PhD Scientific Days 2025

Poster Session I. - F: Pharmaceutical Sciences and Health Technologies

Bioassay-Guided Isolation and Identification of Antibacterial Compounds from Invasive Tree of Heaven Stem and Trunk Bark

Name of the presenter

Cselőtey Anna

Institute/workplace of the presenter

HUN-REN Centre for Agricultural Research

Authors

Anna Cselőtey^1,2, Márton Baglyas^1,2, Nóra Király¹, Péter G. Ott¹, Vesna Glavnik³, Irena Vovk³, Ágnes M. Móricz¹

1: Plant Protection Institute, HUN-REN Centre for Agricultural Research, Fehérvári út 132–144, 1116 Budapest, Hungary
2: Semmelweis University, Doctoral School, Üllői út 26, 1085 Budapest, Hungary
3: Laboratory for Food Chemistry, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia

Text of the abstract

Introduction: Tree of heaven (Ailanthus altissima (Mill.) Swingle) is native to Southeast Asia but has become invasive in many temperate regions of the world, such as Hungary and Slovenia, where it poses a major threat to the local biodiversity. The dried parts of the tree (e.g., bark, stem, and leaves) have been widely used in traditional Asian medicine to treat various illnesses, including asthma, epilepsy, and gastrointestinal and ophthalmic diseases.
Aims: In this work, we aimed to screen, characterize, and identify the antibacterial agents present in the stem and trunk bark of A. altissima.
Method: The bioactive compounds were detected by thin-layer chromatography (TLC)–Bacillus subtilis bioassay and were characterized by chemical reagents and TLC–UV/Vis/FLD–heated electrospray ionization (HESI)-tandem high-resolution mass spectrometry (HRMS/MS). The bioassay-guided flash chromatographic fractionation and purification of antimicrobial compounds were followed by structure elucidation of the isolates using NMR spectroscopy and flow injection analysis (FIA)–HRMS/MS. The anti-Bacillus activity of the isolates was confirmed by microdilution assays determining their minimum inhibitory concentration.
Results: In this study, six bioactive compounds were isolated from the bark extracts of A. altissima: (9Z,11E)-13-hydroxy-9,11-octadecadienoic acid and (10E,12Z)-9-hydroxy-10,12-octadecadienoic acid from the stem bark; hexadecanedioic acid, 16-hydroxyhexadecanoic acid, and alpinagalanate from the outer trunk bark; while canthin-6-one from in the inner trunk bark. All isolates, except alpinagalanate, showed antibacterial activity against B. subtilis in microplate assays, with canthin-6-one exhibiting the strongest effect.
Conclusion: The TLC–B. subtilis bioassay-guided screening and flash chromatographic fractionation of A. altissima stem and trunk bark extracts led to the isolation of six compounds, which were identified by NMR spectroscopy and HRMS/MS. Except for alpinagalanate, all isolated compounds exhibited antibacterial activity against B. subtilis in microdilution assays, with canthin-6-one showing the strongest effect.
Funding: This study was supported by the National Research, Development and Innovation Office of Hungary (NKFIH; project SNN139496) and the Slovenian Research and Innovation Agency (ARIS; research core funding No. P1-0005, project N1-0235).