Physicochemical and antioxidant properties of Apis cerana honey from Lombok and Bali Islands.

Limited honey production worldwide leads to higher market prices, thus making it prone to adulteration. Therefore, regular physicochemical analysis is imperative for ensuring authenticity and safety. This study describes the physicochemical and antioxidant properties of Apis cerana honey sourced from the islands of Lombok and Bali, showing their unique regional traits. A comparative analysis was conducted on honey samples from Lombok and Bali as well as honey variety from Malaysia. Moisture content was found slightly above 20% in raw honey samples from Lombok and Bali, adhering to the national standard (SNI 8664:2018) of not exceeding 22%. Both honey types displayed pH values within the acceptable range (3.40-6.10), ensuring favorable conditions for long-term storage. However, Lombok honey exhibited higher free acidity (78.5±2.14 meq/kg) than Bali honey (76.0±1.14 meq/kg), surpassing Codex Alimentarius recommendations (≤50 meq/kg). The ash content, reflective of inorganic mineral composition, was notably lower in Lombok (0.21±0.02 g/100) and Bali honey (0.14±0.01 g/100) compared to Tualang honey (1.3±0.02 g/100). Electric conductivity, indicative of mineral content, revealed Lombok and Bali honey with lower but comparable values than Tualang honey. Hydroxymethylfurfural (HMF) concentrations in Lombok (14.4±0.11 mg/kg) and Bali (17.6±0.25 mg/kg) were slightly elevated compared to Tualang honey (6.4±0.11 mg/kg), suggesting potential processing-related changes. Sugar analysis revealed Lombok honey with the highest sucrose content (2.39±0.01g/100g) and Bali honey with the highest total sugar content (75.21±0.11 g/100g). Both honeys exhibited lower glucose than fructose content, aligning with Codex Alimentarius guidelines. The phenolic content, flavonoids, and antioxidant activity were significantly higher in Lombok and Bali honey compared to Tualang honey, suggesting potential health benefits. Further analysis by LC-MS/MS-QTOF targeted analysis identified various flavonoids/flavanols and polyphenolic/phenolic acid compounds in Lombok and Bali honey. The study marks the importance of characterizing the unique composition of honey from different regions, ensuring quality and authenticity in the honey industry.

Green extraction of phenolics using deep eutectic solvents: a promising neoteric method.

There has been a growing emphasis on developing extraction methods that are not only efficient but also environmentally friendly and sustainable. One promising avenue is the exploration of deep eutectic solvents (DESs) as neoteric extraction media. This study aims to investigate the potential of DESs as neoteric extraction media for phenolics-rich flower clove extracts. Two DESs were synthesised by mixing choline chloride with glycerol and lactic acid at a molar ratio of 1:2. The thermal profiles of the mixture were analysed using differential scanning calorimetry, and the viscosity and density were measured at different temperatures. The phenolic compounds were quantitatively characterised for all of the extractants using high-performance liquid chromatography. The total phenolic content and the antioxidant activities of the extracts were determined. The results showed that DESs significantly improved the extraction of antioxidant compounds from clove, especially for the case of phenolic compounds, and also considerably enhanced the antioxidant activity of the extracts. The use of DESs offers a green, efficient method for extracting value-added products from natural sources.

Density Functional Theory Studies on New Possible Biobased Gemini Corrosion Inhibitors Derived from Fatty Hydrazide Derivatives.

