Synthesis of spiro-lactam hydrazones by clay catalysis: toxicity, antioxidant, hypolipidemic and In silico assessments

Abstract

The development of sustainable synthesis methodologies for multifunctional bioactive molecules represents a critical challenge in green chemistry. Herein, we report the eco-efficient microwave-assisted synthesis of two novel spiro-lactam hydrazone derivatives (FHHA1, FHHA2) using abundant Moroccan Es-sifa natural clay as a separable and bifunctional heterogeneous catalyst. This three-step protocol achieves 86–87% overall yields in only 36 min, compared to 34–38% in 68 h under conventional heating representing an acceleration factor of 113. ¹H/¹³C NMR, IR, and HRMS spectroscopy rigorously confirmed structures. Acute oral toxicity tests demonstrated the safety of both compounds, with a median lethal dose (LD₅₀) between 2000 and 5000 mg kg⁻¹. In Triton WR-1339-induced hyperlipidemic rats, FHHA1 (40 mg kg⁻¹) significantly reduced LDL-c (p < 0.001), while FHHA2 (40 mg kg⁻¹) decreased TC, TG, and LDL-c (p < 0.05, p < 0.05, p < 0.001). Both compounds exhibited complementary antihyperlipidemic effects, with FHHA1 showing superior LDL-c reduction. Furthermore, DPPH assays revealed dose-dependent antioxidant activity with IC₅₀ values of 140.64 µg mL⁻¹ and 181.91 µg mL⁻¹. In addition to in vivo investigations, in silico studies were conducted, integrating molecular docking, molecular dynamics (MD) simulations, and Density Functional Theory (DFT) calculations, alongside comprehensive ADME analyses. This study establishes spiro-lactam hydrazones as a new class of environmentally friendly multifunctional agents, combining antioxidant and metabolic therapeutic potential through a base-free and sustainable catalytic process.