Synthesis and Biological Activity of Some Bromophenols and Their Derivatives Including Natural Products.

In addition to the first synthesis of the natural bromophenol butyl 2-(3,5-dibromo-4-hydroxyphenyl)acetate (1), indene derivatives 34 and 35 were synthesized from 3-phenylpropenal derivatives in BBr3 medium. Five known natural bromophenols and some derivatives were synthesized by known methods. Cholinesterase (ChEs) inhibitors reduce the breakdown of acetylcholine and are used in the treatment of Alzheimer's disease (AD) and dementia symptoms. The inhibition effects of all obtained compounds were examined towards acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and α-glycosidase enzymes. All synthesized compounds demonstrated the strong inhibition effects against both cholinergic enzymes. For determination of Ki values of novel bromophenols Lineweaver-Burk graphs were obtained. Ki values were found in the ranging of 0.13-14.74 nM for AChE, 5.11-23.95 nM for BChE, and 63.96-206.78 nM for α-glycosidase, respectively. All bromophenols and their derivatives exhibit effective inhibition profile when compared to positive controls.

Synthesis and aldose reductase inhibition effects of celecoxib derivatives containing pyrazole linked-sulfonamide moiety.

In this article, we report the synthesis of Celecoxib derivatives containing the pyrazole-linked sulfonamide moiety. The enzyme inhibition effects of these derivatives on aldose reductase (AR) were also investigated. The IC50 values of the pyrazole sulfonamide derivatives were determined to be in the range of 40.76-8.25 µM. Among the synthesized derivatives, the compound 16 showed the strongest inhibition effect against the AR enzyme, with an IC50 value of 8.25 µM. Molecular docking studies were carried out to determine the interactions of the synthesized compounds with the AR enzyme, and ADMET studies were performed to assess the pharmacokinetic and drug-likeness properties.

Synthesis and antioxidant activities of benzylic bromophenols inclusive of natural products.

The synthesis of natural products 2-(2,3-dibromo-4,5-dihydroxyphenyl)acetic acid (1) and 2-(2,6-dibromo-3,5-dihydroxyphenyl)acetic acid (2) and as well as their derivatives 25 and 26 were carried out by substitution, hydrolysis and demethylation reactions of the corresponding four benzyl bromides. The antioxidant potentials of benzylic acid-derived bromophenols were, for the first time, appraised by several outstanding bioanalytical methods. Besides these, we estimated the antioxidant effects which were studied using the methods of DPPH·, ABTS•+ scavenging activities, ferric (Fe3+) and cupric (Cu2+) ions and Fe3+-TPTZ reducing capacities. Benzylic acid-derived bromophenols were found as effective DPPH•, and ABTS•+ scavengers. The potential antioxidant activities of bromophenol derivatives 1, 2 and 17-28 were compared to standard antioxidants including BHA, BHT, α-Tocopherol, and Trolox, which is a water-soluble analog of vitamin E. We expect that this innovative work will direct future studies exploring the antioxidant properties of food, medicinal, and industrial applications.

Synthesis and Aldose Reductase Inhibition Effects of Novel N-Benzyl-4-Methoxyaniline Derivatives.

In the current study, starting from 4-methoxyaniline, four Schiff bases were synthesized from benzaldehydes with Br and OMe. Corresponding N-benzylanilines and their derivatives were obtained from reductions (by NaBH4 ) and substitutions (by acyl and tosyl chlorides) of these bases, respectively. The inhibitory effects of the sixteen compounds, twelve of which were novel compounds are examined. Then, we conducted molecular docking and binary QSAR studies to determine inhibitory-enzyme interactions of compounds that show an inhibitory effect. Our results reveal that methoxyanilline-derived compounds show good biological activities. The most active compound (22) has IC50 values of 2.83 µM. These novel AR enzyme inhibitors may open new avenues for better AR inhibitors in the future.

The first synthesis, carbonic anhydrase inhibition and anticholinergic activities of some bromophenol derivatives with S including natural products.

Starting from vanillin, known four benzyl bromides with Br were synthesized. The first synthesis of natural product 3,4-dibromo-5-((methylsulfonyl)methyl)benzene-1,2-diol (2) and 3,4,6-tribromo-5-((methylsulfonyl)methyl)benzene-1,2-diol (3) and derivatives were carried out by demethylation, acetylatilation, oxidation and hydrolysis reactions of the benzyl bromides. Also, these compounds were tested against some important enzymes like acetylcholinesterase and butyrylcholinesterase enzymes, carbonic anhydrase I, and II isoenzymes. The novel bromophenols showed Ki values of in range of 53.75 ±â€¯12.54-234.68 ±â€¯46.76 nM against hCA I, 42.84 ±â€¯9.36 and 200.54 ±â€¯57.25 nM against hCA II, 0.84 ±â€¯0.12-14.63 ±â€¯3.06 nM against AChE and 0.93 ±â€¯0.20-18.53 ±â€¯5.06 nM against BChE. Induced fit docking process performed on the compounds inhibiting hCA I, hCA II, AChE, and BChE receptors. Hydroxyl group should exist at the aromatic ring of the compounds for inhibition of the enzymes. The moieties reported in this study will be useful for design of more potent and selective inhibitors against the enzymes.

The first synthesis of 4-phenylbutenone derivative bromophenols including natural products and their inhibition profiles for carbonic anhydrase, acetylcholinesterase and butyrylcholinesterase enzymes.

The first synthesis of (E)-4-(3-bromo-4,5-dihydroxyphenyl)but-3-en-2-one (1), (E)-4-(2-bromo-4,5-dihydroxyphenyl)but-3-en-2-one (2), and (E)-4-(2,3-dibromo-4,5-dihydroxyphenyl)but-3-en-2-one (3) was realized as natural bromophenols. Derivatives with mono OMe of 2 and 3 were obtained from the reactions of their derivatives with di OMe with AlCl3. These novel 4-phenylbutenone derivatives were effective inhibitors of the cytosolic carbonic anhydrase I and II isoenzymes (hCA I and II), acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with Ki values in the range of 158.07-404.16pM for hCA I, 107.63-237.40pM for hCA II, 14.81-33.99pM for AChE and 5.64-19.30pM for BChE. The inhibitory effects of the synthesized novel 4-phenylbutenone derivatives were compared to acetazolamide as a clinical hCA I and II isoenzymes inhibitor and tacrine as a clinical AChE and BChE enzymes inhibitor.