, such as gene identification and advancement in combinatorial chemistry, leads to the aberrant access to a wide range of new synthetic drugs. In fact, natural products act as templates in structure predictions and synthesis of new compounds with enhanced biological activities.

RESULTS

Recent developments in genomics have established the importance of polymorphism, which implies that patients require different drugs for their treatment. This demands the discovery of a large number of drugs, but limited sources restrict the pharmaceutical industry to overcome these major obstacles. The use of natural products and their semisynthetic and synthetic analogues could alleviate these problems. However, the lack of standardization in terms of developing methods for evaluating the chemical composition, efficacy, isolation and international approval is still a major limitation in this field. In the past few years, several drug-approval authorities, including the FDA and WHO have allowed using these naturally derived compounds in humans.

CONCLUSION

In this review, we described the use of some natural products from plant and marine sources in cancer treatment and shed some light on semi-synthetic and synthetic compounds derived from natural sources used in cancer therapy.

Microbial Markers Profile in Anaerobic Mars Analogue Environments Using the LDChip (Life Detector Chip) Antibody Microarray Core of the SOLID (Signs of Life Detector) Platform

One of the main objectives for astrobiology is to unravel and explore the habitability of environments beyond Earth, paying special attention to Mars. If the combined environmental stress factors on Mars are compatible with life or if they were less harsh in the past, to investigate the traces of past or present life is critical to understand its potential habitability. Essential for this research is the characterization of Mars analogue environments on Earth through the development of techniques for biomarker detection in them. Biosensing techniques based on fluorescence sandwich microarray immunoassays (FSMI) have shown to be a powerful tool to detect biosignatures and depict the microbial profiles of different environments. In this study, we described the microbial biomarker profile of five anoxic Mars analogues sites using the Life Detector Chip (LDChip), an antibody microarray for multiple microbial marker detection. Furthermore, we contributed to new targets by developing a new 26-polyclonal antibodies microarray using crude extracts from anaerobic sampling sites, halophilic microorganisms, and anaerobic isolates obtained in the framework of the European Mars Analogues for Space Exploration (MASE) project. The new subset of antibodies was characterized and implemented into a microarray platform (MASE-Chip) for microbial marker searching in salty and anaerobic environments.

Molecular modeling, simulation and principal component analysis of binding of resveratrol and its analogues with DNA

Structure-based drug designing has become a significant subject of research, and several clinically promising DNA binding compounds were evolved using this technique. The interaction of an octamer DNA sequence d(CCAATTGG)₂ with a natural stilbene, resveratrol and its analogues have been studied using molecular docking method. Out of the ten compounds studied, seven compounds were found to bind to the minor groove of AATT segment of the sequence. Pterostilbene, a natural analogue of resveratrol, showed the lowest binding energy. Rhaponticin, a natural analogue of resveratrol and digalloylresveratrol, a synthetic ester of resveratrol bind to the major groove of the AATT segment while dihydroresveratrol binds to the minor groove of GC terminal base pair. ADMET (Absorption, distribution, metabolism, excretion and toxicity) study showed that all compounds obey Lipinski rule and are accepted as orally active drugs based on different physicochemical descriptors. Molecular dynamics simulations were performed for the complex with lowest binding energy and trajectory analysis were performed. Principal component analysis has been performed to underline the prominent motions in alone DNA and when it is bound to pterostilbene. AbbreviationsADMETAbsorption, distribution, metabolism, excretion and toxicityDIGDigalloyl resveratrolDNADeoxyribonucleic acidELElectrostatic energyENPOLARNonpolar solvation energyESURFSurface areaGBGeneralized BornHBAHydrogen bond acceptorsHBDHydrogen bond donorsLGALamarckian genetic algorithmMDMolecular dynamicsPBPoisson-BoltzmannPCAPrincipal component analysisPTPterostilbeneRMSDRoot mean square deviationSASimulated annealingTLX3T-cell leukemia homeobox 3VDWvan der WaalsCommunicated by Ramaswamy H. Sarma.

