Synthesis, biological evaluation, and molecular modeling of berberine derivatives as potent acetylcholinesterase inhibitors

Berberine derivatives as inhibitors of acetylcholinesterase: A systematic review

Alzheimer's disease (AD) is a chronic age-related neurodegenerative brain disorder characterized by the impairment of memory accompanied by worsening of thinking ability of an individual. The exact pathophysiology of AD is not fully understood. However low level of the neurotransmitter named acetylcholine (ACh), aggregation of Aβ peptide into toxic Aβ plaque, hyperphosphorylation of tau, bio-metal imbalance, and oxidative stress are the main hallmarks of this disease. Due to the complex pathophysiology of AD, no specific treatment is available in the market, and treatment is only limited to the symptomatic relief. So, there is an urgent need for the development of new drug candidate, which can have disease-modifying effect and improve learning and memory in AD patient. Therefore, berberine-based multifunction compounds with potential cholinesterase inhibitory properties were reviewed in this article. Structure-activity relationship (SAR) and biological activity provide highlights on the new derivatives used for the management of AD.

Evaluation of berberine nanoparticles as a strategy to modulate acetylcholinesterase activity

Researchers have concentrated efforts in the search for natural-based reversible inhibitors for cholinesterase enzymes as they may play a key role in the treatment of degenerative diseases. Diverse plant alkaloids can inhibit the action of acetylcholinesterase and, among them, berberine is a promising bioactive. However, berberine has poor water solubility and low bioavailability, which makes it difficult to use in treatment. The solid dispersion technique can improve the water affinity of hydrophobic substances, but berberine solid dispersions have not been extensively studied. Safety testing is also essential to ensure that the berberine-loaded solid dispersions are safe for use. This study investigated the effectiveness of berberine-loaded solid dispersions (SD) as inhibitors of acetylcholinesterase enzyme (AChE). Docking simulation was used to investigate the influence of berberine on AChE, and in vitro assays were conducted to confirm the enzymatic kinetics of AChE in the presence of berberine. Berberine SD also showed improved cytotoxic effects on tumoral cells when dispersed in aqueous media. In vivo assays using Allium cepa were implemented, and no cytotoxicity/genotoxicity was found for the berberine solid dispersion. These results suggest that berberine SD could be a significant step towards safe nanostructures for use in the treatment of neurodegenerative diseases.

Synthetic and Natural Bioactive Molecules in Balancing the Crosstalk among Common Signaling Pathways in Alzheimer's Disease: Understanding the Neurotoxic Mechanisms for Therapeutic Intervention

The structure and function of the brain greatly rely on different signaling pathways. The wide variety of biological processes, including neurogenesis, axonal remodeling, the development and maintenance of pre- and postsynaptic terminals, and excitatory synaptic transmission, depends on combined actions of these molecular pathways. From that point of view, it is important to investigate signaling pathways and their crosstalk in order to better understand the formation of toxic proteins during neurodegeneration. With recent discoveries, it is established that the modulation of several pathological events in Alzheimer's disease (AD) due to the mammalian target of rapamycin (mTOR), Wnt signaling, 5'-adenosine monophosphate activated protein kinase (AMPK), peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α), and sirtuin 1 (Sirt1, silent mating-type information regulator 2 homologue 1) are central to the key findings. These include decreased amyloid formation and inflammation, mitochondrial dynamics control, and enhanced neural stability. This review intends to emphasize the importance of these signaling pathways, which collectively determine the fate of neurons in AD in several ways. This review will also focus on the role of novel synthetic and natural bioactive molecules in balancing the intricate crosstalk among different pathways in order to prolong the longevity of AD patients.

Pathogenesis of Alzheimer's Disease and Diversity of 1,2,3-Triazole Scaffold in Drug Development: Design Strategies, Structural Insights, and Therapeutic Potential

Alzheimer's disease is a most prevalent form of dementia all around the globe and currently poses a significant challenge to the healthcare system. Currently available drugs only slow the progression of this disease rather than provide proper containment. Identification of multiple targets responsible for this disease in the last three decades established it as a multifactorial neurodegenerative disorder that needs novel multifunctional agents for its management and the possible reason for the failure of currently available single target clinical drugs. 1,2,3-Triazole is a miraculous nucleus in medicinal chemistry and the first choice for development of multifunctional hybrid molecules. Apart from that, it is an integral component of various drugs in clinical trials as well as in clinical practice. This review is focused on the pathogenesis of Alzheimer's disease and 1,2,3-triazole containing derivatives developed in recent decades as potential anti-Alzheimer's agents. The review will provide (A) precise insight of various established targets of Alzheimer's disease including cholinergic, amyloid, tau, monoamine oxidases, glutamate, calcium, and reactive oxygen species hypothesis and (B) design hypothesis, structure-activity relationships, and pharmacological outcomes of 1,2,3-triazole containing multifunctional anti-Alzheimer's agents. This review will provide a baseline for various research groups working on Alzheimer's drug development in designing potent, safer, and effective multifunctional anti-Alzheimer's candidates of the future.

Multitargeted C9-substituted ester and ether derivatives of berberrubine for Alzheimer's disease: Design, synthesis, biological evaluation, metabolic stability, and pharmacokinetics

Berberrubine is a naturally occurring isoquinoline alkaloid and a bioactive metabolite of berberine. Berberine exhibits a wide range of pharmacological activities, including cholinesterase inhibition. The cholinesterase inhibitors provide symptomatic treatment for Alzheimer's disease; however, multitarget-directed ligands have the potential as disease-modifying therapeutics. Herein, we prepared a series of C9-substituted berberrubine derivatives intending to discover dual cholinesterase and beta-site amyloid-precursor protein cleaving enzyme 1 (BACE-1) inhibitors. Most synthesized derivatives possessed balanced dual inhibition (AChE and BChE) activity in the submicromolar range and a moderate inhibition against BACE-1. Two most active ester derivatives, 12a and 11d, display inhibition of AChE, BChE, and BACE-1. The 3-methoxybenzoyl ester derivative, 12a, inhibits electric eel acetylcholinesterase (EeAChE), equine serum butyrylcholinesterase (eqBChE), and human hBACE-1 with IC₅₀ values of 0.5, 4.3, and 11.9 μM, respectively and excellent BBB permeability (P_e  = 8 × 10^-6  cm/s). The ester derivative 12a is metabolically unstable; however, its ether analog 13 is stable in HLM and exhibits inhibition of AChE, BChE, and BACE-1 with IC₅₀ values of 0.44, 3.8, and 17.9 μM, respectively. The ether analog also inhibits self-aggregation of Aβ and crosses BBB (P_e  = 7.3 × 10^-6  cm/s). Administration of 13 at 5 mg/kg (iv) in Wistar rats showed excellent plasma exposure with AUC_0-∞ of 28,834 ng min/ml. In conclusion, the multitargeted berberrubine ether derivative 13 is CNS permeable and has good ADME properties.

