2-arylbenzofuran Derivatives Research Articles

Benzofuran Derivatives from Cortex Mori Radicis and Their Cholinesterase-Inhibitory Activity.

The phytochemical investigation of Cortex Mori Radicis led to the isolation and identification of a new prenylated benzofuranone (1) and four ring-opening derivatives (2-5) named albaphenol A-E, as well as nigranol A (6), together with ten 2-arylbenzofuran derivatives (7-16). The characterization of the structures of the new compounds and the structural revision of nigranol A (6) were conducted using the comprehensive analysis of spectroscopic data (1D/2D NMR, HRESIMS, CD, and XRD). Compounds 1-16 were tested for their inhibitory effects on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Compounds 1 and 4 showed weak BChE-inhibitory activity (IC50 45.5 and 61.0 μM); six 2-arylbenzofuran derivatives showed more-potent BChE-inhibitory activity (IC50 2.5-32.8 μM) than the positive control galantamine (IC50 35.3 μM), while being inactive or weakly inhibitory toward AChE. Cathafuran C (14) exhibited the most potent and selective inhibitory activity against BChE in a competitive manner, with a Ki value of 1.7 μM. The structure-activity relationships of the benzofuran-type stilbenes were discussed. Furthermore, molecular docking and dynamic simulations were performed to clarify the interactions of the inhibitor-enzyme complex.

Computational evaluation of 2-arylbenzofurans for their potential use against SARS-CoV-2: A DFT, molecular docking, molecular dynamics simulation study

Natural compounds obtained from various sources have been used in the treatment of many diseases for many years and are very important compounds for drug development studies. They can also be an option to treat COVID-19, which is affecting the whole world and not curable with medication, yet. In this study, two 2-arylbenzofuran derivatives from Sesbania cannabina which are newly entered the literature were investigated computationally with the assistance of computational techniques including DFT calculations, molecular docking calculation and molecular dynamics simulations. The study consists of four parts, in the first part of the study DFT calculations were performed on the 2-arylbenzofurans, and geometry optimizations, vibrational analyses, molecular electrostatic potential (MEP) map calculations, frontier molecular orbital (FMO) calculations and Mulliken charge analyses were carried out.In the second part, molecular docking calculations were performed to investigate the interactions between the molecules and two potential target, SARS-CoV-2 main protease (SARS-CoV-2 Mpro) and SARS-CoV-2 spike receptor binding domain – human angiotensin converting enzyme 2 complex (SARS-CoV-2 SRBD – hACE2). In the third part, MD simulations were performed on the top-scoring ligand – receptor complexes to investigate the stability of the complex and the interactions between ligands and receptors in more detail. Finally, drug-likeness analyses and ADME (adsorption, desorption, metabolism, excretion) predictions were performed on the investigated compounds. Results showed that investigated natural compounds effectively interacted with the target receptors and gave comparable results to the reference drug molecules.

Synthesis and biological evaluation of 2-arylbenzofuran derivatives as potential anti-Alzheimer’s disease agents

Alzheimer's disease (AD) is a type of progressive dementia caused by degeneration of the nervous system. A single target drug usually does not work well. Therefore, multi-target drugs are designed and developed so that one drug can specifically bind to multiple targets to ensure clinical effectiveness and reduce toxicity. We synthesised a series of 2-arylbenzofuran derivatives and evaluated their in vitro activities. 2-Arylbenzofuran compounds have good dual cholinesterase inhibitory activity and β-secretase inhibitory activity. The IC50 value of compound 20 against acetylcholinesterase inhibition (0.086 ± 0.01 µmol·L−1) is similar to donepezil (0.085 ± 0.01 µmol·L−1) and is better than baicalein (0.404 ± 0.04 µmol·L−1). And most of the compounds have good BACE1 inhibitory activity, of which 3 compounds (8, 19 and 20) show better activity than baicalein (0.087 ± 0.03 µmol·L−1). According to experimental results, 2-arylbenzofuran compounds provide an idea for drug design to develop prevention and treatment for AD.

