Investigation of physicochemical and biological properties of bacterial cellulose & zein-reinforced edible nanocomposites based on flaxseed mucilage containing Origanum vulgare L. essential oil.

In the present study, the effect of zein and different amounts of bacterial cellulose (BC; 1, 2 and 3 wt%) on the physical, mechanical and barrier properties of flaxseed mucilage/carboxymethyl cellulose (FM/CMC) composite was investigated. The appearance of the absorption band at 1320cm-1 in the ATR-FTIR spectra of nanocomposites indicated the successful introduction of zein into their structure. The characteristic peak at 2θ of 9° belonging to zein disappeared in XRD patterns of the prepared composites suggesting the successful coating of zein via hydrogen bonding interactions. SEM images proved the formation of semi-spherical zein microparticles in the FM/CMC matrix. TGA plots ascertained the addition of zein and nanocellulose caused a significant increase in the thermal stability of FM/CMC film, although zein showed a greater effect. The presence of zein and nanocellulose increased the mechanical strength of nanocomposites. The WVP of FM/CMC decreased after the incorporation of zein and nanocellulose, which created a tortuous path for the diffusion of water molecules. The zein particles exhibited a greater influence on improving the mechanical and barrier properties compared to nanocellulose. FM/CMC-Z film exhibited the highest mechanical strength (49.07 ± 5.89 MPa) and the lowest WVP (1.179 ± 0.076). The composites containing oregano essential oil (EO) showed higher than 60 % antibacterial properties. The bactericidal efficiency of FM/CMC/Z-EO and FM/CMC/Z-EO/BC1 nanocomposites decreased about 10% compared to FM/CMC/EO and FM/CMC-Z/BC1. This evidenced the successful encapsulation of EO molecules in zein particles. According to the in vitro release study, entrapment of EO into zein particles could delay the release and provide the extended antimicrobial effect.

Process optimisation for green synthesis of zero-valent iron nanoparticles using Mentha piperita.

The potential of Mentha piperita in the iron nanoparticles (FeNPs) production was evaluated for the first time. The influences of the variables such as incubation time, temperature, and volume ratio of the extract to metal ions on the nanoparticle size were investigated using central composite design. The appearance of SPR bands at 284 nm in UV-Vis spectra of the mixtures verified the nanoparticle formation. Incubating the aqueous extract and metal precursor with 1.5 volume ratio at 50°C for 30 min leads to the formation of the smallest nanoparticles with the narrowest size distribution. At the optimal condition, the nanoparticles were found to be within the range of 35-50 nm. Experimental measurements of the average nanoparticle size were fitted well to the polynomial model satisfactory with R2 of 0.9078. Among all model terms, the linear term of temperature, the quadratic terms of temperature, and mixing volume ratio have the significant effects on the nanoparticle average size. FeNPs produced at the optimal condition were characterised by transmission electron microscopy, thermogravimetry analysis (TGA), and Fourier-transform infrared spectroscopy. The observed weight loss in the TGA curve confirms the encapsulation of FeNPs by the biomolecules of the extract which were dissociated by heat.

Analysis and evaluation of the antimicrobial and anticancer activities of the essential oil isolated from Foeniculum vulgare from Hamedan, Iran.

In this study, biological properties of the essential oil isolated from seeds of Foeniculum vulgare (F. vulgare) were evaluated. GC-MS analysis revealed Trans-Anethole (80.63%), L-Fenchone (11.57%), Estragole (3.67%) and Limonene (2.68%) were the major compounds of the essential oil. Antibacterial activity of the essential oil against nine Gram-positive and Gram-negative strains was studied using disc diffusion and micro-well dilution assays. Essential oil exhibited the antibacterial activity against three Gram-negative strains of Pseudomonas aeruginosa, Escherichia coli, and Shigella dysenteriae. The preliminary study on toxicity of seed oil was performed using Brine Shrimp lethality test (BSLT). Results indicated the high toxicity effect of essential oil (LC50 = 10 µg/mL). In vitro anticancer activity of seed oil was investigated against human breast cancer (MDA-Mb) and cervical epithelioid carcinoma (Hela) cell lines by MTT assay. Results showed the seed oil behave as a very potent anticancer agent with IC50 of lower than 10 µg/mL in both cases.

Composition of the oily compounds, phytochemical screening and biological activity of different aerial parts of Smirnovia turkestana Bunge.

In the present study, chemical composition of the oily compounds isolated from different parts of Smirnovia turkestana (Kashan, central Iran) using n-hexane was determined for the first time. GC-MS analysis revealed that dodecanoic acid, trans-ß-ionone and methyl palmitate are the major components of leaves extract. Trans-ß-ionone and hexadodecanoic acid were also, identified as the major compounds of flowers extract. Heptacosane, trans-ß-ionone and vitamin E acetate were the main components of fruits. Phytochemical screening of the methanol extract proved the presence of alkaloids, anthraquinones, flavonoids and anthocyanin in the leaves, flowers and fruits of S. turkestana, while tannins were present only in its fruits. Evaluation of the biological activities showed that different aerial parts of S. turkestana have high antioxidant activities; antimicrobial activities were also considerable against some selected bacteria.

Evaluation of the catalytic, antibacterial and anti-biofilm activities of the Convolvulus arvensis extract functionalized silver nanoparticles.

In this study, a rapid green synthesis of the silver nanoparticles (AgNPs) using leaves extract of Convolvulus arvensis was investigated. UV-Visible spectra showed the SPR band at around 430nm which proved the AgNP formation. The reduction of silver ions to nanoparticles was completed within 150min. Particle size analysis verified the formation of AgNPs with average size of 28nm, while their PDI was 0.2. XRD patterns verified the crystalline nature of produced AgNPs. SEM images verified the presence of spherical nanoparticles with no evidence of aggregations. FTIR analysis verified the involvement of the phenolic compounds in AgNP formation. It was found that the biosynthesized AgNPs have the antibacterial activity against human pathogen E. coli. Also, nanoparticles exhibit biofilm degrading activity against both bacterial strains of S. aureus and P. aeruginosa. Furthermore, the synthesized AgNPs prevented the coagulation of blood samples. The accelerated reduction of methylene blue (MB) in the presence of AgNPs with rate constant of 0.108min-1, confirmed the catalytic potential of nanoparticles.