Biochemical Profiling and Physicochemical and Biological Valorization of Iraqi Honey: A Comprehensive Analysis

Our study aimed to analyze five monovarietal honeys from the Salah Eddine region in Iraq, focusing on physicochemical, antioxidant, and antimicrobial properties and polyphenolic compounds. Our objective was to evaluate the strengths and qualities of Iraqi honeys, ensuring compliance with the Codex Alimentarius standard for honey. The spectrophotometric analysis included assessments of reduced sugar (75.8-77.7%), fructose-to-glucose ratio (0.7-0.9%), sucrose (2.2-2.9%), HMF (17.23-18.87 mg/kg), and melanoidin content (0.25-0.44), which were all determined. The electrical conductivity (0.39-0.46 mS/cm) using a conductivity meter, pH (4.02-4.31), and mineral composition were determined in all samples using atomic absorption spectrometry. Antioxidant activities were spectrophotometrically determined, through DPPH free radical scavenging (7.87-95.62 mg/mL), as was the total antioxidant activity (14.26-22.15 mg AAE/g), with correlations established with biochemical constituents such as the total phenol content, highlighting the significant presence of Coumaric acid (0.38-2.34 µg/mL), Catechin (1.80-2.68 µg/mL), and Quercetin (0.30 µg/mL) using HPLC. The study also observed notable antimicrobial activities using Escherichia coli, Staphylococcus aureus, and Candida albicans on Mueller-Hinton agar as well as through diffusion technique. In conclusion, our findings, including the antioxidant and antimicrobial strengths, underscore the substantial potential of Iraqi honeys in mitigating damage and preventing the onset of various diseases, affirming their good quality and adherence to international honey standards.

coli β-Carbonic Anhydrase Inhibition Efficacy of Phenazone-Based Molecules

In this investigation, 4-antipyrinecarboxaldhyde was reacted with methyl hydrazinecarbodithioate to afford the carbodithioate derivative 3. The as-prepared carbodithioate derivative 3 is considered to be a key molecule for the preparation of new antipyrine-1,3,4-thiadiazole-based molecules (4-9) through its reaction with the appropriate hydrazonoyl halides. Furthermore, a typical Biginelli three-component cyclocondensation reaction involving ethyl acetoacetate, 4-antipyrinecarboxaldhyde, and thiourea under the standard conditions is carried out in the presence of sulfuric acid to afford the corresponding antipyrine-pyrimidine hybrid molecule (10). The latter was submitted to react with hydrazine monohydrate to provide the corresponding hydrazide derivative (11) which, under reaction with ethyl acetoacetate in refluxing ethanol containing catalytic amount of acetic acid, afforded the corresponding derivative (12). The structure of the newly synthesized compounds was affirmed by their spectral and microanalytical data. We also screened for their antimicrobial potential (ZOI and MIC) and conducted a kinetic study. Additionally, the mechanism of biological action was assessed by a membrane leakage assay and SEM imaging technique. Moreover, the biological activities and the binding modes of these compounds were further supplemented by an in silico docking study against E. coli β-carbonic anhydrase. The amount of cellular protein released by E. coli is directly correlated to the concentration of compound 9, which was found to be 177.99 µg/mL following treatment with 1.0 mg/mL of compound 9. This finding supports compound 9's antibacterial properties and explains how the formation of holes in the E. coli cell membrane results in the release of proteins from the cytoplasm. The newly synthesized compounds represent acceptable antimicrobial activities with potential action against E. coli β-carbonic anhydrase. The docking studies and antimicrobial activity test proved that compound (9) declared a greater activity than the other synthesized compounds.

