Phytochemical Profiling and Biological Activities of Pericarps and Seeds Reveal the Controversy on "Enucleation" or "Nucleus-Retaining" of Cornus officinalis Fruits.

The fruits of Cornus officinalis are used not only as a popular health food to tonify the liver and kidney, but also as staple materials to treat dementia and other age-related diseases. The pharmacological function of C. officinalis fruits with or without seeds is controversial for treating some symptoms in a few herbal prescriptions. However, the related metabolite and pharmacological information between its pericarps and seeds are largely deficient. Here, comparative metabolomics analysis between C. officinalis pericarps and seeds were conducted using an ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry, and therapeutic effects were also evaluated using several in vitro bioactivity arrays (antioxidant activity, α-glucosidase and cholinesterase inhibitory activities, and cell inhibitory properties). A total of 499 secondary metabolites were identified. Thereinto, 77 metabolites were determined as key differential metabolites between C. officinalis pericarps and seeds, and the flavonoid biosynthesis pathway was identified as the most significantly different pathway. Further, 47 metabolites were determined as potential bioactive constituents. In summary, C. officinalis seeds, which demonstrated higher contents in total phenolics, stronger in vitro antioxidant activities, better α-glucosidase and butyrylcholinesterase inhibitory activities, and stronger anticancer activities, exhibited considerable potential for food and health fields. This work provided insight into the metabolites and bioactivities of C. officinalis pericarps and seeds, contributing to their precise development and utilization.

Aromatic glycosides and lignans glycosides with their acetylcholinesterase inhibitory activities from the leaves of Picrasma quassioides.

In this study, eight new natural products were isolated from the leaves of Picrasma quassioides. Spectroscopic techniques were used for the elucidation of their planar structures. Their absolute configurations were elucidated on the basis of electron circular dichroism (ECD) techniques combined with the P/M helicity rule for the 2,3-dihydrobenzofuran chromophore, and saccharide hydrolysis. Cholinesterase inhibitors are often used as Alzheimer's disease inhibitors.Thus, acetylcholinesterase and butyrylcholinesterase inhibitory activity of these eight compounds were tested, and results showed that only compound 6 showed weakly acetylcholinesterase inhibitory activity. In particular, molecular docking was used to illustrate the bindings between compound 6 and the active sites of AChE.

Mass spectrometry as a tool for the dereplication of specialised metabolites from Pterocaulon angustifolium DC.

Pterocaulon genus comprises 26 species, half of them have been phytochemical investigations regarding the chemical composition, and coumarins have been considered the chemotaxonomic markers in the genus. Herein Pterocaulon angustifolium DC (Asteraceae), a native plant from Brazil, is investigated for the first time. Twenty-six compounds were isolated from aerial parts of P. angustifolium DC., being 5 triterpenes, 4 phytosterols, 9 flavonoids, 3 phenolic acids, and 5 coumarins. Moreover, a total of 177 compounds were putatively identified using the dereplication technique by UHPLC-HRMS/MS, more than 50% correspond to flavonoids and coumarins. Although 41 different coumarins have already been reported in Pterocaulon genus, 16 were identified for the first time in this study. Crude ethanolic extract and fractions of P. angustifolium were also biologically investigates, and dichloromethane fraction was the most active fraction in the evaluation of antiproliferative, antioxidant, antimicrobial and cholinesterase inhibitory activities.

Quercetin-1,2,3-Triazole Hybrids as Multifunctional Anti-Alzheimer's Agents.

The number of patients with Alzheimer's disease (AD) continues to rise and, despite the efforts of researchers, there are still no effective treatments for this multifaceted disease. The main objective of this work was the search for multifunctional and more effective anti-Alzheimer agents. Herein, we report the evaluation of a library of quercetin-1,2,3-triazole hybrids (I-IV) in antioxidant, hydrogen peroxide-induced oxidative stress protection, and cholinesterases (AChE and BuChE) inhibitory activities. Hybrids IIf and IVa-d showed potent in vitro inhibitory activity on eqBuChE (IC50 values between 11.2 and 65.7 µM). Hybrid IIf, the best inhibitor, was stronger than galantamine, displaying an IC50 value of 11.2 µM for eqBuChE, and is also a competitive inhibitor. Moreover, toxicity evaluation for the most promising hybrids was performed using the Artemia salina toxicity assay, showing low toxicity. Hybrids IIf, IVb, and IVd did not affect viability at 12.5 µM and also displayed a protective effect against oxidative stress induced by hydrogen peroxide in cell damage in MCF-7 cells. Hybrids IIf, IVb, and IVd act as multifunctional ligands in AD pathologies.

