Crude Essential Oil Research Articles

Genus Zingiber: A Review on Botanical, Major Bioactivities and Genetic Diversity

Zingiberaceae is a perennial plant family that is found across the tropics, particularly in Southeast Asia from low land to hill forests. In Peninsular Malaysia, it is believed that 160 ginger species are widely distributed belonging to 18 genera. Most of the Zingiber species in Peninsular Malaysia are less investigated and less understood taxonomically, thus remaining as under-utilized crops. The description of their morphologies in parallel with phytochemicals and molecular information are crucial to provide valuable information for further discovery of potent compounds, identification of potential new sources of genetic variation, as well as to provide insight into the domestication and breeding of ginger. The majority of Zingiber species are perennial herbs with a fragrant scent, an upright stem, and a fibrous rhizome. The presence of volatile components such as monoterpenoids, sesquiterpenes, sesquiterpenoids and some non-volatile compounds like gingerols, shagaols, and zingerone have contributed to the strong scent of the ginger oils. Among the dominant components of Zingiber are α-zingiberene, geranial, neral, camphene, neral, neric acid, α-curcumene, and zerumbone. The crude extracts and essential oils of Zingiber have proven to show some biological activities such as antimicrobial, anti-bacterial, insecticidal, larvicidal, anti-cancer, anti-inflammatory, anti-ulceration, antioxidant, anti-fungal, immunomodulatory, and anti-nociceptive. Most Zingiber species are known to have 22 somatic chromosomes (2n=22) which is the lowest among genera in Zingiberaceae. This study underscores the crucial significance of breeding programs and germplasm conservation, specifically emphasizing the potential of common ginger as a prominent contributor.

Enhancing fractionation of terpenoids and terpenes in citrus essential oils by a biphasic extraction system

Efficient deterpenation of essential oils is crucial for obtaining high value-added products. In this work, a biphasic extraction system integrated with associative extraction was utilized to enhance fractionation of terpenoids and terpenes, where organic salt and organic solvent were employed as extractants in each phase. Ten different organic solvents were evaluated in terms of their phase behavior, extraction performance, and EHS-related properties. The positive or negative effect of organic solvents on biphasic extraction performance was elucidated through molecular dynamics simulations and FT-IR spectra analysis. The results indicate that an organic solvent lacking hydrogen bonding ability can reduce its interaction with organic salt or terpenoids, thereby exerting a positive contribution to biphasic extraction. For crude orange sweet essential oil, the biphasic system containing tetrabutylammonium chloride and n-hexane achieves a 6.2-fold concentration of terpenoids, demonstrating its effectiveness in enhancing extractive deterpenation of essential oil.

Essential oil of endemic Centaurea paphlagonica: chemical composition, insecticidal, enzyme inhibitory activities and molecular docking approach

The key objective of this study was to determine the chemical composition, insecticidal and butyrylcholinesterase (BChE) inhibitory activities of crude essential oils (CEO) extracted from the stem-leaf parts of the endemic Centaurea paphlagonica plant via steam distillation, as well as its chromatography-based fractions for the first time. According to GC-MS analysis, eighty-five compounds were identified representing 98.49% of the total essential oil. β-Eudesmol (15.17%), phytol (8.69%), and spathulenol (8.03%) were determined as the main components. The CEO demonstrated a remarkably insecticidal activity against S. granarius and R. dominica insects, ranging from 98.35% to 100%, while achieving a 50% against T. confusum at a 10% concentration. The silica gel-based fractionation of CEO resulted in four qualitatively different fractions (CEO-F1 to F4). The CEO-F2, predominantly comprised of β-eudesmol and spathulenol, exhibited superior activity compared to CEO across all tested insects. In addition, the inhibitory activity of BChE, which causes death in insects by altering nervous system activities, was assessed. BChE inhibition activity of CEO and CEO-F2 was determined as IC50=346.57 μg/mL and 96.02 μg/mL, respectively, supporting the insecticidal activity tests and molecular docking studies. The volatile oil obtained from C. paphlagonica can be considered a potential natural source to combat storage product pests, with its significant natural volatile compounds.

