Effects of NaCl on Antioxidant, Antifungal, and Antibacterial Activities in Safflower Essential Oils

The present study aims to evaluate the antioxidant and antimicrobial activity of essential oils (EO) extracted from safflower plants grown in the absence and presence of NaCl, 50 mM. Plants treated with 50 mM of NaCl showed decreases in root, stem, and leaf dry weight. Results of the essential oils showed that roots have a higher EO yield than leaves and stems. Salinity caused a decrease in this yield in roots and leaves but not in stems. The compounds identified in the EO extracted from these organs belong to seven chemical classes of which the dominant class is the sesquiterpene hydrocarbons. The chemotype of C. tinctorius EO is variable depending on the organ and the treatment. The safflower essential oils showed low antioxidant, antiradical, and iron-reducing activities compared to those of the positive control (BHT). In an antifungal activity test, only two strains, Aspergillus niger and Candida albicans, were found to be highly sensitive to these oils as they showed almost total inhibition of their growth. For antibacterial activity, safflower EOs showed significant antimicrobial activity against Bacillus subtilis, Bacillus cereus, and Xanthomonas campestris in both control and NaCl-treated plants: for these three strains, total inhibition of growth was noted at 50,000 ppm of EO in leaves and roots; whereas for stems, total inhibition was noted only for the third strain (Xanthomonas campestris). For other strains, this inhibition was variable and weak. Salt was found to have no effect on the activities of safflower EOs.

A review on chemical constituents of essential oils of Aframomum genus

Aframomum K.Schum is a genus native to Africa belonging to Zingiberaceae. Members of the genus Aframomum are the aromatic and perennial rhizomatous herbs. Many plant parts of Aframomum species contain essential oils, including fruits, seeds, leaves, stems, rhizomes, pods, husks, pericarps, limbos and leaf sheaths. The major constituents of Aframomum plants are mainly composed of sesquiterpene hydrocarbons, oxygenated monoterpenes, oxygenated sesquiterpenes and monoterpene hydrocarbons. The present work provides the comprehensive information regarding the volatile components of various Aframomum species.

Volatolomics of Three South African Helichrysum Species Grown in Pot under Protected Environment

Helichrysum decorum DC, Helichrysum lepidissimum S. Moore, and Helichrysum umbraculigerum are three species traditionally used in the South African medicine. The present work deals with the investigation of the spontaneous emission and the essential oils obtained from these plants cultivated in open field under uniform conditions. Fractions of the volatile organic compounds of the three species were rich in monoterpene hydrocarbons, representing more than 70% of the total composition. Pinene isomers were the most representative compounds: β-pinene in H. decorum (53.0%), and α-pinene in H. lepidissimum (67.9%) and H. umbraculigerum (54.8%). These latter two species evidenced an important amount of sesquiterpene hydrocarbons (SH) especially represented by γ-curcumene (H. lepidissimum) and α- and β-selinene (H. umbraculigerum). On the contrary, in the EOs, sesquiterpenes compounds prevailed, representing more than 64% of the identified fraction to reach more than 82 and 87% in H. umbraculigerum and H. lepidissimum, respectively. Although the chemical classes and their relative abundances were comparable among the three species, the individual compounds of EOs showed large differences. In fact, caryophyllene oxide (26.7%) and γ-curcumene (17.4%) were the main constituents in H. decorum, and H. lepidissimum respectively, while neo-intermedeol (11.2%) and viridiflorol (10.6%) characterized H. umbraculigerum.