Computational Study of the Binding Modes of Diverse DPN Analogues on Estrogen Receptors (ER) and the Biological Evaluation of a New Potential Antiestrogenic Ligand

Estrogen (17β-estradiol) is essential for normal growth and differentiation in the mammary gland. In the last three decades, previous investigations have revealed that Estrogen Receptor Alpha (ERα) plays a critical role in breast cancer. More recently, observations regarding the widespread expression of ERβ-like proteins in normal and neoplastic mammary tissues have suggested that ERβ is also involved in the mentioned pathology. Design of new drugs both steroidal and nonsteroidal that target any of these receptors represents a promise to treat breast cancer although it remains a challenge due to the sequence similarity between their catalytic domains. In this work, we propose a new set of compounds that could effectively target the estrogen receptors ERα and ERβ. These ligands were designed based on the chemical structure of the ERβ-selective agonist Diarylpropionitrile (DPN). The designed ligands were submitted to in silico ADMET studies, yielding in a filtered list of ligands that showed better drug-like properties. Molecular dynamics simulations of both estrogen receptors and docking analysis were carried-out employing the designed compounds, from which two were chosen due to their promising characteristics retrieved from theoretical results (docking analysis or targeting receptor predictions). They were chemically synthetized and during the process, two precursor ligands were also obtained. These four ligands were subjected to biological studies from which it could be detected that compound mol60b dislplayed inhibitory activity and its ability to activate the transcription via an estrogenic mechanism of action was also determined. Interestinly, this observation can be related to theoretical binding free energy calculations, where the complex: ERβ-mol60b showed the highest energy ΔGbind value in comparison to others.

N ɛ -acetyl lysine derivatives with zinc binding groups as novel HDAC inhibitors

HDAC inhibitors have been developed very rapidly in clinical trials and even in approvals for treating several cancers. However, there are few reported HDAC inhibitors designed from N ɛ -acetyl lysine. In the current study, we raised a novel design, which concerns N ɛ -acetyl lysine derivatives containing amide acetyl groups with the hybridization of ZBG groups as novel HDAC inhibitors.

falciparum

Fatty acid biosynthesis enzymes (Fab enzyme) are important targets for anti-malarial drug development. The present study describes the toxicity screening of designed novel analogues which inhibit FabI enzyme regulation, a protein with multifunctional property. New analogues were prepared using ChemDraw Ultra 10 Software and converted into 3D PDB structure format for binding studies with FabI (PDB ID: 4IGE). Further Lipinski's rule of FIVE and ADMET profiling for toxicity prediction has been performed on the designed analogues. The result shows that ISN-23 is potential analogue exhibiting inhibition at the active site of FabI enzyme with good binding features.

Efficacy of tenofovir disoproxil fumarate switch therapy in chronic hepatitis B patients with suboptimal response to adefovir-based combination therapy

In the present study, the efficacy and safety of tenofovir disoproxil fumarate (TDF) switch therapy were assessed in patients with chronic hepatitis B exhibiting a suboptimal response to adefovir (ADV)-based combination therapy. First, the efficacy of the TDF switch therapy was retrospectively evaluated in 50 patients with chronic hepatitis B who failed to respond to ADV-based combination treatment. Among those, 48 patients with a median age of 35 years were hepatitis B e antigen (HBeAg)-positive and 17, 14 and 19 patients were previously treated with lamivudine (LAM) plus ADV, telbivudine plus ADV and entecavir (ETV) plus ADV, respectively. A total of 41 patients were treated with TDF alone and 9 with TDF plus ETV. The median time of follow-up was 102 weeks. The primary end-point was the cumulative probability of achieving a complete virologic response (CVR). The secondary end-points were the rate of alanine aminotransferase (ALT) normalization, HBeAg seroconversion in HBeAg-positive patients, and the plasma levels of creatinine and creatine kinase. The mean serum hepatitis B virus DNA levels prior to initiation of the TDF switch therapy were 4.8±1.6 log₁₀IU/ml. The cumulative probability of achieving a VR at 24, 48, 96 and 108 weeks was 52.0, 76.0, 89.8 and 94.9%, respectively. The cumulative probability of normalization of ALT at 12, 24, 36, 48, 60,72, 84, 96, 108, 120 and 132 weeks was 34, 44, 50, 58, 66, 70, 74, 80, 90, 92 and 94%, respectively. HBeAg seroconversion was achieved in 5 patients. During the follow-up, 6 patients suffered from a virologic breakthrough, 3 patients failed to respond to the TDF treatment and the remaining patients were able to obtain VR following the continuation of TDF treatment. Slightly elevated serum levels of creatinine were observed in one patient, whereas creatine kinase activity did not increase in any of the subjects. In conclusion, TDF switch therapy is efficient and safe for patients with chronic hepatitis B with a suboptimal response to ADV-based combination therapy.

