scholarly journals Functional Properties of Antimicrobial Neem Leaves Extract Based Macroalgae Biofilms for Potential Use as Active Dry Packaging Applications

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1664
Author(s):  
A. A. Oyekanmi ◽  
U. Seeta Uthaya Kumar ◽  
Abdul Khalil H. P. S. ◽  
N. G. Olaiya ◽  
A. A. Amirul ◽  
...  
Keyword(s):  
Composite Film ◽  
Functional Properties ◽  
Storage Stability ◽  
Storage Period ◽  
Antimicrobial Activities ◽  
Gas Chromatography Mass Spectrometry ◽  
Ambient Conditions ◽  
Neem Extract ◽  
Control Film ◽  
Neem Leaves

Antimicrobial irradiated seaweed–neem biocomposite films were synthesized in this study. The storage functional properties of the films were investigated. Characterization of the prepared films was conducted using SEM, FT-IR, contact angle, and antimicrobial test. The macroscopic and microscopic including the analysis of the functional group and the gas chromatography-mass spectrometry test revealed the main active constituents present in the neem extract, which was used an essential component of the fabricated films. Neem leaves’ extracts with 5% w/w concentration were incorporated into the matrix of seaweed biopolymer and the seaweed–neem bio-composite film were irradiated with different dosages of gamma radiation (0.5, 1, 1.5, and 2 kGy). The tensile, thermal, and the antimicrobial properties of the films were studied. The results revealed that the irradiated films exhibited improved functional properties compared to the control film at 1.5 kGy radiation dosage. The tensile strength, tensile modulus, and toughness exhibited by the films increased, while the elongation of the irradiated bio-composite film decreased compared to the control film. The morphology of the irradiated films demonstrated a smoother surface compared to the control and provided surface intermolecular interaction of the neem–seaweed matrix. The film indicated an optimum storage stability under ambient conditions and demonstrated no significant changes in the visual appearance. However, an increase in the moisture content was exhibited by the film, and the hydrophobic properties was retained until nine months of the storage period. The study of the films antimicrobial activities against Staphylococcus aureus (SA), and Bacillus subtilis (BS) indicated improved resistance to bacterial activities after the incorporation of neem leaves extract and gamma irradiation. The fabricated irradiated seaweed–neem bio-composite film could be used as an excellent sustainable packaging material due to its effective storage stability.

scholarly journals Extracted Compounds from Neem Leaves as Antimicrobial Agent on the Physico-Chemical Properties of Seaweed-Based Biopolymer Films

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1119 ◽  
Author(s):  
U. Seeta Uthaya Kumar ◽  
S. N. Abdulmadjid ◽  
N. G. Olaiya ◽  
A. A. Amirul ◽  
S. Rizal ◽  
...  
Keyword(s):  
Gamma Irradiation ◽  
Water Solubility ◽  
Composite Films ◽  
Chemical Properties ◽  
Antimicrobial Activities ◽  
Vapour Permeability ◽  
Control Film ◽  
Biocomposite Films ◽  
Neem Leaves ◽  
The Matrix

Neem leaves extract was incorporated into the matrix of seaweed biopolymer, and the seaweed-neem biocomposite films were irradiated with various doses of gamma irradiation (0.5, 1.5, 2.5, 3.5, and 4.5 kGy). The physical, barrier, antimicrobial, and mechanical properties of the films were studied. The incorporation of 5% w/w neem leaves extract into a seaweed-based film, and gamma irradiation dose of 2.5 kGy was most effective for improved properties of the film. The results showed that the interfacial interaction of the seaweed-neem improved with physical changes in colour and opacity. The water solubility, moisture content, and water vapour permeability and biodegradability rate of the film reduced. The contact angle values increased, which was interpreted as improved hydrophobicity. The tensile strength and modulus of the films increased, while the elongation of the composite films decreased compared to the control film. The film’s antimicrobial activities against bacteria were improved. Thus, neem leaves extract in combination with the application of gamma irradiation enhanced the performance properties of the film that has potential as packaging material.

scholarly journals Antimicrobial Activity and Chemical Characterization of a Non-Polar Extract of Saffron Stamens in Food Matrix

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 703
Author(s):  
Severino Zara ◽  
Giacomo L. Petretto ◽  
Alberto Mannu ◽  
Giacomo Zara ◽  
Marilena Budroni ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Fatty Acid Content ◽  
Chemical Characterization ◽  
Antimicrobial Activities ◽  
Added Value ◽  
Gas Chromatography Mass Spectrometry ◽  
Food Matrix ◽  
Bacterial Strains ◽  
By Products