Chemical Chaperones to Inhibit Endoplasmic Reticulum Stress: Implications in Diseases

The endoplasmic reticulum (ER) is responsible for structural transformation or folding of de novo proteins for transport to the Golgi. When the folding capacity of the ER is exceeded or excessive accumulation of misfolded proteins occurs, the ER enters a stressed condition (ER stress) and unfolded protein responses (UPR) are triggered in order to rescue cells from the stress. Recovery of ER proceeds toward either survival or cell apoptosis. ER stress is implicated in many pathologies, such as diabetes, cardiovascular diseases, inflammatory diseases, neurodegeneration, and lysosomal storage diseases. As a survival or adaptation mechanism, chaperone molecules are upregulated to manage ER stress. Chemical versions of chaperone have been developed in search of drug candidates for ER stress-related diseases. In this review, synthetic or semi-synthetic chemical chaperones are categorized according to potential therapeutic area and listed along with their chemical structure and activity. Although only a few chemical chaperones have been approved as pharmaceutical drugs, a dramatic increase in literatures over the recent decades indicates enormous amount of efforts paid by many researchers. The efforts warrant clearer understanding of ER stress and the related diseases and consequently will offer a promising drug discovery platform with chaperone activity.

Characterization of the anti-AChE potential and alkaloids in Rhizoma Coptidis from different Coptis species combined with spectrum-effect relationship and molecular docking

Coptis species are the main source of Rhizoma Coptidis (RC) drugs, which have always been used to treat Alzheimer's disease in the clinical experience of ancient China. However, many species of this genus have been largely underutilized until now. With this fact, this research has been designed to investigate for the first time the anti-acetylcholinesterase (AChE) property of different extracts for RC drugs from four Coptis species (C. chinensis, C. deltoidea, C. teeta and C. omeiensis) and to quantify the main alkaloids. Petroleum ether, ethyl acetate and n-butanol fractions of RC drugs were sequentially collected using an accelerated solvent extraction technique. Spectrum-effect relationship and molecular docking were applied to analyse the relationships between alkaloids and AChE inhibitory activity. The N-butanol extract was proven to be the main active fraction, and C. teeta may be the best source of RC drugs for Alzheimer's disease treatment, with significantly lower IC 20, IC 50 and IC 80 values for AChE inhibition. The UPLC/QqQ-MS quantitative analysis showed that the accumulations of 10 alkaloids in RC drugs from different sources greatly varied. Three data processing methods (Random forest, Boruta and Pearson correlation) comprehensively analysed the spectrum-effect relationship and revealed that columbamine, berberine and palmatine were the most important AChE inhibitors that could be used as quality markers to select RC drugs for Alzheimer's disease treatment. In addition, the dominant compounds were successfully docked against AChE to verify the binding affinity and interactions with the active site. The present study can contribute to the reasonable development and utilization of RC drugs from different sources, especially to provide certain evidence for their application in the treatment of Alzheimer's disease.

3-[(1H-Benzo[d][1,2,3]triazol-1-yl)oxy]propyl 9-hydroxy-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)icosahydro-3aH-cyclopenta[a]chrysene-3a-carboxylate

We herein report on the synthesis of a pentacyclic triterpene functionalized through derivation of betulinic acid with hydroxybenzotriazole. The compound was fully characterized by proton (1H-NMR), carbon-13 (13C-NMR), heteronuclear single quantum coherence (HSQC) and distortionless enhancement by polarization transfer (DEPT-135 and DEPT-90) nuclear magnetic resonance. Ultraviolet (UV), and Fourier-transform infrared (FTIR) spectroscopies as well as and high-resolution mass spectrometry (HRMS) were also adopted. Computational studies were conducted to foresee the interactions between compound 3 and phosphodiesterase 9, a relevant target in the field of neurodegenerative diseases. Additionally, preliminary calculation of physico-chemical descriptors was performed to evaluate the drug-likeness of compound 3.

Molecular Insights into Therapeutic Potentials of Hybrid Compounds Targeting Alzheimer's Disease

Alzheimer's disease (AD) is one of the most complex progressive neurological disorders involving degeneration of neuronal connections in brain cells leading to cell death. AD is predominantly detected among elder people (> 65 years), mostly diagnosed with the symptoms of memory loss and cognitive dysfunctions. The multifarious pathogenesis of AD comprises the accumulation of pathogenic proteins, decreased neurotransmission, oxidative stress, and neuroinflammation. The conventional therapeutic approaches are limited to symptomatic benefits and are ineffective against disease progression. In recent years, researchers have shown immense interest in the designing and fabrication of various novel therapeutics comprised of naturally isolated hybrid molecules. Hybrid therapeutic compounds are developed from the combination of pharmacophores isolated from bioactive moieties which specifically target and block various AD-associated pathogenic pathways. The method of designing hybrid molecules has numerous advantages over conventional multitarget drug development methods. In comparison to in silico high throughput screening, hybrid molecules generate quicker results and are also less expensive than fragment-based drug development. Designing hybrid-multitargeted therapeutic compounds is thus a prospective approach in developing an effective treatment for AD. Nevertheless, several issues must be addressed, and additional researches should be conducted to develop hybrid therapeutic compounds for clinical usage while keeping other off-target adverse effects in mind. In this review, we have summarized the recent progress on synthesis of hybrid compounds, their molecular mechanism, and therapeutic potential in AD. Using synoptic tables, figures, and schemes, the review presents therapeutic promise and potential for the development of many disease-modifying hybrids into next-generation medicines for AD.