Sequential Separation of Essential Oil Components during Hydrodistillation of Fresh Foliage from Azorean Cryptomeria japonica (Cupressaceae): Effects on Antibacterial, Antifungal, and Free Radical Scavenging Activities.

Cryptomeria japonica wood industry generates large amounts of foliage biomass residues. Due to the increasing applications and markets for essential oils (EOs), fresh Azorean C. japonica foliage (Az-CJF) residues are used for local EO production. Hydrodistillation (HD), a common process for obtaining EOs, also provides the possibility to fractionate them. Thus, this study evaluated the in vitro antimicrobial and antioxidant activities of six Az-CJF EO fractions (Frs. 1-6), collected at sequential HD timeframes (HDTs: 0-2, 2-10, 10-30, 30-60, 60-120, and 120-240 min), in comparison to the crude EO, obtained from a non-fractionated HD (0-240 min HDT). Antimicrobial activities were assessed via disc diffusion method against seven bacteria (foodborne and/or human pathogens) and two Penicillium spp. (phytopathogenic fungi), and antioxidant activity was estimated using DPPH and ABTS assays. Concerning the antibacterial activity, all the EO samples were effective only toward Gram-positive bacteria. Fractions 1-3 (<30 min HDT) were the most active, with growth inhibition zones (GIZ) of 7.0-23.3 mm (1.4-2.2 times higher than those of the crude EO), being Bacillus spp. (B. licheniformis and B. subtilis) the most sensitive, followed by Staphylococcus aureus and Micrococcus luteus. Regarding the antifungal activity, Frs. 1-3 also displayed the best activities, but only against P. italicum (GIZ around 9.0 mm), while the crude EO showed no antifungal activity. Overall, the best antimicrobial properties of Frs. 1-3 could be attributed, at least in part, to their highest content in α-pinene and bornyl acetate. On the other hand, Frs. 4-6 (>30 min HDT) exhibited the strongest antioxidant activities (EC50 values: 1.5-2.3 and 1.0-1.7 mg mL-1 for DPPH and ABTS, respectively), being at least 1.3-fold higher than those of the crude EO. The presence of nezukol, elemol, and eudesmol isomers could strongly contribute to the best free radical scavenging properties of Frs. 4-6. In conclusion, HD was found to be an efficient process for obtaining new Az-CJF EO fractions with variable and enhanced bioactivities due to their differential composition, as assessed using GC-MS. Hence, these findings could contribute to increasing the commercial potential of the C. japonica EO industry, namely, the Fr2 and Fr6, which presented the most significant activities and can have potential applications in the food, medical, and agriculture sectors.

A novel antifungal nanoemulsion based on reuterin-assisted synergistic essential oils: Preparation and in vitro/in vivo characterization

This research aimed to develop, optimize, and evaluate a new antifungal nanoemulsion system based on the crude reuterin-synergistic essential oils (EOs) hybrid to overcome the EOs application limits. At first, the antifungal effects of the Lactobacillus plantarum and Lactobacillus reuteri cell-free extracts (CFE) were tested against the Botrytis cinerea, Penicillium expansum, and Alternaria alternata as indicator fungus using broth microdilution method. The L. reuteri CFE with the MIC of 125 μL/mL for B. cinerea and 250 μL/mL for P. expansum and A. alternata showed more inhibitory effects than L. plantarum. Next, reuterin as a significant antibacterial compound in the L. reuteri CFE was induced in glycerol-containing culture media. To reach a nanoemulsion with maximum antifungal activity and stability, the reuterin concentration, Tween 80 %, and ultrasound time were optimized using response surface methodology (RSM) with a volumetric constant ratio of 5 % v/v oil phase including triple synergistic EOs (thyme, cinnamon, and rosemary) at MIC concentrations. Based on the Box-Behnken Design, the maximum antifungal effect was observed in the treatment with 40 mM reuterin, 1 % Tween 80, and 3 min of ultrasound. The growth inhibitory diameter zones of B. cinerea, P. expansum, and A. alternata were estimated 6.15, 4.25, and 4.35 cm in optimum nanoemulsion, respectively. Also, the minimum average particle size diameter (16.3 nm) was observed in nanoemulsion with reuterin 40 mM, Tween 80 5 %, and 3 min of ultrasound treatment. Zeta potential was relatively high within −30 mV range in all designed nanoemulsions which indicates the nanoemulsion's stability. Also, the prepared nanoemulsions, despite initial particle size showed good stability in a 90-d storage period at 25 °C. In vivo assay, showed a significant improvement in the protection of apple fruit treated with reuterin-EOs nanoemulsions against fungal spoilage compared to free reuterin nanoemulsion. Treatment of apples with nanoemulsion containing 40 mM reuterin showed a maximum inhibitory effect on B. cinerea (5.1 mm lesion diameter compared to 29.2 mm for control fruit) within 7 d at 25 °C. In summary, the present study demonstrated that reuterin-synergistic EOs hybrid with boosted antifungal activities can be considered as a biopreservative for food applications.

