Phytoremediation of formaldehyde by three selected non-native indoor plant species.

Formaldehyde is an organic volatile compound and a commonly used chemical in various construction materials thus causing dwellers to be exposed to it inside a building. Its remediation from indoor air has been carried out through various techniques where potted plants and living walls are at the front foot. It is necessary to study plants under various conditions for their efficiency. We selected three plant species Epipremnum aureum, Chlorophytum comosum, and Spathiphyllum wallisii non-native of Bahrain. These plants were tested under normal conditions in a sealed fumigation box where formaldehyde concentration was kept ∼3 ppm, CO2 ∼ 450 ppm, light intensity 1000 Lx (equal to 13.5 µmol.m-2.s-1), irrigated with tap water. Analysis of Variance (ANOVA) statistical method was performed to test the significant differences of purification efficiencies of the tested indoor plants against HCHO. In addition, the statistical method was used to test the significant difference, if any, of the plants to CO2 emission because of absorbing HCHO. The physical health of plants and their short-term remediation ability reveals that all plants exhibited up to 70% remediation potential and tolerance to remediate the target chemical. It is evident that the impact of local environmental factors on the plants is negligible.

Epipremnum aureum, Chlorophytum comosum, and Spathiphyllum wallisii are non-native plants available in Bahrain for decorative purposes.Their efficiency against formaldehyde under local indoor environment was studied for the first time.Under normal conditions the plant proved to be sufficiently tolerant toward normal conditions. The efficiency in normal soil system is very good.The efficiency of the three species was mutually compared, statistical modeling reveal that they are significantly close to each other in terms of formaldehyde remediation to purify ambient air.

Phytoremediation of indoor formaldehyde by plants and plant material.

Formaldehyde evolves from various household items and is of environmental and public health concern. Removal of this contaminant from the indoor air is of utmost importance and currently, various practices are in the field. Among these practices, indoor plants are of particular importance because they help in controlling indoor temperature, moisture, and oxygen concentration. Plants and plant materials studied for the purpose have been reviewed hereunder. The main topics of the review are, mechanism of phytoremediation, plants and their benefits, plant material in formaldehyde remediation, and airtight environmental and health issues. Future research in the field is also highlighted which will help new researches to plan for the remediation of formaldehyde in indoor air. The remediation capacity of several plants has been tabulated and compared, which gives easy access to assess various plants for remediation of the target pollutant. Challenges and issues in the phytoremediation of formaldehyde are also discussed.Novelty statement: Phytoremediation is a well-known technique to mitigate various organic and inorganic pollutants. The technique has been used by various researchers for maintaining indoor air quality but its efficiency under real-world conditions and human activities is still a question and is vastly affected relative to laboratory conditions. Several modifications in the field are in progress, here in this review article we have summarized and highlighted new directions in the field which could be a better solution to the problem in the future.

Thiourea Derivatives, Simple in Structure but Efficient Enzyme Inhibitors and Mercury Sensors.

In this study six unsymmetrical thiourea derivatives, 1-isobutyl-3-cyclohexylthiourea (1), 1-tert-butyl-3-cyclohexylthiourea (2), 1-(3-chlorophenyl)-3-cyclohexylthiourea (3), 1-(1,1-dibutyl)-3-phenylthiourea (4), 1-(2-chlorophenyl)-3-phenylthiourea (5) and 1-(4-chlorophenyl)-3-phenylthiourea (6) were obtained in the laboratory under aerobic conditions. Compounds 3 and 4 are crystalline and their structure was determined for their single crystal. Compounds 3 is monoclinic system with space group P21/n while compound 4 is trigonal, space group R3:H. Compounds (1-6) were tested for their anti-cholinesterase activity against acetylcholinesterase and butyrylcholinesterase (hereafter abbreviated as, AChE and BChE, respectively). Potentials (all compounds) as sensing probes for determination of deadly toxic metal (mercury) using spectrofluorimetric technique were also investigated. Compound 3 exhibited better enzyme inhibition IC50 values of 50, and 60 µg/mL against AChE and BChE with docking score of -10.01, and -8.04 kJ/mol, respectively. The compound also showed moderate sensitivity during fluorescence studies.