Several new possible biobased corrosion inhibitors derived from fatty hydrazide derivatives were analyzed using quantum chemical calculations via the density functional theory method to investigate the chemical reactivity and inhibition efficiencies against corrosion in metal steel. The study confirmed that the fatty hydrazides showed significant inhibitive performances based on their electronic properties, revealing band gap energies of 5.20 to 7.61 eV between the HOMO and LUMO. These energy differences decreased from 4.40 to 7.20 eV when combined with substituents of varying chemical compositions, structures, and functional groups, associated with higher inhibition efficiency. The most promising fatty hydrazide derivatives are terephthalic acid dihydrazide combined with a long-chain alkyl chain, which resulted in the lowest energy difference of 4.40 eV. Further inspection showed that the fatty hydrazide derivatives' inhibitive performances increased with increasing carbon chain length [from 4 (4-s-4) to 6 (6-s-6)], with a concomitant increase and decrease in hydroxyl and carbonyl groups, respectively. Fatty hydrazide derivatives containing aromatic rings also showed increased inhibition efficiencies following their contribution to improve the compounds' binding ability and adsorption on the metal surface. Overall, all data were consistent with previously reported findings, envisaging the potential of fatty hydrazide derivatives as effective corrosion inhibitors.

Molecular interactions of trichoderma ß-1,4-glucosidase (ThBglT12) with mycelial cell wall components of phytopathogenic Macrophomina phaseolina.

Efficacy of a ß-1,4-glucosidase from Trichoderma harzianum T12 (ThBglT12) in disrupting the cell wall of the phytopathogenic fungus M. phaseolina (Macrophomina phaseolina) was studied, as the underlying molecular mechanisms of cell wall recognition remains elusive. In this study, the binding location identified by a consensus of residues predicted by COACH tool, blind docking, and multiple sequence alignment revealed that molecular recognition by ThBglT12 occurred through interactions between the α-1,3-glucan, ß-1,3-glucan, ß-1,3/1,4-glucan, and chitin components of M. phaseolina, with corresponding binding energies of -7.4, -7.6, -7.5 and -7.8 kcal/mol. The residue consensus verified the participation of Glu172, Tyr304, Trp345, Glu373, Glu430, and Trp431 in the active site pocket of ThBglT12 to bind the ligands, of which Trp345 was the common interacting residue. Root mean square deviation (RMSD), root mean square fluctuation (RMSF), total energy, and minimum distance calculation from molecular dynamics (MD) simulation further confirmed the stability and the closeness of the binding ligands into the ThBglT12 active site pocket. The h-bond occupancy by Glu373 and Trp431 instated the role of the nucleophile for substrate recognition and specificity, crucial for cleaving the ß-1,4 linkage. Further investigation showed that the proximity of Glu373 to the anomeric carbon of ß-1,3/1,4-glucan (3.5 Å) and chitin (5.5 Å) indicates the nucleophiles' readiness to form enzyme-substrate intermediates. Plus, the neighboring water molecule appeared to be correctly positioned and oriented towards the anomeric carbon to hydrolyze the ß-1,3/1,4-glucan and chitin, in less than 4.0 Å. In a nutshell, the study verified that the ThBglT12 is a good alternative fungicide to inhibit the growth of M. phaseolina.Communicated by Ramaswamy H. Sarma.

In silico analysis of a putative dehalogenase from the genome of halophilic bacterium Halomonas smyrnensis AAD6T.

Microbial-assisted removal of natural or synthetic pollutants is the prevailing green, low-cost technology to treat polluted environments. However, the challenge with enzyme-assisted bioremediation is the laborious nature of dehalogenase-producing microorganisms' bioprospecting. This bottleneck could be circumvented by in-silico analysis of certain microorganisms' whole-genome sequences to predict their protein functions and enzyme versatility for improved biotechnological applications. Herein, this study performed structural analysis on a dehalogenase (DehHsAAD6) from the genome of Halomonas smyrnensis AAD6 by molecular docking and molecular dynamic (MD) simulations. Other bioinformatics tools were also employed to identify substrate preference (haloacids and haloacetates) of the DehHsAAD6. The DehHsAAD6 preferentially degraded haloacids and haloacetates (-3.2-4.8 kcal/mol) and which formed three hydrogen bonds with Tyr12, Lys46, and Asp182. MD simulations data revealed the higher stability of DehHsAAD6-haloacid- (RMSD 0.22-0.3 nm) and DehHsAAD6-haloacetates (RMSF 0.05-0.14 nm) complexes, with the DehHsAAD6-L-2CP complex being the most stable. The detail of molecular docking calculations ranked complexes with the lowest binding free energies as: DehHsAAD6-L-2CP complex (-4.8 kcal/mol) = DehHsAAD6-MCA (-4.8 kcal/mol) < DehHsAAD6-TCA (-4.5 kcal/mol) < DehHsAAD6-2,3-DCP (-4.1 kcal/mol) < DehHsAAD6-D-2CP (-3.9 kcal/mol) < DehHsAAD6-2,2-DCP (-3.5 kcal/mol) < DehHsAAD6-3CP (-3.2 kcal/mol). In a nutshell, the study findings offer valuable perceptions into the elucidation of possible reaction mechanisms of dehalogenases for extended substrate specificity and higher catalytic activity.Communicated by Ramaswamy H. Sarma.