A comparative study on the synergistic activities of fractions and crude essential oil of Syzygium aromaticum

BackgroundSyzygium aromaticum has been used for over a century because it has biological qualities for several health-related problems, and the crude essential oils are known to contain several components that could be responsible for synergistic or antagonistic potentials in relation to their biological uses. The study was designed to compare the biological activities of the crude essential oil from the bud of Syzygium aromaticum and fractions obtained from column chromatography.Materials and methodsThe essential oil was extracted by hydrodistillation, and two prominent fractions, C1 and C2, were obtained from the column chromatography separation of the crude essential oil. The quantitative phytochemical analysis was done by standard methods, the antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging assays. The antifungal activities were assessed by the agar diffusion method, while the anti-inflammatory activity was done using a lipoxygenase inhibitory assay. The major component observed in the crude and fractions was determined by gas chromatography–mass spectrometry (GC–MS) analysis.ResultsThe phytochemical analysis showed that phenolic acid, tannin, saponin, flavonoids, alkaloids, cardiac glycosides, and terpenoids were present in variable quantities in all of the fractions and crude essential oil. The half-maximal inhibitory concentration (IC50) value for DPPH scavenging activity ranged from 226.1 to 301.2 µg/mL while that of ABTS scavenging activity ranged from 211.0 to 316.0 µg/mL. The lowest value of IC50 for both DPPH and ABTS was observed in fraction C1. The crude essential oil with a minimum inhibitory concentrations (MIC) value of 8.00 mg/mL was the most efficient against Candida albicans, Aspergillus penicillum, and Aspergillus niger. The anti-inflammatory assay showed C1 to have the lowest value of IC50 for the lipoxygenase assay. The major component observed in the crude essential oil as well as fraction C1 was eugenol, while fraction C2 had β-caryophyllene as the major component.ConclusionsThe result showed that all fractions as well as the crude essential oil exhibited antioxidant, antifungal, and anti-inflammatory activities, and the crude essential oil was synergic only with respect to its antifungal activity, while fraction C1 was more efficient as an anti-inflammatory and antioxidant agent.

Chemical profiling and antimicrobial potential of crude extract and essential oil from Conyza bonariensis leaves

Background and objectives: Microbial infections have made significant contributions to the global health burden, particularly in developing countries with lagging economies. Challenges arising from the evolution of antimicrobial resistant (AMR) bacteria have led to the search for novel antimicrobial agents, especially those derived from medicinal plants. Therefore, this study aimed to assess the antibacterial activity of ethyl acetate crude extracts and essential oils from C. bonariensis collected from the Mbeya region of Tanzania. Methods: Initial experimental activities involved preparation of crude extracts and essential oil, which were then, tested for antimicrobial activity against selected test organisms (Staphlococcus aureus (ATCC29213), Bacillus subtilis (ATCC6051), Escherichia coli (ATCC8736), Salmonella typhi (ATCC6539), and Candida albicans (DSM1665)) by using the disc diffusion method. On the other hand, the chemical composition profiling of ethyl acetate and essential oils was performed by gas chromatography mass spectrometry (GC-MS). Results: The crude extracts and essential oil of C. bonariensis leaves from Tanzania demonstrated to have antibacterial and antifungal activity. The minimum inhibition concentration (MIC) of leaves ethyl acetate crude extract was 25 mg/mL &gt; MIC &gt; 12.5 mg/mL for tested organisms, with the exception of C. albicans, where the MIC was 50 mg/mL &gt; MIC &gt; 25 mg/mL. Similary, for all tested organisms, the MIC of leaves essential oils was :1 &gt; MIC &gt; l:2, except S. typhi, where the MIC was 2:1 &gt; MIC &gt; 1:1. On the other hand, 2,4-di-tert-butyl phenol in leaves crude extracts had the highest percentage composition of peak area (41%); whereas, in essential of, 2,4-Di-tert-butyl phenol had the highest percentage composition (38.8%). Conclusions: The present findings have demonstrated antimicrobial potential of ethyl acetate crude extract and essential oil of C. bonariensis leaves from Tanzania, and validate the wide use of the plant by local communities, particularly the local community of Mbeya region in Tanzania.