Bioaccumulation of Cr, Ni, Cd and Pb in the Economically Important Freshwater Fish Schizothorax plagiostomus from Three Rivers of Malakand Division, Pakistan: Risk Assessment for Human Health.

Contamination of freshwater ecosystems such as rivers with hazardous heavy metals is an environmental problem of public health concern. Accumulation of potentially toxic heavy metals in freshwater fish causes a potential health threat to their consumers including humans. The present research aimed to (1) investigate the accumulation of four potentially toxic heavy metals viz. Cr, Ni, Cd and Pb in muscle tissue of the commercially important freshwater fish Schizothorax plagiostomus at different sites of River Swat, River Panjkora and River Barandu in northern Pakistan (2) to compare gross metal accumulation in the fish samples by calculating metal pollution index (MPI) and (3) to assess potential risk to the health of the fish consumers. Samples were analyzed for the heavy metals by flame atomic absorption spectrophotometry (FAAS). Risk analysis showed that Ni risk was higher at River Panjkora and River Barandu, Pb risk was higher at River Swat and River Panjkora while Cd risk was quite low at all the three rivers.

Isolation, crystal structure determination and cholinesterase inhibitory potential of isotalatizidine hydrate from Delphinium denudatum.

CONTEXT: Delphinium denudatum Wall (Ranunculaceae) is a rich source of diterpenoid alkaloids and is widely used for the treatment of various neurological disorders such as epilepsy, sciatica and Alzheimer's disease. OBJECTIVE: The present study describes crystal structure determination and cholinesterase inhibitory potential of isotalatazidine hydrate isolated from the aerial part of Delphinium denudatum. MATERIALS AND METHODS: Phytochemical investigation of Delphinium denudatum resulted in the isolation of isotalatazidine hydrate in crystalline form. The molecular structure of the isolated compound was established by X-ray diffraction. The structural data (bond length and angles) of the compound were calculated by Density Functional Theory (DFT) using B3LYP/6-31 + G (p) basis set. The cholinesterase inhibitory potential of the isolated natural product was determined at various concentrations (62.5, 125, 250, 500 and 1000 µg/mL) followed by molecular docking to investigate the possible inhibitory mechanism of isotalatazidine hydrate. RESULTS: The compound crystallized in hexagonal unit cell with space group P65. Some other electronic properties such as energies associated with HOMO-LUMO, band gaps, global hardness, global electrophilicity, electron affinity and ionization potential were also calculated by means of B3LYP/6-31 + G (p) basis set. The compound showed competitive type inhibition of both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with IC50 values of 12.13 µM and 21.41 µM, respectively. DISCUSSION AND CONCLUSION: These results suggest that isotalatazidine hydrate is a potent dual cholinesterase inhibitor and can be used as a target drug in Alzheimer diseases. This is first report indicating isotalatazidine hydrate with anticholinesterase potential.

Chemical and biological evaluation of Ranunculus muricatus.

Ranunculus muricatus is commonly known as spiny fruit buttercup and is used in the treatment of intermittent fevers, gout and asthma. Qualitative analysis of phytochemicals of Ranunculus muricatus indicated the presence of saponins, tannins, phenols, flavonoids and alkaloids. Saponins were present in high amount as compared with other chemicals. Inorganic and heavy metals constituents were determined. Heavy metals estimation in the sample showed that iron was present in high amount followed by zinc even then the concentration of these metals is below acceptable limit. The physical parameters, antioxidant and antimicrobial activities of the extracts were determined. Acetone extract fraction showed optimal antioxidant activity as compared to ethanol and chloroform fractions of the candidate plant. The antimicrobial and antifungal activities of the crude extract and extract fractions were determined by well agar diffusion method. Highest zone of inhibitions were observed for crude extract followed by acetone extract fraction against Micrococcus luteus. Antifungal activities were high for crude extracts against Candida Albican. Findings of this study show that Ranunculus muricatus has a good medicinal impact.

Predicting medical waste generation and associated factors using machine learning in the Kingdom of Bahrain.