An Overview into Polyethylene Terephthalate (PET) Hydrolases and Efforts in Tailoring Enzymes for Improved Plastic Degradation.

Plastic or microplastic pollution is a global threat affecting ecosystems, with the current generation reaching as much as 400 metric tons per/year. Soil ecosystems comprising agricultural lands act as microplastics sinks, though the impact could be unexpectedly more far-reaching. This is troubling as most plastic forms, such as polyethylene terephthalate (PET), formed from polymerized terephthalic acid (TPA) and ethylene glycol (EG) monomers, are non-biodegradable environmental pollutants. The current approach to use mechanical, thermal, and chemical-based treatments to reduce PET waste remains cost-prohibitive and could potentially produce toxic secondary pollutants. Thus, better remediation methods must be developed to deal with plastic pollutants in marine and terrestrial environments. Enzymatic treatments could be a plausible avenue to overcome plastic pollutants, given the near-ambient conditions under which enzymes function without the need for chemicals. The discovery of several PET hydrolases, along with further modification of the enzymes, has considerably aided efforts to improve their ability to degrade the ester bond of PET. Hence, this review emphasizes PET-degrading microbial hydrolases and their contribution to alleviating environmental microplastics. Information on the molecular and degradation mechanisms of PET is also highlighted in this review, which might be useful in the future rational engineering of PET-hydrolyzing enzymes.

Preliminary forensic assessment of the visualised fingerprints on nonporous substrates immersed in water using the green and optimised novel nanobio-based reagent.

The discovery of forensic evidence (e.g. weapons) during forensic underwater investigations has seen an increasing trend. To date, small particle reagent (SPR) has been one of the routinely used methods for visualising fingerprints on wet, non-porous substrates. However, the long term use of SPR is detrimental to humans and environment due to the use of toxic chemicals. Although previously we have successfully developed and optimised a greener nanobio-based reagent (NBR), its suitable practical use in a more realistic scene (e.g. outdoor pond) was not evaluated. Therefore, this present research is aimed at (1) investigating the performance of NBR against the benchmark SPR in visualising fingerprints immersed in a natural outdoor pond and (2) evaluating the greenness of NBR against the analytical Eco-Scale. Results showed that the performance of the optimised NBR was mostly comparable (University of Canberra (UC) comparative scale: 0) with SPR at visualising fingerprints on three different non-porous substrates immersed in a natural outdoor pond. Observably, the NBR had higher preference towards aged fingerprints (up to 4 weeks of immersion). In addition, its greenness assessment revealed 76 points, indicating 'excellent green analysis'. The findings gathered here further supported the practical use of the NBR in forensic investigations.

Development of Aloe Vera-Green Banana Saba-Curcumin Composite Film for Colorimetric Detection of Ferrum (II).

