In Silico and Experimental Characterization of Chimeric Bacillus thermocatenulatus Lipase with the Complete Conserved Pentapeptide of Candida rugosa Lipase

Lipases are one of the highest value commercial enzymes as they have broad applications in detergent, food, pharmaceutical, and dairy industries. To provide chimeric Bacillus thermocatenulatus lipase (BTL2), the completely conserved pentapeptide (¹¹²Ala-His-Ser-Gln-Gly¹¹⁶) was replaced with similar sequences (²⁰⁷Gly-Glu-Ser-Ala-Gly²¹¹) of Candida rugosa lipase (CLR) at the nucleophilic elbow region. For this purpose, three mutations including A112G, H113E, and Q115A were inserted in the conserved pentapeptide sequence of btl2 gene. Based on the crystal structures of 2W22, the best structure of opened form of the chimeric lipases were garnered using the MODELLER v9.10 software. The native and chimeric lipases were docked to a set of ligands, and a trial version of Molegro Virtual Docker (MVD) software was used to obtain the energy values. Docking results confirmed chimeric lipase to be better than the native lipase. Following the in silico study, cloning experiments were conducted and expression of native and chimeric btl2 gene in Pichia pastoris was performed. The native and chimeric lipases were purified, and the effect of these mutations on characteristics of chimeric lipase studied and then compared with those of native lipase. Chimeric lipase exhibited 1.6-fold higher activity than the native lipase at 55 °C. The highest percentage of both lipases activity was observed at 60 °C and pH of 8.0. The ion Ca²⁺ slightly inhibited the activity of both lipases, whereas the organic solvent enhanced the lipase stability of chimeric lipase as compared with the native lipase. According to the results, the presence of two glycine residues at the conserved pentapeptide region of this chimeric lipase (¹¹² Gly-Glu-Ser-Ala-Gly ¹¹⁶) may increase the flexibility of the nucleophilic elbow region and affect the enzyme activity level.     

Sol–gel derived LaFeO3/SiO2 nanocomposite: synthesis,characterization and its application as a new,green and recoverable heterogeneous catalyst for the efficient acetylation of amines,alcohols and phenols

LaFeO₃/SiO₂ nanocomposite was synthesized by the sol–gel process from metal nitrates and tetraethyl orthosilicate (TEOS) as the SiO₂ source. The nanocomposite product was characterized by XRD, FT-IR, SEM, and surface area measurements and was used as a heterogeneous catalyst for the efficient acetylation of amines, alcohols and phenols to the corresponding acetates using acetic anhydride under solvent-free conditions. Among the various substrates, acetylation of amines was preceded rapidly, so that an amine group could be selectively acetylated in the presence of alcoholic or phenolic hydroxyl groups by the appropriate choice of reaction time. The catalyst can also be reused several times without the loss of activity. In addition, the catalytic activity of the LaFeO₃/SiO₂ nanocomposite was higher than that of the pure LaFeO₃ nanoparticles. The method is high yielding, clean, cost effective, compatible with the substrates having other functional groups and very suitable for the practical organic synthesis.     

Steric and Electronic Influence on the Coordination Aptitude of 4‐Formylpiperazine‐1‐Carbodithioate Towards Triorganotin(IV) Moieties

A fascinating ligand, 4‐formylpiperazinium 4‐formylpiperazine‐1‐carbodithioate (L‐salt) has been reacted with two electronically and sterically different trimethyltin(IV) chloride and triphenyltin(IV) chloride. The complexes 1 and 2 were characterized by elemental analysis, spectroscopic techniques, and X‐ray single crystal analysis. The latter technique confirmed the polymeric and monomeric nature of 1 and 2 , respectively. Both 1 and 2 showed intriguing molecular packing properties in the solid state. However, the packing of 1 is more interesting and unique where one‐dimensional polymer chains self assemble in two‐over‐two saltire‐shaped fashion to provide an overall multilayered structure. The different behavior of L toward two different tin(IV) compounds can be attributed to different electronic and steric environments around metal center.     

