Chemical composition, antioxidant and antimicrobial activities of essential oils of different Pinus species from Kosovo

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.

Antibacterial and Antiviral Properties of Pinus densiflora Essential Oil

The Korean mountains are home to the Korean red pine (Pinus densiflora). Pine needle oil has been used as a food additive and a traditional herbal medicine; however, any health-related properties of its trunk oil remain unknown. Herein, we assessed antibacterial and antiviral properties of essential oil extracted from the trunk of P. densiflora. Th extracted oil was hydrodistilled using a Clevenger apparatus and analyzed using gas chromatography-mass spectrometry. The antimicrobial activity of the oil was tested using the microbroth dilution technique against 10 bacterial species (6 g-positive and 4 g-negative) and fungi. The extract exerted strong antimicrobial activity against Vibrio parahaemolyticus, Bacillus cereus, Listeria monocytogenes, Propionibacterium acnes, and Malassezia furfur (minimum inhibitory concentration = 10 mL/L). Additionally, it exhibited dose-dependent activity against influenza virus A and feline coronavirus. Furthermore, among 20 identified constituents accounting for 98.7% of the oil contents, the major components included 3-cyclohexene-1-methanol (10.12%), 2-(4-methylcyclohexyl)-2-propanol (9.09%), fenchone (8.14%), O-isopropyltoluene (6.35%), and isothymol methyl ether (6.14%). The P. densiflora trunk essential oil showed antibacterial and antiviral activities that depended on its chemical composition and the microbial strains tested herein. The essential oil can be used as an antimicrobial agent and disinfectant.

Effect of pine essential oil and rotating magnetic field on antimicrobial performance

This work presents the results ofa study which concerns the influence of rotating magnetic field (RMF) on the antibacterial performance of commercial pine essential oil. A suspension of essential oil in saline solution and Escherichia coli were exposed to the rotating magnetic Afield (the frequency of electrical current supplied by a RMF generator f = 1–50 Hz; the averaged values of magnetic induction in the cross-section of the RMF generator B = 13.13 to − 19.92 mT, time of exposure t = 160 min, temperature of incubation 37 °C). The chemical composition of pine (Pinus sylvestris L.) essential oil was determined by gas chromatography coupled with mass spectrometry (GC–MS). The main constituents were α-pinene (28.58%), β-pinene (17.79%), δ-3-carene (14.17%) and limonene (11.58%). The present study indicates the exposition to the RMF, as compared to the unexposed controls causing an increase in the efficacy of antibacterial properties of pine oil. We have shown that rotating magnetic fields (RMF) at a frequency, f, between 25 Hz to and 50 Hz increased the antimicrobial efficiency of oil a concentration lower than 50%.

Chemical Composition, Total Phenolic Content, and Antioxidant Activity of the Essential Oils Extracted from the Needle of Ten Pinus Taxa

This study investigated the chemical compositions of essential oils (EOs) from ten taxa belonging to the Pinus genus. The studied taxa that grow wildly in China, and the EOs were extracted by steam distillation; the chemical compositions were isolated and characterized by GC-MS. Eighty-one components, representing over 92.10% of the EOs, were identified. The main constituents of EOs were α-pinene (6.44%–53.00%), β-caryophyllene (2.43%–24.64%), β-pinene (0.00%–22.32%), δ-cadinene (2.56%–17.56%), germacrene D (0.74%–11.38%), and camphene (0.78%–10.48%). Furthermore, we determined the total phenolic content (TPC) of the EOs, with the values from 26.50 to 60.01 mg eq GAE/mL EO. DPPH free radical scavenging activity (DPPH), ferric reducing antioxidant power (FRAP), and ABTS radical cation scavenging activity (ABTS) were used to evaluate the antioxidant capacity of the EOs, and the obtained values were ranged from 499.15 to 1,272.75 mmol eq Trolox/mL EO, 1,255.67 to 3,857.93 mmol eq Trolox/mL EO, and 370.81 to 1,677.19 mmol eq Trolox/mL EO, respectively. The results showed that all of the EOs studied had strong antioxidant activity, and these pine plants could be used as natural antioxidants in functional food and pharmaceutical industries.