Palladium-Catalyzed C-H Arylation of Benzofurans with Triarylantimony Difluorides for the Synthesis of 2-Arylbenzofurans.

Pd-catalyzed regioselective C–H arylation is a useful tool for the chemical modification of aromatic heterocycles and 2-arylbenzofuran derivatives are of interest as biologically active substances. Herein, the reaction of triarylantimony difluorides with benzofurans under aerobic conditions in 1,2-DCE, using 5 mol% Pd (OAc)2 and 2 eq. of CuCl2 at 80 °C, produced a variety of 2-arylbenzofurans in moderate-to-high yields. The reaction is sensitive to the electronic nature of the substituents on the benzene ring of the triarylantimony difluorides: an electron-donating group showed higher reactivity than an electron-withdrawing group. Single crystal X-ray analysis of tri(p-methylphenyl) antimony difluoride revealed that the central antimony atom exhibits trigonal bipyramidal geometry.

Inhibition of PTP1B by farnesylated 2-arylbenzofurans isolated from Morus alba root bark: unraveling the mechanism of inhibition based on in vitro and in silico studies.

Among the 2-arylbenzofuran derivatives isolated from Morus alba, the farnesylated 2-arylbenzofuran is a rarer constituent. The derivative has been reported to exert anti-obesity effect; however, its inhibitory effect on protein tyrosine phosphatase 1B (PTP1B) has not been investigated. In the previous study, the presence of the farnesyl group in the structure of 2-arylbenzofurans was found to have positive influences on their pancreatic lipase inhibitory activity. In the present study, we have confirmed the authenticity of the notation based on the PTP1B inhibitory activity of farnesylated 2-arylbenzofurans. Specifically, two farnesylated 2-arylbenzofurans [morusalfurans B (2) and C (3)] showed strong inhibitory effects on PTP1B with IC50 values of 8.92 and 7.26 µM, respectively, which was significantly higher than that of the positive controls [sodium orthovanadate (IC50 = 15.10 µM) and ursolic acid (IC50 = 11.34 µM)]. Besides, two 2-arylbenzofurans [morusalfurans A (1) and F (6)], one flavonoid [morusalnol B (9)], and one geranylated stilbene [morusibene A (11)] exhibited PTP1B inhibition with IC50 values ranging from 11.02 to 26.56 µM. Kinetic studies revealed compounds 2, 3, 6, and 11 as mixed type PTP1B inhibitors, while 1 and 9 are known as noncompetitive. Molecular docking simulations demonstrated that these active compounds can bind with the respective catalytic or/and allosteric sites of PTP1B with negative binding energies and the results are in accordance with that of the kinetic studies. To the best of our knowledge, this is the first time, the PTP1B inhibitory activity of eleven compounds (1–11), as well as the mechanism of action underlying the effects on PTP1B enzyme of the active compounds, were investigated. In vitro and in silico results suggest that the farnesylated 2-arylbenzofurans from M. alba may potentially be utilized as an effective treatment therapy for type 2 diabetes mellitus and its associated complications.

Antioxidant and anti-browning property of 2-arylbenzofuran derivatives from Morus alba Linn root bark

Oxidation and enzymatic browning of food can affect nutritional quality, physical and chemical properties, and food safety, emphasizing the utmost importance of discovering new natural antioxidants and anti-browning agents. The present study aimed to characterize the antioxidant and anti-browning potential of 2-arylbenzofuran derivatives from the root bark of Morus alba Linn. All test compounds showed good antioxidant effects on non-enzymatic antioxidant assays. Only mulberrofuran H demonstrated potent inhibition against substrates l-tyrosine (IC50; 4.45 ± 0.55 µM) and l-DOPA (IC50; 19.70 ± 0.54 µM), indicating negative effects of the prenyl and geranyl groups in the other compounds. Molecular docking simulation predicted the involvement of an -OH group in the bulky substituent in C-11 in van der Waals interactions with copper ions (Cu400, Cu401) and peroxide ions (Per404) in the active site. Overall results characterize MH as an antioxidant and anti-browning agent, highlighting its potential role in food preservation.