Polyphenol-Rich Extracts and Essential Oil from Egyptian Grapefruit Peel as Potential Antioxidant, Antimicrobial, and Anti-Inflammatory Food Additives

Grapefruit (GF) processing generates significant nutrient and economic losses due to the production of 50% by-products, primarily peels. GF peels are a rich and sustainable source of bioactive compounds (BCs), such as essential oils (EOs) and phenolic compounds. Thus, finding value-added solutions based on a circular economy is paramount. This research aims to assess the antioxidant, anti-inflammatory, and antimicrobial properties of a hydroethanolic polyphenol-rich extract from crude GF peels (GF-CE), essential oil (GF-EO), and polyphenol-rich extract from GF peels after essential oil extraction (GF-PE). The GF-CE and GF-PE showed high concentrations of naringenin (7.71 and 48.60 mg/g dry extract (DE)), narirutin (15.03 and 28.73 mg/g DE), and hesperidin (0.67 and 0.29 mg/mL), respectively. Extracting firstly EOs from GF improved the release of phenolic acids (p-coumaric, ferulic, and chlorogenic acid). The GF-CE exhibited stronger free radical scavenging activity mainly in DPPH (IC50 = 75.69 ± 0.81 µg/mL) than GF-EO (1271 ± 0.85 µg/mL) and GF-PE (113.45 ± 0.85 µg/mL). The GF-EO demonstrated moderate antimicrobial activity against Gram-positive bacteria compared to the reference standard (amoxicillin) and strong activity against the yeast Candida albicans (inhibition zone of 16 mm). The major compounds in the GF-EO included D-limonene (25%), nootkatone (24%), and β-pinene (8%). Both polyphenol-rich extracts showed promising activities as COX1 and COX2 inhibitors with IC50 values of 25 ± 0.1 and 0.28 ± 0.00 µg/mL (compared to celecoxib (97.5 ± 0.1 and 0.31 ± 0.01 µg/mL) and indomethacin (6.25 ± 0.00 and 0.52 ± 0.01 µg/mL) as the standards), respectively. The study concludes that GF peels are a valuable source of BCs with significant bioactivities, offering a sustainable multi-cascade approach to recovering value-added compounds from GF peels in alignment with circular economy principles and open opportunities as functional ingredients for food applications.

Isolation of Geranyl Acetate and Chemical Analysis of the Essential Oil from Melaleuca armillaris (Sol. ex Gaertn.) Sm.

A method was developed for the isolation of geranyl acetate from the crude essential oil (EO) of Melaleuca armillaris (Sol. ex Gaertn.) Sm. leaves, and the purity of the isolated compound was analyzed by GC/MS spectral and NMR analysis and was found to have high purity (98.9%). In addition, the EO isolated presented 0.907 g/cm3, 1.474 and [α]D20=−17.6 of density, refraction index and optical rotation, respectively. The chemical composition of the EO obtained for steam distillation from M. armillaris was analyzed by gas chromatographic and spectroscopic techniques (GC/MS and GC/FID). Thirty-eight compounds were identified, representing 99.92% of the total EO analyzed on a DB-5 ms (5% phenylmethylpolysiloxane) capillary column. This analysis showed that the EO consisted mainly of oxygenated monoterpenes (77.01%), followed by monoterpene hydrocarbons (21.31%) and sesquiterpene hydrocarbons (1.31%). Furthermore, the essential oil of M. armillaris was rich in 1,8-cineol (67 ± 2%), followed by limonene (10 ± 1%), α-Terpineol (9 ± 1%) and α-Pinene (5 ± 1%). Finally, the results suggest that the geranyl acetate isolated with high purity from crude essential oil is recommended to be explored as a component in medicinal or industrial use.

