Development of starch-rich thermoplastic polymers based on mango kernel flour and different plasticizers.

This work reports on the development of starch-rich thermoplastic based formulations produced by using mango kernel flour, avoiding the extraction process of starch from mango kernel to produce these materials. Glycerol, sorbitol and urea at 15 wt% are used as plasticizers to obtain thermoplastic starch (TPS) formulations by extrusion and injection-moulding processes. Mechanical results show that sorbitol and urea allowed to obtain samples with tensile strength and elongation at break higher than the glycerol-plasticized sample, achieving values of 2.9 MPa of tensile strength and 42 % of elongation at break at 53 % RH. These results are supported by field emission scanning electron microscopy (FESEM) micrographs, where a limited concentration of voids was observed in the samples with sorbitol and urea, indicating a better interaction between starch and the plasticizers. Thermogravimetric analysis (TGA) shows that urea and sorbitol increase the thermal stability of TPS in comparison to the glycerol-plasticized sample. Differential scanning calorimetry (DSC) and dynamic-mechanical-thermal analysis (DMTA) verify the increase in stiffness of the sorbitol and urea plasticized TPS and also illustrate an increase in the glass transition temperature of both samples in comparison to the glycerol-plasticized sample. Glass transition temperatures of 45 °C were achieved for the sample with sorbitol.

1,5-Anhydro-d-glucitol derivative and galloylated flavonoids isolated from the leaves of Acer ginnala Maxim. as dual inhibitors of PTP1B and α-glucosidase enzymes: In vitro and in silico studies.

Four undescribed compounds (two 1,5-anhydro-d-glucitol derivatives and two galloyl derivatives) and fourteen known compounds were isolated and structurally identified from leaves of Acer ginnala Maxim. (Amur maple). Structures and absolute configurations of the four undescribed compounds were determined using extensive analysis of NMR spectroscopic, HRESI-MS, modified Mosher ester method, and comparison with spectroscopic data of known compounds. Bioactivity evaluation revealed that the isolated 1,5-anhydro-d-glucitol derivative, galloylated flavonol rhamnosides, and galloylated flavanols had inhibitory effects on both protein tyrosine phosphatase-1B (PTP1B, IC50 values ranging of 3.46-12.65 µM) and α-glucosidase (IC50 values ranging of 0.88-6.06 µM) in comparison with a positive control for PTP1B (ursolic acid, IC50 = 5.10 µM) or α-glucosidase (acarbose, IC50 = 141.62 µM). A combination of enzyme kinetic analysis and molecular docking provided additional evidence in favor of their inhibitory activities and mechanism. These data demonstrate that A. ginnala Maxim. together with its constituents are promising sources of potent candidates for developing novel anti-diabetic medications.

Effects of different ratios of mannitol to sorbitol on the functional properties of sweet potato starch films.

Sorbitol as a plasticizer is easily crystallized from starch film, resulting in the reduction in plasticizing effect. To improve the plasticizing performance of sorbitol in starch films, mannitol, an acyclic hexahydroxy sugar alcohol, was used to cooperate with sorbitol. The effects of different ratios of mannitol (M) to sorbitol (S) as a plasticizer on mechanical properties, thermal properties, water resistance and surface roughness of sweet potato starch films were investigated. The results showed that the surface roughness of starch film with M:S (60:40) was the smallest. The number of hydrogen bonds between plasticizer and starch molecule was proportional to the mannitol content starch film. With the decrease of mannitol contents, the tensile strength of starch films gradually decreased except for M:S (60:40). Moreover, the transverse relaxation time value of starch film with M:S (100:0) was the lowest, indicating that it had the lowest degree of freedom of water molecules. Starch film with M:S (60:40) is the most effective in delaying the retrogradation of starch film. This study offered a new theoretical basis that different ratios of mannitol to sorbitol improve different performances of starch films.

A survey on the stabilizing effect of osmolytes on the ultrasound-irradiated lipase for efficient enzymatic hydrolysis of coconut oil.