Original Contributions to the Chemical Composition, Microbicidal, Virulence-Arresting and Antibiotic-Enhancing Activity of Essential Oils from Four Coniferous Species

This study aimed to establish the essential oil (EO) composition from young shoots of Picea abies, Larix decidua, Pseudotsuga menziesii, and Pinus nigra harvested from Romania and evaluate their antimicrobial and anti-virulence activity, as well as potential synergies with currently used antibiotics. The samples’ EO average content varied between 0.62% and 1.02% (mL/100 g plant). The mono- and sesquiterpene hydrocarbons were dominant in the composition of the studied EOs. The antimicrobial activity revealed that the minimum inhibitory concentration (MIC) values for the tested EOs and some pure compounds known for their antimicrobial activity ranged from 6.25 to 100 µL/mL. The most intensive antimicrobial effect was obtained for the Pinus nigra EO, which exhibited the best synergistic effect with some antibiotics against Staphylococcus aureus strains (i.e., oxacillin, tetracycline, erythromycin and gentamycin). The subinhibitory concentrations (sMIC) of the coniferous EOs inhibited the expression of soluble virulence factors (DN-ase, lipase, lecithinase, hemolysins, caseinase and siderophore-like), their efficiency being similar to that of the tested pure compounds, and inhibited the rhl gene expression in Pseudomonas aeruginosa, suggesting their virulence-arresting drug potential.

Chemical composition and insecticidal activity of Garcinia gardneriana (Planchon & Triana) Zappi (Clusiaceae) essential oil

The present study aimed to analyze the chemical composition of the essential oil from Garcinia gardneriana (Planchon & Triana) Zappi leaves and fruits, and to determine its acaricidal activity on Rhipicephalus microplus by larval packet test and larvicidal action on Aedes aegypti by larval immersion test. The chemical analysis of the essential oil by gas chromatography-mass spectrometry identified sesquiterpene hydrocarbons and oxygenated sesquiterpenes in bacupari leaves and fruits, and α-cedrene, α-chamigrene, α-trans-bergamotene, and β-curcumene as major compounds. Essential oil from leaves of G. gardneriana presented acaricidal activity on R. microplus (LC50 = 4.8 mg/mL; LC99 = 10.8 mg/mL) and larvicidal effect on A. aegypti (LC50 = 5.4 mg/mL; LC99 = 11.6 mg/mL), whereas essential oil from the fruits of G. gardneriana showed LC50 = 4.6 mg/mL and LC99 = 8.9 mg/mL against R. microplus and LC50 = 6.4 mg/mL and LC99 = 13.9 mg/mL against A. aegypti. These results thus demonstrate the potential acaricidal and larvicidal activity of essential oil of G. gardneriana, offering new perspectives for the realization of bioassays from this essential oil.

Variability of exotic ginger (Zingiber officinale Rosc.) accessions for quality parameters

Ginger (Zingiber officinale) is one of the important and widely used spices throughout the world in fresh and dried forms. The study on quality characterization and essential oil profiling of 13 ginger genotypes was conducted at ICAR-Indian Institute of Spices Research, Kozhikode, Kerala, during 2019-2020. The genotypes included eight promising exotic accessions (Acc. 393, Acc. 607, Acc. 736, Acc. 833, Acc. 869, Acc. 872, Acc. 873 and Acc. 874), four popular cultivars (Nadan, Himachal, Maran, Rio-de-Janeiro) and a released variety IISR Varada. Significant differences among the genotypes were recorded for various quality parameters such as oleoresin, essential oil and crude fibre content. Among the exotic genotypes, Acc. 869 recorded the highest essential oil content (2.44%), followed by Acc. 393 (2.42%), Acc. 833 and Acc. 873 (2.10%). The accessions, Acc. 869, Acc. 874, Acc. 873 and Acc. 393 recorded higher oleoresin content of 5.88 per cent, 5.63 per cent, 5.34 per cent and 5.28 per cent, respectively. Considering essential oil and oleoresin contents, the exotic accessions, Acc. 873, Acc. 393 and Acc. 869 were identified as promising genotypes. Among the other genotypes, Rio-de-Janeiro recorded the highest essential oil (2.76%) and oleoresin content (6.69%). The exotic genotypes, viz., Acc. 607, Acc. 736 and Acc. 393 recorded crude fibre content of less than 5 per cent whereas, Acc. 869 recorded the maximum of 7.85 per cent. Fifty compounds were identified through essential oil profiling, and the major classes were sesquiterpene hydrocarbons followed by monoterpene hydrocarbons. The major compound identified was α-zingiberene and was highest in Acc. 393 (30.49%), followed by Maran (30.32%).