Discovery of novel benzofuran-based compounds with neuroprotective and immunomodulatory properties for Alzheimer's disease treatment

To address the multifactorial nature of Alzheimer's Disease (AD), a multi-target-directed ligand approach was herein developed. As a follow-up of our previous studies, a small library of newly designed 2-arylbenzofuran derivatives was evaluated towards cholinesterases and cannabinoid receptors. The two most promising compounds, 8 and 10, were then assessed for their neuroprotective activity and for their ability to modulate the microglial phenotype. Compound 8 emerged as able to fight AD from several directions: it restored the cholinergic system by inhibiting butyrylcholinesterase, showed neuroprotective activity against Aβ1-42 oligomers, was a potent and selective CB2 ligand and had immunomodulatory effects, switching microglia from the pro-inflammatory M1 to the neuroprotective M2 phenotype. Derivative 10 was a potent CB2 inverse agonist with promising immunomodulatory properties and could be considered as a tool for investigating the role of CB2 receptors and for developing potential immunomodulating drugs addressing the endocannabinoid system.

Isolation, Identification, and Quantification of Tyrosinase and α-Glucosidase Inhibitors from UVC-Irradiated Mulberry (Morus alba L.) Leaves.

Methanol extracts from ultraviolet (UV) C-irradiated mulberry leaves (UVC-IML) exhibit stronger tyrosinase and α-glucosidase inhibitory activities than those from unirradiated mulberry leaves. Through a bioassay-guided fractionation and purification process, two oxyresveratrol derivatives, oxyresveratrol (ORT) and 4′-prenyloxyresveratrol (PORT), and six 2-arylbenzofuran derivatives [moracin B (MCB), moracin C (MCC), moracin M (MCM), moracin N (MCN), 6,5′-dimethoxymoracin M (DMMCM), and chalcomoracin (CMC)] were isolated from the methanol extract from UVC-IML. Their chemical structures were determined by UV, mass, and nuclear magnetic resonance spectrometry. ORT and PORT showed potent tyrosinase inhibitory activities with the half maximal inhibitory concentration (IC50) values of 0.57 and 0.90 μM, respectively, and CMC exhibited significant tyrosinase and α-glucosidase inhibitory activity with IC50 values of 5.61 and 6.00 μM, respectively. Levels of these eight compounds were increased significantly following irradiation compared with untreated mulberry leaves; ORTs increased approximately 4 fold and moracins increased 2~16 fold. These data suggest that UVC-IML may represent a promising source of nutraceuticals and cosmeceuticals for prevention of diabetes and skin aging.

Two new 2-arylbenzofurnan derivatives from the leaves of Morus alba

Two new 2-arylbenzofuran derivatives, moracinfurol A and B (1–2), and ten known compounds (3–12) were isolated from the leaves of Morus alba. Their structures were determined on the basis of spectroscopic analysis including 1D, 2D NMR and HR-ESI-MS. All of the 2-arylbenzofuran derivatives were evaluated for cytotoxicity against A549 cells. Some cytotoxic 2-arylbenzofuran derivatives might induce autophagy characterized by the accumulation of LC-3 Ⅱ.

(R)- and (S)-18F-labeled 2-arylbenzofurans with improved pharmacokinetics as β-amyloid imaging probes

A new class of optical isomers of 2-arylbenzofuran derivatives were synthesized and evaluated as potential β-amyloid plaques imaging agents. Both lipophilicity and signal-to-noise ratio were significantly improved by adding a chiral hydroxyl group to 1-fluoro-3-(oxidanyl)propan-2-ol side chain. These derivatives displayed moderate to high binding affinity towards Aβ1-42 aggregates. Four tracers possessing potent binding affinity (Ki < 30 nM) were chosen for further investigation. In in vitro autoradiography studies, the four selected probes showed effective binding to Aβ plaques in Tg mouse and AD human brain tissue after labeled by 18F. The purified enantiomers displayed apparent discrepancy in biodistribution experiments in normal mice, for (S)-enantiomers provided rather faster clearance than (R)-enantiomers. All in all, (S)-[18F]17 (Ki = 14.6 nM) with excellent pharmacokinetics (brain2 min = 8.60% ID/g, brain2 min/brain60 min = 14.1) deserves further evaluation.

