Highly simple, sensitive and selective method is developed for the spectrophotometric determination of Metronidazole (MDZ) antibacterial drug either in pure form or in pharmaceutical formulations. This method is based on reduction of potassium permanganate by Metronidazole drug in sodium hydroxide solution to give green manganate ion which recorded at 610 nm. The method produced linear responses in the concentration range 4.28 – 59.91 µg mL−1 with limit of detection (LOD) and limit of quantification (LOQ) 0.21 and 0.69 µg mL−1 for Metronidazole drug respectively. The apparent molar absorptivity is 0.865 × 104 L mol−1 cm−1, Sandell sensitivity is 0.019 µg cm−2 and correlation coefficient is 0.951. The method is highly reproducible and has been applied to a wide variety of pharmaceutical formulations and the results compare favourably with those of official methods.
5-Acetyl-3-cyano-6-methyl-4-(2-phenylethenyl)pyridine-2(1H)-thione (2) was synthesized by interaction of cinnamylidene-2-cyanothioacetamide 1 and acetylacetone or via one-pot reaction of E-cinnamaldehyde, 2-cyanothioacetamide, and acetylacetone. Reaction of 2 with ethyl iodide (3a) or N-chloroacetyl derivative of aromatic amines 3b–e in boiling ethanol containing sodium ethoxide gave the corresponding thioether 4a and 5-acetyl-3-amino-2-(N-arylcarbamoyl)-6-methyl-4-(2-phenylethenyl)thieno[2,3-b]pyridines 5b–e, respectively. Compound 5e was reacted with 2,5-dimethoxytetrahydrofuran or triethyl orthoformate to furnish pyrrolylthienopyyridine 6 or pyrdiothienopyrimidinone 7, respectively. The photophysical properties of 5b, 5c, 5e, and 7 were fully studied and the obtained results included herein. The fluorescence data confirmed that compounds 5b, 5c, 5e, and 7 exhibit aggregation-induced emission behavior with high absolute quantum yields.
The endophytic fungus Paecilomyces sp. (AUMC 15510) was isolated from healthy stem samples of the
Egyptian medicinal plant Cornulaca monacantha. We used GC–MS and HPLC analysis to identify the
bioactive constituents of ethyl acetate crude extract of Paecilomyces sp. (PsEAE). Six human microbial
pathogens have been selected to evaluate the antimicrobial activity of PsEAE. Our data showed
that the extract has significant antimicrobial activity against all tested pathogens. However, the
best inhibitory effect was observed against Bacillus subtilis ATCC 6633 and Pseudomonas aeruginosa
ATCC 90274 with a minimum inhibitory concentration (MIC) of 3.9 μg/ml and minimum bactericidal
concentration (MBC) of 15.6 μg/ml, for both pathogens. Also, PsEAE exerts a significant inhibition on
the biofilm formation of the previously mentioned pathogenic strains. In addition, we evaluated the
wound healing efficiency of PsEAE on earthworms (Lumbricus castaneus) as a feasible and plausible
model that mimics human skin. Interestingly, PsEAE exhibited a promising wound healing activity and
enhanced wound closure. In conclusion, Paecilomyces sp. (AUMC 15510) could be a sustainable source
of antimicrobial agents and a potential therapeutic target for wound management.
Explicit expressions for single moments, recurrence relations for single and product 1
moments of order statistics of the omega distribution are derived. The L-moments are also obtained. 2
We also consider different methods for estimating the model parameters, namely: maximum 3
likelihood, maximum product of spacings, ordinary least-squares and weighted least-squares, 4
percentiles, Anderson–Darling and right–tail Anderson–Darling. For different parameter settings and 5
sample sizes, various simulation results are performed to compare the performance of the proposed 6
estimators. Further, the method of maximum likelihood is adopted to estimate the omega parameters 7
under type-II censoring scheme. The flexibility of the omega distribution is proved by means of a real 8
data set.
Collagen integrity should be considered on using a sterilizing agent for fish skin grafts. This study
defined the optimal concentration of silver nanoparticles (Ag NPs) for sterilization of fish skin
grafts without disrupting collagen content based on microbiological and histological evaluation.
Strips of tilapia skin (n = 5) were randomly allocated to be immersed in Ag NPs solution at different
concentrations of 25, 50, 100, and 250 μg/mL, respectively, for 5 min. The treated skin strips
underwent bacteriological and histological evaluation. Yeast and fungi were more sensitive to Ag NPs
than bacteria. On increasing the nanoparticles concentration, the total counts of aerobic bacteria
decrease giving 933.3 ± 28.67, 601 ± 27.66, 288 ± 16.8, 15 ± 4.08 (CFU/cm2 ± S.D) at 25, 50, 100, and
250 μg/mL, respectively, comparing with untreated sample (1453.3 ± 57.92). Yeasts and filamentous
fungi also exhibited a similar response, achieving a complete inhibition at 100 and 250 μg/mL. Bacillus
cereus and Escherichia coli were the dominant aerobic bacteria, Candida albicans and Rhodotorula
glutinis were the dominant aerobic yeasts, whereas Aspergillus niger, Aspergillus fumigatus, and
Rhizopus stolonifer were the dominant aerobic fungi. The collagen fibers were loose with a wavey
pattern at 25 μg/mL, wavey and slightly disorganized at 50 μg/mL, highly disorganized at 100 μg/
mL, and compactly arranged and slightly loose at 250 μg/mL. Ag NPs at a concentration of 250 μg/
mL could be considered a reliable and feasible method for the sterilization of fish skin grafts before
application on human skin with an effective antimicrobial effect and less disrupting impact on collagen
content.