Organotin(IV) Carboxylates of Substituted α‐Cinnamic Acid,RnSn(OCOC(R2)=CHR1)4 – n: Synthesis,Spectroscopic Characterization and Biological Evaluation

Di‐ and triorganotin(IV) carboxylates, R_nSn(OCOC(R²)=CHR¹)_4–n (n = 2 and 3; R = Me, Et, n‐Bu, Ph; R¹ = 3‐CH₃O‐4‐OHC₆H₃, R² = C₆H₅) were prepared by reacting the corresponding organotin(IV) chloride with the silver salt of the (E)‐3‐(4‐hydroxy‐3‐methoxyphenyl)‐2‐phenylpropenoic acid. The title compounds were investigated and characterized by elemental analysis, infrared (FT‐IR), multinuclear (¹H, ¹³C, ¹¹⁹Sn) NMR, and mass spectrometry, and possible structures were proposed. The complexes and ligand acid ( HL ) have been evaluated in vitro against various bacteria and fungi. The results noticed during the biocidal activity screenings proved their in vitro biological potential. They were also tested for cytotoxicity.     

Synergistic effect of aluminum trihydrate and zirconium hydroxide nanoparticles on mechanical properties,flammability, and thermal degradation of polyester/jute fiber composite

Cellulose - This study focuses on the synergistic effects of hydroxide based nanoparticles namely aluminum trihydrate (ATH) and zirconium hydroxide (ZHO) on the mechanical characteristics, thermal...     

The exploring microstructural,caloric, and corrosion behavior of NiTiNb shape-memory alloys

Journal of Thermal Analysis and Calorimetry - The influence of four different quantities of niobium (Nb) on some physical and chemical properties of Ni-Ti alloy was examined in this study....     

Riboflavin as a green sorbent in dispersive micro-solid-phase extraction of several pesticides from fruit juices combined with dispersive liquid–liquid microextraction

A vortex-assisted dispersive micro-solid-phase extraction procedure using a new and green sorbent was developed as a simple, fast, and efficient sample preparation method for the extracting five pesticides in several fruit juice samples. In this study, for the first time, riboflavin was used as an efficient sorbent. A few milligrams of riboflavin was directly added into the aqueous solution containing the analytes to adsorb them. After adsorption the analytes, they were desorbed and more concentrated by a dispersive liquid–liquid microextraction procedure. The influence of several effective parameters such as amount of riboflavin, pH, vortex time, eluent nature and volume, and extraction solvent type and volume on the extraction efficiency was investigated. In optimal conditions, linear ranges of the calibration curves were broad. The limits of detection and quantification were attained in the ranges of 0.56–1.5  and 1.9–0.52 ng mL⁻¹, respectively. The proposed method demonstrated to be suitable for concurrent extraction of the studied pesticides in various fruit juice samples with high enrichment factors (320–360) and precision (relative standard deviation ≤7.8% for intra- [n = 6] and interday [n = 4] precisions at a concentration of 25 ng mL⁻¹ of each pesticide).     

Ornamental Plant Efficiency for Heavy Metals Phytoextraction from Contaminated Soils Amended with Organic Materials

Accumulation of heavy metals (HMs) by ornamental plants (OPs) from contaminated agriculture soils is a unique technique that can efficiently reduce the metal load in the food chain. Amaranthus tricolor L. has attractive characteristics acquiring a higher growth rate and large biomass when grown at heavy metal contaminated soils. Site-specific detailed information is not available on the use of A. tricolor plant in metal phytoremediation from the polluted sites. The study aimed to enhance the uptake of HMs (Pb, Zn, and Cu) via amending poultry litter extract (PLE), vinasse sugarcane (VSC), and humic acid (HA) as natural mobilized organic materials compared to ethylene diamine tetraacetic acid (EDTA), as a common mobilized chemical agent by A. tricolor plant. The studied soils collected from Helwan, El-Gabal El-Asfar (Cairo Governorate), Arab El-Madabeg (Assiut Governorate), Egypt, and study have been conducted under pot condition. Our results revealed all organic materials in all studied soils, except EDTA in EL-Gabal El-Asfar soil, significantly increased the dry weight of the A. tricolor plant compared to the control treatment. The uptake of Pb and Zn significantly (p > 0.05) increased due to applying all organic materials to the studied soils. HA application caused the highest uptake as shown in Pb concentration by more than 5 times in Helwan soil and EDTA by 65% in El-Gabal El-Asfar soil while VSC increased it by 110% in El-Madabeg soil. Also, an increase in Zn concentration due to EDTA application was 58, 42, and 56% for Helwan, El-Gabal El-Asfar, and El-Madabeg soil, respectively. In all studied soils, the application of organic materials increased the remediation factor (RF) than the control. El-Madabeg soil treated with vinasse sugarcane gave the highest RF values; 6.40, 3.26, and 4.02% for Pb, Zn, and Cu, respectively, than the control. Thus, we identified A. tricolor as a successful ornamental candidate that, along with organic mobilization amendments, most efficiently develop soil health, reduce metal toxicity, and recommend remediation of heavy metal-contaminated soils. Additionally, long-term application of organic mobilization amendments and continued growth of A. tricolor under field conditions could be recommended for future directions to confirm the results.     

