Combination of Chromatographic Analysis and Chemometric Methods with Bioactivity Evaluation of the Antibacterial Properties of Helichrysum italicum Essential Oil.

Helichrysum italicum (immortelle) essential oil is one of the most popular essential oils worldwide and it has many beneficial properties, including antimicrobial. However, in this plant, the chemical diversity of the essential oil is very pronounced. The aim of this work was to process the GC-MS results of four samples of H. italicum essential oil of Serbian origin by chemometric tools, and evaluate the antimicrobial activity in vitro and in silico. Overall, 47 compounds were identified, the most abundant were γ-curcumene, α-pinene, and ar-curcumene, followed by α-ylangene, neryl acetate, trans-caryophyllene, italicene, α-selinene, limonene, and italidiones. Although the four samples of H. italicum essential oil used in this study were obtained from different producers in Serbia, they belong to the type of essential oil rich in sesquiterpenes (γ-curcumene and ar-curcumene chemotype). In vitro antimicrobial potential showed that five were sensitive among ten strains of tested microorganisms: Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Saccharomyces cerevisiae, and Candida albicans. Therefore, these microorganism models were used further for in silico molecular docking through the mechanism of ATP-ase inhibitory activity. Results showed that among all compounds from H. italicum essential oil, neryl acetate has the highest predicted binding energy. Artificial neural network modeling (ANN) showed that two major compounds γ-curcumene and α-pinene, as well as minor compounds such as trans-ß-ocimene, terpinolene, terpinene-4-ol, isoitalicene, italicene, cis-α-bergamotene, trans-α-bergamotene, italidiones, trans-ß-farnesene, γ-selinene, ß-selinene, α-selinene, and guaiol are responsible for the antimicrobial activity of H. italicum essential oil. The results of this study indicate that H. italicum essential oil samples rich in γ-curcumene, α-pinene, and ar-curcumene cultivated in Serbia (Balkan) have antimicrobial potential both in vitro and in silico. In addition, according to ANN modeling, the proportion of neryl acetate and other compounds detected in these samples has the potential to exhibit antimicrobial activity.

New esters from the essential oil of dry flowers of elder (Sambucus nigra L.).

BACKGROUND: Elder (Sambucus nigra L.) has relevance for the food, fragrance and pharmaceutical industries. Flowers of this species emit a very pleasant scent; for processing purposes, inflorescences are either collected from the wild or harvested from a cultivated crop. The study of elderflower-derived volatiles bears both phytochemical and commercial importance. RESULTS: Three samples of dry elderflower essential oil obtained from laboratory-scale hydrodistillations were analyzed. By use of gas chromatography-mass spectrometry, synthesis and NMR studies of chromatographic fractions of a distillation water extract prepared in a semi-industrial scale steam distillation, 252 constituents of the oil were identified; 115 compounds were not previously reported as elderflower volatiles, seven of which were new natural esters. Particularly interesting were those of isosenecioic (3-methylbut-3-enoic) acid because these were never before found in the plant kingdom. CONCLUSION: With these identifications, the known essential oil constituents accounted for 89.0-93.0% of the analyzed samples. Although the number of known S. nigra flower-derived volatiles is now quite high, further research (both analytical and olfactory) is needed to unveil all of the relevant contributions to the unique odor of elderflowers. © 2023 Society of Chemical Industry.

Screening of Volatile Compounds, Traditional and Modern Phytotherapy Approaches of Selected Non-Aromatic Medicinal Plants (Lamiaceae, Lamioideae) from Rtanj Mountain, Eastern Serbia.

Ironwort (Sideritis montana L.), mountain germander (Teucrium montanum L.), wall germander (Teucrium chamaedrys L.), and horehound (Marrubium peregrinum L.) are species widely distributed across Europe and are also found in North Africa and West Asia. Because of their wide distribution they express significant chemical diversity. For generations, these plants have been used as medical herbs for treating different aliments. The aim of this paper is to analyze volatile compounds of four selected species that belong to the subfamily Lamioideae, family Lamiaceae, and inspect scientifically proven biological activities and potential uses in modern phytotherapy in relation to traditional medicine. Therefore, in this research, we analyze the volatile compounds from this plants, obtained in laboratory by a Clevenger-type apparatus, followed by liquid-liquid extraction with hexane as the solvent. The identification of volatile compounds is conducted by GC-FID and GC-MS. Although these plants are poor in essential oil, the most abundant class of volatile components are mainly sesquiterpenes: germacrene D (22.6%) in ironwort, 7-epi-trans-sesquisabinene hydrate (15.8%) in mountain germander, germacrene D (31.8%) and trans-caryophyllene (19.7%) in wall germander, and trans-caryophyllene (32.4%) and trans-thujone (25.1%) in horehound. Furthermore, many studies show that, in addition to the essential oil, these plants contain phenols, flavonoids, diterpenes and diterpenoids, iridoids and their glycosides, coumarins, terpenes, and sterols, among other active compounds, which affect biological activities. The other goal of this study is to review the literature that describes the traditional use of these plants in folk medicine in regions where they grow spontaneously and compare them with scientifically confirmed activities. Therefore, a bibliographic search is conducted on Science Direct, PubMed, and Google Scholar to gather information related to the topic and recommend potential applications in modern phytotherapy. In conclusion, we can say that selected plants could be used as natural agents for promoting health, as a source of raw material in the food industry, and as supplements, as well as in the pharmaceutical industry for developing plant-based remedies for prevention and treatment of many diseases, especially cancer.