Investigation of anti-nociceptive, anti-inflammatory potential and ADMET studies of pure compounds isolated from Isodon rugosus Wall. ex Benth.

The strong ethnopharmacological utilization of Isodon rugosus Wall. Ex. Benth is evident in the treatment of several types of pain and inflammation, including toothache, earache, abdominal pain, gastric pain, and generalized body pain and inflammation. Based on this background, the antinociceptive effects of the crude extract, various fractions, and essential oil have been reported previously. In this research work, we isolate and characterize pure bioactive compounds from I. rugosus and evaluate possible mechanisms using various in vivo and in vitro models. The pure compounds were analyzed for analgesic and anti-inflammatory activities through various assays. The column chromatography of the chloroform fraction of I. rugosus led to the identification of two pure compounds, i.e., 1 and 2. Compound 1 demonstrated notable inhibition (62% writhing inhibition, 72.77% COX-2 inhibition, and 76.97% 5-LOX inhibition) and anti-inflammatory potential (>50% paw edema inhibition at various intervals). The possible mechanism involved in antinociception was considered primarily, a concept that has already been elucidated through the application of naloxone (an antagonist of opioid receptors). The involvement of adrenergic receptors was investigated using a hot plate model (an adrenergic receptor antagonist). The strong ethnomedicinal analgesic background of I. rugosus, supported by previous reports and current observations, leads to the conclusion that I. rugosus is a potential source of antinociceptive and anti-inflammatory bioactive compounds. It may be concluded from the results that the isolated analgesic compounds of I. rugosus may be a possible alternative remedy for pain and inflammation management with admirable efficacy and safety profiles.

Enhancing the antimicrobial efficacy of common herbs and spices through an optimized polyherbal approach

Herbs and spices are used globally by most population groups across the world. In sub-Saharan Africa, they have medicinal significance in addition to their culinary uses. Although herbs and spices are often used in combination, there are few studies that report on their interactive antimicrobial effect. This study screened 17 culinary herbs and spices (crude extracts and essential oils) for antimicrobial activity, individually, followed by 1:1 combinations of the active extracts, to determine the outcome of combining these for antibacterial activity. The minimum inhibitory concentrations (MIC) were determined against six common foodborne pathogens using the broth microdilution assay. The design of experiments (DOE) approach was subsequently employed in MODDE 9.1® software, to optimise the experimental runs so as to identify the best interaction that would produce the best possible antimicrobial effect. Phytochemical profiling of the most active extracts was achieved using ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-MS) analysis. The results demonstrated that combining Rosmarinus officinalis with either Syzygium aromaticum, or Salvia officinalis methanol extracts produced synergistic antimicrobial effects towards B. cereus with ΣFIC = 0.25 mg/ml and 0.31 mg/ml, respectively. The DOE predicted that a combination of higher ratios of R. officinalis (59.5 %), higher ratios of S. officinalis (40 %), and lower ratios of S. aromaticum (0.5 %) would produce the best antimicrobial effect with MIC = 0.17 mg/ml. This was experimentally confirmed and there was a strong correlation (r-value 0.73) between the predicted and experimental MIC values, leading to the identification of an optimal antimicrobial combination. The combination of R. officinalis (56 %) and S. officinalis (44 %) produced the antimicrobial effect (MIC = 0.19 mg/ml) which can be recommended for future studies.