The production of saffron spice generates large quantities of plant by-products: over 90% of the plant material collected is discarded, and a consideration fraction of this waste is plant stamens. This work investigated the chemical composition and the antimicrobial activities of the non-polar fraction extracted from four different saffron flower stamens. The chemical composition of ethereal extracts of the saffron stamens was qualitatively assessed by means of gas–chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) analyses. These analyses revealed ethereal extracts to possess a high polyunsaturated fatty acid content. In vitro antibacterial activity of stamen extracts showed no large differences between Gram-positive and Gram-negative bacteria in terms of minimal inhibitory concentration (MIC). In food matrix microbial analysis of the bacterial strains belonging to the main foodborne pathogen species, including Staphylococcus aureus DSM 20231, Escherichia coli DSM 30083, and Listeria monocytogenes DSM 20600, using low-fat UHT milk, revealed a statistically significant reduction in the number of cells (particularly for E. coli and S. aureus with a complete elimination of the population of the two target bacteria following incubation in diethyl ether extracts of saffron stamen (DES) at high concentrations tested, both at 37 °C and 6 °C (for 48 h and 7 days, respectively). A synergic effect was observed when the pathogens were incubated at 6 °C with DES. This work shows these by-products to be excellent sources of bioactive compounds, which could be exploited in high-added-value products, such as food, cosmetics, and drugs.

scholarly journals Chemical Composition and Antimicrobial Activities of the Essential Oil From the Leaves of Pterocephalus hookeri

2020 ◽  
Vol 15 (12) ◽  
pp. 1934578X2098123
Author(s):  
Peng-fei Yang ◽  
Hui Lu ◽  
Qiong-bo Wang ◽  
Zhi-wei Zhao ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Chemical Composition ◽  
Essential Oil ◽  
Chemical Constituents ◽  
Antimicrobial Activities ◽  
Gas Chromatography Mass Spectrometry ◽  
Flame Ionization ◽  
And Staphylococcus Aureus ◽  
Antimicrobial Assay ◽  
Detailed Chemical

Detailed chemical constituents of essential oil from the Pterocephalus hookeri leaves and its antimicrobial activities were investigated in this study. The essential oil, obtained by hydrodistillation, was characterized by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry analyses. Among the 90 identified compounds, hexadecanoic acid (21.27%), phytol (8.03%), furfural (7.08%), oleic acid (5.25%), and phytone (4.56%) were the major components. In the antimicrobial assay, the essential oil showed strong inhibitory activities against Escherichia coli, Candida albicans, and Staphylococcus aureus with minimum inhibitory concentration values of 31.3, 62.5, and 125 µg/mL, respectively. To our knowledge, this is the first report concerning chemical composition and antimicrobial activities of the essential oil from Pterocephalus hookeri.

scholarly journals Composition and biological assays of the leaf essential oil of Asparagus flagellaris (Kunth) Bak

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Oluwakayode O. Odeja ◽  
Michael Gabriel Ibok ◽  
Ejike O. Okpala
Keyword(s):  
Free Radical ◽  
Essential Oil ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Salmonella Typhi ◽  
Antimicrobial Activities ◽  
Free Radical Scavenging ◽  
Gas Chromatography Mass Spectrometry ◽  
Klebsiella Pneumonia ◽  
Leaf Essential Oil