Exploring the Functional Properties of Propolis, Geopropolis, and Cerumen, with a Special Emphasis on Their Antimicrobial Effects

Bee propolis has been touted as a natural antimicrobial agent with the potential to replace antibiotics. Numerous reports and reviews have highlighted the functionalities and applications of the natural compound. Despite much clamor for the downstream application of propolis, there remain many grounds to cover, especially in the upstream production, and factors affecting the quality of the propolis. Moreover, geopropolis and cerumen, akin to propolis, hold promise for diverse human applications, yet their benefits and intricate manufacturing processes remain subjects of intensive research. Specialized cement bees are pivotal in gathering and transporting plant resins from suitable sources to their nests. Contrary to common belief, these resins are directly applied within the hive, smoothed out by cement bees, and blended with beeswax and trace components to create raw propolis. Beekeepers subsequently harvest and perform the extraction of the raw propolis to form the final propolis extract that is sold on the market. As a result of the production process, intrinsic and extrinsic factors, such as botanical origins, bee species, and the extraction process, have a direct impact on the quality of the final propolis extract. Towards the end of this paper, a section is dedicated to highlighting the antimicrobial potency of propolis extract.

Transcriptomic Analysis Followed by the Isolation of Extracellular Bacteriolytic Proteases from Lysobacter capsici VKM B-2533T

The aim of the study was to search for, isolate and characterize new bacteriolytic enzymes that show promising potential for their use in medicine, agriculture and veterinary. Using a transcriptomic analysis, we annotated in Lysobacter capsici VKM B-2533^T the genes of known bacteriolytic and antifungal enzymes, as well as of antibiotics, whose expression levels increased when cultivated on media conducive to the production of antimicrobial agents. The genes of the secreted putative bacteriolytic proteases were also annotated. Two new bacteriolytic proteases, Serp and Serp3, were isolated and characterized. The maximum bacteriolytic activities of Serp and Serp3 were exhibited at low ionic strength of 10 mM Tris-HCl, and high temperatures of, respectively, 80 °C and 70 °C. The pH optimum for Serp was 8.0; for Serp3, it was slightly acidic, at 6.0. Both enzymes hydrolyzed autoclaved cells of Micrococcus luteus Ac-2230^T, Proteus vulgaris H-19, Pseudomonas aeruginosa and Staphylococcus aureus 209P. Serp also digested cells of Bacillus cereus 217. Both enzymes hydrolyzed casein and azofibrin. The newly discovered enzymes are promising for developing proteolytic antimicrobial drugs on their basis.

Antimicrobial Potential, Antioxidant Activity, and Phenolic Content of Grape Seed Extracts from Four Grape Varieties

The aim of this study was to evaluate the total phenolic content, composition, and antioxidant and antibacterial activities of four grape seed extracts (Cabernet Sauvignon, Marselan, Pinot Noir, and Tamyanka). The total phenolic content (TPC) and flavonoid, anthocyanin, procyanidin, ascorbic acid, DPPH, and ABTS antioxidant capacities of the grape seed extracts (GSEs) were determined. The extracts showed high TPC values (79.06-111.22 mg GAE/g). The individual components in the GSEs were determined using HPLC. High contents of catechin, epicatechin, and procyanidin B1 were found in the extracts. The antimicrobial activity of the obtained GSEs against Staphylococcus aureus, Bacillus cereus, and Escherichia coli was evaluated using the agar diffusion test and a test to determine the minimum inhibitory concentration (MIC). According to the effect on the growth of pathogens, the extracts were ranked in the following order: Pinot Noir > Marselan > Cabernet Sauvignon > Tamyanka. The tested bacteria showed high sensitivity to the extracts (MIC = 0.12-0.50 mg/mL). According to the MIC values, the bacteria were in the following order: S. aureus > B. cereus > E. coli. A correlation was found between the phenolic content of the GSEs and their antibacterial potential. The obtained results show that the studied GSEs have good potential as antioxidant and antimicrobial agents.