Biomedical Applications of Scutellaria edelbergii Rech. f.: In Vitro and In Vivo Approach

In the current study, in vitro antimicrobial and antioxidant activities and in vivo anti-inflammatory and analgesic activities of Scutellaria edelbergii Rech. f. (crude extract and subfractions, i.e., n-hexane, ethyl acetate (EtOAc), chloroform, n-butanol (n-BuOH) and aqueous) were explored. Initially, extraction and fractionation of the selected medicinal plant were carried out, followed by phytochemical qualitative tests, which were mostly positive for all the extracts. EtOAc fraction possessed a significant amount of phenolic (79.2 ± 0.30 mg GAE/g) and flavonoid (84.0 ± 0.39 mg QE/g) content. The EtOAc fraction of S. edelbergii exhibited appreciable antibacterial activity against Gram-negative (Escherichia coli and Klebsiella pneumoniae) strains and significant zones of inhibition were observed against Gram-positive bacterial strains (Bacillus subtilis and Staphylococcus aureus). However, it was found inactive against Candida Albicans and Fusarium oxysporum fungal strains. The chloroform fraction was the most effective with an IC₅₀ value of 172 and 74 µg/mL against DPPH (1,1-Diphenyl-2-picryl-hydrazyl) and ABTS assays, in comparison with standard ascorbic acid 59 and 63 µg/mL, respectively. Moreover, the EtOAc fraction displayed significant in vivo anti-inflammatory activity (54%) using carrageenan-induced assay and significant (55%) in vivo analgesic activity using acetic acid-induced writing assay. In addition, nine known compounds, ursolic acid (UA), ovaul (OV), oleanolic acid (OA), β-sitosterol (BS), micromeric acid (MA), taraxasterol acetate (TA), 5,3′,4′-trihydroxy-7-methoxy flavone (FL-1), 5,7,4′-trihydroxy-6,3′-dimiethoxyflavone (FL-2) and 7-methoxy catechin (FL-3), were isolated from methanolic extract of S. edelbergii. These constituents have never been obtained from this source. The structures of all the isolated constituents were elucidated by spectroscopic means. In conclusion, the EtOAc fraction and all other fractions of S. edelbergii, in general, displayed a significant role as antibacterial, free radical scavenger, anti-inflammatory and analgesic agents which may be due to the presence of these constituents and other flavonoids.     

Protease Inhibitors Purified from the Canola Meal Extracts of Two Genetically Diverse Genotypes Exhibit Antidiabetic and Antihypertension Properties

Valorization of vegetable oil waste residues is gaining importance due to their high protein and polyphenol contents. Protease inhibitors (PIs), proteins from these abundantly available waste residues, have recently gained importance in treating chronic diseases. This research aimed to use canola meal of genetically diverse Brassica napus genotypes, BLN-3347 and Rivette, to identify PIs with diverse functionalities in therapeutic and pharmacological applications. The canola meal PI purification steps involved: native PAGE and trypsin inhibition activity, followed by ammonium sulfate fractionation, anion exchange, gel filtration, and reverse-phase chromatography. The purified PI preparations were characterized using SDS-PAGE, isoelectric focusing (IEF), and N terminal sequencing. SDS-PAGE analysis of PI preparations under native reducing and nonreducing conditions revealed three polymorphic PIs in each genotype. The corresponding IEF of the genotype BLN-3347, exhibited three acidic isoforms with isoelectric points (pI) of 4.6, 4.0, and 3.9, while Rivette possessed three isoforms, exhibiting two basic forms of pI 8.65 and 9.9, and one acidic of pI 6.55. Purified PI preparations from both the genotypes displayed dipeptidyl peptidase-IV (DPP-IV) and angiotensin-converting enzyme (ACE) inhibition activities; the BLN-3347 PI preparation exhibited a strong inhibitory effect with lower IC₅₀ values (DPP-IV 37.42 µg/mL; ACE 129 µg/mL) than that from Rivette (DPP-IV 67.97 µg/mL; ACE 376.2 µg/mL). In addition to potential human therapy, these highly polymorphic PIs, which can inhibit damaging serine proteases secreted by canola plant pathogens, have the potential to be used by canola plant breeders to seek qualitative trait locus (QTLs) linked to genes conferring resistance to canola diseases.