The stabilizing effect of some osmolytes including betaine, mannitol, proline, sorbitol, and trehalose (each 0.5 M) was investigated on the ultrasound-irradiated (60 kHz and 138 W, for 240 min) lipase by determination of the enzyme half-life time, evaluation of the enzymatic reaction velocity (Vmax), and hydrolysis of coconut oil for production of lauric acid (the main saturated fatty acid of the oil). The enzyme conformational stability was also assessed by circular dichroism (CD) and fluorescence spectroscopy. The average half-life time of mannitol- and sorbitol-treated lipase under the ultrasound irradiation was 511 ± 3 min and 531 ± 2 min, respectively; 3-fold higher than the unirradiated enzyme. The Vmax value of the ultrasound-treated lipase increased from 100 ± 3 nmol min-1 in the absence of osmolyte to 500 ± 7 nmol min-1 and 500 ± 9 nmol min-1 in the presence of mannitol and sorbitol, respectively. CD and fluorescence spectra indicated that mannitol and sorbitol enhanced the rigidity of the lipase molecular conformational structure, increasing the enzyme stability against the ultrasonic field. The ultrasound-irradiated lipase was then used to hydrolyze coconut oil in the absence or presence of the selected osmolytes, which led to liberate 310 ± 6 mg g-1, 413 ± 7 mg g-1, and 420 ± 4 mg g-1 of lauric acid in the absence or presence of sorbitol and mannitol, respectively. In the absence of an ultrasonic field, the non-osmotically-treated lipase was able to liberate only 211 ± 5 mg g-1 of lauric acid. These promising results indicate that sorbitol and mannitol stabilize the structural conformation of lipase under an ultrasonic field which in turn could improve the enzymatic hydrolysis of coconut oil.

Glassy dynamics in polyalcohols: intermolecular simplicity vs. intramolecular complexity.

Using depolarized light scattering, we have recently shown that structural relaxation in a broad range of supercooled liquids follows, to good approximation, a generic line shape with high-frequency power law ω-1/2. We now continue this study by investigating a systematic series of polyalcohols (PAs), frequently used as model-systems in glass-science, i.a., because the width of their respective dielectric loss spectra varies strongly along the series. Our results reveal that the microscopic origin of the observed relaxation behavior varies significantly between different PAs: while short-chained PAs like glycerol rotate as more or less rigid entities and their light scattering spectra follow the generic shape, long-chained PAs like sorbitol display pronounced intramolecular dynamic contributions on the time scale of structural relaxation, leading to systematic deviations from the generic shape. Based on these findings we discuss an important limitation for observing the generic shape in a supercooled liquid: the dynamics that is probed needs to reflect the intermolecular dynamic heterogeneity, and must not be superimposed by effects of intramolecular dynamic heterogeneity.

Can analyte protectants compensate wastewater matrix induced enhancement effects in gas chromatography - mass spectrometry analysis?

This study aimed to investigate the ability of analyte protectants to enhance GC-MS signals and compensate matrix effects for a range of micropollutants in pure standard, effluent, and influent wastewater samples during analysis and detection. Wastewater samples were prepared for analysis using multilayer solid phase extraction for the purpose of extracting sample components with a broad range of physical-chemical properties. The sample extracts were either spiked or not spiked with target compounds and four analyte protectants: 3-ethoxy-1,2-propanediol, D-sorbitol, gluconolactone, and shikimic acid. In this way, it was possible to evaluate the matrix effects of wastewater samples and compare the use of analyte protectants with the conventional correction method of allocating a best matching internal standard to each target compound. A relation was observed between level of wastewater treatment and matrix effects, with the largest effects observed for influent samples and the smallest effects for effluent samples. Compensation of matrix effects with analyte protectants gave comparable results with the conventional correction method of allocating a best matching internal standard to each of the 13 investigated micropollutants. The best overall compensation was observed using analyte protectants and the internal standard correction method in combination.

Electronic skin based on cellulose/KCl/sorbitol organohydrogel.

With the increasing interests in the fields of wearable devices, it is essential yet also challenging to develop electronic skin with customized functionalities, especially for harsh conditions. Herein, by using KCl as both anti-solvent for cellulose regeneration and ionic charge carrier in the cellulose gel network, cellulose/KCl/sorbitol organohydrogel (CKS) combining transparency (over 95% at 550 nm), stretchability (235%), high conductivity (3.88 S/m), and low temperature tolerance (-51.8 °C) was prepared. The CKS based electronic skin achieved simultaneous monitoring of object contact-separation/pressure, stretching/bending and thermal variation, with excellent reliability and stability even in harsh conditions, resembling the human skin with multiply functions. The CKS based electronic skin as efficient human-machine interface was also demonstrated. Furthermore, the CKS based triboelectric nanogenerator delivered a power density of 991 mW/m2, potential as mechanical energy harvesters for wearable devices. We believe the present work will inspire the development of cellulose based skin-like materials and contribute to the comprehensive utilization of naturel polymer in the field of smart devices.