Effects of Natural Products on Neuromuscular Junction

Neuromuscular junction (NMJ) disorders result from damage, malfunction or absence of one or more key proteins involved in neuromuscular transmission, comprising a wide range of disorders. The most common pathology is antibody-mediated or downregulation of ion channels or receptors, resulting in Lambert-Eaton myasthenic syndrome, myasthenia gravis, and acquired neuromyotonia (Isaac's syndrome), and rarely congenital myasthenic syndromes caused by mutations in NMJ proteins. A wide range of symptomatic treatments, immunomodulating therapies, or immunosuppressive drugs have been used to treat NMJ diseases. Future research must be directed at better understanding of the pathogenesis of these diseases, and developing novel disease-specific treatments. Numerous secondary metabolites, especially alkaloids isolated from plants have been used to treat NMJ diseases in traditional and clinical practices. An ethnopharmacological approach has provided leads for identifying new treatment for NMJ diseases. In this review, we performed a literature survey in Pubmed, Science Direct, and Google Scholar to gather information on drug discovery from plant sources for NMJ disease treatments. To date, most research has focused on the effect of herbal remedies on cholinesterase inhibitory and antioxidant activities. This review provides leads for identifying potential new drugs from plant sources for the treatment of NMJ diseases.

Current Quest in Natural Bioactive Compounds for Alzheimer's Disease: Multi-Targeted-Designed-Ligand Based Approach with Preclinical and Clinical Based Evidence

Alzheimer's disease is a common and most chronic neurological disorder (NDs) associated with cognitive dysfunction. Pathologically, Alzheimer's disease (AD) is characterized by the presence of β-amyloid (Aβ) plaques, hyper-phosphorylated tau proteins, and neurofibrillary tangles, however, persistence oxidative-nitrative stress, endoplasmic reticulum stress, mitochondrial dysfunction, inflammatory cytokines, pro-apoptotic proteins along with altered neurotransmitters level are common etiological attributes in its pathogenesis. Rivastigmine, memantine, galantamine, and donepezil are FDA approved drugs for symptomatic management of AD, whereas tacrine has been withdrawn because of hepatotoxic profile. These approved drugs only exert symptomatic relief and exhibit poor patient compliance. In the current scenario, the number of published evidence shows the neuroprotective potential of naturally occurring bioactive molecules via their antioxidant, anti-inflammatory, antiapoptotic and neurotransmitter modulatory properties. Despite their potent therapeutic implications, concerns have arisen in context to their efficacy and probable clinical outcome. Thus, to overcome these glitches, many heterocyclic and cyclic hydrocarbon compounds inspired by natural sources have been synthesized and showed improved therapeutic activity. Computational studies (molecular docking) have been used to predict the binding affinity of these natural bioactive as well as synthetic compounds derived from natural sources for the acetylcholine esterase, α/β secretase Nuclear Factor kappa- light-chain-enhancer of activated B cells (NF-kB), Nuclear factor erythroid 2-related factor 2(Nrf2) and other neurological targets. Thus, in this review, we have discussed the molecular etiology of AD, focused on the pharmacotherapeutics of natural products, chemical and pharmacological aspects and multi-targeted designed ligands (MTDLs) of synthetic and semisynthetic molecules derived from the natural sources along with some important on-going clinical trials.

In vitro and in silico studies of the larvicidal and anticholinesterase activities of berberine and piperine alkaloids on Rhipicephalus microplus

Rhipicephalus microplus is responsible for high economic losses in livestock and its control has become difficult due to the establishment of tick populations resistant to commercial acaricides. This study aimed to evaluate the in vitro larvicidal effect of the alkaloids berberine and piperine, and also to investigate their inhibitory mechanisms against the acetylcholinesterase enzyme. The effects of the alkaloids on larvae were observed through the immersion test at the following concentrations: 1.5; 3; 6; 12; 16 and 24 mM. Berberine and piperine presented larvicidal activity greater than 95 %, not differing from 100 % for the positive fipronil control (p > 0.05). Of the two alkaloids, piperine had a lower effective concentration (EC), with an EC₅₀ of 6.04 mM. The acetylcholinesterase enzyme used in the study was obtained from R. microplus larvae (RmAChE) and the anticholinesterase activity was determined spectrophotometrically. The highest anticholinesterase activity, measured as inhibition concentration (IC), was observed for berberine (IC50 = 88.13 μM), while piperine showed lower activity (IC50 > 200 μM). Docking studies in RmAChE, followed by 10 ns molecular dynamics simulation, suggest that berberine stabilizes the RmAChE at lower Root-Mean-Square Deviation (RMSD) than Apo protein. Few hydrogen-bond interactions between berberine and RmAChE residues were balanced by hydrophobic and π-type interactions. Berberine fills preferentially the peripheral anionic site (PAS), which correlates with its non-competitive mechanism. These results suggest that berberine and piperine alkaloids have an in vitro acaricidal action on R. microplus larvae, and the likely mechanism of action of berberine is related to RmAChE inhibition when accessing the PAS residues. These findings could help the study of new natural products that could inhibit RmAChE and aid in the development of new acaricides.

Network pharmacology-based strategy to investigate pharmacological mechanisms of Tinospora sinensis for treatment of Alzheimer's disease

ETHNOPHARMACOLOGICAL RELEVANCE

Tinospora sinensis (Lour.) Merr. belongs to the family Menispermaceae. It is called LeZhe and is widely used as a kind of folk medicine especially in the Tibetan Plateau of China. T. sinensis has the functions of clearing away heat and detoxification, dispelling wind and dredging collaterals, calming and soothing the nerves. T. sinensis is an effective medicine for the prevention and treatment of aging diseases such as Alzheimer's disease (AD) in the Tibetan Plateau of China, whereas its material basis and underlying mechanisms are not clear. The aim of this study was to investigate the material basis and potential mechanisms of T. sinensis in the treatment of AD by using network pharmacology and molecular docking.

MATERIALS AND METHODS

In this study, targets were collected from DrugBank database, Therapeutic Target Database (TTD) and literatures reports for the treatment of AD. Compounds were searched by literatures and systematic separation from T. sinensis. The molecular docking experiment was carried out by using Autodock Vina software to screen the bioactive compounds in T. sinensis and target proteins for AD. Then, the "compound-target network" was constructed by Cytoscape software. The drug-like properties of the active compounds were analyzed by pKCSM performs, and the protein-protein interaction (PPI) network was constructed by Search Tool for the Retrieval of Interacting Genes/Proteins (STRING). The Kyoto Encyclopedia of Genes and Genomes (KEGG) target pathway enrichment analysis was carried out by Database for Annotation, Visualization and Integrated Discovery (DAVID). Furthermore, the protective effect of neurons of two active compounds were verified with the injury cell model of PC12 and primary hippocampus neurons induced by Aβ_25-35. Finally, the key proteins of related pathways were quantitatively analyzed with Western blot method.