Effective planning and managing medical waste necessitate a crucial focus on both the public and private healthcare sectors. This study uses machine learning techniques to estimate medical waste generation and identify associated factors in a representative private and a governmental hospital in Bahrain. Monthly data spanning from 2018 to 2022 for the private hospital and from 2019 to February 2023 for the governmental hospital was utilized. The ensemble voting regressor was determined as the best model for both datasets. The model of the governmental hospital is robust and successful in explaining 90.4% of the total variance.Similarly, for the private hospital, the model variables are able to explain 91.7% of the total variance. For the governmental hospital, the significant features in predicting medical waste generation were found to be the number of inpatients, population, surgeries, and outpatients, in descending order of importance. In the case of the private hospital, the order of feature importance was the number of inpatients, deliveries, personal income, surgeries, and outpatients. These findings provide insights into the factors influencing medical waste generation in the studied hospitals and highlight the effectiveness of the ensemble voting regressor model in predicting medical waste quantities.

Antioxidant, antibacterial, enzyme inhibition and fluorescence characteristics of unsymmetrical thiourea derivatives.

A series of six unsymmetrical thiourea derivatives, namely 1-cyclohexyl-3-(pyridin-2-yl) thiourea (1), 1-cyclohexyl-3-(3-methylpyridin-2-yl)thiourea (2), 1-cyclohexyl-3-(2,4-dimethylphenyl) thiourea (3), 1-(4-chlorophenyl)-3-cyclohexylthiourea (4), 1-(3-methylpyridin-2-yl)-3-phenylthiourea (5), and 1-(3-chlorophenyl)-3-phenylthiourea (6), were successfully synthesized via reaction between different amines with isothiocyanates under a non-catalytic environment. Structural elucidation of compounds (1-6) was performed using FT-IR and NMR (1H and 13C) spectroscopy. The infrared spectra displayed characteristic stretching vibrations, while the 13C NMR chemical shifts of the thiourea moiety (C[bond, double bond]S) were observed in the range of 179.1-181.4 ppm. The antioxidative and antimicrobial properties of the compounds were assessed, as well as their inhibitory effects on acetylcholinesterase and butyrylcholinesterase were evaluated. In order to analyze the fluorescence characteristics of each compound (1-6), the excitation (λex) and emission (λem) wavelengths were scanned within the range of 250-750 nm, with the solvent blank serving as a standard. It was observed that when dissolved in acetone, toluene, tetrahydrofuran, and ethyl acetate, these compounds exhibited emission peaks ranging from 367 to 581 nm and absorption peaks ranging from 275 to 432 nm.

Metal-Organic Frameworks (MOFs)-Based Sensors for the Detection of Heavy Metals: A Review.

Metal-organic-frameworks (MOFs) have emerged as promising candidates in different scientific disciplines owing to their intriguing characteristics. Their unique structural properties, including large surface area to volume ratio with multi-functionalities and ultra-high porosity, tunability, uniformity, and easy derivation and fabrication, render them effective materials for sensing applications. The detection of heavy metals in different environmental matrices using various MOF-based sensors is in practice. They include luminescent, electrochemical, electrochemiluminescent, colorimetric, and surface-enhanced Raman scattering, are of great interest. This review elaborates on selected synthetic methods for the fabrication of MOF-based sensors, modification routes for tailoring and enhancing the desired properties, basic characterization techniques, and their limitations in the detection of heavy metals. Also, it emphasizes the use of various types of MOF-based sensors alternatively for the detection of different heavy metals such as Fe(III), Cr(III), Hg(II), Cd(II), and Pb(II) in addition to a normal metal Al(III). A collection of recent references is provided for researchers interested in such applications. Results from the literature have been summarized in tables which give an easy comparison and will help to develop efficient materials.

Organic Molecules Containing N, S and O Heteroatoms as Sensors for the Detection of Hg(II) Ion; Coordination and Efficiency toward Detection.