Abstract Background Asparagus flagellaris leaves are ethnomedicinally used to treat syphilis, gonorrhea and other sexually transmitted diseases (STDs), with no reports on the volatile constituents. This study was aimed to quantitatively and qualitatively characterise the composition of essential oil, evaluates the free radical scavenging and antimicrobial capacity of the essential oil. Methods The essential oil was isolated by hydrodistillation method using all-glass Clevenger-type apparatus, while the identification and quantification of constituents were performed by gas chromatography-mass spectrometry (GC-MS) technique. The antioxidant activity on 2, 2-diphenyl-1-picrylhydrazyl (DPPH) was evaluated and the oil was also tested against 10 strains of microorganisms consisting of 6 bacteria: Escherichia coli, Salmonella typhi, Klebsiella pneumonia, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis and 4 fungi: Candida albicans, Penicillium notatum, Aspergillus niger and Rhizopus spp. using broth dilution and surface plate methods, respectively. Results A pale yellow essential oil with a characteristic scent was obtained, with a yield of 0.80% (w/w). A total of 28 compounds accounting for 97.41% of the total oil contents were identified. The oil was predominated by Thymol and its derivatives, accounting for 57.48%. The most abundance (% area) constituents of the essential oil were 5-Thymyl tiglate (18.49%), Thymyl-2-methyl butyrate (17.34%), Thymol hydroquinone dimethyl ether (10.52%), Thymol methyl ether (9.42%) and 5-Propyl-1, 3-benzodioxole (4.59%). The essential oil showed a significant free radical scavenging activity compared to the standard antioxidant drugs used in this study, with % inhibition varying from 88.06 ± 0.0001 to 93.05 ± 0.0006. The leaf essential oil exhibited antimicrobial activity on all the tested organisms at 500–125 μg/mL, with an 18–10 mm inhibitory zone. Conclusion The leaf essential oil of A. flagellaris contains notable chemical compounds responsible for its antioxidant and antimicrobial activities.

scholarly journals Photorhabdus sp. ETL Antimicrobial Properties and Characterization of Its Secondary Metabolites by Gas Chromatography–Mass Spectrometry

Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 787
Author(s):  
Tshikala Eddie Lulamba ◽  
Ezekiel Green ◽  
Mahloro Hope Serepa-Dlamini
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Secondary Metabolites ◽  
Pathogenic Bacteria ◽  
Insect Pests ◽  
Antimicrobial Properties ◽  
Antimicrobial Activities ◽  
Gas Chromatography Mass Spectrometry ◽  
Toxigenic Fungi ◽  
Properties And Characterization

Entomopathogenic nematodes (EPNs) are known to be highly pathogenic to insect pests, due to their associated symbiotic bacteria, which produce virulence factors, exo-enzymes and other harmful secondary metabolites to conquer, kill, and degrade their insect hosts. However, these properties are not fully characterized. This study reports on the antimicrobial activities of Photorhabdus sp. strain ETL, symbiotically associated to an insect pathogenic nematode, Heterorhabditis zealandica, against human pathogenic bacteria and toxigenic fungi, as well as the non-targeted profiling of its secondary metabolites (SMs) using gas chromatography coupled to high-resolution time-of-flight mass spectrometry. Fatty acids including 3-eicosene, (E)-; 5-eicosene, (E)-; eicosene; 9-octadecenamide; undecanoic acid with shown antimicrobial activities were detected. This provided more insight on the composition and bioactivities of SMs produced by the Photorhabdus sp.

scholarly journals Chemical Composition and Antioxidant and Antimicrobial Activities of Wormwood (Artemisia absinthiumL.) Essential Oils and Phenolics

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Kamel Msaada ◽  
Nidhal Salem ◽  
Olfa Bachrouch ◽  
Slim Bousselmi ◽  
Sonia Tammar ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Essential Oil ◽  
Essential Oils ◽  
Methanolic Extract ◽  
Biological Activities ◽  
Reducing Power ◽  
Antimicrobial Activities ◽  
Gas Chromatography Mass Spectrometry ◽  
Oil Composition ◽  
Antioxidant And Antimicrobial Activities

The aim of this study was to determine the chemical variability of wormwood extracts as affected by the growing region. Antioxidant and antimicrobial activities were also investigated. The essential oil composition variability ofA. absinthiumL. aerial parts collected from four different Tunisian regions was assessed by gas chromatography (GC/FID) and by gas chromatography mass spectrometry (GC/MS). In addition, total polyphenols, flavonoids, and condensed tannins as well as antioxidant, antibacterial, and antifungal activities of methanolic extract and essential oils were undertaken. Chromatographic analysis of wormwood essential oils showed the predominance of monoterpene hydrocarbons represented mainly by chamazulene. RP-HPLC analysis of wormwood methanolic extract revealed the predominance of phenolic acids. Antiradical activity was region-dependant and the methanolic extract of Bou Salem region has the strongest activity (CI50=9.38±0.82 µg/mL). Concerning the reducing power, the methanolic extract of Bou Salem, Jérissa, and Boukornine regions was more active than the positive control. Obtained results of antimicrobial activities showed that wormwood essential oil is endowed with important antibacterial activity which was strongly related to the organoleptic quality of oil which appeared strongly region-dependant.A. absinthiumL. EOs investigated are quite interesting from a pharmaceutical standpoint because of their biological activities.

scholarly journals Ambient measurements of aromatic and oxidized VOCs by PTR-MS and GC-MS: intercomparison between four instruments in a boreal forest in Finland

2015 ◽  
Vol 8 (4) ◽  
pp. 3753-3802 ◽  
Author(s):  
M. K. Kajos ◽  
P. Rantala ◽  
M. Hill ◽  
H. Hellén ◽  
J. Aalto ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Boreal Forest ◽  
Proton Transfer Reaction ◽  
Systematic Difference ◽  
Gas Chromatography Mass Spectrometry ◽  
Forest Site ◽  
Ambient Conditions ◽  
Mixing Ratios ◽  
R Value ◽  
Ambient Measurements

Abstract. Proton transfer reaction mass spectrometry (PTR-MS) and gas chromatography mass spectrometry GC-MS) allow real-time measurements of various atmospheric volatile organic compounds (VOC). By taking parallel measurements in ambient conditions, two PTR-MSs and two GC-MSs were studied for their ability to measure methanol, acetaldehyde, acetone, benzene and toluene. The measurements were conducted at a rural boreal forest site in southern Finland between 13 April and 14 May 2012. This paper presents correlations and possible biases between the concentrations measured using the four instruments. This paper presents correlations and possible biases between the concentrations measured using the four instruments. A very good correlation was found for benzene and acetone measurements between all instruments (the mean R value was 0.88 for both compounds), while for acetaldehyde and toluene the correlation was weaker (with a mean R value of 0.50 and 0.62, respectively). For some compounds, notably for methane, there were considerable systematic differences in the mixing ratios measured by the different instruments, despite the very good correlation between the instruments (mean R = 0.90). The systematic difference arises as a difference in the linear regression slope between measurements conducted between instruments, rather than as an offset. This mismatch indicates that the systematic uncertainty in the sensitivity of a given instrument can lead to an uncertainty of 50–100% in the methanol emissions measured by commonly used methods.

scholarly journals Volatile Compounds and Antioxidant and Antimicrobial Activities of Selected Citrus Essential Oils Originated from Nepal

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6683
Author(s):  
Devi Prasad Bhandari ◽  
Darbin Kumar Poudel ◽  
Prabodh Satyal ◽  
Karan Khadayat ◽  
Sital Dhami ◽  
...  
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Citrus Sinensis ◽  
Antioxidant Properties ◽  
Antimicrobial Activities ◽  
Gas Chromatography Mass Spectrometry ◽  
Diffusion Method ◽  
Citrus Species ◽  
Citrus Peel ◽  
Antioxidant And Antimicrobial Activities

Citrus species of plants are among the most commercially cultivated crops, mainly for their fruit. Besides, the generally consumed flesh inside the fruit, the peel is quite important too. Essential oils extracted from the peel have a history of being used by humankind for centuries. These essential oils are rich in antioxidants and antimicrobial agents. Comparative investigation of volatile constituents, and antioxidant and antimicrobial activities were undertaken. The essential oils were evaluated through gas chromatography-mass spectrometry (GC–MS), and enantiomeric composition by chiral GC–MS. Similarly, the antioxidant properties were evaluated by 2,2-diphenyl-1-picrylhydrazyl scavenging assay, and antimicrobial activities were assayed using the disk diffusion method. The highest extraction yield of 1.83% was observed in Citrus sinensis Osbeck. GC–MS analysis showed limonene (63.76–89.15%), γ-terpinene (0.24–6.43%), β-pinene (0.15–6.09%), linalool (0.35–3.5%), sabinene (0.77–2.17%), myrcene (0.74–1.75%), α-terpineol (0.28–1.15%), and α-pinene (0.2–0.58%) as the major constituents of the essential oil of the Citrus species studied. For the first time, through our study, chiral terpenoids have been observed from Citrus grandis Osbeck essential oil. The order of antioxidant activity is as follows: Citrus grandis Osbeck red flesh > Citrus reticulata Blanco > Citrus sinensis Osbeck > Citrus grandis Osbeck white flesh. Except for Citrus grandis Osbeck white flesh (52.34 µL/mL), all samples demonstrated stronger antioxidant activities than those of the positive control, quercetin (5.60 µL/mL). Therefore, these essential oils can be used as a safe natural antioxidant to prevent product oxidation. Likewise, citrus peel essential oil showed antimicrobial activity against tested bacterial strains, albeit marginal.

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