Discovery of Novel Tryptanthrin Derivatives with Benzenesulfonamide Substituents as Multi-Target-Directed Ligands for the Treatment of Alzheimer's Disease.

Based on the multi-target-directed ligands (MTDLs) approach, two series of tryptanthrin derivatives with benzenesulfonamide substituents were evaluated as multifunctional agents for the treatment of Alzheimer's disease (AD). In vitro biological assays indicated most of the derivatives had good cholinesterase inhibitory activity and neuroprotective properties. Among them, the target compound 4h was considered as a mixed reversible dual inhibitor of acetylcholinesterase (AChE, IC50 = 0.13 ± 0.04 µM) and butyrylcholinesterase (BuChE, IC50 = 6.11 ± 0.15 µM). And it could also potentially prevent the generation of amyloid plaques by inhibiting self-induced Aß aggregation (63.16 ± 2.33%). Molecular docking studies were used to explore the interactions of AChE, BuChE, and Aß. Furthermore, possessing significant anti-neuroinflammatory potency (NO, IL-1ß, TNF-α; IC50 = 0.62 ± 0.07 µM, 1.78 ± 0.21 µM, 1.31 ± 0.28 µM, respectively) reduced ROS production, and chelated biometals were also found in compound 4h. Further studies showed that 4h had proper blood-brain barrier (BBB) permeability and suitable in vitro metabolic stability. In in vivo study, 4h effectively ameliorated the learning and memory impairment of the scopolamine-induced AD mice model. These findings suggested that 4h may be a promising compound for further development as a multifunctional agent for the treatment of AD.

Synthesis and evaluation of multitarget new 2-aminothiazole derivatives as potential anti-Alzheimer's agents.

In this study, two diverse series of 2-aminothiazole-based multitarget compounds, one propenamide and the other propanamide derivatives, were designed and synthesized. Subsequently, their anticholinesterease and antioxidant (ORAC) activities were tested. Among them, compound 3e was the most potent acetylcholinesterase (AChE) inhibitor (AChE IC50 = 0.5 µM, butyrylcholinesterase [BChE] IC50 = 14.7 µM) and compound 9e was the most potent BChE inhibitor (AChE IC50 = 3.13 µM, BChE IC50 = 0.9 µM). Kinetic experiments showed that both compounds were mixed-type inhibitors. According to the anticholinesterease activity results, five compounds (3e, 4e, 5e, 9d, and 9e) were selected for further activity studies, all of which are dual cholinesterase inhibitors. Then, selected compounds were investigated in terms of their metal chelation activity. Moreover, their neuroprotective effects against H2 O2 -induced damage in the PC12 cell line were evaluated at 10 µM and the results showed that the neuroprotective effect of 3e was 53% compared with the reference ferulic acid (77%). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) results of selected compounds revealed that the compounds were noncytotoxic. Additionally, 3e was more effective in reducing lipopolysaccharides-induced interleukin-1ß (IL-1ß), IL-6, tumor necrosis factor-α (TNF-α), and nitric oxide (NO) production in the human monocyte derived from patient with acute monocytic leukemia cell line compared with other selected compounds. Finally, a molecular docking study was also performed.

New thiourea and benzamide derivatives of 2-aminothiazole as multi-target agents against Alzheimer's disease: Design, synthesis, and biological evaluation.