Identification of potential inhibitors for Klebsiella pneumoniae carbapenemase-3: a molecular docking and dynamics study

Klebsiella pneumoniae (K. pneumoniae) is a Gram-negative bacterium, which is a leading causal agent for nosocomial infections. Penicillin, cephalosporin and carbapenems along with the inhibitors such as tazobactam, sulbactam and clavulanic acid are prescribed for the treatment of K. pneumoniae infections. Prolonged exposure to β-lactam antibiotics leads to the development of resistance. The major reason for the β-lactam resistance in K. pneumoniae is the secretion of the enzyme K. pneumoniae carbapenemase (KPC). Secretion of KPC-2 and its variant KPC-3 by the K. pneumoniae strains causes resistance to both the substrate imipenem and the β-lactamase inhibitors. Hence, molecular docking and dynamics studies were carried out to analyze the resistance mechanism of KPC-2-imipenem and KPC-3-imipenem at the structural level. It reveals that KPC-3-imipenem has the highest c-score value of 4.03 with greater stability than the KPC-2-imipenem c-score value of 2.36. Greater the interaction between the substrate and the β-lactamase enzyme, higher the chances of hydrolysis of the substrate. Presently available β-lactamase inhibitors are also ineffective against KPC-3-expressing strains. This situation necessitates the need for development of novel and effective inhibitors for KPC-3. We have carried out the virtual screening process to identify more effective inhibitors for KPC-3, and this has resulted in ZINC48682523, ZINC50209041 and ZINC50420049 as the best binding energy compounds, having greater binding affinity and stability than KPC-3-tazobactam interactions. Our study provides a clear understanding of the mechanism of drug resistance and provides valuable inputs for the development of inhibitors against KPC-3 expressing K. pneumoniae. Communicated by Ramaswamy H. Sarma.

Overview of Cantharidin and its Analogues

BACKGROUND

Cantharidin has been categorized as highly toxicant in Chinese medicine. But cantharidin can efficiently treat different types of diseases, such as molluscum contagiosum. While cantharidin is quite useful, unfortunately, due to its side effects, increasing regulations have limited access to this useful therapeutic option. Cantharidin's toxic effects have caused it to fall into disuse for most legitimate medical purposes. Although cantharidin generates effects and its advantages must be realized. Recently, cancer affects people's life more and more. Because cantharidin can treat some cancers, so solutions must be used to reduce side effects. This review aims to describe some its analogues, several efficient methods to inhibit the side effects of cantharidin and pharmacogenomics of cantharidin.

METHODS

We searched for research about cantharidin by entering the database. Then evaluated these papers and analyzed their founding, solution, mechanism, etc., and targeted to screen the papers related to the content of our research, and then sorted them out in accordance with the solution, mechanism research and other content. Finally, these content was unified into a framework.

RESULTS

Some cantharidin's analogues were found that they show some similar functions to cantharidin and we found that norcantharidin, acylthiourea derivatives, cantharidinamides, anhydride-modified derivatives and other derivatives have less side effects. The modified cantharidin analogues reduce toxicity in hepatocytes. Cantharidin consists of a six-ring and a five-ring, the moiety of oxygen on the six-ring and the anhydride section exhibit biochemical activity. Protein phosphatases are associated with many cellular processes including apoptosis, cell cycle progression and so on. Cantharidin can cause apoptosis and double-stand breakage of DNA. Cantharidin and norcantharidin can efficiently inhibit the activity of mammalian and plant protein phosphatase 1 (PP1) and protein phosphatase 2A (PP2A) in vivo. Cantharidin inhibits PP5 at the nanomolar level with an IC50 value of 600 nM. PP5 can manage the cellular survival, death, proliferation and other some intracellular biological activities in mammals. After cantharidin's treatment, the level of EtPP5 mRNA expression was downregulated. Their also can be used to inhibit the Glutathione S-transferases (GSTs), angiogenesis and the expression of A549 human lung cancer cells, trigger eryptosis and induced bladder cancer cell apoptosis. We found that using Vitamin C and ginsenosides and translating cantharidin into nanoparticles can minimize the cantharidin side effects in the patients.

CONCLUSION

Cantharidin can inhibit various tumor cell lines. Cantharidin causes both DNA single- and double- strand breaks and induces apoptosis. Although cantharidin shows some toxicity for human, its anti-cancer effects should be taken seriously. Several viable methods can help solve this problem. The most important pharmacogenomics of cantharidin is that cantharidin can inhibit PPs, because PPs are associated with many cellular processes. This prospect is very broad and needs to continue studying.

Production costs and potential prices for biosimilars of human insulin and insulin analogues

Introduction

High prices for insulin pose a barrier to treatment for people living with diabetes, with an estimated 50% of 100 million patients needing insulin lacking reliable access. As insulin analogues replace regular human insulin (RHI) globally, their relative prices will become increasingly important. Three originator companies control 96% of the global insulin market, and few biosimilar insulins are available. We estimated the price reductions that could be achieved if numerous biosimilar manufacturers entered the insulin market.