Influence of the Use of an Ionic Liquid as Pre-Hydrodistillation Maceration Medium on the Composition and Yield of Cannabis sativa L. Essential Oil

Cannabis sativa L. is a multi-purpose crop, whose resilience, adaptability and soil-enriching properties make it a low-impact production. In the last years, the cultivation of the “industrial” hemp varieties (THC < 0.2%) has been promoted by many Countries, opening a whole new market of hemp-derived products, such as its essential oil (EO). Its distillation might represent an effective method to exploit a residue of the hemp fiber production (flowers), complying with the guidelines of the circular economy. In the present work, different concentrations of an ionic liquid (IL; 1,3-dimethyl-1H-imidazol-3-ium dimethylphosphate) have been studied as a pre-hydrodistillation maceration medium. The EO yields have been evaluated, and their compositions have been analyzed by GC-EIMS. The use of 100% and 90% IL concentrations gave a hydrodistillation yield increment of 250% and 200%, respectively. The 200% yield increase was maintained when the 100% IL was recycled after the hydrodistillation. The lower IL concentrations incremented the cannabinoid and oxygenated sesquiterpene contents, while the opposite was true for sesquiterpene hydrocarbons. The proposed IL-enhanced hydrodistillation medium applied to hemp, studied for the first time in the present work, might be used to both (i) noteworthy increment the hydrodistillation yield and (ii) modulate the obtained EO composition based on the desired final product.

Essential Oils of the Leaf and Stem of Polyalthia viridis Craib and Their Biological Activities

Plants of the genus Polyalthia can be seen as a rich resource of essential oils type terpenoids. In this study, the essential oils obtained by hydro-distillation from the leaf and stem of Polyalthia viridis were analysed by gas chromatography/mass spectrometry–flame ionization detection. Thirty-nine constituents (95.3%) were identified in the leaf oils and 42 constituents (90.9%) in the stem oils. Sesquiterpene hydrocarbons and oxygenated sesquiterpenes were the main constituents of both oils, in which 2 sesquiterpene hydrocarbons, germacrene D (45.1%-47.4%) and bicyclogermacrene (8.2%-17.1%), were the 2 major compounds. The stem oils inhibited the growth of 3 cancer cell lines, HepG2, MCF7, and A549, with half inhibitory concentration (IC50) values of 56.7 to 68.4 μg/mL. The stem oils also successfully suppressed the growth of the filamentous fungus Aspergillus niger and the yeast Candida albicans with minimum inhibitory concentration values of 50 μg/mL. P viridis oils suppressed NO production in lipopolysaccharide-stimulated BV2 microglial cells, with IC50 values of 57.6 to 76.7 μg/mL.

Variability of the Chemical Composition of the Essential Oil from the Amazonian Ishpingo Species (Ocotea quixos)

Ocotea quixos (Lam.) Kosterm. is an aromatic tree native to Ecuador, whose leaves are used to prepare aromatic beverages to which different health benefits are attributed. In this study, Ocotea quixos leaves were collected in the Amazon region in different environmental conditions and subjected to hydrodistillation to isolate the essential oil. The collection variables used were type of soil, amount of shade, and height; in addition, the presence of twig and leaf age and moisture were used as variables. Chemical composition was analyzed by means of gas chromatography equipped with a flame ionization detector and gas chromatography coupled to mass spectrometry. A wide variety of chemical compositions were detected in the samples. In total, forty-seven compounds were identified, which represented between 97.17% and 99.89% of the total composition. The constituents were mainly grouped into aliphatic sesquiterpene hydrocarbons (33.03–55.89%), other compounds (8.94–47.83%), and oxygenated monoterpenes (1.97–39.66%). The main constituents were found to be (E)-cinnamyl acetate (5.96–41.65%), (E)-methyl cinnamate (0.38–37.91%), and trans-caryophyllene (8.77–37.02%). The statistical analysis suggested the existence of two essential oil chemotypes and a direct correlation between environmental conditions and chemical composition of the essential oils.