In this study, two series of compounds were designed and synthesized, bearing thiourea and benzamide derivatives at position 2 of 4-subtituted-2-aminothiazole, respectively. Then, the inhibition potency of all final compounds for cholinesterase enzymes were evaluated. Among the thiourea derivatives, 3c (IC50 = 0.33 µM) was identified as the most potent and selective butyrylcholinesterase inhibitor. Additionally, benzamide derivative 10e (AChE IC50 = 1.47 and BChE IC50 = 11.40 µM) was found as a dual cholinesterase inhibitor. The type of inhibition for both compounds was determined by kinetic studies and the results showed that the compounds were mixed type inhibitors. Moreover, all title compounds were investigated in terms of their antioxidant (DPHH, ORAC) and metal chelator activities. In addition, the neuroprotective effects of selected compounds (3c, 3e, 6c, 6e and 10e) against H2O2-induced damage in the PC12 cell line were tested. The experimental findings demonstrated that thiourea-derived 6e (40.4 %) and benzamide-derived 10e (37.8 %) have a neuroprotective effect of about half as ferulic acid at 10 µM. Subsequently, the cytotoxicity of selected compounds was examined by the MTT assay, and the compounds were found not to have cytotoxic effect on the PC12 cell line in 24 h. Additionally, compounds 6e and 10e were also found to be more effective in inhibiting the release of IL-1ß, IL-6, TNF-α and NO compared to other selected compounds in this study.

Resveratrol-Maltol and Resveratrol-Thiophene Hybrids as Cholinesterase Inhibitors and Antioxidants: Synthesis, Biometal Chelating Capability and Crystal Structure.

New resveratrol-thiophene and resveratrol-maltol hybrids were synthesized as cholinesterase inhibitors and antioxidants. As with photostability experiments, biological tests also found remarkable differences in the properties and behavior of thiophene and maltol hybrids. While resveratrol-thiophene hybrids have excellent inhibitory and antioxidant properties (similar to the activity of reference drug galantamine), maltols have been proven to be weaker inhibitors and antioxidants. The molecular docking of selected active ligands gave insight into the structures of docked enzymes. It enabled the identification of interactions between the ligand and the active site of both cholinesterases. The maltols that proved to be active cholinesterase inhibitors were able to coordinate Fe3+ ion, forming complexes of 1:1 composition. Their formation constants, determined by spectrophotometry, are very similar, lgK = 11.6-12.6, suggesting that Fe3+ binds to the common hydroxy-pyranone moiety and is hardly affected by the other aromatic part of the ligand. Accordingly, the characteristic bands in their individual absorption spectra are uniformly red-shifted relative to those of the free ligands. The crystal structures of two new resveratrol-maltol hybrids were recorded, giving additional information on the molecules' intermolecular hydrogen bonds and packing. In this way, several functionalities of these new resveratrol hybrids were examined as a necessary approach to finding more effective drugs for complicated neurodegenerative diseases.

Design, synthesis and biological evaluation of novel N-phosphorylated and O-phosphorylated tacrine derivatives as potential drugs against Alzheimer's disease.

In this work, we designed, synthesised and biologically investigated a novel series of 14 N- and O-phosphorylated tacrine derivatives as potential anti-Alzheimer's disease agents. In the reaction of 9-chlorotacrine and corresponding diamines/aminoalkylalcohol we obtained diamino and aminoalkylhydroxy tacrine derivatives. Next, the compounds were acid to give final products 6-13 and 16-21 that were characterised by 1H, 13 C, 31 P NMR and MS. The results of the docking studies revealed that the designed phosphorus hybrids, in theory can bind to AChE and BChE. All compounds exhibited significantly lower AutoDock Vina scores compared to tacrine. The inhibitory potency evaluation was performed using the Ellman's method. The most inhibitory activity against AChE exhibited compound 8 with an IC50 value of 6.11 nM and against BChE 13 with an IC50 value of 1.97 nM and they were 6- and 12-fold potent than tacrine. Compound 19 showed the lack of hepatocytotoxicity in MTT assay.

Bioactivity-Guided Separation of Anti-Cholinesterase Alkaloids from Uncaria rhynchophlly (Miq.) Miq. Ex Havil Based on HSCCC Coupled with Molecular Docking.