This study was performed to develop and characterize a bio-film composed of Aloe vera (Aloe barbadensis), green banana Saba (Musa acuminata x balbisiana), and curcumin for the detection of Fe2+ ions. Cross-linking interaction between banana starch-aloe vera gel and banana starch-curcumin enhanced l the sensing performance of the composite film towards divalent metal ions of Fe2+. The morphological structure of the Aloe vera-banana starch-curcumin composite revealed a smooth and compact surface without cracks and some heterogeneity when observed under Scanning Electron Microscopy (SEM). The thickness, density, color property, opacity, biodegradation, moisture content, water-solubility, water absorption, swelling degree, and water vapor permeability of bio-films were measured. The incorporation of aloe vera gel and curcumin particles onto the banana starch film has successfully improved the film properties. The formation of the curcumin-ferrum (II) complex has triggered the film to transform color from yellow to greenish-brown after interaction with Fe2+ ions that exhibit an accuracy of 101.11% within a swift reaction time. Good linearity (R2 = 0.9845) of response on colorimetric analysis was also obtained in Fe2+ ions concentration that ranges from 0 to 100 ppm, with a limit of detection and quantification found at 27.84 ppm and 92.81 ppm, respectively. In this context, the film was highly selective towards Fe2+ ions because no changes of color occur through naked eye observation when films interact with other metal ions, including Fe3+, Pb2+, Ni2+, Cd2+, and Cu2+. Thus, these findings encourage curcumin-based starch films as sensing materials to detect Fe2+ ions in the field of food and agriculture.

Ananas comosus Peels Extract as a New Natural Cosmetic Ingredient: Oil-in-Water (O/W) Topical Nano Cream Stability and Safety Evaluation.

Ananas comosus peels (AcP) are among the agro-industrial biomasses contributing to a significant volume of waste in Malaysia. Thus, the AcP extract (AcPE) may prove useful for other applications, such as an ingredient in a nanocream for controlled delivery for dermal application. Therefore, this study aimed to develop an oil-in-water (O/W) nanocream using ingredients derived from the AcPE and test its stability alongside safety evaluation. The extract is a rich source of polyphenolic compounds viz., catechin, quercetin, and gallic acid. The study discovered that the optimized AcPE nano cream was stable against coalescence during the accelerated test but was influenced by Ostwald ripening over 6 weeks of storage at 4°C. Safety assessments affirmed the AcPE nano cream to be free of microbial contamination and heavy metals. The findings conveyed that the A. comosus nano cream is a good cosmetic ingredient and may contribute to the cosmeceutical industry's new and safe topical products.

Exploring the genome of Lactobacillaceae spp. Sy-1 isolated from Heterotrigona itama honey.

Background: Honey produced by Heterotrigona itama is highly preferred among consumers due to its high-value as a functional food and beneficial lactic acid bacteria (LAB) reservoir. Fructophilic lactic acid bacteria (FLAB) are a group of LAB with unique growth characteristics and are regarded as promising producers of bioactive compounds. Hence, it is not surprising that LAB, especially FLAB, may be involved with the excellent bioactivity of H. itama honey. With the trending consumer preference for H. itama honey coupled with increasing awareness for healthy food, the genomic background of FLAB isolated from this honey must, therefore, be clearly understood. In this study, one FLAB strain designated as Sy-1 was isolated from freshly collected H. itama honey. Its FLAB behavior and genomic features were investigated to uncover functional genes that could add value to functional food. Methods: The fructophilic characteristics of strain Sy-1 were determined, and the genome was sequenced using Illumina iSeq100 and Oxford Nanopore. The average nucleotide identity and phylogenetic analyses based on 16S rRNA, 92 core genes, and whole-genome sequence were performed to unravel the phylogenetic position of strain Sy-1. NCBI Prokaryotic Genome Annotation Pipeline annotated the genome, while the EggNOG-mapper, BLASTKoala, and GHOSTKoala were used to add functional genes and pathways information. Results: Strain Sy-1 prefers D-fructose over D-glucose and actively metabolizes D-glucose in the presence of electron acceptors. Genomic annotation of strain Sy-1 revealed few genes involved in carbohydrate transport and metabolism, and partial deletion of adhE gene, in line with the characteristic of FLAB. The 16S rRNA gene sequence of strain Sy-1 showed the highest similarity to unknown LAB species isolated from the gut of honeybees. The phylogenetic analyses discovered that strain Sy-1 belonged to the Lactobacillaceae family and formed a separate branch closer to type strain from the genera of Acetilactobacillus and Apilactobacillus. The ANI analysis showed the similarity of the closest relative, Apilactobacillus micheneri Hlig3T. The assembled genome of Sy-1 contains 3 contigs with 2.03 Mbp and a 41% GC content. A total of 1,785 genes were identified, including 1,685 protein-coding genes, 68 tRNA, and 15 rRNA. Interestingly, strain Sy-1 encoded complete genes for the biosynthesis of folate and riboflavin. High-performance liquid chromatography analysis further confirmed the high production of folic acid (1.346 mg/L) by Sy-1. Discussion: Based on phylogenetic and biochemical characteristics, strain Sy-1 should be classified as a novel genus in the family of Lactobacillaceae and a new member of FLAB. The genome information coupled with experimental studies supported the ability of strain Sy-1 to produce high folic acid. Our collective findings support the suitable application of FLAB strain Sy-1 in the functional food and pharmaceutical industries.