Rapid detection of potentially toxic heavy metals like Hg(II) has attracted great attention in the last few decades due to the importance to maintain a safe and sustainable environment for human beings. Coordination chemistry and concepts therein, play an important role in the detection of Hg(II). Size, charge, and nature of the donor atom and the respective cation (metal ion), are crucial in selective interactions between the sensor and metal ions. The sensors designed for the purpose, coordinate to Hg(II) ion through various donor sites, coordination causes a change in the electron density in organic molecules and results in either visible color change or enhancing/quenching fluorescence intensity. Since Hg(II) is soft metal, with d10 electron system, so majority of the sensors have soft donor sites which prefer to coordinate with Hg(II). Oxygen is also present in some chelating ligands which is least preferred coordination site, due to its hard nature. There are several reports of replacing other ligating sites by sulfur for enhanced mercury sensing. In some cases, desulfurization is being detected as clear change in spectral behavior during the sensing process. Efforts are still in progress to design and introduce a sensor with utmost sensitivity and selectivity. In this review, we made an attempt to explain the coordination aspects of Hg(II) detectors, reasons for poor efficiency and possible suggestions to improve the selection criterion of various compounds. It will help researchers to know about important concepts in designing more sensitive and selective sensors for detection of Hg(II) in environmental and biological samples.

Levofloxacin Cocrystal/Salt with Phthalimide and Caffeic Acid as Promising Solid-State Approach to Improve Antimicrobial Efficiency.

To overcome the issue of multidrug resistant (MDR) microbes, the exploration of ways to improve the antimicrobial efficiency of existing antibiotics is one of the promising approaches. In search of synthons with higher efficiency, in current investigations, cocrystal and amorphous salt of levofloxacin hemihydrate (LEV) were developed with phthalimide (PTH) and caffeic acid (CFA). New materials were characterized with the help of FT-IR, Raman spectroscopy, powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Shifting, attenuation, appearance/disappearance and broadening of bands were observed in the FT-IR and Raman spectra of the materials as evidence of the required product. The PXRD diffraction pattern observed for LEV-PTH indicated cocrystal while halo diffractogram of LEV-CFA revealed amorphous nature. DSC/TG analysis confirmed the hydrated nature of the cocrystal/salt. The dissolution rate and antimicrobial activity against selected strains, K.pneumonia, E. coli and S. typhi of parent drug and the new material were compared. The zone of inhibition (ZI) observed for 5 µg LEV-PTH was 30.4 + 0.36 (K. pneumonia), 26.33 + 0.35 (E. coli) and 30.03 + 0.25 mm (S. typhi) while LEV-CFA salt (5 µg) against the same strains inhibited 33.96 ± 0.25, 31.66 ± 0.35 and 27.93 ± 0.40 mm, respectively. These novel formulations enhance the dissolution rate as well as antibacterial efficiency and are expected to be potent against MDR bacterial strains.

Medicinal Importance, Coordination Chemistry with Selected Metals (Cu, Ag, Au) and Chemosensing of Thiourea Derivatives. A Review.

Thiourea and its derivatives are versatile compounds used in several fields of life ranging from medicinal to chemosensor applications. In this review article, generally used preparative methods of thiourea, its coordination compounds with selected metals (Cu, Ag, Au) for biological and medicinal applications and the potentials of thiourea derivatives in analytical chemistry as chemosensors have been discussed. The improved activities of these derivatives in the field of pharmaceutical chemistry can be achieved by coordination with a suitable metal ion. The two fields, selected coordination chemistry and chemosensing of thiourea derivatives are discussed. Since thiourea derivatives are biologically active therefore, their use as chemosensors can be useful to detect anions and cations in environmental and biological samples. The review contains 212 references.

Estimation of COVID-19 generated medical waste in the Kingdom of Bahrain.

Coronavirus disease 2019 (COVID-19) is not only a great matter of concern from a medical and health perspective, but it is a serious threat to the environment in terms of waste generated during the prevention and cure of COVID-19. The world has so far compromised more than 3 million human lives, and millions are being infected. Environmental threat is most serious because it can cause secondary complications. As per our knowledge, the amount of waste generated during the pandemic and its estimated quantity has not been assessed, thereby keeping the scientific community, Government authorities and public ignorant of its adverse effects. In this context, we have evaluated the waste generated by the Kingdom of Bahrain, estimated to be 35.480 kg/day (face masks), 1894 kg/day (PPEs) by the selected health facilities, 16,633.505 kg (vaccination-related) and 53,551.240 kg (related to tests conducted so far) in the Kingdom of Bahrain.