RESULTS

In total, 105 compounds and 38 targets have been screened. The main active compounds contained berberine, which belongs to alkaloids, Aurantiamide acetate, N-P-coumaroyltyramine, which belongs to amides, Trans-syringin and 3-demethyl-phillyrin, which belongs to phenylpropanoids. The targets covered inflammation-related proteins, including Protein kinase B (AKT), Phosphoinositide 3-kinase (PI3K), Tyrosine-protein kinase JAK1 (JAK1), mammalian target of rapamycin (mTOR), tumor necrosis factor alpha (TNF-α), Neuronal NOS (NOS1), and cholinergic function-related proteins, including α4-Nicotinic acetylcholine receptor (α4 nAChR), Muscarinic acetylcholine receptor M1 (Muscarnic M1). Inflammation and cholinergic dysfunction were the center of the network and occupy a dominant position. And the results of enrichment analysis shown the pathways mainly contained phosphoinositide-3-kinase/Akt (PI3K/Akt) signal pathway, neurotrophic factors (NTFs) signal pathway, Hypoxia-inducible factor 1 (HIF-1) signal pathway, mechanistic Target of Rapamycin (mTOR) signal pathway, Tumor necrosis factor (TNF) signal pathway, insulin resistance (IR). The results of in vitro assays showed that the tested compounds could significantly improve the survival rate and inhibit the apoptosis of PC12 cells and primary hippocampal neurons injured by Aβ_25-35. Western blot results showed that T. sinensis had a significant effect on the expression of protein PI3K and Akt.

CONCLUSION

Our results revealed that T. sinensis could prevent and treat AD through a multi-compound-multi-target-multi-pathway regulatory network. Our work also expected to provide new ideas and theoretical bases for searching for the active compounds in T. sinensis and potential mechanism in the prevention and treatment of AD by the network pharmacology and molecular docking. The results of in vitro assay and in vivo assay supported the results of molecular docking.

Discovery of novel berberine derivatives with balanced cholinesterase and prolyl oligopeptidase inhibition profile

Berberine, a naturally occurring compound, possesses an interesting multipotent pharmacological profile potentially applicable for Alzheimer's disease (AD) treatment. In this study, a series of novel 22 berberine derivatives was developed and tested in vitro. Berberine core was substituted at position 9-O of its aromatic ring region. All the hybrids under the study revealed multi-targeted profile inhibiting prolyl oligopeptidase, acetylcholinesterase and butyrylcholinesterase highlighting 4a, 4g, 4j, 4l and 4s possessing balanced activities in the micromolar range. The top-ranked candidates in terms of the most pronounced potency against POP, AChE and BChE can be classified as 4d, 4u and 4v, bearing 4-methylbenzyl, (naphthalen-2-yl)methylene and 1-phenoxyethyl moieties, respectively. In vitro data were corroborated by detailed kinetic analysis of the selected lead molecules. 4d, 4u and 4v were also inspected for their potential to inhibit aggregation of two abberant proteins in AD, namely amyloid beta and tau, indicating their potential disease-modifying properties. To explain the results of our study, we carried out docking simulation to the active sites of the respective enzyme with the best berberine derivatives, along with QSAR study. We also investigated compounds' potential permeability through blood-brain barrier by applying parallel artificial membrane permeation assay and addressed their cytotoxicity profile.

Molecular Docking Study, Cytotoxicity, Cell Cycle Arrest and Apoptotic Induction of Novel Chalcones Incorporating Thiadiazolyl Isoquinoline in Cervical Cancer

Background:

Chalcones are naturally occurring compounds found in various plant species which are widely used for the traditional popular treatments. Chalcones are distinguished secondary metabolites that are reported to display diverse biological activities such as antiviral, antiplatelet, anti-inflammatory, anticancer, antibacterial and antioxidant agents. The presence of a,ß-unsaturated carbonyl group in chalcones is assumed to be responsible for their bioactivity. In addition, heterocyclic compounds having nitrogen such as isoquinolines are of considerable interest as they constitute the core structural element of many alkaloids that have enormous pharmacological activities.

Objective:

The objective of this study is the synthesis and biological activity of novel chalcones incorporating thiadiazolyl isoquinoline as potential anticancer candidates. Different genetic tools were used in an attempt to know the mechanism of action of this compound against breast cancer.

Methods:

An efficient one pot synthesis of novel chalcones incorporating thiadiazolyl isoquinoline has been developed. The cytotoxic activity of the novel synthesized compounds was performed against four different kinds of cancer cell lines.

Results:

Among all the tested derivatives, chalcone 3 has the best cytotoxic profile against A549, MCF7, and HeLa cell lines, with IC50s (66.1, 51.3, and 85.1μM, respectively). Molecular docking studies for chalcone 3 revealed that CDK2, and EGFRTK domains have strong binding affinities toward the novel chalcone 3, while tubulin-colchicine-ustiloxin, and VEGFRTK domains illustrated moderate mode of binding.

Conclusion:

We have developed an efficient method for the synthesis of novel chalcones incorporating thiadiazolyl isoquinoline. All compounds showed better cytotoxicity results against four kinds of cancer cell lines (A549, MCF7, HCT116, and HELA cells). The results depicted that chalcone 3 has a high and promising cytotoxic effect against HELA cell line and the mechanism of cytotoxicity was widely studied through different theoretical and experimental tools. Thus, the newly synthesized derivative 3 can be utilized as a novel chemotherapeutic compound for cervical carcinoma.

Synthesis, in vitro and in vivo biological evaluation of novel graveolinine derivatives as potential anti-Alzheimer agents

A novel series of graveolinine derivatives were synthesized and evaluated as potential anti-Alzheimer agents. Compound 5f exhibited the best inhibitory activity for acetylcholinesterase (AChE) and had surprisingly potent inhibitory activity for butyrylcholinesterase (BuChE), with IC₅₀ values of 0.72 μM and 0.16 μM, respectively. The results from Lineweaver-Burk plot and molecular modeling study indicated non-competitive inhibition of AChE by compound 5f. In addition, these derivatives showed potent self-induced β-amyloid (Aβ) aggregation inhibition. Moreover, 5f didn't show obvious toxicity against PC12 and HepG2 cells at 50 μM. Finally, in vivo studies confirmed that 5f significantly ameliorates the cognitive performances of scopolamine-treated ICR mice. Therefore, these graveolinine derivatives should be thoroughly and systematically studied for the treatment of Alzheimer's disease.