A comprehensive approach to chitosan-gelatine edible coating with ß-cyclodextrin/lemongrass essential oil inclusion complex - Characterization and food application.

Biopolymer-based films present an ideal matrix for the incorporation of active substances such as antimicrobial agents, giving active packaging a framework of green chemistry and a step forward in food packaging technology. The chitosan-gelatine active coating has been prepared using lemongrass oil as an antimicrobial compound applying a different approach. Instead of surfactants, to achieve compatibilization of compounds, ß-cyclodextrin was used to encapsulate lemongrass oil. The antimicrobial effect was assessed using the dip-coating method on freshly harvested cherry tomatoes artificially contaminated by Penicillium aurantiogriseum during 20 days of cold storage. According to the evaluation of the antimicrobial effect of coating formulation on cherry tomato samples, which was mathematically assessed by predictive kinetic models and digital imaging, the applied coating formulation was found to be very effective since the development of fungal contamination for active-coated samples was observed for 20 days.

Agricultural Parameters and Essential Oil Content Composition Prediction of Aniseed, Based on Growing Year, Locality and Fertilization Type-An Artificial Neural Network Approach.

Predicting yield is essential for producers, stakeholders and international interchange demand. The majority of the divergence in yield and essential oil content is associated with environmental aspects, including weather conditions, soil variety and cultivation techniques. Therefore, aniseed production was examined in this study. The categorical input variables for artificial neural network modelling were growing year (two successive growing years), growing locality (three different locations in Vojvodina Province, Serbia) and fertilization type (six different treatments). The output variables were morphological and quality parameters, with agricultural importance such as plant height, umbel diameter, number of umbels, number of seeds per umbel, 1000-seed weight, seed yield per plant, plant weight, harvest index, yield per ha, essential oil (EO) yield, germination energy, total germination, EO content, as well as the share of EOs compounds, including limonene, cis-dihydro carvone, methyl chavicol, carvone, cis-anethole, trans-anethole, ß-elemene, α-himachalene, trans-ß-farnesene, γ-himachalene, trans-muurola-4(14),5-diene, α-zingiberene, ß-himachalene, ß-bisabolene, trans-pseudoisoeugenyl 2-methylbutyrate and epoxy-pseudoisoeugenyl 2-methylbutyrate. The ANN model predicted agricultural parameters accurately, showing r2 values between 0.555 and 0.918, while r2 values for the forecasting of essential oil content were between 0.379 and 0.908. According to global sensitivity analysis, the fertilization type was a more influential variable to agricultural parameters, while the location site was more influential to essential oils content.

Chemical Composition, Antioxidant, and Antimicrobial Activity of Dracocephalum moldavica L. Essential Oil and Hydrolate.

Steam distillation was used for the isolation of Dracocephalum moldavica L. (Moldavian dragonhead) essential oil (DMEO). This aromatic herbaceous plant is widespread across the Northern Hemisphere regions and has been utilized in health-improving studies and applications. In addition to the DMEO, the hydrolate (DMH), a byproduct of the distillation process, was also collected. The DMEO and DMH were analyzed and compared in terms of their chemical composition, as well as their in vitro biological activities. The main component in DMEO was geranyl acetate, while geranial was dominant in DMH. The DMEO demonstrated better antioxidant and antimicrobial activities compared with the DMH against Staphylococcus aureus, Escherichia coli, Salmonella Typhimurium, and Listeria monocytogenes, which represent sources of food-borne illness at the global level. The DMEO and DMH show promise as antioxidant and antimicrobial additives to various products.

Comparative Study of the Essential Oil and Hydrosol Composition of Sweet Wormwood (Artemisia annua L.) from Serbia.