Phenolic constituents from the root bark of Morus alba L. and their cardioprotective activity in vitro

A flavanone C-glycoside, steppogenin-5′-C-β-D-glucopyranoside, six prenylated 2-arylbenzofuran derivatives, moracin O-3″-O-β-D-glucopyranoside, moracin O-3′-O-β-D-xylopyranoside, moracin P-2″-O-β-D-glucopyranoside, moracin P-3′-O-β-D-glucopyranoside, moracin P-3′-O-α-L-arabinopyranoside and moracin P-3′-O-[β-D-glucopyranosyl-(1 → 2)]-α-L-arabinopyranoside, two phenolic acids, 2,4-dihydroxy-5-(4-hydroxybenzyl) benzoic acid and 2,4-dihydroxy-5-(3,4-dihydroxybenzyl) benzoic acid, as well as three known compounds, moracinoside C, moracin O, and moracin P were isolated from the root bark of Morus alba L. Their structures were ascertained on the basis of spectroscopic evidence. The protective effects of the compounds against doxorubicin-induced cardiomyopathy in H9c2 cells was investigated in vitro. Of all of the isolated compounds, moracin P-3′-O-β-D-glucopyranoside, moracin O and moracin P had a strong protective influence against doxorubicin-induced cell death with EC50 values of 9.5 ± 2.6, 4.5 ± 1.3, and 8.8 ± 2.4 μM, respectively.

Synthesis and Antiacetylcholinesterase Activity Evaluation of New 2-aryl Benzofuran Derivatives

Starting from 2-hydroxybenzyl alcohol, a series of 2-arylbenzofurans have been synthesized and evaluated as acetylcholinesterase inhibitors at 23 µM by using modified colorimetric Ellman’s method. The reaction sequence was completed in four steps. All of the fourteen synthesized products were obtained in excellent yields without the need to tedious work-up step. In the last step, different derivatives were obtained by the substitution of bromine with five and six-membered cyclic and acyclic amines. Among the synthesized compounds, the best activity was observed in 1-(4- (Benzofuran-2-yl) benzyl)piperidine 5c with 74% activity compared to donepezil as a reference drug. Keywords: Benzofuran, acetylcholinesterase, N-bromosuccinimide (NBS), wittig reagent; alzheimer’s disease, 2-hydroxybenzyl alcohol.

New phenolic compounds from the leaves of Artocarpus heterophyllus

One new 2-arylbenzofuran derivative, artocarstilbene B (1), one new benzaldehyde derivative, (E)-3,5-dihydroxy-4-(3-methylbut-1-enyl)benzaldehyde (2), as well as 18 known compounds (3–20) were obtained from the leaves of Artocarpus heterophyllus. Their structures were elucidated on the basis of extensive spectroscopic techniques including 2D NMR and HR-ESIMS. Many compounds exhibited moderate to weak inhibitory activity against the proliferation of the PC-3, NCI-H460, and A549 cancer cell lines.

Moracin M inhibits airway inflammation by interrupting the JNK/c-Jun and NF-κB pathways in vitro and in vivo

The therapeutic effectiveness of moracins as 2-arylbenzofuran derivatives against airway inflammation was examined. Moracin M, O, and R were isolated from the root barks of Morus alba, and they inhibited interleukin (IL)-6 production from IL-1β-treated lung epithelial cells (A549) at 101–00μM. Among them, moracin M showed the strongest inhibitory effect (IC50=8.1μM). Downregulation of IL-6 expression by moracin M was mediated by interrupting the c-Jun N-terminal kinase (JNK)/c-Jun pathway. Moracin derivatives inhibited inducible nitric oxide synthase (iNOS)-catalyzed NO production from lipopolysaccharide (LPS)-treated alveolar macrophages (MH-S) at 50–100μM. In particular, moracin M inhibited NO production by downregulating iNOS. When orally administered, moracin M (20–60mg/kg) showed comparable inhibitory action with dexamethasone (30mg/kg) against LPS-induced lung inflammation, acute lung injury, in mice with that of dexamethasone (30mg/kg). The action mechanism included interfering with the activation of nuclear transcription factor-κB in inflamed lungs. Therefore, it is concluded that moracin M inhibited airway inflammation in vitro and in vivo, and it has therapeutic potential for treating lung inflammatory disorders.