Emerging therapeutic potentials of dual-acting MAO and AChE inhibitors in Alzheimer's and Parkinson's diseases

No drug has been approved to prevent neuronal cell loss in patients suffering from Parkinson's disease (PD) or Alzheimer's disease (AD); despite increased comprehension of the underlying molecular causes, therapies target cognitive functional improvement and motor fluctuation control. Drug design strategies that adopt the "one protein, one target" philosophy fail to address the multifactorial aetiologies of neurodegenerative disorders such as AD and PD optimally. On the contrary, restoring neurotransmitter levels by combined combinatorial inhibition of cholinesterases, monoamine oxidases, and adenosine A_2A A receptors, in conjunction with strategies to counter oxidative stress and beta-amyloid plaque accumulation, would constitute a therapeutically robust, multitarget approach. This extensive review delineates the therapeutic advantages of combining dual-acting molecules that inhibit monoamine oxidases and cholinesterases and/or adenosine A_2A A receptors, and describes the structure-activity relationships of compound classes that include, but are not limited to, alkaloids, coumarins, chalcones, donepezil-propargylamine conjugates, homoisoflavonoids, resveratrol analogs, hydrazones, and pyrazolines. In the wake of recent advances in network biology, in silico approaches, and omics, this review emphasizes the need to consider conceptually informed research strategies for drug discovery, in the context of the mounting burden posed by chronic neurodegenerative diseases with complex aetiologies and pathophysiologies involving multiple signalling pathways and numerous drug targets.

Metal based donepezil analogues designed to inhibit human acetylcholinesterase for Alzheimer's disease

Among neurodegenerative disorders, Alzheimer's disease (AD) is one of the most common disorders showing slow progressive cognitive decline. Targeting acetylcholinesterase (AChE) is one of the major strategies for AD therapeutics, as cholinergic pathways in the cerebral cortex and basal forebrain are compromised. Herein, we report the design of some copper and other metal based donepezil derivatives, employing density functional theory (DFT). All designed compounds are optimized at the B3LYP/SDD level of theory. Dipole moments, electronic energie, enthalpies, Gibbs free energies, and HOMO-LUMO gaps of these modified compounds are also investigated in the subsequent analysis. The molecules were then subjected to molecular docking analysis with AChE to study the molecular interactions broadly. Ensemble based docking and molecular dynamics (MD) simulations of the best candidates were also performed. Docking and MD simulation reveal that modified drugs are more potent than unmodified donepezil, where Trp86, Tyr337, Phe330 residues play some important roles in drug-receptor interactions. According to ensemble based docking, D9 shows greater binding affinity compared to the parent in most conformations obtained from protein data bank and MD simulation. In addition, it is observed that the π- π stacking with the residues of Trp86, Tyr337, Tyr341, Tyr124 and Trp286 may be required for strong ligand binding. Moreover, ADME/T analysis suggests that modified derivatives are less toxic and have improved pharmacokinetic properties than those of the parent drug. These results further confirm the ability of metal-directed drugs to bind simultaneously to the active sites of AChE and support them as potential candidates for the future treatment of Alzheimer's disease.

Natural Aromatic Compounds as Scaffolds to Develop Selective G-Quadruplex Ligands: From Previously Reported Berberine Derivatives to New Palmatine Analogues

In this paper, the selective interactions of synthetic derivatives of two natural compounds, berberine and palmatine, with DNA G-quadruplex structures were reported. In particular, the previous works on this subject concerning berberine were further presented and discussed, whereas the results concerning palmatine are presented here for the first time. In detail, these palmatine derivatives were developed by inserting seven different small peptide basic chains, giving several new compounds that have never been reported before. The preliminary studies of the interactions of these compounds with various G-quadruplex-forming sequences were carried out by means of various structural and biochemical techniques, which showed that the presence of suitable side chains is very useful for improving the interaction of the ligands with G-quadruplex structures. Thus, these new palmatine derivatives might act as potential anticancer drugs.

Comparative Evaluation of the Antioxidant and Anti-Alzheimer's Disease Potential of Coumestrol and Puerarol Isolated from Pueraria lobata Using Molecular Modeling Studies

The current study assesses the antioxidant effects of two similar isoflavonoids isolated from Pueraria lobata, coumestrol and puerarol, along with the cholinergic and amyloid-cascade pathways to mitigate Alzheimer’s disease (AD). Antioxidant activity was evaluated via 1,1-diphenyl-2-picryhydrazyl (DPPH) and peroxynitrite (ONOO⁻) scavenging ability further screened via ONOO⁻-mediated nitrotyrosine. Similarly, acetyl- and butyrylcholinesterase (AChE/BChE) and β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitory activities were assessed together with docking and kinetic studies. Considering DPPH and ONOO⁻ scavenging activity, coumestrol (EC₅₀ values of 53.98 and 1.17 µM) was found to be more potent than puerarol (EC₅₀ values of 82.55 and 6.99 µM) followed by dose dependent inhibition of ONOO⁻-mediated nitrotyrosine. Coumestrol showed pronounced AChE and BChE activity with IC₅₀ values of 42.33 and 24.64 µM, respectively, acting as a dual cholinesterase (ChE) inhibitor. Despite having weak ChE inhibitory activity, puerarol showed potent BACE1 inhibition (28.17 µM). Kinetic studies of coumestrol showed AChE and BChE inhibition in a competitive and mixed fashion, whereas puerarol showed mixed inhibition for BACE1. In addition, docking simulations demonstrated high affinity and tight binding capacity towards the active site of the enzymes. In summary, we undertook a comparative study of two similar isoflavonoids differing only by a single aliphatic side chain and demonstrated that antioxidant agents coumestrol and puerarol are promising, potentially complementary therapeutics for AD.

Success stories of natural product-based hybrid molecules for multi-factorial diseases

Complex diseases comprises of highly complicated etiology resulting in limited applicability of conventional targeted therapies. Consequently, conventional medicinal compounds suffer major failure when used for such disease conditions. Additionally, development of multidrug resistance (MDR), adverse drug reactions and clinical specificity of single targeted drug therapy has increased thrust for novel drug therapy. In this rapidly evolving era, natural product-based discovery of hybrid molecules or multi-targeted drug therapies have shown promising results and are trending now a days. Historically, nature has blessed human with different sources viz. plant, animal, microbial, marine and ethnopharmaceutical sources which has given a wide variety of medicinally active compounds. These compounds from natural origin are always choice of interest of medicinal chemists because of their minimum side effects. Hybrid molecules synthesized by fusing or conjugating different active molecules obtained from these sources are reported to synergistically block different pathways which contribute in the pathogenesis of complex diseases. This review strives to encompass all natural product-derived hybrid molecules which act as multi-targeting agents striking various targets involved in different pathways of complex diseased conditions reported in literature.