Trends in Chitosan as a Primary Biopolymer for Functional Films and Coatings Manufacture for Food and Natural Products

Some of the current challenges faced by the food industry deal with the natural ripening process and the short shelf-life of fresh and minimally processed products. The loss of vitamins and minerals, lipid oxidation, enzymatic browning, and growth of microorganisms have been the main issues for many years within the innovation and improvement of food packaging, which seeks to preserve and protect the product until its consumption. Most of the conventional packaging are petroleum-derived plastics, which after product consumption becomes a major concern due to environmental damage provoked by their difficult degradation. In this sense, many researchers have shown interest in edible films and coatings, which represent an environmentally friendly alternative for food packaging. To date, chitosan (CS) is among the most common materials in the formulation of these biodegradable packaging together with polysaccharides, proteins, and lipids. The good film-forming and biological properties (i.e., antimicrobial, antifungal, and antiviral) of CS have fostered its usage in food packaging. Therefore, the goal of this paper is to collect and discuss the latest development works (over the last five years) aimed at using CS in the manufacture of edible films and coatings for food preservation. Particular attention has been devoted to relevant findings in the field, together with the novel preparation protocols of such biodegradable packaging. Finally, recent trends in new concepts of composite films and coatings are also addressed.

Liquid and Vapor Phase of Four Conifer-Derived Essential Oils: Comparison of Chemical Compositions and Antimicrobial and Antioxidant Properties

In this study, the chemical composition of the vapor and liquid phase of Pinus cembra L., Pinus mugo Turra, Picea abies L., and Abies Alba M. needles essential oils (EOs) was investigated by Headspace-Gas Chromatography/Mass Spectrometry (HS-GC/MS). In the examined EOs, a total of twenty-eight components were identified, most of which belong to the monoterpenes family. α-Pinene (16.6-44.0%), β-pinene (7.5-44.7%), limonene (9.5-32.5%), and γ-terpinene (0.3-19.7%) were the most abundant components of the liquid phase. Such major compounds were also detected in the vapor phase of all EOs, and α-pinene reached higher relative percentages than in the liquid phase. Then, both the liquid and vapor phases were evaluated in terms of antibacterial activity against three Gram-negative bacteria (Escherichia coli, Pseudomonas fluorescens, and Acinetobacter bohemicus) and two Gram-positive bacteria (Kocuria marina and Bacillus cereus) using a microwell dilution assay, disc diffusion assay, and vapor phase test. The lowest Minimum Inhibitory Concentration (MIC) (13.28 mg/mL) and Minimal Bactericidal Concentration (MBC) (26.56 mg/mL) values, which correspond to the highest antibacterial activities, were reported for P. abies EO against A. bohemicus and for A. alba EO against A. bohemicus and B. cereus. The vapor phase of all the tested EOs was more active than liquid phase, showing the inhibition halos from 41.00 ± 10.15 mm to 80.00 ± 0.00 mm for three bacterial strains (A. bohemicus, K. marina, and B. cereus). Furthermore, antioxidant activities were also investigated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis (3- ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assays, and a concentration-dependent antioxidant capacity for all EOs was found. P. mugo EO showed the best antioxidant activity than the other Pinaceae EOs. The four Pinaceae EOs could be further investigated for their promising antibacterial and antioxidant properties, and, in particular, α-pinene seems to have interesting possibilities for use as a novel natural antibacterial agent.

Antioxidant Potential of Pine Needles: A Systematic Study on the Essential Oils and Extracts of 46 Species of the Genus Pinus

The antioxidant activity of the essential oils, as well as of the organic and hydroethanolic extracts, of the fresh needles of 54 pine taxa was evaluated using the peroxy-oxalate and luminol chemiluminescence assays. Among all evaluated essential oils, P. canariensis and P. attenuata displayed the highest levels of activity. P. contorta var. murrayana, followed by P. nigra var. caramanica, exhibited the highest antioxidant capacity among the organic extracts, while the most active hydroethanolic extract was that of P. nigra subsp. nigra. Based on the overall levels of activity, the latter taxon was selected for phytochemical analysis targeting the isolation of the bioactive constituents. As such, the organic extract of P. nigra subsp. nigra was subjected to chromatographic separations to yield 11 secondary metabolites (1-11) that were evaluated for their antioxidant activity. Nonetheless, the isolated compounds were found to be less active than the crude extract, thus suggesting the potential role of synergism.