Potential pancreatic lipase inhibitory activity of phenolic constituents from the root bark of Morus alba L.

Detailed phytochemical investigation from the root bark of Morus alba resulted in the isolation of eleven new compounds, including seven 2-arylbenzofuran derivatives (morusalfurans A–G), three flavonoids (morusalnols A–C), and one geranylated stilbene (morusibene A), as well as 22 known compounds. The structures of the identified compounds were elucidated based on a comprehensive analysis of spectroscopic data and Mosher’s method. Compounds 2, 3, 6–8, 11, 23, 24, and 29 showed potent inhibition of PL in comparison with the positive control treatment (orlistat, IC50=0.012μM), with IC50 values ranging from 0.09 to 0.92μM.

Acid-Catalyzed Ring-Opening Cyclization of Spirocyclopropanes for the Construction of a 2-Arylbenzofuran Skeleton: Total Synthesis of Cuspidan B

Acid-catalyzed ring-opening cyclization of cyclohexane-1,3-dione-2-spirocyclopropanes under metal-free conditions proceeded smoothly at room temperature to provide 2-aryl-3,5,6,7-tetrahydro-1-benzofuran-4(2H)-ones in excellent yields without the formation of 3-substituted isomers. The obtained product was converted into a 2-arylbenzofuran derivative via a synthetically useful 2-aryl-2,3-dihydrobenzofuran intermediate. Furthermore, the first total synthesis of cuspidan B was achieved by using the present method.

A Convenient Synthesis of 2-Arylbenzo[b]furans from Aryl Halides and 2-Halophenols by Catalytic One-Pot Cascade Method

The development of a multicatalytic one-pot synthesis of 2-arylbenzofurans starting from aryl halides and 2-halophenols is described. The protocol involves two Sonogashira coupling reactions, followed by 2-ethynylphenol cyclization leading to 2-arylbenzofuran derivatives. The process occurs smoothly under mild conditions, giving products in good yields, and can be applied to many 2-arylbenzofurans substituted both at 2-aryl position and in the benzodifuran moiety. Substituents such as halogens, hydroxyl, cyano, nitro, and amino groups are tolerated, enabling further functionalization of the system.

Prenylated 2-arylbenzofuran derivatives with potent antioxidant properties from Chlorophora regia (Moraceae)

Extracts of Chlorophora regia are frequently used in Ghana in traditional medicine. There is, however, no reported data on the chemical composition of the plant. Comprehensive phytochemical investigation of the stem bark of C. regia resulted in the isolation of three new prenylated 2-arylbenzofuran derivatives, regiafuran A–C (1–3), and one new prenylated flavonol (4), together with fifteen known compounds (5–19). Their structures were elucidated by combined spectroscopic analysis of their NMR and HRESI-MSn data. Compounds 1, 2, 5, 9 and 15 exhibited remarkable free radical scavenging properties with IC50 values of 1.9μg/ml, 2.4μg/ml, 2.2μg/ml, 2.1μg/ml and 1.8μg/ml, respectively, compared to the standard trolox (IC50 1.1μg/ml). The isolated compounds did not, however, show any anti-inflammatory potential when tested using a PGE2 (prostaglandin E2) competitive enzyme immunoassay.

Potential pancreatic lipase inhibitory activity of 2-arylbenzofuran derivatives from Morus alba

Potential pancreatic lipase inhibitory activity of 2-arylbenzofuran derivatives from Morus alba

ChemInform Abstract: One‐Pot Preparation of 2‐Arylbenzofurans from Oximes with Diaryliodonium Triflate.

AbstractA one‐pot transition metal‐free method for the preparation of 2‐arylbenzofuran derivatives of type (III) or (VI) is presented.