Mitochondria targeting molecular transporters: synthesis, lipophilic effect, and ionic complex.

As mitochondria are potential therapeutic targeting sites for the treatment of human diseases, delivering cytotoxic drugs, antioxidants, and imaging molecules to mitochondria can provide new therapeutic opportunities. In an attempt to develop a new mitochondria-targeting vector, we synthesized sorbitol-based molecular transporters with multiple guanidines, measured their partition coefficients, compared their targeting efficiency using fluorescent images and Pearson's correlation coefficients, and studied cellular uptake mechanisms. To increase the targeting ability of these molecular transporters to mitochondria, alanine-naphthalene as a lipophilic group was attached to the molecular transporter, which improved translocation across cellular membranes and led to higher accumulation in mitochondria. The molecular transporter was able to form an ionic complex with antibiotics, resulting in low cell viability. These data demonstrate that the molecular transporter with a lipophilic group could be utilized as a potential drug delivery vector for treating mitochondrial dysfunction.

Development and characterization of a novel multifunctional film based on wheat filter flour incorporated with carvacrol: Antibacterial, antifungal, and insecticidal potentials.

Wheat filter flour is a by-product derived from the modern wheat milling process. In this study, the influence of plasticizer type (glycerol (G) and sorbitol (S)) and content (25, 35, and 45 g/100 g polymer) on the wheat filter flour-based film was evaluated. Regardless of plasticizer type, increasing the plasticizer content enhanced moisture content, water solubility, and water vapor permeability of film samples. The S-plasticized films presented the greatest tensile strength and the lowest EAB%. The scanning electron microscope observations confirmed the uniform structure of G-plasticized film. Moreover, antimicrobial and physico-mechanical properties of G-plasticized (25%) film were evaluated at the presence of carvacrol (5 and 10 g/100 g polymer). The considerable improvement was achieved in water affinity (14.2%) and flexibility (8.6%) by incorporating 10% carvacrol in G-plasticized films. The greatest inhibitory properties of active wheat filter flour films were observed against Aspergillus niger. By increasing the carvacrol concentration in film-forming solution, the inhibitory activity against Listeria monocytogenes and Escherichia coli in the liquid food model system was increased by 90.3% and 66.95%, respectively. Moreover, the active wheat filter flour-based film released a considerable insecticidal activity against Sitophilus granarius and Tribolium confusum. This work offers a novel utilization of wheat filter flour as an inexpensive blend polymer to manufacture multifunctional active film, which provides a promising approach for pest management besides enhancing the safety of products.

Differential effect of polyol and sugar osmolytes on the refolding of homologous alpha amylases: A comparative study.

Polyol and sugar osmolytes are known to enhance the stability of proteins, however, their role in assisting protein folding is not well understood. We asked whether these osmolytes have the same effect during refolding of a pair of thermophilic and mesophilic proteins. Herein, we have chosen α-amylases from Bacillus licheniformis (BLA) and Bacillus amyloliquefaciens (BAA) as thermophilic like and mesophilic counterparts respectively, having similar structures but differing thermostability. The effect of a series of polyols with varying number of -OH groups from 2 to 6 (Ethylene glycol, glycerol, erythritol, xylitol and sorbitol) and sugars (trehalose and sucrose) has been studied on the refolding of BLA and BAA. Our study demonstrates that glycerol, sorbitol and trehalose are the efficient cosolvents for BAA refolding, while comparatively less effective for BLA. Urea induced destabilization of BLA and BAA is differently compensated by polyol and sugar osmolytes during refolding. This suggests that the early species formed during BLA and BAA refolding are differently susceptible towards urea, indicating differential nature of their refolding pathways. Addition of trehalose at different times during refolding showed that the presence of trehalose is essential at the early stages of refolding. It is one of the first systematic study wherein the comparative effect of polyol and sugar assisted refolding of thermophilic and mesophilic protein has been carried out. The study highlights the differential effect of protein-osmolyte interactions during refolding of thermophilic and mesophilic proteins which may have implications in protein formulations, refolding and inhibition of aggregation.

