Evaluation of olive leaf and rosemary extracts as natural antifungal agents for wood protection

Nowrouzi, Zahra (author), Petrič, Marko (author), Skrt, Mihaela (author), Simić, Pavle (author), Poklar Ulrih, Nataša (author), Humar, Miha (author), Žagar, Andreja (author)

Wood used in outdoor applications is susceptible to fungal degradation, resulting in reduced structural integrity and service life. Increasing environmental and health concerns associated with synthetic fungicides have increased interest in sustainable alternatives. The Capsule project aims to improve wood durability using encapsulated herbal extracts, particularly olive leaf and rosemary, which are rich in phenolic compounds with antioxidant and antifungal properties. In accordance with the Capsule project programme, olive and rosemary leaves were air-dried, powdered, and extracted with ethanol using an ultrasonic bath to increase the yield of extraction. The extracts were chemically characterised by determining total phenolic content (TPC) and antioxidant capacity (DPPH assay). Based on the results, olive leaf extract exhibited higher total phenolic content than rosemary extract. Antioxidant activity values were greater when expressed relative to rosmarinic acid and oleuropein compared with gallic acid equivalents. In addition, antifungal activity was evaluated against white-rot fungi (Trametes versicolor and Pleurotus ostreatus) and brown-rot fungi (Gloeophyllum trabeum and Coniophora puteana) using extract concentrations of 2%, 3%, and 5% (w/v in DMSO). The radial mycelial growth was measured to assess antifungal efficacy prior to wood impregnation. Olive leaf extract exhibited prolonged antifungal activity at 2% concentration against Pleurotus ostreatus at day 10, whereas the 2%, 5% concentration was most effective against Trametes versicolor at day 10. In contrast, rosemary extract showed significant inhibitory activity only against Coniophora puteana, with the most effective result observed at the 2% concentration at day 7.

• Language: English
• Keywords: Olive leave, rosemary, antioxidant activity, antifungal activity, white-rot fungi, brown-rot fungi
• Work type: Other
• Typology: 1.08 - Published Scientific Conference Contribution
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Author Accepted Manuscript
• Year: 2026
• Number of pages: 13 str.
• PID: 20.500.12556/RUL-183030
• UDC: 630*8
• COBISS.SI-ID: 280077059
• Publication date in RUL: 02.06.2026

Record is a part of a monograph

• Title: IRG documents database and compendium
• Place of publishing: Stockholm
• Publisher: IRG Secretariat
• Year: 2004
• COBISS.SI-ID: 82640387

Secondary language

• Language: Slovenian
• Keywords: oljčni listi, rožmarin, antioksidativno delovanje, protiglivično delovanje, glive bele trohnobe, glive rjave trohnobe