Population Variability of Essential Oils ofPinus heldreichiifrom the Scardo-Pindic Mountains Ošljak and Galičica

Chemical profile, antioxidant and antimicrobial activity of Pinus heldreichii Christ. Distributed in Bulgaria

Pinus heldreichii Christ. (Bosnian pine), a Tertiary relict and Balkan sub-endemic, has not been comprehensively studied for its essential oil (EO) profile and bioactivity of its different plant parts. This study aimed to determine the EO yield, composition and antimicrobial activity from different parts of P. heldreichii at three different populations (mountains) in Bulgaria. Furthermore, the study assessed the antioxidant activities of plant tissue, including leaves (needles), twigs wood, male and female cones. The EOs yield from different plant parts ranged from 0.09 % (leaves) to 0.74 % (wood of twigs), with monoterpenes being the predominant class. Limonene, α-pinene, β-caryophyllene, germacrene D, β-pinene, and β-myrcene were detected in the EO extracted from all analyzed trees. However, these compounds were not found in the EO extracted from all plant parts of the same trees. Four chemical groups (chemotypes) were identified for EO from twigs, and three chemotypes were identified for EO from leaves. The chemotypes were based on the percent ratio of the main EO constituents (>5 %). Leaves tissue showed the highest values in terms of polyphenols and flavonoids, as well as higher ABTS radical scavenging activity, while the highest antimicrobial activity against Staphylococcus aureus subsp. aureus was seen in the EOs obtained from twigs. This is the first study to identify several chemotypes based on leaf and twigs EO of P. heldreichii distributed in Bulgarian flora. Furthermore, the EO of twigs tips (TT), male cones (MC), and wood of one-two-year-old twigs (WT) of the same trees were reported for the first time. The total polyphenol, flavonoid content, and radical scavenging activity of tissues of annual twigs wood and biennial twigs wood, leaf tissue, MC tissue, and the twigs tips tissue is also reported for the first time in the accessible literature. These findings highlight the potential of P. heldreichii to provide EOs with varying compositions and bioactivities, making them suitable for nutraceutical, pharmacological, and potentially food additive applications. Furthermore, the identification of chemotype accessions in this study suggests their selection for the development of new forest crop as a source for natural products with desirable composition and bioactivity.

Phytochemical composition, anti-inflammatory activity and cytotoxic effects of essential oils from three Pinus spp

Context: Inflammation and cell differentiation lead to a number of severe diseases. In the recent years, various studies focused on the anti-inflammatory and anticancer activity of essential oils (EOs) of numerous plants, including different Pinus species.

Objective: The phytochemical composition, anti-inflammatory and cytotoxic activity of EOs from needles and twigs of Pinus heldreichii Christ (Pinaceae) and P. peuce Griseb., and from needles, twigs and cones of P. mugo Turra were determined.

Materials and methods: For separation and identification of the EOs, gas chromatography/flame ion detector (GC/FID) and GC/mass spectrometry were performed. The amount of secreted IL-6 in a lipopolysaccharide (LPS)-stimulated macrophage model was quantified (concentration of oils: 0.0001–0.2%, 3 h incubation). Cytotoxicity on the cancer cell lines HeLa, CaCo-2 and MCF-7 were determined using a MTT (Thiazolyl Blue Tetrazolium Bromide) assay (concentration of oils: 0.001–0.1%, 24 h incubation).

Results: The most prominent members in the oils include: δ-3-carene, α-pinene and linalool-acetate (P. mugo); α-pinene, β-phellandrene and β-pinene (P. peuce); limonene, α-pinene and (E)-caryophyllene (P. heldreichii). EOs showed significant cytotoxic effects on cancer cell lines (IC₅₀ 0.007 to >0.1%), with a reduction in cell viability with up to 90% at a concentration of 0.1%, and anti-inflammatory activity (IC₅₀ 0.0008–0.02%) with a reduction of IL-6 secretion with up to 60% at a concentration of 0.01%.

Discussion and conclusion: The EOs of needles and twigs from P. peuce and P. heldreichii as well as of needles, twigs and cones of P. mugo can be considered as promising agents for anticancer and anti-inflammatory drugs.

Pinus halepensis, Pinus pinaster, Pinus pinea and Pinus sylvestris Essential Oils Chemotypes and Monoterpene Hydrocarbon Enantiomers, before and after Inoculation with the Pinewood Nematode Bursaphelenchus xylophilus

Pinewood nematode (PWN), Bursaphelenchus xylophilus, is the causal agent of pine wilt disease, a serious threat to global forest populations of conifers, especially Pinus spp. A time-course study of the essential oils (EOs) of 2-year-old Pinus halepensis, Pinus pinaster, Pinus pinea and Pinus sylvestris following inoculation with the PWN was performed. The constitutive and nematode inoculation induced EOs components were analyzed at both the wounding or inoculation areas and at the whole plant level. The enantiomeric ratio of optically active main EOs components was also evaluated. External symptoms of infection were observed only in P. pinaster and P. sylvestris 21 and 15 days after inoculation, respectively. The EO composition analysis of uninoculated and unwounded plants revealed the occurrence of chemotypes for P. pinaster, P. halepensis and P. sylvestris, whereas P. pinea showed a homogenous EO composition. When whole plants were evaluated for EO and monoterpene hydrocarbon enantiomeric chemical composition, no relevant qualitative and quantitative differences were found. Instead, EO analysis of inoculated and uninoculated wounded areas revealed an increase of sesquiterpenes and diterpenic compounds, especially in P. pinea and P. halepensis, comparatively to healthy whole plants EOs.

Chemical Composition and Interpopulation Variability of Essential Oils of Taxus baccata L. from Serbia

The composition of the essential oil of the twigs and needles of Taxus baccata L. from three natural populations in Serbia has been determined by GC/MS analysis. Of the 91 detected compounds, 87 were identified. The most abundant compound classes were aliphatic alcohols, terpenes, aliphatic hydrocarbons, and aliphatic aldehydes, which together comprised ca. 86.92% of the total oil composition. The dominant constituents were oct-1-en-3-ol (23.48%), (3Z)-hex-3-en-1-ol (11.46%; aliphatic alcohols), and myrtenol (11.38%; oxygenated monoterpene). The PCA of 22 selected compounds revealed differentiations of populations based on geographic distribution. The CA showed that Populations I and II from the Dinaric Alps were similar, and that Population III from the Balkan mountain system was distinct. This was the first investigation of interpopulation variability of T. baccata populations based on essential oil composition. The results of this study were compared with those of previous studies concerning volatile compounds produced by Taxus species. The results indicate that the essential oil content of T. baccata populations from this study is unique, mostly resembling the population from southeast Serbia.