As an important source of cholinesterase inhibitors, alkaloids in natural products have high potential value in terms of exerting pharmacological activities. In this study, a strategy for targeted preparation of cholinesterase inhibitors in Uncaria rhynchophlly (Miq.) Miq. ex Havil (UR) by high-speed counter-current chromatography was provided. In the method, a two-phase polar solvent system composed of ethyl acetate/n-butanol/water (1:4:5, v/v/v) was used, which isolated five alkaloids from the UR extract for the first time. All alkaloids were identified by HR-ESI-MS and NMR as 7-epi-javaniside (1), vincosamide (2), strictosamide (3), cadambine (4), and 3α-dihydrocadambine (5). The poorly resolved compounds 2 and 3 were separated by preparative HPLC (prep-HPLC). Among them, compounds 1, 4, and 5 were firstly obtained from UR. The purity of these plant isolates was 98.8%, 98.7%, 99.2%, 95.7%, and 98.5%, respectively. Compounds 1-5 exhibited an inhibitory effect on acetyl-cholinesterase and butyryl-cholinesterase with an IC50 from 1.47 to 23.24 µg/mL and 1.01 to 18.24 µg/mL. Molecular docking and inhibitory activities indicated that compound 1 showed stronger inhibitory activity on acetyl-cholinesterase and butyryl-cholinesterase.

Phytochemical Screening, In vitro Antioxidant and Enzyme Inhibitory Properties, and Acute Toxicity of Extracts from the Aerial Parts of Ephedra nebrodensis, a Source of Bioactive Compounds.

BACKGROUND: Due to the strong association between the chemistry of medicinal plants and their biological properties, it is important to determine their phytochemical composition to justify experimental tests. OBJECTIVE: The aim of this study was to evaluate the in vitro antioxidant and the enzyme inhibitory properties and to identify the bioactive compounds present in the extracts of Ephedra nebrodensis growing in Algeria. METHODS: Total phenolic and flavonoids content in these extracts were quantified by Folin- Ciocalteu and aluminum chloride methods. The antioxidant capacity was assessed using DPPH, ABTS, ß-carotene/linoleic acid, CUPRAC and FRAP assays, and in vitro cholinesterase activity against acetylcholinesterase and butyrylcholinesterase were evaluated. The chemical constituents of the extracts were analyzed by high-performance liquid chromatography coupled with mass spectrometric detection and gas chromatography. For the acute toxicity study, extracts were administered to mice at single dose of 2 g/kg and 5 g/kg by gavage. RESULTS: Plant extracts were rich in phenolic compounds. Ethyl acetate extract presented the highest phenolic (238.44 ± 1.50 µg GAE /mg of extract) and flavonoid (21.12 ± 0.00 µg QE /mg of extract) contents. Likewise, ethyl acetate extract showed potent radical scavenging and reducing properties. Ethanol-acetone extract showed inhibitory activity against acetylcholinesterase, and was a potent inhibitor of butyrylcholinesterase. In all extracts, flavonoids were the most abundant compounds. The phytochemical investigation showed the presence of alkaloids (ephedrine and pseudo-ephedrine). In the acute toxicity, the LD50 was superior to 5 g/kg body weight. There were no alterations in the histology of the liver and kidneys. CONCLUSION: This study demonstrated a good antioxidant potential and anticholinesterase activity of aerial parts of E. nebrodensis.

Chemical Composition and Biological Activities of Essential Oils from the Leaves, Stems, and Roots of Kadsura coccinea.