A scaffolded approach to unearth potential antibacterial components from epicarp of Malaysian Nephelium lappaceum L.

The emergence and spread of antimicrobial resistance have been of serious concern to human health and the management of bacterial infectious diseases. Effective treatment of these diseases requires the development of novel therapeutics, preferably free of side effects. In this regard, natural products are frequently conceived to be potential alternative sources for novel antibacterial compounds. Herein, we have evaluated the antibacterial activity of the epicarp extracts of the Malaysian cultivar of yellow rambutan fruit (Nephelium lappaceum L.) against six pathogens namely, Bacillus subtilis, methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pyogenes, Pseudomonas aeruginosa, Klebsiella pneumoniae and Salmonella enterica. Among a series of solvent extracts, fractions of ethyl acetate and acetone have revealed significant activity towards all tested strains. Chemical profiling of these fractions, via HPLC, LC-MS and GC-MS, has generated a library of potentially bioactive compounds. Downstream virtual screening, pharmacological prediction, and receptor-ligand molecular dynamics simulation have eventually unveiled novel potential antibacterial compounds, which can be extracted for medicinal use. We report compounds like catechin, eplerenone and oritin-4-beta-ol to be computationally inhibiting the ATP-binding domain of the chaperone, DnaK of P. aeruginosa and MRSA. Thus, our work follows the objective to propose new antimicrobials capable of perforating the barrier of resistance posed by both the gram positives and the negatives.

Enhancing Dissolution Rate and Antibacterial Efficiency of Azithromycin through Drug-Drug Cocrystals with Paracetamol.

Cocrystallization is a promising approach to alter physicochemical properties of active pharmaceutical ingredients (hereafter abbreviated as APIs) bearing poor profile. Nowadays pharmaceutical industries are focused on preparing drug-drug cocrystals of APIs that are often prescribed in combination therapies by physicians. Physicians normally prescribe antibiotic with an analgesic/antipyretic drug to combat several ailments in a better and more efficient way. In this work, azithromycin (AZT) and paracetamol (PCM) cocrystals were prepared in 1:1 molar ratio using slow solvent evaporation method. The cocrystals were characterized by Fourier transform infrared (FTIR), Raman spectroscopy, powder X-ray diffraction (PXRD), differential scanning calorimeter (DSC), thermo gravimetric analysis (TGA) and high-performance liquid chromatography (HPLC). Vibrational spectroscopy and DSC confirmed that both APIs interact physically and showed chemical compatibility, while PXRD pattern of the starting material and products revealed that cocrystal have in a unique crystalline phase. The degree of hydration was confirmed by TGA analysis and result indicates monohydrate cocrystal formation. The HPLC analysis confirmed equimolar ratio of AZT:PCM in the cocrystal. The in vitro dissolution rate, saturation solubility, and antimicrobial activity were evaluated for AZT dihydrate and the resulting cocrystals. The cocrystals exhibited better dissolution rate, solubility and enhanced biological activities.

Phytoremediation of heavy metals--concepts and applications.

The mobilization of heavy metals by man through extraction from ores and processing for different applications has led to the release of these elements into the environment. Since heavy metals are nonbiodegradable, they accumulate in the environment and subsequently contaminate the food chain. This contamination poses a risk to environmental and human health. Some heavy metals are carcinogenic, mutagenic, teratogenic and endocrine disruptors while others cause neurological and behavioral changes especially in children. Thus remediation of heavy metal pollution deserves due attention. Different physical and chemical methods used for this purpose suffer from serious limitations like high cost, intensive labor, alteration of soil properties and disturbance of soil native microflora. In contrast, phytoremediation is a better solution to the problem. Phytoremediation is the use of plants and associated soil microbes to reduce the concentrations or toxic effects of contaminants in the environments. It is a relatively recent technology and is perceived as cost-effective, efficient, novel, eco-friendly, and solar-driven technology with good public acceptance. Phytoremediation is an area of active current research. New efficient metal hyperaccumulators are being explored for applications in phytoremediation and phytomining. Molecular tools are being used to better understand the mechanisms of metal uptake, translocation, sequestration and tolerance in plants. This review article comprehensively discusses the background, concepts and future trends in phytoremediation of heavy metals.