Trimetazidine-Profen Hybrid Molecules: Synthesis, Chemical Characterization, and Biological Evaluation of Their Racemates

Abstract

Background: Trimetazidine is a clinically established cardioprotective agent with anti-ischemic and antioxidant properties, widely used in the management of coronary artery disease. Combining its metabolic and cytoprotective effects with the potent anti-inflammatory activity of profens presents a promising therapeutic strategy. Methods: Five novel trimetazidine-profen hybrid compounds were synthesized using N,N'-dicyclohexylcarbodiimide-mediated coupling and structurally characterized by NMR and high-resolution mass spectrometry. Their antioxidant activity was evaluated by hydroxyl radical scavenging assays (HRSA), and the anti-inflammatory potential was assessed via the inhibition of albumin denaturation (IAD). Lipophilicity was determined chromatographically. Molecular docking and 100 ns molecular dynamics simulations were performed to investigate the binding modes and stability in human serum albumin (HSA) binding sites. The acute toxicity of the hybrid molecules was predicted in silico using GUSAR software. Results: All synthesized hybrids demonstrated varying degrees of biological activity, with compound 3c exhibiting the most potent antioxidant (HRSA IC₅₀ = 71.13 µg/mL) and anti-inflammatory (IAD IC₅₀ = 108.58 µg/mL) effects. Lipophilicity assays indicated moderate membrane permeability, with compounds 3c and 3d showing favorable profiles. Docking studies revealed stronger binding affinities of S-enantiomers, particularly 3c and 3d, to Sudlow sites II and III in HSA. Molecular dynamics simulations confirmed stable ligand-protein complexes, highlighting compound 3c as maintaining consistent and robust interactions. The toxicity results indicate that most hybrids, particularly compounds 3b-3d, exhibit a favorable safety profile compared to the parent trimetazidine. Conclusion: The hybrid trimetazidine-profen compounds synthesized herein, especially compound 3c, demonstrate promising dual antioxidant and anti-inflammatory therapeutic potential. Their stable interaction with serum albumin and balanced physicochemical properties support further development as novel agents for managing ischemic heart disease and associated inflammatory conditions.

Keywords: HPSA; HRSA; IAD; amide; angina pectoris; anti-inflammatory activity; antioxidant activity; in vitro; lipophilicity; profens; toxicity; trimetazidine.

Figure 1

Structural formula of trimetazidine.

Figure 2

Structural formulas of pharmacological agents that inhibit fatty acid oxidation in the heart myocytes.

Figure 3

Structural formulas of flunarizine and ciprofloxacin.

Figure 4

Structural formulas of trimetazidine derivatives.

Figure 5

Structural formulas of maleimide derivatives with a trimetazidine fragment.

Figure 6

General structural formula of the target hybrid molecules.

Scheme 1

Synthesis of compounds 3a–e via N,N′-dicyclohexylcarbodiimide-mediated coupling.

Figure 7

HPSA results of the trimetazidine hybrids. The values are presented as IC₅₀, µg/mL. Quercetin (Qrc) was used as the standard. Different letters for the same method indicate significant difference at p < 0.05 levels by Duncan’s test. Duncan’s test compares the average values of the groups and classifies them by significance levels. Group average values that do not differ significantly are united into homogeneous subgroups.

Figure 8

Results of the HRSA of trimetazidine derivatives. The values are presented as IC₅₀, µg/mL. Quercetin (Qrc) was utilized as the standard. Different letters for the same method indicate significant difference at p < 0.05 levels by Duncan’s test. Duncan’s test compares the average values of the groups and classifies them by significance levels. Group average values that do not differ significantly are united into homogeneous subgroups.

Figure 9

IAD results of the trimetazidine hybrids. Values are presented as IC₅₀, µg/mL. Ibuprofen (Ibu) was used as the standard. Different letters for the same method indicate significant difference at p < 0.05 levels by Duncan’s test. Duncan’s test compares the average values of the groups and classifies them by significance levels. Group average values that do not differ significantly are united into homogeneous subgroups.

Figure 10

The top ranked conformation of compound 3e[S] (carbon atoms depicted in magenta) in the cleft site, where it had the strongest affinity among the current series of compounds. The compound was accommodated in an environment with numerous and complex polar interactions between the amino acids, for example, the salt bridges between the sidechains of Asp187, Glu425, and Lys432. In the same region other polar sidechains are present—Asp187, Lys436, Asn429, or Tyr452, which can be considered less favorable for stable interactions with compound 3e[R]. Some of the polar amino acids in the respective site are interacting with the ligand—the positively charged sidechain of Lys190 was predicted to interact with one of the oxygen atoms from the ether groups from the trimethoxy moiety of the molecule, while the hydrogen from the amine of the carbazole moiety is predicted to make a hydrogen bond with the peptide bond Ser436–Lys436.

Figure 11

The top ranked conformation of compound 3d[S] (carbon atoms depicted in magenta) bound in Sudlow site II of albumin, where it had the strongest affinity among the current series of compounds. The present compound is predicted to be involved in a hydrogen bond with Tyr411 as the acceptor via the amide oxygen atom. The molecule is found in a hydrophobic environment, surrounded by several sidechains of hydrophobic amino acids, such as Phe488, Leu387, Ile388, Ala449, Leu453, Leu457, and Leu460.

Figure 12

The top ranked conformation of compound 3b[R] (carbon atoms depicted in magenta) bound in Sudlow site I of albumin, where it had the strongest affinity among the current series of compounds. Two polar contacts were predicted to appear—one between amide oxygen and the positively charged sidechain of Lys195 and the second between the positively charged sidechain of Arg257 and one of piperazine nitrogen atoms. The trimethoxyphenyl region of the ligand seems to accommodate well in a mainly hydrophobic region, surrounded by Leu238, Val241, Ala291, Leu260, and Ile290.

Figure 13

The top ranked conformation of compound 3b[R] (carbon atoms depicted in magenta), bound in site 3 of albumin, where it had the strongest affinity among the current series of compounds. The benzenes from the diphenyl-ketone moiety of the compound are predicted to be involved in π–π stacking with sidechains of Tyr138 and Tyr161, respectively. The positively charged sidechain of Arg186 is predicted to be involved in one polar contact with a nitrogen atom from piperazine.

Figure 14

Acute rat toxicity estimated using GUSAR.