The chemical composition and biological activities of the essential oils from the leaves, stems, and roots of Kadsura coccinea (K. coccinea) were investigated. The essential oils were extracted by hydro distillation and analyzed by gas chromatography mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID). Antioxidant activities of the essential oils were examined with DPPH radical scavenging assay, ABTS cation radical scavenging assay, and ferric reducing antioxidant power assay. Antimicrobial activities were evaluated by determining minimum inhibitory concentrations (MIC) and minimum microbiocidal concentrations (MMC). Acetylcholinesterase and butyrylcholinesterase inhibitory activity of the essential oils were also tested. A total of 46, 44, and 47 components were identified in the leaf, stem, and root oils, representing 95.66%, 97.35%, and 92.72% of total composition, respectively. The major compounds of three essential oils were α-pinene (16.60-42.02%), ß-pinene (10.03-18.82%), camphene (1.56-10.95%), borneol (0.50-7.71%), δ-cadinene (1.52-7.06%), and ß-elemene (1.86-4.45%). The essential oils were found to have weak antioxidant activities and cholinesterase inhibition activities. The essential oils showed more inhibitory effects against Staphylococcus aureus (S. aureus) than those of other strains. The highest antimicrobial activity was observed in the root oil against S. aureus, with MIC of 0.78 mg/mL. Therefore, K. coccinea essential oils might be considered as a natural antibacterial agent against S. aureus with potential application in food and pharmaceutical industries.

Cholinesterase inhibitory activity of highly functionalized fluorinated spiropyrrolidine heterocyclic hybrids.

Two series of dimethoxyindanone imbedded novel fluorinated spiropyrrolidine heterocyclic hybrids were synthesized employing two different less explored azomethine ylides and were measured for their efficiency as inhibitors for Alzheimer's disease. Among the spiropyrrolidine heterocyclic hybrids, the indole based fluorinated compound with a methoxy substituent at the meta- position of the aryl ring exhibited the utmost potent AChE and BChE inhibitory activities with an IC50 of 1.97 ± 0.19 µM and 7.08 ± 0.20 µM respectively. The plausible mechanism of inhibition on ChE receptors was unveiled via molecular docking studies.

Design, synthesis and biological evaluation of new benzoxazolone/benzothiazolone derivatives as multi-target agents against Alzheimer's disease.

In this study, four series of compounds with benzoxazolone and benzothiazolone cores were designed, synthesized and evaluated as multifunctional agents against Alzheimer's disease (AD). Additionally, in order to shed light on the effect of the carbonyl groups of benzoxazolone/benzothiazolone, benzoxazole/benzothiazole-containing analogues were also synthesized and evaluated. Inhibition potency of all final compounds towards cholinesterase enzymes and their antioxidant activity were tested. Subsequently, the anti-inflammatory activity, cytotoxicity, apoptosis, and Aß aggregation inhibition tests were also performed for selected compounds. The results indicated that compounds 11c, a pentanamide derivative with benzothiazolone core, and 14b, a keton derivative with benzothiazolone core, were considered as promising multi-functional agents for further investigation against AD. The reversibility, kinetic and molecular docking studies were also performed for the compounds with the highest AChE 14b (eeAChE IC50 = 0.34 µM, huAChE IC50 = 0.46 µM) and BChE 11c (eqBChE IC50 = 2.98 µM, huBChE IC50 = 2.56 µM) inhibitory activities.

(-)-Grandiflorimine, a new dibenzopyrrocoline alkaloid with cholinesterase inhibitory activity from Illigera grandiflora.

A new dibenzopyrrocoline alkaloid, (-)-grandifloramine (1), together with five known ones, actinodaphnine (2), N-methyllaurotetanine (3), boldine (4), lindcarpine (5), and (+)-norboldine (6), were isolated from Illigera grandiflora W. W. Sm. et J. F. Jeff. The structure of 1 was identified by HRESIMS, 1D/2D NMR, and electronic circular dichroism (ECD) spectra. Compound 1 and 2 exhibited the moderate inhibitory activity against acetylcholinesterase and 3 showed moderate butyrylcholinesterase inhibitory activity. This is the first report of the chemical constituents of I. grandiflora.

Chemical composition and biological activities of an essential oil from the aerial parts of Artemisia Gmelinii weber ex Stechm.