The most abundant volatile compounds of sweet wormwood (Artemisia annua L.) essential oil were artemisia ketone (25.4 %) and trans-caryophyllene (10.2 %), followed by 1,8-cineole, camphor, germacrene D and ß-selinene. The major volatile compounds in the hydrosol were camphor (25.1 %), 1,8-cineole (20.5 %) and artemisia ketone (10.7 %), followed by trans-pinocarveol and yomogi alcohol. Tested essential oil was rich in oxygenated monoterpenes and sesquiterpene hydrocarbons, while the former were identified as the major class of volatile compounds in the hydrosol, due to higher water solubility. Classification of all sweet wormwood chemotypes, according to essential oil composition, in available literature (17 studies and 61 accessions) could be done according to four chemotypes: artemisia ketone+artemisia alcohol (most abundant), artemisia ketone, camphor and nonspecific chemotype. According to this classification, essential oil of sweet wormwood from this study belongs to artemisia ketone (content varied between 22.1 and 55.8 %). Bearing in mind that hydrosols are a by-product of industrial production of essential oils, and the fact that sweet wormwood hydrosol has high contents of camphor, 1,8-cineole and artemisia ketone, there is a great potential for the use of this aromatic plant primary processing waste product as a water replacement in cosmetic industry, beverages flavoring, for food preservation, as well as in post-harvest pre-storage treatments in organic agriculture.

Chemical Characterization and Antibacterial Activity of Essential Oil of Medicinal Plants from Eastern Serbia.

The objective of this study was to evaluate wild growing Satureja kitaibelii, Thymus serpyllum, Origanum vulgare, Achillea millefolium and Achillea clypeolata with respect to their essential oil (EO) content, composition and antimicrobial activity. The five species were collected at Mt. Rtanj and the village of Sesalac, Eastern Serbia. The main EO constituents of Lamiaceae plants were p-cymene (24.4%), geraniol (63.4%) and germacrene D (21.5%) in Satureja kitaibelii, Thymus serpyllum and Origanum vulgare ssp. vulgare, respectively. A. millefolium EO had multiple constituents with major ones being camphor (9.8%), caryophyllene oxide (6.5%), terpinen-4-ol (6.3%) and 1,8-cineole (5.6%), while the main EO constituents of A. clypeolata were 1,8-cineole (45.1%) and camphor (18.2%). Antimicrobial testing of the EO showed that Staphylococcus aureus (Gram-positive) was more sensitive to all of the tested EOs than Escherichia coli (Gram-negative). S. kitaibelii EO showed the highest antimicrobial activity against both tested bacterial strains. This is the first study to characterize the EO composition and antimicrobial activity of these five medicinal species from Eastern Serbia in comparison with comprehensive literature data. The results can be utilized by the perfumery, cosmetics, food and pharmaceutical industries, but also for healing purposes in self-medication.

Marrubium vulgare L.: A Phytochemical and Pharmacological Overview.

Marrubium vulgare is a plant with high bioactive potential. It contains marrubiin, a labdane diterpene that is characteristic for this genus, as well as a complex mixture of phenolic compounds. According to numerous studies, M. vulgare acts as a good antioxidant agent, and due to this, it could potentially be useful in treatments of cancer, diabetes mellitus, and liver diseases. In addition, its anti-inflammatory, wound-healing, antihypertensive, hypolipidemic, and sedative potential are discussed. Apart from that, its antimicrobial activity, especially against Gram+ bacteria, fungi, herpes simplex virus, and parasites such as Toxoplasma gondii, Trichomonas vaginalis, and Plasmodium berghei-berghei was recorded. Additionally, it could be used as a chicken lice repellent, herbicide, and natural insecticide against mosquito larvae and natural molluscicide. In veterinary medicine, M. vulgare can be used as an anthelmintic against the eggs and larvae of bovine strongyles parasites, and as an antibiotic against bovine mastitis caused by resistant bacterial strains. Due to the mentioned benefits, there is a tendency for the cultivation of M. vulgare in order to ensure high-quality raw material, but more firm scientific evidence and well-designed clinical trials are necessary for the well-established use of M. vulgare herb and its preparations.

Chemical Composition and Antibacterial Activity of Angelica archangelica Root Essential Oil.

Roots of wild growing Angelica archangelica L. from Mt. Ozren (Serbia) were subjected to hydrodistillation and GC-MS analysis. The roots contained 0.10% of essential oil with a-pinene (29.7%), 8-3-carene (14.2%), and a mixture of P-phellandrene and limonene (13.2%) as main compounds. The modified resazurin microtiter-plate assay was used to evaluate the antibacterial activity of the essential oil against Staphylococcus aureus and Escherichia coli. The minimum inhibitory concentration (MIC) values were 14.2 µL/mL for S. aureus and 28.4 µL/mL for E. coli, while the minimum bactericidal concentrations (MBC) were 56.8 µL/mL and 113.6 µL/mL, respectively. According to the obtained results, the angelica root essential oil can be applied as a natural preservative in food and as a natural antibiotic for the treatment of several infectious diseases caused by these two bacteria.