The Emergence and Impact of Ethylene Scavengers Techniques in Delaying the Ripening of Fruits and Vegetables.

As the top grocery list priorities, the primary challenge when purchasing fruits and vegetables from supermarkets is obtaining fresh, minimally processed perishable goods. This source of diet is critical for obtaining vitamins, minerals, antioxidants, and fibres. However, the short shelf life caused by moisture content in rapid deterioration and decay caused by microbial growth, results in unappealing appearances. Fruits and vegetables undergo ripening and eventually the ageing process, in which the tissues of the plants degrade. Even after harvesting, numerous biological processes occur, generating a significant variation of ethylene production along with respiration rates between fruits and vegetables. Thus, the utilization of ethylene scavengers in food packaging or films has been revealed to be beneficial. The synergistic effects of these biomaterials have been demonstrated to reduce microorganisms and prolong the shelf life of greens due to antimicrobial activity, oxygen scavenging capacity, enzyme immobilization, texture enhancers, and nutraceuticals. The current review fills this void by discussing the most recent advances in research on ethylene scavengers and removal mechanisms of ethylene, including oxidation in fruit and vegetable packaging. The application and advantages of ethylene scavengers in packaging are then discussed with the addition of how the efficiency related to ethylene scavengers can be increased through atmospheric packaging tools. In this context, the article discusses characteristics, types of applications, and efficacy of ethylene control strategies for perishable commodities with the inclusion of future implications.

Thermodynamic stability, in-vitro permeability, and in-silico molecular modeling of the optimal Elaeis guineensis leaves extract water-in-oil nanoemulsion.

Nanoemulsion is a delivery system used to enhance bioavailability of plant-based compounds across the stratum corneum. Elaeis guineensis leaves are rich source of polyphenolic antioxidants, viz. gallic acid and catechin. The optimal E. guineensis leaves extract water-in-oil nanoemulsion was stable against coalescence, but it was under significant influence of Ostwald ripening over 90 days at 25 °C. The in-vitro permeability revealed a controlled and sustained release of the total phenolic compounds (TPC) of EgLE with a cumulative amount of 1935.0 ± 45.7 µgcm-2 after 8 h. The steady-state flux and permeation coefficient values were 241.9 ± 5.7 µgcm-2 h-1 and 1.15 ± 0.03 cm.h-1, respectively. The kinetic release mechanism for TPC of EgLE was best described by the Korsmeyer-Peppas model due to the highest linearity of R2 = 0.9961, indicating super case II transport mechanism. The in-silico molecular modelling predicted that the aquaporin-3 protein in the stratum corneum bonded preferably to catechin over gallic acid through hydrogen bonds due to the lowest binding energies of - 57.514 kcal/mol and - 8.553 kcal/mol, respectively. Thus, the in-silico study further verified that catechin could improve skin hydration. Therefore, the optimal nanoemulsion could be used topically as moisturizer to enhance skin hydration based on the in-silico prediction.

Molecular simulation on the stability and adsorption properties of choline-based ionic liquids/IRMOF-1 hybrid composite for selective H2S/CO2 capture.

