Willow-deived antimicrobial against foodborne pathogenic bacteria

Bacillus spp. are identified as the major causes of foodborne illness and diarrhea worldwide [ 1 ]. Willow species including Salix starkeana belong to the family Salicaceae, and were reported in European traditional medicine for their uses against gastrointestinal disorder, as well as for food packing application and preservation. Antimicrobial and phytochemical evaluations reveal the presence of promising antimicrobial constituents in willows extracts [ 2 ] [ 3 ]. This study aims to explore the anti- Bacillus activity of S. starkeana -derived components, their possible synergestic action with conventional antibiotics and their chemical constituents. Methanol extracts of S. starkeana twigs demonstrated MIC value at 625 μg/ml against the growth of B. cereus. Furthermore, when S. starkeana methanol extracts (9.7 μg/ml) combined with tetracycline hydrochloride (0.061 μg/ml), the results showed a synergistic effect with the FIC value of 0.13. This result paves the way for possible development of alternative and complementary antimicrobial therapies using sustainable plant-based extracts. The chemical composition of S. starkeana extracts, as analyzed by UPLC/QTOF-MS (negative ionization mode) revealed the presence of galloylglucose (331,0660), benzylprimeveroside (401,1453), salicortin (423,1293), acetyl salicortin (465,1397), procyanidin B1 (577,1357), and catechin (289,0704). Notably, two unknown compounds were idetentifided for the first time in Salix species with the molecular ion at [M-H] − 453,1753 and [M-H] − 495,1511. This study demonstrates that S. starkeana could be used as an excellent source of natural food preservatives. Also, this result paves the way for the possible development of alternative and complementary antimicrobial therapies using sustainable plant-based extracts. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany