Synthesis, characterization, and biological evaluation of some novel Schiff bases as potential metabolic enzyme inhibitors

Abstract

In this study, a series of novel Schiff base derivatives containing a pyrazolone ring (2a-e) were designed, successfully synthesized for the first time, and characterized by elemental analysis and some spectroscopic methods. These compounds were tested for their inhibitory activities on acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and the human carbonic anhydrase isoenzymes I and II (hCA I and II). All synthesized molecules indicated significant inhibition effects with IC 50 values ranging from 14.15 to 107.62 nM against these enzymes. Compound 2d showed the most potent inhibitory activity among the tested molecules toward AChE and BChE (IC 50 = 15.07 and 14.15 nM) compared to the standard drug neostigmine. We determined that the IC 50 values of the tested molecules ranged between 16.86 and 57.96 nM for hCA I and 15.24-46.21 nM for hCA II. As a consequence, we may say that some of the Schiff base derivatives may be used as potential drug candidates in later studies.

Anticholinesterase and antioxidant activities of novel heterocyclic Schiff base derivatives containing an aryl sulfonate moiety

“…On the other hand, none of the aryl sulfonates had higher antioxidant activity than the standard compounds. However, it was calculated that all Schiff bases except for compound Also, the concentration-dependent percent inhibition graph of the ABTS cation radical scavenging activity of Schiff base derivatives (10)(11)(12)(13)(14)(15)(16)(17) and the standard compounds (BHT, BHA, and α-TOC) was given in Figure 2. As expected, the antioxidant activities of all tested molecules increase with increasing concentration (10, 25, 50, and 100 μM).…”

“…In this research, new heterocyclic Schiff base derivatives (10)(11)(12)(13)(14)(15)(16)(17)(18) as the target molecules were synthesized in two steps in good yields according to the previously reported methods. [61,75] In the first step, fluorine atom-containing aryl sulfonates (1-9) were readily obtained with 75%-86% yield by the treatment of nine phenolic aldehydes with 4-FBSC in the presence of triethylamine (TEA) in dichloromethane (DCM) medium under reflux conditions for 5 hr.…”

“…Among the obtained aryl sulfonates, six of them are new (3, 4, 5, 6, 8, and 9), two are known (1 and 2), and one is commercial (7). On the other hand, all heterocyclic Schiff base derivatives (9)(10)(11)(12)(13)(14)(15)(16)(17)(18) were synthesized for first time.…”

“…Although these drugs, which are effective on the cholinergic system, can improve the clinical findings of Alzheimer's patients and slow down the course of the disease, they cannot completely prevent the process of the disease. [16][17][18] This has made necessary the discovery of novel alternative cholinesterase inhibitors for the therapy of Alzheimer patients.…”

“…Encouraged by above-mentioned information, and in a continuation of our ongoing research toward the discovery novel and potent antioxidant agents and cholinesterase inhibitors, [61] herein we have synthesized, and characterized new hybrid molecules, that is, heterocyclic Schiff base derivatives (10)(11)(12)(13)(14)(15)(16)(17)(18). These molecules were synthesized by amalgamating diverse aryl sulfonates (1-9) and 4-AAP.…”