The compatibility and performance of an Isoreticular Metal-Organic Frameworks (IRMOF-1) impregnated with choline-based ionic liquids (ILs) for selective adsorption of H2S/CO2, were studied by molecular dynamics (MD) simulation. Cholinium alanate ([Chl][Ala]) was nominated as the suitable IL for impregnation into IRMOF-1, consistent with the low RMSD values (0.546 nm, 0.670 nm, 0.776 nm) at three IL/IRMOF-1 w/w ratios (WIL/IRMOF-1 = 0.4, 0.8, and 1.2). The [Chl]+ and [Ala]- ion pair was located preferentially around the carboxylate group within the IRMOF-1 framework, with the latter interacting strongly with the host than the [Chl]+. Results of radius of gyration (Rg) and root mean square displacement (RMSD) revealed that a ratio of 0.4 w/w of IL/IRMOF-1 (Rg = 1.405 nm; RMSD = 0.546 nm) gave the best conformation to afford an exceptionally stable IL/IRMOF-1 composite. It was discovered that the IL/IRMOF-1 composite was more effective in capturing H2S and CO2 compared to pristine IRMOF-1. The gases adsorbed in higher quantities in the IL/IRMOF-1 composite phase compared to the bulk phase, with a preferential adsorption for H2S, as shown by the uppermost values of adsorption ( [Formula: see text] = 17.954 mol L-1 bar-1) and an adsorption selectivity ( [Formula: see text] = 43.159) at 35 IL loading.

Substrate docking and molecular dynamic simulation for prediction of fungal enzymes from Trichoderma species-assisted extraction of nanocellulose from oil palm leaves.

Fungi of the Trichoderma species are valued industrial enzymes in support of the 'zero-waste' technology to convert agro-industrial biomass into valuable products, i.e. nanocellulose (NC). In this study, an in silico approach using substrate docking and molecular dynamic (MD) simulation was used to predict the order of which the multilayers of cellulosic polymers, i.e. lignin, hemicellulose and cellulose in oil palm leaves (OPL) are degraded by fungal enzymes, endocellulase and exocellulase. The study aimed to establish the catalytic tendencies of the enzymes to optimally degrade the cellulosic components of OPL for high yield production of NC. Energy minimized endocellulase and exocellulase models revealed satisfactory scores of PROCHECK (90.0% and 91.2%), Verify3D (97.23% and 98.85%) and ERRAT (95.24% and 91.00%) assessments. Active site prediction by blind docking, COACH meta-server and multiple sequence alignment indicated the catalytic triads for endocellulase and exocellulase were Ser116-His205-Glu249 and Ser382-Arg124-Asp385, respectively. Binding energy of endocellulase docked with hemicellulose (-6.0 kcal mol-1) was the most favourable followed by lignin (-5.6 kcal mol-1) and cellulose (-4.4 kcal mol-1). Exocellulase, contrarily, bonded favorably with lignin (-8.7 kcal mol-1), closely followed by cellulose (-8.5 kcal mol-1) and hemicellulose (-8.4 kcal mol-1). MDs simulations showed that interactions of complexes, endocellulase-hemicellulose and the exocellulase-cellulose being the most stable. Thus, the findings of the study successfully identified the specific actions of sugar-acting enzymes for NC production. Communicated by Ramaswamy H. Sarma.

Theoretical analyses on enantiospecificity of L-2-haloacid dehalogenase (DehL) from Rhizobium sp. RC1 towards 2-chloropropionic acid.