Sanguinarine and chelerythrine: two natural products for mitochondria-imaging with aggregation-induced emission enhancement and pH-sensitive characteristics

In this paper, two natural products: chelerythrine (Che) and sanguinarine (San) were systematically explored for aggregation-induced emission enhancement (AIEE) characteristics by a series of spectroscopic and theoretical experiments.

Synthesis, Characterization, and Biological Evaluations of 1,3,5-Triazine Derivatives of Metformin Cyclization with Berberine and Magnolol in the Presence of Sodium Methylate

The novel target products were synthesized in the formation of a triazine ring from berberine, magnolol, and metformin catalyzed by sodium methylate. The structures of products 1–3 were firstly confirmed by extensive spectroscopic analyses and single-crystal X-ray diffraction. The crystal structures of the target product 2 and the intermediate product 7b were reported for the first time. All target products were evaluated for their anti-inflammatory and antidiabetic activities against INS-1 and RAW264.1 cells in vitro and all products showed excellent anti-inflammatory effects and anti-insulin resistance effects. Our studies indicated that new compounds 1–3 were found to be active against inflammation and insulin resistance.

BACE1 inhibitory activity and molecular docking analysis of meroterpenoids from Sargassum serratifolium

A wide range of pharmacological properties of Sargassum spp. extracts and isolated components have been recognized. Although individual meroterpenoids of Sargassum species have been reported to possess strong activity against Alzheimer's disease (AD), the active compounds of Sargassum serratifolium have not been fully explored. Therefore, we evaluated the anti-AD activity of S. serratifolium extract through enzyme inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1). Three meroterpenoids (sargahydroquinoic acid (1), sargachromenol (2) and sargaquinoic acid (3)) were isolated from S. serratifolium. These compounds showed moderate AChE inhibitory activity, but exhibited potent inhibitory activity against BChE and BACE1 (15.1, 9.4, and 10.4µM for BChE; 4.3, 6.9, and 12.5µM for BACE1, respectively). Kinetic study and molecular docking simulation of these compounds demonstrated that 1 and 3 interacted with both catalytic aspartyl residues and allosteric sites of BACE1, whereas 2 interacted with the allosteric site of BACE1. The results of the present study demonstrate that meroterpenoids from S. serratifolium might be beneficial in the treatment of AD.

Prolyl oligopeptidase and its role in the organism: attention to the most promising and clinically relevant inhibitors

Prolyl oligopeptidase (POP), also called prolyl endopeptidase, is a cytosolic enzyme investigated by several research groups. It has been proposed to play an important role in physiological processes such as modulation of the levels of several neuronal peptides and hormones containing a proline residue. Due to its proteolytic activity and physiological role in cell signaling pathways, inhibition of POP offers an emerging approach for the treatment of Alzheimer's and Parkinson's diseases as well as other diseases related to cognitive impairment. Furthermore, it may also represent an interesting target for treatment of neuropsychiatric disorders, and as an antiangiogenesis or antineoplastic agent. In this review paper, we summarized naturally occurring POP inhibitors together with peptide-like inhibitors and their biological effects. Some of them have shown promising results and interesting pharmacological profiles. However, to date, there is no POP inhibitor available on the market although several clinical trials have been undertaken.

Pharmacology of mangostins and their derivatives: A comprehensive review

Mangosteen (Garcinia mangostana Linn.) is a well-known tropical tree indigenous to Southeast Asia. Its fruit's pericarp abounds with a class of isoprenylated xanthones which are referred as mangostins. Numerous in vitro and in vivo studies have shown that mangostins and their derivatives possess diverse pharmacological activities, such as antibacterial, antifungal, antimalarial, anticarcinogenic, antiatherogenic activities as well as neuroprotective properties in Alzheimer's disease (AD). This review article provides a comprehensive review of the pharmacological activities of mangostins and their derivatives to reveal their promising utilities in the treatment of certain important diseases, mainly focusing on the discussions of the underlying molecular targets/pathways, modes of action, and relevant structure-activity relationships (SARs). Meanwhile, the pharmacokinetics (PK) profile and recent toxicological studies of mangostins are also described for further druggability exploration in the future.

An Efficient K2CO3-Promoted Synthesis of 1-Bromo-2-aryloxyethane Derivatives and Evaluation of Larval Mortality against Aedes aegypti

The influences of reaction parameters on the etherification of phenols to obtain 1-bromo-2-aryloxyethane derivatives were evaluated. The compounds were prepared by direct etherification of phenols with 1,2-dibromoethane using anhydrous K2CO3 and acetonitrile as solvent reaction, at 80°C, in a reaction time of 6 h. Under these conditions, excellent yields (71%–94%) were obtained, with low yields of secondary products. The anhydrous K2CO3 was recycled by simple filtration, dried in vacuum, and reused. The compounds were characterized by conventional spectral data (MS and NMR). Larvicidal activity results showed a 100% larval mortality after 24-hour exposure to the compound 1-(2-bromoethoxy)-2-phenylbenzene.

Synthesis and Biological Evaluation of Novel Jatrorrhizine Derivatives with Amino Groups Linked at the 3-Position as Inhibitors of Acetylcholinesterase

Jatrorrhizine was considered as one of the active constituents of Coptis chinensis Franch. Herein, jatrorrhizine derivatives with substituted amino groups linked at the 3-position were designed, synthesized, and biologically evaluated as inhibitors of acetylcholinesterase. Jatrorrhizine derivatives inhibited the activity of acetylcholinesterase (AChE) to a greater extent than the lead compound jatrorrhizine. All these jatrorrhizine derivatives were proved to be potent inhibitors of acetylcholinesterase (AChE) with submicromolar IC50 values, but less sensitive to butyrylcholinesterase (BuChE), which suggests that these jatrorrhizine derivatives are selective for AChE/BuChE. Compound 3g gave the most potent inhibitor activity for AChE (IC50 = 0.301 μM), which is greater than the lead compound jatrorrhizine. All these results demonstrated that these jatrorrhizine derivatives are potential inhibitors for AChE.