Methods

Data on the price of active pharmaceutical ingredient (API) exported from India were retrieved from an online customs database. Manufacturers of insulins were contacted for price quotes. Where market API prices could not be identified, prices were estimated based on comparison of similarity, in terms of manufacturing process, with APIs for which prices were available. Potential biosimilar prices were estimated by adding costs of excipients, formulation, transport, development and regulatory costs, and a profit margin.

Results

The manufacturing processes for RHI and insulin analogues are similar. API prices were US$24 750/kg for RHI, US$68 757/kg for insulin glargine and an estimated US$100 000/kg for other analogues. Estimated biosimilar prices were US$48-71 per patient per year for RHI, US$49-72 for neutral protamine Hagedorn (NPH) insulin and US$78-133 for analogues (except detemir: US$283-365).

Conclusion

Treatment with biosimilar RHI and insulin NPH could cost ≤US$72 per year and with insulin analogues ≤US$133 per year. Estimated biosimilar prices were markedly lower than the current prices for insulin analogues. Widespread availability at estimated prices may allow substantial savings globally.

Semi-synthesis and insecticidal activity of spinetoram J and its D-forosamine replacement analogues

Spinetoram, a mixture of spinetoram J (XDE-175-J, major component) and spinetoram L (XDE-175-L), is a new kind of fermentation-derived insecticide with a broad range of action against many insect pests, especially Cydia pomonella, Leaf miner and Thrips. Similar to spinosad, spinetoram is friendly to the environment, and non-toxic to animals and human beings. Therefore, spinetoram has been widely applied in pest control and grain storage. In a previous study, we had reported a semi-synthesis of spinetoram J. However, in that synthesis, there were more experimental steps, and the operations were troublesome. So an improved synthesis based on a self-protection strategy was designed and discussed. In this work, 3-O-ethyl-2,4-di-O-methylrhamnose was used as both the reaction substrate of C9-OH and the protecting group of C17-OH. The number of synthetic steps and costs were significantly reduced. In addition, a variety of D-forosamine replacement analogues of spinetoram J were synthesized based on the improved semi-synthesis, and their insecticidal activities were evaluated against third-instar larvae of Plutella xylostella. Although none of the analogues were as potent as spinetoram, a few of the analogues have only a 20-40 times lower activity than spinetoram. In particular, one of these analogues was approximately as active as spinosad. This study highlights the possibility of developing new insecticidal chemistries by replacing sugars on natural products with other groups, and the improved semi-synthesis will be helpful for further researches on spinetoram.

Synthesis and Bioassay of Neurogenically Potent Gangliosides DSG-A, Hp-s1 and Their Analogues

In the search of a potent candidate for neurotherapy, we designed and synthesized various analogues of ganglioside Hp-s1. The modification includes the change in hydrophobicity by varying the carbon chain length, altering the number of hydrogen bonds, and replacing the anomeric atom. The chemical synthesis was carried out by using various methods and discussed in details. The neuritogenic activities of these analogues are confirmed in a human neuroblastoma cell line SH-SY5Y. A higher activity of ganglioside Hp-s1 analogue on IL-17A transcript upregulation than ganglioside Hp-s1 was found.

Structure⁻Activity Relationship of Piplartine and Synthetic Analogues against Schistosoma mansoni and Cytotoxicity to Mammalian Cells

Schistosomiasis, caused by helminth flatworms of the genus Schistosoma, is an infectious disease mainly associated with poverty that affects millions of people worldwide. Since treatment for this disease relies only on the use of praziquantel, there is an urgent need to identify new antischistosomal drugs. Piplartine is an amide alkaloid found in several Piper species (Piperaceae) that exhibits antischistosomal properties. The aim of this study was to evaluate the structure–function relationship between piplartine and its five synthetic analogues (19A, 1G, 1M, 14B and 6B) against Schistosoma mansoni adult worms, as well as its cytotoxicity to mammalian cells using murine fibroblast (NIH-3T3) and BALB/cN macrophage (J774A.1) cell lines. In addition, density functional theory calculations and in silico analysis were used to predict physicochemical and toxicity parameters. Bioassays revealed that piplartine is active against S. mansoni at low concentrations (5⁻10 µM), but its analogues did not. In contrast, based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays, piplartine exhibited toxicity in mammalian cells at 785 µM, while its analogues 19A and 6B did not reduce cell viability at the same concentrations. This study demonstrated that piplartine analogues showed less activity against S. mansoni but presented lower toxicity than piplartine.