Using Medicinal Plants in Valmalenco (Italian Alps): From Tradition to Scientific Approaches

This ethnobotanical survey was carried out in Caspoggio (Valmalenco, SO, Italy) with the purpose of investigating the traditional uses of medicinal plants. Moreover, a bibliographic research meant to validate or refute the uses, focusing on the potentially responsible compounds, was performed. Fifty-nine species, attributable to 30 families (Asteraceae, Pinaceae, Malvaceae, and Lamiaceae the most cited), were mentioned. Arnica montana, anti-inflammatory for traumas and musculoskeletal pains; Pinus mugo, expectorant; Malva sylvestris, anti-inflammatory and soothing; Achillea moschata, digestive. The compounds, responsible for the therapeutic activities, are often polyphenols and terpenoids: helenanin in A. montana, α-pinene, δ-3-carene, and limonene in P. mugo, gossypin and malvin in M. sylvestris, luteolin and apigenin in A. moschata. Scientific evidence for at least one of the traditional activities described was found for 50 species but only in 26 out of 196 works consulted, it is possible to make a comparison between investigated extracts and traditional preparations. This study is thus a stimulus to new phytochemical investigations, mimicking as much as possible the traditional preparations. This work is part of the European Interreg Italy-Switzerland B-ICE project, aimed at creating a management model for the ongoing climate change and searching for new sources of territory valorization as attractions for tourists.

Verification of Chromatographic Profile of Primary Essential Oil of Pinus sylvestris L. Combined with Chemometric Analysis

Chromatographic profiles of primary essential oils (EO) deliver valuable authentic information about composition and compound pattern. Primary EOs obtained from Pinus sylvestris L. (PS) from different global origins were analyzed using gas chromatography coupled to a flame ionization detector (GC-FID) and identified by GC hyphenated to mass spectrometer (GC-MS). A primary EO of PS was characterized by a distinct sesquiterpene pattern followed by a diterpene profile containing diterpenoids of the labdane, pimarane or abietane type. Based on their sesquiterpene compound patterns, primary EOs of PS were separated into their geographical origin using component analysis. Furthermore, differentiation of closely related pine EOs by partial least square discriminant analysis proved the existence of a primary EO of PS. The developed and validated PLS-DA model is suitable as a screening tool to assess the correct chemotaxonomic identification of a primary pine EOs as it classified all pine EOs correctly.

GC-MS analysis and biological activity of hydroalcholic extracts and essential oils of Rhus typhina L. wood (anacardiaceae) in comparison with leaves and fruits

Hydroalcoholic extracts (HE) and essential oils (EO) of branches, leaves and fruits of Rhus typhina L., were characterized by GC-MS. HE (yealds: branches 68.30 mg/g, leaves 35.82 mg/g and fruits 257.76 mg/g), showed different compositions dominated by gallic acid (33.46%) in branches, its precursor 1-cyclohexane-3,4,5-hydroxy-carboxylic acid (20.55%) in leaves and malic acid (89.15%) in fruits. EO yields were 210 µg/g for branches (main component δ-cadinene, 22.00%), followed by fruits with 132 µg/g (β-pinene 32.2%) and by leaves with 54 µg/g and phenylacetaldehyde as major component (40.13%). Total phenolic content (TPC) was highest in branches HE (5.87 µg _GAE/mL) and in EO leaves (17.71 µg _GAE/mL). The highest value of radical scavenging activity (DPPH test) was detected in leaves HE and EO. The branches EO antimicrobial activity was strong against C. albicans and negligible against E. coli. Leaves and fruits EO showed strong activity against C. albicans and intermediate activity against Escherichia coli.