Therapeutic effect of berberine on TDP-43-related pathogenesis in FTLD and ALS

Background

In the central nervous system regions of the sporadic and familial FTLD and ALS patients, TDP-43 has been identified as the major component of UBIs inclusions which is abnormally hyperphosphorylated, ubiquitinated, and cleaved into C-terminal fragments to form detergent-insoluble aggregates. So far, the effective drugs for FTLD and ALS neurodegenerative diseases are yet to be developed. Autophagy has been demonstrated as the major metabolism route of the pathological TDP-43 inclusions, hence activation of autophagy is a potential therapeutic strategy for TDP-43 pathogenesis in FTLD and ALS. Berberine, a traditional herbal medicine, is an inhibitor of mTOR signal and an activator for autophagy. Berberine has been implicated in several kinds of diseases, including the neuronal-related pathogenesis, such as Parkinson’s, Huntington’s and Alzheimer’s diseases. However, the therapeutic effect of berberine on FTLD or ALS pathology has never been investigated.

Results

Here we studied the molecular mechanism of berberine in cell culture model with TDP-43 proteinopathies, and found that berberine is able to reverse the processing of insoluble TDP-43 aggregates formation through deregulation of mTOR/p70S6K signal and activation of autophagic degradation pathway. And inhibition of autophagy by specific autophagosome inhibitor, 3-MA, reverses the effect of berberine on reducing the accumulation of insoluble TDP-43 and aggregates formation. These results gave us the notion that inhibition of autophagy by 3-MA reverses the effect of berberine on TDP-43 pathogenesis, and activation of mTOR-regulated autophagy plays an important role in berberine-mediated therapeutic effect on TDP-43 proteinopathies.

Conclusion

We supported an important notion that the traditional herb berberine is a potential alternative therapy for TDP-43-related neuropathology. Here we demonstrated that berberine is able to reverse the processing of insoluble TDP-43 aggregates formation through deregulation of mTOR/p70S6K signal and activation of autophagic degradation pathway. mTOR-autophagy signals plays an important role in berberine-mediated autophagic clearance of TDP-43 aggregates. Exploring the detailed mechanism of berberine on TDP-43 proteinopathy provides a better understanding for the therapeutic development in FTLD and ALS.

BACE1 molecular docking and anti-Alzheimer's disease activities of ginsenosides

ETHNOPHARMACOLOGICAL RELEVANCE

Ginsenosides are natural product steroid glycosides and triterpene saponins obtained from the Panax species. Panax ginseng has been widely used as a traditional Chinese medicine (TCM) for around a thousand years, especially in East Asian countries. Ginseng, the root and rhizome of the most popular species P. ginseng, used as tonic, prophylactic agent and restorative. In TCM, ginseng is highly valued herb and has been applied to a variety of pathological conditions and illnesses such as hypodynamia, anorexia, shortness of breath, palpitation, insomnia, impotence, hemorrhage and diabetes.

AIM OF THE STUDY

The basic aim of this study was to evaluate the anti-Alzheimer's disease activities of selected ginsenosides (Rb1, Rb2, Rc, Re, Rg1, and Rg3) according to peroxynitrite (ONOO(‒)) scavenging activity and inhibitory activity of ONOO(-)-mediated nitrotyrosine formation as a measure of changes in oxidative stress. In addition, molecular docking simulation studies were performed to predict binding energies of the ginsenosides with β-site amyloid precursor protein cleaving enzyme 1 (BACE1, β-secretase) and identify the interacting residues.

MATERIALS AND METHODS

In vitro cholinesterase enzyme assays by using acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and BACE1 were performed. In vitro authentic peroxynitrite scavenging activity and inhibitory activity against ONOO(-)-mediated nitrotyrosine formation were also performed. Molecular docking simulation studies were performed with Autodock Vina software and Discovery studio 4.1.

RESULTS

In vitro enzyme assays demonstrated that ginsenosides have significant inhibitory potential against AChE, BChE, and BACE1, as well as ONOO(-) and nitrotyrosine formation. Most importantly, significant AChE inhibitory activities were observed for Re; BChE for Rg3; and BACE1 for Rc, with IC50 values of 29.86±3.20, 16.80±0.36, and 59.81±2.74μg/mL, respectively. Among the tested ginsenosides, Rb1 exhibited a higher scavenging activity against ONOO(-) with an IC50 value of 27.86±1.34μg/mL, while Rc and Rg3 exhibited impressive inhibitory activity against the formation of nitrotyrosine. In addition, molecular docking studies revealed potential BACE1 inhibitory activity of ginsenosides, especially Rb1 and Rb2, which exhibited good binding affinities towards BACE1, with docking scores of -10kcal/mol.

CONCLUSION

The findings of the present study suggest the potential of ginsenosides (Rb1, Rb2, Rc, Re, Rg1, and Rg3) for use in the development of therapeutic or preventive agents for Alzheimer's disease, especially through inhibition of AChE, BChE and BACE1 activities, as well as scavenging of ONOO(-) and inhibition of nitrotyrosine formation.

Building Bridges: Biocatalytic C-C-Bond Formation toward Multifunctional Products

Carbon-carbon bond formation is the key reaction for organic synthesis to construct the carbon framework of organic molecules. The review gives a selection of biocatalytic C-C-bond-forming reactions which have been investigated during the last 5 years and which have already been proven to be applicable for organic synthesis. In most cases, the reactions lead to products functionalized at the site of C-C-bond formation (e.g., α-hydroxy ketones, aminoalcohols, diols, 1,4-diketones, etc.) or allow to decorate aromatic and heteroaromatic molecules. Furthermore, examples for cyclization of (non)natural precursors leading to saturated carbocycles are given as well as the stereoselective cyclopropanation of olefins affording cyclopropanes. Although many tools are already available, recent research also makes it clear that nature provides an even broader set of enzymes to perform specific C-C coupling reactions. The possibilities are without limit; however, a big library of variants for different types of reactions is required to have the specific enzyme for a desired specific (stereoselective) reaction at hand.