Dehalogenases continue to garner interest of the scientific community due to their potential applications in bioremediation of halogen-contaminated environment and in synthesis of various industrially relevant products. Example of such enzymes is DehL, an L-2-haloacid dehalogenase (EC 3.8.1.2) from Rhizobium sp. RC1 that catalyses the specific cleavage of halide ion from L-2-halocarboxylic acids to produce the corresponding D-2-hydroxycarboxylic acids. Recently, the catalytic residues of DehL have been identified and its catalytic mechanism has been fully elucidated. However, the enantiospecificity determinants of the enzyme remain unclear. This information alongside a well-defined catalytic mechanism are required for rational engineering of DehL for substrate enantiospecificity. Therefore, using quantum mechanics/molecular mechanics and molecular mechanics Poisson-Boltzmann surface area calculations, the current study theoretically investigated the molecular basis of DehL enantiospecificity. The study found that R51L mutation cancelled out the dehalogenation activity of DehL towards it natural substrate, L-2-chloropropionate. The M48R mutation, however introduced a new activity towards D-2-chloropropionate, conveying the possibility of inverting the enantiospecificity of DehL from L-to d-enantiomer with a minimum of two simultaneous mutations. The findings presented here will play important role in the rational design of DehL dehalogenase for improving substrate utility.

The mechanistic role of active site residues in non-stereo haloacid dehalogenase E (DehE).

Dehalogenase E (DehE) is a non-stereospecific enzyme produced by the soil bacterium, Rhizobium sp. RC1. Till now, the catalytic mechanism of DehE remains unclear although several literature concerning its structure and function are available. Since DehE is non-stereospecific, the enzyme was hypothesized to follow a 'direct attack mechanism' for the catalytic breakdown of a haloacid. For a molecular insight, the DehE modelled structure was docked in silico with the substrate 2-chloropropionic acid (2CP) in the active site. The ideal position of DehE residues that allowed a direct attack mechanism was then assessed via molecular dynamics (MD) simulation. It was revealed that the essential catalytic water was hydrogen bonded to the 'water-bearer', Asn114, at a relatively constant distance of ∼2.0 Šafter 50 ns. The same water molecule was also closely sited to the catalytic Asp189 at an average distance of ∼2.0 Å, signifying the imperative role of the latter to initiate proton abstraction for water activation. This reaction was crucial to promote a direct attack on the α-carbon of 2CP to eject the halide ion. The water molecule was oriented favourably towards the α-carbon of 2CP at an angle of ∼75°, mirrored by the formation of stable enzyme-substrate orientations throughout the simulation. The data therefore substantiated that the degradation of a haloacid by DehE followed a 'direct attack mechanism'. Hence, this study offers valuable information into future advancements in the engineering of haloacid dehalogenases with improved activity and selectivity, as well as functionality in solvents other than water.

Capillary electrophoresis for the analysis of antidepressant drugs: A review.

Depression is a common mental disorder that may lead to major mental health problems, and antidepressant drugs have been used as a treatment of choice to mitigate symptoms of major depressive disorders by ameliorating the chemical imbalances of neurotransmitters in brain. Since abusing antidepressant drugs such as selective serotonin reuptake inhibitors and tricyclic antidepressant drugs can cause severe adverse effects, continuous toxicological monitoring of the parent compounds as well as their metabolites using numerous analytical methods appears pertinent. Among them, capillary electrophoresis has been popularly utilized since the method has a lot of advantages viz. using small amounts of sample and solvents, ease of operation, and rapid analysis. This review paper brings a survey of more than 30 papers on capillary electrophoresis of antidepressant drugs published approximately from 1999 until 2018. It focuses on the reported capillary electrophoresis techniques and their applications and challenges for determining antidepressant drugs and their metabolites. It is organized according to the commonly used capillary zone electrophoresis method, followed by non-aqueous capillary electrophoresis and micellar electrokinetic chromatography, with details on breakthrough findings. Where available, information is given about the background electrolyte used, detector utilized, and sensitivity obtained.

Toxic metals in Perna viridis mussel and surface seawater in Pasir Gudang coastal area, Malaysia, and its health implications.

