Antispasmodic Activity of Green-Synthesized Phenylaminojuglones: In Vitro and In Silico Studies

  • ACS Omega. 2026 Feb 6;11(7):12078-12094. doi: 10.1021/acsomega.5c11293.
Daniel Asunción-Alvarez  1 ,  Roberto O Ybañez-Julca  1 ,  Gabriela Y Paredes-Doroteo  1 ,  Iván M Quispe-Díaz  1 ,  Elena Mantilla-Rodríguez  1 ,  Cinthya Enriquez-Lara  2 ,  Edison Vásquez-Corales  3 ,  Pedro Buc Calderon  2  4 ,  Marcelo A Catalán  5 ,  Wilfredo O Gutiérrez-Alvarado  6 ,  Julio Benites  2  7
Affiliations
  • 1. Grupo de Investigación en Estudios de Compuestos Naturales y Sintéticos con Actividad a Nivel Sistema Nervioso Central y Musculo Liso, Laboratorio de Farmacología. Facultad de Farmacia y Bioquímica, Universidad Nacional de Trujillo, Trujillo 13011, Peru.
  • 2. Programa de Doctorado en Química Medicinal, Facultad de Ciencias de La Salud, Universidad Arturo Prat, Casilla 121, Iquique 1100000, Chile.
  • 3. Talleres y Laboratorio, Universidad Católica Los Ángeles de Chimbote, Chimbote 02801, Peru.
  • 4. Research Group in Metabolism and Nutrition, Louvain Drug Research Institute, Université Catholique de Louvain, 73 Avenue E. Mounier, 1200 Brussels, Belgium.
  • 5. Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile, Valdivia 5090000, Chile.
  • 6. Facultad de Farmacia y Bioquímica, Universidad Nacional de La Amazonía Peruana, Iquitos 16001, Peru.
  • 7. Laboratorio de Química Medicinal. Química y Farmacia, Facultad de Ciencias de La Salud, Universidad Arturo Prat, Casilla 121, Iquique 1100000, Chile.
PMID: 41768659 DOI: 10.1021/acsomega.5c11293
Abstract

Phenylaminojuglones were synthesized under solvent-free conditions via silica gel-mediated aza-Michael addition between juglone and substituted anilines, namely, aniline, 4-methoxyaniline, and 3,4,5-trimethoxyaniline. Among the synthesized derivatives, phenylaminojuglone (AJ-2) exhibited the most potent spasmolytic activity on rat ileal smooth muscle. Molecular docking studies revealed that AJ-2 exhibits potential binding affinities with multiple targets implicated in smooth muscle contraction, including muscarinic receptors, β-adrenergic receptors, nitric oxide synthase, Guanylate Cyclase, and the CAV1.2 Calcium Channel. Absorption, distribution, metabolism, excretion, and toxicity predictions indicated that AJ-2, AJ-8, and AJ-11 comply with Lipinski's rule of five and do not present major predicted toxicity liabilities, supporting their pharmacological viability. Functional assays demonstrated that AJ-2 significantly inhibited both pharmacomechanical (ACh-induced) and electromechanical (KCl-induced) contractions. Mechanistic studies suggested that its relaxant effects might be mediated by the activation of β-adrenergic receptors, the NO-sGC-cGMP signaling pathway, and the opening of KV and KCA channels. AJ-2 also inhibited extracellular CA2+ influx, as shown by its interaction with verapamil and attenuation of CaCl2-induced contractions. These findings support AJ-2 as a promising multifunctional spasmolytic agent derived from green chemistry principles and highlight the pharmacological relevance of phenylaminojuglones as novel modulators of the intestinal smooth muscle tone.

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