Molecular Modeling on Berberine Derivatives toward BuChE: An Integrated Study with Quantitative Structure-Activity Relationships Models, Molecular Docking, and Molecular Dynamics Simulations

A dataset of 67 berberine derivatives for the inhibition of butyrylcholinesterase (BuChE) was studied based on the combination of quantitative structure-activity relationships models, molecular docking, and molecular dynamics methods. First, a series of berberine derivatives were reported, and their inhibitory activities toward butyrylcholinesterase (BuChE) were evaluated. By 2D- quantitative structure-activity relationships studies, the best model built by partial least-square had a conventional correlation coefficient of the training set (R(2)) of 0.883, a cross-validation correlation coefficient (Qcv2) of 0.777, and a conventional correlation coefficient of the test set (Rpred2) of 0.775. The model was also confirmed by Y-randomization examination. In addition, the molecular docking and molecular dynamics simulation were performed to better elucidate the inhibitory mechanism of three typical berberine derivatives (berberine, C2, and C55) toward BuChE. The predicted binding free energy results were consistent with the experimental data and showed that the van der Waals energy term (ΔEvdw) difference played the most important role in differentiating the activity among the three inhibitors (berberine, C2, and C55). The developed quantitative structure-activity relationships models provide details on the fine relationship linking structure and activity and offer clues for structural modifications, and the molecular simulation helps to understand the inhibitory mechanism of the three typical inhibitors. In conclusion, the results of this study provide useful clues for new drug design and discovery of BuChE inhibitors from berberine derivatives.

The therapeutic potential of berberine against the altered intrinsic properties of the CA1 neurons induced by Aβ neurotoxicity

It was demonstrated that treatment with beta amyloid (Aβ) led to extreme alterations in the intrinsic electrophysiological properties of CA1 pyramidal neurons. Also, malfunction of the cholinergic system is correlated to the memory and cognitive impairments. Several new studies have suggested that Berberis vulgaris can act as a cholinesterase inhibitor. The present study aimed to investigate the effects of berberine (BER) on the Aβ-induced impairments in learning and memory. The male Wistar rats were divided into 4 groups of Sham, BER, Aβ and Aβ+BER. The administration of BER or its vehicle started immediately after the injection of Aβ and followed by 13 days. Then, the animals were tested for learning and memory performance using the Morris water maze (MWM) and passive avoidance tests. Then, they were sacrificed for the whole cell patch clamp recording. The results of the MWM and passive avoidance tasks indicated that administration of the BER in the Aβ+BER group prevented the memory impairment induced by Aβ. The results of the whole cell patch clamp also showed that administration of the BER restored the Aβ-induced impairments in the firing frequency, half-width and rebound action potential. These results suggested that administration of the BER could ameliorate neurotoxicity induced by Aβ. However, this neuroprotection impact could be resulted from the balance effect of the Ca(2+) entry. The optimal level of Ca(2+) entry by BER could be a major factor that modified the function of the Ca(2+)-activated K(+) channels and decreased the half-width in the Aβ treated rats.

Recent development of multifunctional agents as potential drug candidates for the treatment of Alzheimer's disease

Alzheimer's disease (AD) is a complex and progressive neurodegenerative disorder. The available therapy is limited to the symptomatic treatment and its efficacy remains unsatisfactory. In view of the prevalence and expected increase in the incidence of AD, the development of an effective therapy is crucial for public health. Due to the multifactorial aetiology of this disease, the multi-target-directed ligand (MTDL) approach is a promising method in search for new drugs for AD. This review updates information on the development of multifunctional potential anti-AD agents published within the last three years. The majority of the recently reported structures are acetylcholinesterase inhibitors, often endowed with some additional properties. These properties enrich the pharmacological profile of the compounds giving hope for not only symptomatic but also causal treatment of the disease. Among these advantageous properties, the most often reported are an amyloid-β antiaggregation activity, inhibition of β-secretase and monoamine oxidase, an antioxidant and metal chelating activity, NOreleasing ability and interaction with cannabinoid, NMDA or histamine H3 receptors. The majority of novel molecules possess heterodimeric structures, able to interact with multiple targets by combining different pharmacophores, original or derived from natural products or existing therapeutics (tacrine, donepezil, galantamine, memantine). Among the described compounds, several seem to be promising drug candidates, while others may serve as a valuable inspiration in the search for new effective therapies for AD.

Inhibition of acetylcholinesterase by two genistein derivatives: kinetic analysis, molecular docking and molecular dynamics simulation

In this study two genistein derivatives (G1 and G2) are reported as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), and differences in the inhibition of AChE are described. Although they differ in structure by a single methyl group, the inhibitory effect of G1 (IC₅₀=264 nmol/L) on AChE was 80 times stronger than that of G2 (IC₅₀=21,210 nmol/L). Enzyme-kinetic analysis, molecular docking and molecular dynamics (MD) simulations were conducted to better understand the molecular basis for this difference. The results obtained by kinetic analysis demonstrated that G1 can interact with both the catalytic active site and peripheral anionic site of AChE. The predicted binding free energies of two complexes calculated by the molecular mechanics/generalized born surface area (MM/GBSA) method were consistent with the experimental data. The analysis of the individual energy terms suggested that a difference between the net electrostatic contributions (ΔE_ele+ΔG_GB) was responsible for the binding affinities of these two inhibitors. Additionally, analysis of the molecular mechanics and MM/GBSA free energy decomposition revealed that the difference between G1 and G2 originated from interactions with Tyr124, Glu292, Val294 and Phe338 of AChE. In conclusion, the results reveal significant differences at the molecular level in the mechanism of inhibition of AChE by these structurally related compounds.

Rational design of berberine-based FtsZ inhibitors with broad-spectrum antibacterial activity

Inhibition of the functional activity of Filamenting temperature-sensitive mutant Z (FtsZ) protein, an essential and highly conserved bacterial cytokinesis protein, is a promising approach for the development of a new class of antibacterial agents. Berberine, a benzylisoquinoline alkaloid widely used in traditional Chinese and native American medicines for its antimicrobial properties, has been recently reported to inhibit FtsZ. Using a combination of in silico structure-based design and in vitro biological assays, 9-phenoxyalkyl berberine derivatives were identified as potent FtsZ inhibitors. Compared to the parent compound berberine, the derivatives showed a significant enhancement of antibacterial activity against clinically relevant bacteria, and an improved potency against the GTPase activity and polymerization of FtsZ. The most potent compound 2 strongly inhibited the proliferation of Gram-positive bacteria, including methicillin-resistant S. aureus and vancomycin-resistant E. faecium, with MIC values between 2 and 4 µg/mL, and was active against the Gram-negative E. coli and K. pneumoniae, with MIC values of 32 and 64 µg/mL respectively. The compound perturbed the formation of cytokinetic Z-ring in E. coli. Also, the compound interfered with in vitro polymerization of S. aureus FtsZ. Taken together, the chemical modification of berberine with 9-phenoxyalkyl substituent groups greatly improved the antibacterial activity via targeting FtsZ.