Bioactivity of Allium sativum essential oil-based nano-emulsion against Planococcus citri and its predator Cryptolaemus montrouzieri

Botanical extracts, in particular essential oils (EOs), could be the ideal candidates for the development of biopesticides as an alternative to synthetic pesticides. However, some limitations of EOs (high flammability, volatility, degradability, poor solubility in water) prevent their use under real operational conditions. Nanotechnologies are useful tools to overcome the above-mentioned limitations of these natural substances. Furthermore, encapsulation in nano-delivery systems (nanoparticles and nano-emulsions) can improve the functional properties of EOs. In this context, this study aimed to develop a highly stable, concentrated garlic nano-emulsion (15%) and to evaluate the acute toxicity with different exposure routes towards Planococcus citri and its predator Cryptolaemus montrouzieri. First, garlic EO was used to develop a nano-emulsion (15% EO; 5% Tween 80; 80% water) using a high-pressure microfluidizer; then both the crude EO and EO in nano-emulsion were chemically investigated by Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry (SPME-GC-MS) technique. The nano-emulsion was physically characterized by dynamic light scattering analysis over time (24 h, 3 months and 1 year after preparation) and used in bioassays involving both the target and non-target organisms. Results showed that the garlic EO consisted of over 95% sulphur compounds with diallyl disulphide as the most abundant component, and the developed nano-emulsion remained stable even after 1 year, with droplets’ dimension within the nanometric range (221.4 nm). The nano-formulation was effective against the target pest after 48 h from the treatment (Direct: LC90 = 0.967%; Indirect: LC90 = 1.088%), while it had no effect on C. montrouzieri. These promising results highlight the potential of garlic-based nano-emulsion as effective and environmentally friendly insecticide for pest control.

Synergistic and antagonistic medicinal activities of essential oil of Monodora myristica

Synergetic and antagonistic medicinal activities of crude and fractionated essential oil from the seed of Monodora myristica were investigated. The crude essential oil was extracted by steam distillation and then subjected to column chromatography; three fractions (N1, N2, and N3) were obtained. To identify the components, gas chromatography and mass spectrometry (GC-MS) investigation was utilized. The phytochemical parameters were determined by standard analytical methods. 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) were used to evaluate the antioxidative capacity. and, the anti-diabetic activity was performed using α-amylase and α-glucosidase assay. The Agar diffusion method was used to determine the antibacterial activities. The GC-MS analysis indicated p-cymene (21.12%) as the major component of the crude essential oil. The antioxidant activity using DPPH varied from 614 to 704 µg/mL, while the ABTS activity ranged between 281-342 µg/mL. The α-amylase assay showed fraction N1 with IC50 value of 3.21 µg/mL, while for α-glucosidase assay, fraction N2 with IC50 2.15 µg/mL recorded the least value. The minimum inhibitory concentration values for the crude extract and all the fractions against the strains of bacteria ranged from 6 to 12.5 mg/mL Both crude extract and fractionated essential oil showed antioxidant, anti-diabetic and antibacterial activities.

Comparing the sensitivity of aquatic organisms relative to Daphnia sp. toward essential oils and crude extracts: A meta-analysis

Interest on aromatic and medicinal plants (AMP)-based products, especially crude extracts (CE) and essential oils (EO), has increased over recent years due to their bioactive and biopesticide properties, though a variety of these compounds is environmentally damaging. Aquatic organisms can easily be exposed to the toxicological risks of AMP-based products, but research exploring existing ecotoxicity data to non-target organisms is limited. The present study aimed to, for the first time, systematically review published evidence on the acute/short-term toxicity (LC50, EC50 or IC50) of CE and EO from AMP, comparing sensitivity of aquatic organisms. Eleven studies that reported the sensitivity of aquatic taxa and Daphnia sp. to CE and/or EO, were included in the review, contributing with 27 effect sizes, calculated as the response ratio R (EcotoxicityAquatTaxa/EcotoxicityDaphnia). Meta-analytic technics were used to estimate the overall sensitivity of aquatic taxa relative to Daphnia sp. while identifying moderators [plant preparation (CE or EO), extraction type, plant part, plant family, and aquatic taxa identity] potentially affecting relative sensitivities. The overall effect size R was 1.51 (95 % CI = 0.97 to 2.34, N = 27), indicating a non-significant difference in the toxicity of CE and EO to aquatic taxa relative to Daphnia sp. However, the high heterogeneity among individual effect sizes (I2 = 99 %) suggested opposing responses of aquatic taxa relative to Daphnia sp. The magnitude of effects (R) was strongly influenced only by plant family. Daphnia sp. arose as a potential model organism for assessing the ecotoxicity of CE and EO, along with the fish Danio rerio and the crustacean Thamnocephalus platyurus, while Artemia sp. seems a relevant alternative for a preliminary screening. Likewise, the current study sheds light on the (underestimated) toxicity of CE and EO to aquatic ecosystems and that much remains to be uncovered, providing insights and recommendations for future research.

