Assessment of antioxidant, acetylcholinesterase, paraoxonase inhibition activities and phenolic content of Alchemilla lithophila.

In the present study, antioxidant activity and inhibition of acetylcholinesterase (AChE) and paraoxonase (hPON 1) of Alchemilla lithophila extracts were evaluated for the first time. Besides, there is no research on the contents of phenolic compounds except for fatty acids. In this context, phenolic compounds of A. lithophila were investigated by liquid chromatography/ mass spectrometry (LC-MS/MS). The methanol extract of the A. lithophila exhibited significant inhibition on the AChE (IC50 value for methanol extract 0.162 ± 0.25 mg /mL, R2:0.992). Besides, antioxidant activities of the A. lithophila extracts were examined using by the methods ABTS•+ and DPPH• free radical scavenging potentials, FRAP and CUPRAC metal-reducing activities. ABTS•+ and DPPH• scavenging activities were found for methanol extract at 70.67% and water extract at 75.38%, respectively. Also, FRAP and CUPRAC metal-reducing were determined for water extract 0.796 and hexane extract 1.570 as absorbance. According to LC-MS/MS analyses, the amounts of ellagic acid, catechin hydrate, gallic acid, fumaric acid, luteolin, quercetin, kaempferol, acetohydroxamic acid, caffeic acid, syringic acid, hydroxybenzoic acid and salicylic acid were determined by LC-MS/MS, respectively. As a consequence, this study will be a useful resource for determining bioactivity and phenolic compound profile for natural medicine research.

N-Heterocyclic Compounds, In silico Molecular Docking Studies, and In vitro Enzyme Inhibition Effect against Acetylcholinesterase Inhibitors.

BACKGROUND: This work contains the synthesis of seven new N-heterocyclic compounds bearing imidazole, benzimidazole, pyridine, and morpholine moieties. OBJECTIVES: We aimed to synthesize N-heterocyclic compounds for a more effective drug candidate to increase the amount of acetylcholine in synapses in Alzheimer's disease. All compounds were characterized by 1H NMR, 13C NMR, FTIR and elemental analysis. Enzyme inhibition activity of all compounds against acetylcholinesterase was investigated, which is an indirect treatment for Alzheimer's. Molecular docking was applied to estimate the binding energy of these compounds to the acetylcholinesterase. METHODS: All compounds were synthesized from reactions of 2 equivalents of N-heterocyclic starting material and 1 equivalent of 4,4'-bis(chloromethyl)-1,1'-biphenyl. The inhibition parameters of IC50 and Ki were calculated by the spectrophotometric method. AutoDock4 was used to define the binding pose of the compounds. RESULTS: Ki values were found in the range of 80.03 ± 19.64 to 5014.98 ± 1139.60 nM for AChE as an enzyme inhibition strategy, which is an important parameter for the treatment of neurodegenerative such as Alzheimer's disease. In this study, molecular docking is exerted to predict the binding energy of heterocyclic compounds (especially 2, 3, and 5) against acetylcholinesterase enzyme. Their docking binding energies are in good agreement with experimental findings. CONCLUSION: These new syntheses are drugs that can be used as AChE inhibitors in Alzheimer's disease.

Relationship Between Phenolic Content Determined by LC/MS/MS and Antioxidant Capacity and Enzyme Inhibition of Cyclotrichium niveum L.