Contamination of toxic metals in P. viridis mussels has been prevalently reported; hence, health risk assessment for consuming this aquaculture product as well as the surrounding surface seawater at its harvesting sites appears relevant. Since Kampung Pasir Puteh, Pasir Gudang is the major harvesting site in Malaysia, and because the last heavy metal assessment was done in 2009, its current status remains unclear. Herein, flame atomic absorption spectrometry and flow injection mercury/hydride system were used to determine the concentrations of Pb, Cd, Cu and total Hg in P. viridis mussels and surface seawater (January-March 2015), respectively. Significantly higher concentrations of these metals were found in P. viridis mussels (p < 0.05) than that of surface seawater samples. The concentrations for Pb (4.27-6.55 µg/g) and Cd (1.55-2.21 µg/g) in P. viridis mussels exceeded the maximum permitted proportion prescribed by the Malaysian law. The concentrations of all metals in surface seawater also violated the Malaysia Marine Water Quality Criteria and Standards. Significant (p < 0.05) and high strength of association (r = 0.787) observed between Pb concentration in P. viridis mussel with the surface seawater indicates its possible application for inferring Pb concentrations in the mussel. Since both the calculated target hazard quotient and hazard index for Pb and Cd exceeded 1, the possible detrimental health impacts on human for consuming P. viridis mussels from this rearing site cannot be ignored. Hence, promoting continuous monitoring programmes and developing efficient toxic metal removal techniques prior to entering the market are required.

Insight into the Rhizomucor miehei lipase supported on chitosan-chitin nanowhiskers assisted esterification of eugenol to eugenyl benzoate.

To overcome drawbacks in the conventional chemical route to synthesize eugenyl benzoate, immobilized Rhizomucor miehei lipase (RML) as the biocatalyst was proposed. The RML conjugated to a hybrid support consisting of biopolymers, chitosan (CS) and chitin nanowhiskers (CNWs). 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDAC) was used as the crosslinker to bind the lipase. Immobilization of RML was the highest on crosslinked CS/CNWs which gave a protein loading of ∼8.12 mg/g, corresponding to specific and residual activity of 537 U/g and 137%, respectively. Fourier transform infrared spectroscopy, thermogravimetric analysis-differential thermogravimetry, field emission scanning electron and atomic force microscopy of RML-CS/CNWs revealed that RML was successfully attached to the surface of crosslinked CS/CNWs. Under an optimized condition, the highest yield of eugenyl benzoate (56.3%) was attained after 5 h using 3 mg/mL of RML-CS/CNWs with molar ratio of eugenol: benzoic acid of 3:1, as compared to only 47.3% for the free RML. Analyses of FTIR and NMR on purified eugenyl benzoate affirmed that the ester was successfully produced in the enzymatic esterification. Therefore, the use of the RML-CS/CNWs biocatalysts appears promising to afford good yields of eugenyl benzoate within a relatively shorter reaction time.

Novel Safranin-Tinted Candida rugosa Lipase Nanoconjugates Reagent for Visualizing Latent Fingerprints on Stainless Steel Knives Immersed in a Natural Outdoor Pond.

Waterways are popular locations for the disposition of criminal evidence because the recovery of latent fingerprints from such evidence is difficult. Currently, small particle reagent is a method often used to visualize latent fingerprints containing carcinogenic and hazardous compounds. This study proposes an eco-friendly, safranin-tinted Candida rugosa lipase (triacylglycerol ester hydrolysis EC 3.1.1.3) with functionalized carbon nanotubes (CRL-MWCNTS/GA/SAF) as an alternative reagent to the small particle reagent. The CRL-MWCNTS/GA/SAF reagent was compared with the small particle reagent to visualize groomed, full fingerprints deposited on stainless steel knives which were immersed in a natural outdoor pond for 30 days. The quality of visualized fingerprints using the new reagent was similar (modified-Centre for Applied Science and Technology grade: 4; p > 0.05) to small particle reagent, even after 15 days of immersion. Despite the slight decrease in quality of visualized fingerprints using the CRL-MWCNTS/GA/SAF on the last three immersion periods, the fingerprints remained forensically identifiable (modified-Centre for Applied Science and Technology grade: 3). The possible chemical interactions that enabled successful visualization is also discussed. Thus, this novel reagent may provide a relatively greener alternative for the visualization of latent fingerprints on immersed non-porous objects.