Flavonoid Content of Phaleria macrocarpa Fruit and Its Proximate Compositions

Flavonoids are one of the compounds in phenolic compounds in fruits. Flavonoids have been documented to modulate or modify lipid peroxidation, free radical scavenging activity, and inhibition of hydrolytic and oxidative enzymes. Flavonoids also influence anti-inflammatory action, anti-tumour, anti-hyperglycemia, anti-viral, anti-microbial, and anti-fungal effects. In this research, flavonoid content in P. macrocarpa fruits was determined, as well as its proximate compositions. To extract flavonoids in the fruit, P. macrocarpa fruits were extracted by the Soxhlet extraction method using aqueous as a solvent. Total flavonoid content in P. macrocarpa fruit extract was 89.89 ± 3.71 mg QE/100 mL. Proximate analyses were conducted to determine the fruit’s moisture content, ash content, dry matter, crude protein, crude fibre, and crude essential oil. Results obtained for proximate composition were 9.45 ± 2.67% (crude protein), 21.633 ± 1.17 (fibre), and 5.605 ± 0.88 (essential oil). Moisture content in this fruit was 88.401 ± 0.749%, the dry matter was 10.96%, and the ash content was 6.33 ± 3.72%. FTIR analysis shows the extract’s functional spectra of phenol, alkane, alkene, and alkyne groups.

Chemical composition and antibacterial activity of essential oil of Pelargonium graveolens and its fractions

This work aims to study the chemical composition and evaluate the antibacterial activity of Pelargonium graveolens essential oil and its fractions collected in the Er-Rachidia region of Morocco. GC-MS analysis of Pelargonium graveolens essential oil and its fractions yielded majority compounds such as; epi-γ-Eudesmol (16.67 %), Geraniol (12.54 %), β-Citronellol (12, 34 %), Citronellyl formate (7.70 %) and Geranyl tiglate (5.21 %), for the crude essential oil of Pelargonium graveolons, while the fractions that is obtained by preparative plate chromatography gave the following compounds, fraction 1 consists mainly of β-Citronellol (35. 83 %) Geraniol (38.78 %), fraction 2 is dominated by epi-γ-Eudesmol (55. 10 %) and α-agorofuran (8.41 %)), as well as fraction 3 is revealed the presence of Geranylgeraniol (23.70 %) and epi-γ-Eudesmol (17.53 %) and Phenylethyl tiglate (12.01 %), fraction 4 consists mainly of Phenylethyl tiglate (58.19 %) and α-agorofuran (8.49 %), then the fraction 5 is represented by the compound majorities such as Geranyl tiglate (30.75 %) and Geranyl butanoate (10.94 %), while the fraction 6 is characterized mainly by 1-Isopropyl-4,7-dimethyl-1,2,3,5,6,8a-hexahydronaphthalene (12.08 %). Concerning the antibacterial activity of the essential oil and its fractions 1, 2, 3, and 4 showed bactericidal power against all tested bacteria: Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium, also fractions 5 and 6 have bactericidal power against Escherichia coli, Salmonella typhimurium and no power against Staphylococcus aureus and Listeria monocytogenes.

Antimicrobial activity of essential oils of Curcuma longa and Syzygium aromaticum against multiple drug-resistant pathogenic bacteria.

