Biological activities and essential oils composition of Balkans endemic species Pinus peuce Griseb. from Bulgaria

Authors: SEMERDJIEVA, IVANKA - Agricultural University Plovdiv; Cantrell, Charles; KACÁNIOVÁ, MIROSLAVA - Slovak University Of Agriculture; ASTATKIE, TESS - Dalhousie University; KOLEVA-VALKOVA, LYUBKA - Agricultural University Plovdiv; RADOUKOVA, TZENKA - University Of Plovdiv Paisii Hilendarski; MANEVA, VASILINA - Institute Of Agriculture Karnobat; ATANASOVA, DINA - Institute Of Agriculture Karnobat; BORISOVA, DANIELA - Ministry Of Agriculture And Food - Bulgaria; ZHELJAZKOV, VALTCHO - Oregon State University

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/29/2025
Publication Date: 8/17/2025
Citation: Semerdjieva, I.B., Cantrell, C.L., Kacániová, M., Astatkie, T., Koleva-Valkova, L., Radoukova, T., Maneva, V., Atanasova, D., Borisova, D., Zheljazkov, V.D. 2025. Biological activities and essential oils composition of Balkans endemic species Pinus peuce Griseb. from Bulgaria. Industrial Crops and Products. 235:121759. https://doi.org/10.1016/j.indcrop.2025.121759.
DOI: https://doi.org/10.1016/j.indcrop.2025.121759

Interpretive Summary: This study aimed to investigate the phytochemical compositions of Pinus peuce (Balkan pine) essential oils (EO), total polyphenol, and flavonoid content from different plant parts: leaves, twigs, wood, and cones. Furthermore, this study aimed to evaluate the biological activities of EO (biopesticidal and antimicrobial) and the radical scavenging activity of different plant parts. The working hypothesis was that EOs, phenols, and flavonoids of different plant parts of the same tree would have similar composition and biological activity. Generally, the P. peuce EOs obtained from different plant parts by hydrodistillation differed between plant parts (L, T, W, TT, MC, FC) and consisted primarily of a-pinene, ß-pinene, bornyl acetate, and limonene. These compounds were found in the EOs of all analyzed trees (T1-T14) from the five Bulgarian populations in differing amounts, depending on the plant parts. Furthermore, EO yield ranged between different plant parts, with its highest values in the wood of one-two-year-old twigs (1.08% – 2.40%). Regarding the predominant compounds (>5%) of EOs of different plant parts (L, T, and WT), nine chemotypes were identified for L, and six chemotypes for T and W. The analyzed FC had the highest concentration of polyphenolic compounds (56.03), followed by the annual wood (24.56) and leaves (22.86), which is related to the higher antiradical activity of the extracts from these plant parts. Polyphenols and antioxidant activities slightly decreased with wood age, possibly due to oxidative or degradation processes. Furthermore, as seen in both ABTS• and DPPH•, results remain higher than the young plant parts, such as TT and MC.

Technical Abstract: This study aimed to investigate the phytochemical compositions of Pinus peuce (Balkan pine) essential oils (EO), total polyphenol, and flavonoid content from different plant parts: leaves, twigs, wood, and cones. Furthermore, this study aimed to evaluate the biological activities of EO (biopesticidal and antimicrobial) and the radical scavenging activity of different plant parts. The working hypothesis was that EOs, phenols, and flavonoids of different plant parts of the same tree would have similar composition and biological activity. Gas chromatography-mass spectrometry with simultaneous FID detection was utilized for quantitative analyses of the EOs. The total amount of phenols, flavonoids, and antiradical activity was determined spectrophotometrically with a UV/Vi spectrophotometer. The biopesticidal potential (insecticidal, repellent, and bioherbicidal activities) was evaluated in Petri dishes with three replicates. EO yield varied among different plant parts and it was highest in the wood of one-two year-old twigs (1.08% – 2.40%). Depending on the plant part types, the predominant compounds of the EOs, a-pinene, ß-pinene, and limonene, were found in all analyzed trees from the five populations but in different amounts. The concentration ranges for a-pinene were 32-56% in leaves (L), 24-49% in twigs (T), 26-48% in tips of twigs (TT), wood of one-two year old twigs. The concentrations of ß-pinene were 7.9% to 18.3% in L, 5.9%-15.7% in T, 7.9-13.2% in TT, and 4.2-6.5% in WT. The concentration of limonene was L from 2.9-12% in L, 5.7-45% in T, and 1.2-60% in WT. Furthermore, camphene, ß-myrcene, bornyl acetate, germacrene D, and ß-caryophyllene were found in large quantities in some plant parts. The female cones had the highest concentration of polyphenolic compounds (56.03 mg GAE g-1), followed by the annual wood (24.56 mg GAE g-1) and leaves (22.86 mg GAE g-1), which is related to the higher antiradical activity of the extracts from these plant parts. The tested EOs of all plant parts of P. peuce had a higher antimicrobial effect against Salmonella enterica susp. enterica and Escherichia coli. The EOs were tested at six concentrations (5%, 4.5%, 3.5%, 2.5%, 1.5%, and 1%) for insecticidal activity against Sitobion avenae and Rhopalosiphum padi and had significant efficacy (100%) 24 h after treatment; however, the EO demonstrated weak repellent activity against these pests. P. peuce EO from twigs demonstrated significant bioherbicidal activity against weed seeds of Anthemis arvensis L. and Papaver rhoeas L. at concentrations of 0, 1, 2, 5, 10, and 20 µL. It effectively reduced and inhibited both sprout and root growth.