RT journal article T1 Metabolite Screening From Pinus pinea Needles Reveals (+)-Isocupressic Acid as a Key Phytotoxin for Weed Management A1 Hlail, Hajer A1 García Zorrilla, Jesús A1 Salvatore, Maria Michela A1 Abassi, Mejda A1 Russo, Maria Teresa A1 Martínez González, Miriam Inmaculada A1 DellaGreca, Marina A1 Cimmino, Alessio A1 Macías Domínguez, Francisco Antonio A1 Andolfi, Anna A1 Varela Montoya, Rosa María A1 Masi, Marco A2 Química Orgánica K1 allelopathy K1 bioprospection K1 by-product valorization K1 GC–MS K1 phytochemistry K1 stone pine AB Introduction: Weeds are a major threat to crop productivity, competing for essential resources and often developing resistance to herbicides, which underscores the need for novel, sustainable control strategies. The valorization of agricultural and forestry underutilized byproducts, such as plant needles, presents a promising opportunity for developing eco-friendly bioherbicides based on allelopathy. Objectives: This study investigates the phytotoxicity of Pinus pinea needle extracts and metabolites to evaluate their potential for controlling dicotyledonous weeds. Material and Methods: The chemical characterization of extracts and isolated compounds was performed via GC–MS, NMR, and optical methods while phytotoxicity bioassays were carried out using the herbicides Pacifica Plus (Bayer CropScience) and pendimethalin, the active ingredient in Stone Aqua (Tokyo Chemical Industry), as positive controls. Results: The dichloromethane extract exhibited the highest phytotoxicity, significantly inhibiting Portulaca oleracea and Plantago lanceolata weeds. GC–MS analysis revealed an array of aromatic compounds of interest for phytochemical research, and through bio-guided purification, five lignans and the diterpenic acid (+)-isocupressic acid were isolated. (+)-Isocupressic acid showed the strongest phytotoxicity on P. oleracea, particularly on root growth (−83% ± 4% at 1000 μM), which could be correlated with structural moieties in its structure (fused-ring scaffold with an exocyclic double bond, an exocyclic chain containing a double bond or hydroxyl group, and a carboxylic acid group), a number of H-bond donors ≤ 2, and higher lipophilicity (Clog p = 5.11). Some lignans displayed mild inhibitory or stimulatory effects on P. lanceolata. Conclusion: P. pinea needle extracts and metabolites have demonstrated potential as natural bioherbicides for weed management. Further research is prompted to explore large-scale applicability, environmental safety through ecotoxicological studies, and optimized formulations to enhance their practical use in sustainable agriculture. PB Wiley SN 1099-1565 YR 2025 FD 2025-05 LK http://hdl.handle.net/10498/39547 UL http://hdl.handle.net/10498/39547 LA eng DS Repositorio Institucional de la Universidad de Cádiz RD 08-nov-2026