The present study was conducted to investigate the antimicrobial potential of essential oils of Curcuma longa and Syzygium aromaticum against multidrug-resistant pathogenic bacteria. Four identified bacterial isolates including Methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii were selected and their antibiotic sensitivity was checked by disc diffusion assay. C. longa and S. aromaticum were subjected to steam distillation to obtain their essential oils. The crude essential oils were fractioned by employing column chromatography. Crude essential oils and their fractions were evaluated for their antibacterial activity by agar well diffusion assay and minimum inhibitory concentrations were calculated. All the selected bacterial isolates showed resistance to three or more than three antibiotic groups and were declared as multidrugresistant (MDRs). Crude essential oils of C. longa and S. aromaticum exhibited antimicrobial activity against all selected isolates but S. aromaticum activity was better than the C. longa with a maximum 19.3±1.50 mm zone of inhibition against A. baumannii at 1.04 µL/mL MIC. GC/MS analysis revealed the abundance of components including eugenol, eugenyl acetate, b- caryophyllene, and a- Humulene in both crude oil and fractions of S. aromaticum. While the main components of C. longa essential oil were Ar-tumerone, a-tumerone, b- Tumerone, I-Phellandrene, a-zingibirene, b- sesquiphellandrene, and p- Cymene. This study highlights that plant-based essential oils could be a promising alternative to antibiotics for which pathogens have developed resistance. C. longa and S. aromaticum carry compounds that have antimicrobial potential against multiple drug-resistant bacteria including MRSA. E. coli, K. pneumoniae and A. baumannii.

The effect of garlic extract and volatile oil on growth of Trichophyton mentagrophytes

This study was conducted in the College of Medicine- laboratory of microbiology to assess the effect of crude garlic extract and essential volatile oil on growth of Trichophyton mentagrophytes. Antidermatophytic activity of different concentrations of volatile oil, aqueous extract of garlic were investigated in vitro against T. mentagrophytes by using agar dilution technique. The results showed that minimal inhibitory concentration (MIC) of aqueous garlic extract (crude) was 0.5 mg/ ml, while the MIC of essential oil was 0.25 mg/ml

Evaluation of the Antioxidant Properties of Carvacrol as a Prospective Replacement for Crude Essential Oils and Synthetic Antioxidants in Food Storage.

The phenolic structural analogues of synthetic antioxidants such as butylated hydroxytoluene (BHT) in essential oils have been reported to exhibit antioxidant properties. Additionally, their lipophilicity makes them suitable for use in lipid-rich foods. This study evaluated the antioxidant capacity of carvacrol, a monoterpenoid antioxidant compound in the Monodora myristica (Gaertn.) seed essential oil, compared to the seed essential oil and BHT. In vitro studies (ferric reducing antioxidant power (FRAP), metal chelating activity (MCA), and nitric oxide scavenging activity (NOSA)) were conducted to ascertain if the antioxidant capacity of carvacrol was comparable to that of the seed essential oil. The potential binding affinity and molecular interactions between carvacrol and lipoxygenase (LOX) and its homologous model were investigated in silico. The molecular docking was performed using Autodock Vina, and the best poses were subjected to molecular dynamics simulation. The IC50 for MCA and NOSA were: carvacrol 50.29 µL/mL, seed essential oil (SEO) 71.06 µL/mL; and carvacrol 127.61 µL/mL, SEO 165.18 µL/mL, respectively. The LOX model was Ramachandran favoured (97.75%) and the overall quality factor in the ERRAT plot was 95.392. The results of the molecular docking and molecular dynamics simulations revealed that lipoxygenase has a higher affinity (-22.79 kcal/mol) for carvacrol compared to BHT. In the LOX-BHT and LOX-carvacrol complexes, the root-mean-square deviation (RMSD), root-mean-square fluctuation (RMSF), and the radius of gyration (RoG) were not significantly different, indicating similar molecular interactions. The results obtained from this study suggest that carvacrol exhibits an antioxidant capacity that may be explored as an alternative for crude essential oils and synthetic compounds during the storage of lipid-rich foods.

Anti-microbial effect of Piper betle crude extract and essential oil incorporated into short-term soft lining material

Anti-microbial effect of Piper betle crude extract and essential oil incorporated into short-term soft lining material