Fluoride Bio-Sorption Efficiency and Antimicrobial Potency of Macadamia Nut Shells

This paper presents the potential application of macadamia nut shells (MNS) in the bio-sorption of fluoride and its antimicrobial potency against common pathogens encountered in surface water resources. The efficiency of MNS in the sorption of fluoride was determined using batch mode experiments, while the antimicrobial potency was investigated using the well disc diffusion assay method. The maximum fluoride sorption capacity of 1.26 mg/g was recorded at an initial fluoride concentration of 5 mg/L, adsorbent dosage of 0.5 g/100 mL, contact time of 120 min and initial pH of 6. The adsorption kinetics data were better described with a pseudo second order model, indicating the dominance of the chemisorption mechanisms. The Langmuir adsorption isotherm model described the isotherm data suggesting a monolayered adsorption. The thermodynamic parameters, ∆Gº and ∆Hº, confirmed that F⁻ sorption by MNS is a spontaneous and endothermic process. The bio-sorbent was regenerated for seven continuous cycles when HCl was used as regenerating solution. The antimicrobial studies revealed that MNS has minimal activity towards Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae. The MNS showed potentials for application in bio-sorption of fluoride. However, the doping of MNS with metal ions is recommended to enhance its anti-microbial potency.

New and Potent Quinuclidine-Based Antimicrobial Agents

Developing new antibiotics is currently very important since antibiotic resistance is one of the biggest problems of global health today. In the search for a new class of potential antimicrobial agents, ten new compounds were designed and synthesized based on the quinuclidinium heterocyclic core and the oxime functional group. The antimicrobial activity was assessed against a panel of representative gram-positive and gram-negative bacteria. All compounds demonstrated potent activity against the tested microorganisms, with the minimum inhibitory concentration (MIC) values ranging from 0.25 to 256.00 μg/mL. Among the tested compounds, two quaternary compounds, para-N-chlorobenzyl and meta-N-bromobenzyl quinuclidinium oximes, displayed the most potent and broad-spectrum activity against both gram-positive and gram-negative bacterial strains (MIC values from 0.25 to 4.00 μg/mL), with the lowest value for the important multidrug resistant gram-negative pathogen Pseudomonas aeruginosa. In the case of Klebsiella pneumoniae, activity of those compounds are 256-fold and 16-fold better than gentamicin, respectively. MTT assays showed that compounds are nontoxic for human cell lines. Multi-way analysis was used to separately reduce dimensionality of quantum chemical data and biological activity data to obtain a regression model and the required parameters for the enhancement of biological activity.

Assessment of the Antimicrobial Potentiality and Functionality of Lactobacillus plantarum Strains Isolated from the Conventional Inner Mongolian Fermented Cheese Against Foodborne Pathogens

Lactobacillus plantarum are amongst the diversified lactic acid bacteria (LAB) species which are being utilized abundantly in the food industry. Numerous L. plantarum strains have been reported to produce several antimicrobial compounds. Diacetyl, hydrogen peroxide, organic acids, as well as bacteriocins can also be exemplified by a variable spectrum of actions. The current study was intended to conduct the screening and characterization of antimicrobial prospective of L. plantarum from traditional Inner Mongolian fermented hard cheese. Foodborne pathogens, Salmonella typhimurium, Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus, were examined by using the Oxford cup technique and the mixed culture inhibition assays. The resulting analyses disclosed that L. plantarum KLDS1.0344 indicated broad antimicrobial spectrum against all selected pathogens as compared to other LAB used in this study. Additionally, the decrement of the pathogen population was observed up to 3.47 logs in mixed culture inhibition assays. L. plantarum KLDS 1.0344 acid production was recorded up to 71.8 ± 3.59 °D in mixed culture while antimicrobial particles released in cell free supernatants demonstrated bacteriocin-like characteristics showing substantial pH stability (2.0–6.0), proteolytic enzyme reduced the antibacterial activity (15.2 ± 0.6 mm–20.4 ± 0.8 mm), heat stability (20 min at 120 °C) against selected pathogens. Moreover, the spectrum range of antimicrobial peptides after the partial purification was decreased as compared to the crude bacteriocin-like compound. The SDS-PAGE analysis showed the molecular weight range of partially purified bacteriocin from 12 to 45 kDa. After analyzing the obtained data from the current experimentation showed that the capability of L. plantarum KLDS 1.0344 to oppose the pathogen growth in vitro relies on the occurrence of organic acids along with bacteriocin-like compounds proving L. plantarum KLDS 1.0344 as a potentially appropriate candidate as an alternative bio-control agent against foodborne pathogens.