The aerial parts of Artemisia gmelinii Weber ex Stechm were collected from the northeast of China. The essential oil was obtained by hydrodistillation and analysed by GC-MS. A set of 66 compounds were identified representing 99.1% of the oil composition. The major compounds in the oil were cyclobutaneethanol, endo-borneol, germacrene D, eucalyptol, selin-6-en-4α-ol, bisabolone oxide A, caryophyllene and terpinen-4-ol. Moreover, the essential oil was evaluated for its antioxidant, antidiabetic, and anticholinesterase activities in vitro. Additionally, the antioxidant potential of the oil was evaluated using DPPH and ABTS assays. The oil showed good antidiabetic activity with an IC50 of 63.2 µg/mL, which was similar to that of the positive control acarbose, and weak anticholinesterase activities. These findings demonstrated that the essential oil of Artemisia gmelinii may be a good natural antidiabetic.

The Essential Oil of Salvia rosmarinus Spenn. from Italy as a Source of Health-Promoting Compounds: Chemical Profile and Antioxidant and Cholinesterase Inhibitory Activity.

The chemical composition of the essential oil from Salvia rosmarinus Spenn. collected in Calabrian Ionian (R1) and Tyrrhenian (R2) coast (Southern Italy) was examined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Essential oils are mainly characterized by monoterpene hydrocarbons (39.32-40.70%) and oxygenated monoterpenes (36.08-39.47%). The 1,8-cineole, α-pinene, camphor, and trans-caryophyllene are the most representative compounds. S. rosmarinus essential oils were investigated for their antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing ability power (FRAP), and ß-carotene bleaching tests. Additionally, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity assays were used to screen the neuroprotective effects of S. rosmarinus. R2 showed the highest antioxidant potential as confirmed by relative antioxidant capacity index (RACI) and exhibited a selective activity against AChE (half maximal inhibitory concentration, IC50, value of 41.86 µg/mL). These results suggest S. rosmarinus essential oil as a potential source of bioactive compounds.

Chemical composition, antioxidant, antibacterial and cholinesterase inhibitory activities of three Juniperus species.

The chemical composition, antioxidant, antibacterial and cholinesterase inhibitory activities of three Juniperus species were studied. The contents of total phenolic and 10 phenolic compounds were highest in Juniperus rigida Sieb.et Zucc., of which catechin and cumaric acid were the predominant phenolic compounds, but were lowest in Juniperus sibirica Burgsd. GC-MS analysis showed the highest contents of essential oils were in J. rigida (92.61%), followed by Juniperus formosana Hayata (87.30%) and J. sibirica (84.89%). The a-pinene was the most dominant compound in J. rigida (23.99%) and J. formosana (9.71%), however, it has not been detected in J. sibirica. Ethanol extracts showed the higher radical scavenging capacity in ABTS, FRAP and DPPH assays than essential oils. The essential oils and ethanol extracts of J.sibirica showed the strong antibacterial activity against Salmonella typhimurium and Escherichia coli. Three Juniperus species showed certain acetylcholinesterase and butyrylcholinesterase inhibitions and J. formosana showed better cholinesterase inhibitory.

A new diterpenoid alkaloid from Aconitum hemsleyanum.

A new C19-diterpenoid alkaloid named hemsleyaline (1), along with fourteen known alkaloids (2-15), were isolated from the roots of Aconitum hemsleyanum Pritz. (Ranunculaceae), a herbal medicine in southwest China. Their structures were established on the basis of extensive spectroscopic analyses. Compound 1 showed mild cholinesterase inhibitory effect with IC50 value of 471 ± 9 µM.

Cholinesterase inhibitory isoquinoline alkaloids from Corydalis mucronifera.

Eight previously undescribed isoquinoline alkaloids, mucroniferanines H-M, together with 16 known isoquinoline alkaloids, were isolated from Corydalis mucronifera Maxim.. The structures of the previously undescribed compounds were elucidated by interpretation of 1D and 2D NMR spectroscopic and HRMS data, and their absolute configurations were established by computational electronic circular dichroism (ECD) calculations and X-ray diffraction data. Mucroniferanine L is reported as the first natural amide bond linked isoquinoline alkaloid dimer. The isolated compounds were evaluated for AChE and BuChE inhibitory activities and mucroniferanine H showed significant activities with IC50 values of 2.31 µM and 36.71 µM, respectively.