Cyclotrichium niveum (Boiss.) Manden & Scheng belonging to the Lamiaceae family, which is an endemic species in the eastern Anatolian region of Turkey, has an important place in terms of ethno-botany. The phytochemical composition of the plant, inhibition of acetylcholinesterase (AChE) (which hydrolyzes the neurotransmitter acetylcholine), inhibition of paraoxonase for antiatherosclerotic activity (hPON 1) (which detoxifies organophosphates), and antioxidant capacity were all investigated in this study. Phytochemical content was determined by LC/MS/MS, and enzyme inhibition and antioxidant capacity studies were determined by spectrophotometer. Antioxidant capacity of C. niveum extracts (methanol, hexane, and water) was determined by applying ABTS⋅+ , DPPH⋅, FRAP, and CUPRAC methods. Both the water and the methanol extracts of the C. niveum exhibited significant inhibition on the AChE (IC50 value for methanol and water extract 0.114±0.14 mg/mL (R2:0.997) and 0.178±0.12 mg/mL (R2 : 0.994), respectively). In contrast, the methanol and water extracts of the C. niveum did not exhibit the inhibition effect on hPON 1. The highest activity for ABTS⋅+ was 66.53 % in the water extract, and DPPH⋅ was 55.03 % in the methanol extract. In the metal-reducing power assay, the absorbance was 0.168±0.04 for FRAP water extract and 0.621±0.01 for CUPRAC methanol extract. According to LC/MS/MS analyses, hydroxybenzoic acid, salicylic acid, syringic acid, acetohydroxamic acid and luteolin determined in the plant extract. As a consequence, C. niveum which has antioxidant, anti-atherogenic and anti-neurodegenerative properties has the potential to be used as a natural medication instead of synthetic drugs used in Alzheimer's patients.

Synthesis, characterisation, biological evaluation and in silico studies of sulphonamide Schiff bases.

Sulphonamides are biologically important compounds with low toxicity, many bioactivities and cost-effectiveness. Eight sulphonamide derivatives were synthesised and characterised by FT-IR, 13C NMR, 1H NMR, LC-MS and elemental analysis. Their inhibitory effect on AChE, and carbonic anhydrase I and II enzyme activities was investigated. Their antioxidant activity was determined using different bioanalytical assays such as radical scavenging tests with ABTS•+, and DPPH•+ as well as metal-reducing abilities with CUPRAC, and FRAP assays. All compounds showed satisfactory enzyme inhibitory potency in nanomolar concentrations against AChE and CA isoforms with KI values ranging from 10.14 ± 0.03 to 100.58 ± 1.90 nM. Amine group containing derivatives showed high metal reduction activity and about 70% ABTS radical scavenging activity. Due to their antioxidant activity and AChE inhibition, these novel compounds may be considered as leads for investigations in neurodegenerative diseases.

Bioassay-guided isolation and identification of antioxidant flavonoids from Cyclotrichium origanifolium (Labill.) Manden and Scheng.

BACKGROUND: Medicinal and aromatic plants play a significant role in drug discovery and development process. Flavonoids, revealing a wide spectrum of biological activities, extensively found in plants are important secondary metabolites. MATERIALS AND METHODS: Aerial parts of Cyclotrichium origanifolium were collected, dried, and boiled in water then extracted with hexane, ethyl acetate, and n-butanol. Total phenolic content, DPPH• scavenging activity, reducing power (FRAP) activity, and ABTS•+ scavenging activity assays were applied for all extracts. The ethyl acetate extract revealing the most antioxidant activity as well as including the highest phenolic contents was subjected to chromatographic techniques (column chromatography, sephadex LH-20, semipreparative HPLC) to isolate the active compounds. The structure of isolated compounds were elucidated by spectroscopic methods (1D NMR, 2D NMR, and LC-TOF/MS). RESULTS: Isosakuranetin (1), eriodictyol (2), luteolin (3), naringenin (4), and apigenin (5) were isolated and identified. All isolated flavonoids displayed the excellent antioxidant activity. CONCLUSION: The isolated flavonoids and also plant extract have potency to be a natural antioxidant. SUMMARY: Five flavonoids were isolated from Cyclotrichium origanifoliumIsolated compounds revealed the good antioxidant activityC. origanifolium has a potency to be used in food industries Abbreviations used: DPPH•: 1,1-diphenyl-2-picryl-hydrazyl free radical, ABTS•+: 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), UV:Ultraviolet, DNA: Deoxyribonucleic acid, BHT: Butylated hydroxytoluene, BHA: Butylated hydroxyanisole, HPLC: High performance liquid chromatography.