Thermoplastic starch blown films with improved mechanical and barrier properties.

The development and production of thermoplastic starch (TPS) films based on blown film extrusion have been spurred by increasing interest in renewable resources and an alternative solution to meet industrial-scale demand. The chemical structure of the plasticizer and its proportion have a significant effect on the mechanical and barrier properties of TPS films. Therefore, this research aims to evaluate the influence of plasticizer type and content on the performance of TPS blown films. TPS films were prepared by mixing cassava starch with three types of plasticizer, i.e. glycerol, glycerol/xylitol, and glycerol/sorbitol with a weight ratio of 1:1. The quantity of plasticizer varied among 38, 40, and 42 parts per hundred parts of starch. Although TPS films plasticized with the small-sized plasticizer glycerol were easily processed and extensible, the surface stickiness leading to single-wall films, low tensile strength, and poor water vapor barrier properties would limit their use. By replacing glycerol with larger-sized plasticizers such as xylitol or sorbitol, the films exhibited reduced stickiness and separable double walls and showed improved tensile strength, stiffness, and water vapor and oxygen barrier properties. The obtained TPS blown films offer potential applications as edible films for food and pharmaceutical products.

Preparation and Characterization of Co-Processed Mannitol and Sorbitol Using NanoCrySP Technology.

Particle engineering of excipients, at sub-particulate level using co-processing, can provide high functionality excipients. NanoCrySP technology has been recently explored as a novel approach for the generation of nanocrystalline solid dispersion of poorly soluble drugs, using spray drying process. The purpose of the present study was to generate co-processed mannitol and sorbitol (SD-CSM) using NanoCrySP technology having similar composition to commercial co-processed excipient (Compressol® SM, CP). The characterization of excipients was performed to evaluate their various physicomechanical properties. The sub-micron crystallite size of sorbitol in the matrix of mannitol was determined using the Williamson-Hall equation and Halder-Wagner equation. The reduction in crystallite size of sorbitol and mannitol, lower melting point, and lower heat of fusion of SD-CSM could be responsible for excellent compactibility, better tabletability, and comparable compressibility with respect to CP. This was confirmed by the compressibility-tabletability-compactibility (CTC) profile and Heckel plot analysis. Overall, SD-CSM generated using NanoCrySP technology improved functionalities of excipients over CP and would be useful for direct compression application.

D-Sorbitol Physical Properties Effects on Filaments Used by 3D Printing Process for Personalized Medicine.

Fused filament fabrication (FFF) is a process used to manufacture oral forms adapted to the needs of patients. Polyethylene oxide (PEO) filaments were produced by hot melt extrusion (HME) to obtain a filament suitable for the production of amiodarone hydrochloride oral forms by FFF 3D printing. In order to produce personalized oral forms adapted to the patient characteristics, filaments used by FFF must be controlled in terms of mass homogeneity along filament. This work highlights the relation between filament mass homogeneity and its diameter. This is why the impact of filler excipients physical properties was studied. It has been showed that the particle's size distribution of the filler can modify the filament diameter variability which has had an impact on the mass of oral forms produced by FFF. Through this work it was shown that D-Sorbitol from Carlo Erba allows to obtain a diameter variability of less than 2% due to its unique particle's size distribution. Using the filament produced by HME and an innovating calibration method based on the filament length, it has been possible to carry out three dosages of 125 mg, 750 mg and 1000 mg by 3D printing with acceptable mass uniformity.

Effect of plasticizers on physical, thermal, and tensile properties of thermoplastic films based on Dioscorea hispida starch.

This study examines the effects of varying the concentrations of sorbitol (S) and glycerol (G) on the physical, morphological, thermal, and mechanical properties of Dioscorea hispida, starch-based films. In this context, the films of Dioscorea hispida starch were developed using solution casting technique with glycerol (G), sorbitol (S), and a mixture of sorbitol-glycerol (SG) as plasticizers at the ratios of 0, 30, 45, and 60 wt%. The films' moisture contents were increased when increasing the plasticizer contents. The tensile strengths were decreased, but elongations at break were increased; 7.38%-11.54% for G-plasticized films, 10.17%-15.76% for S-plasticized films, and 14.41%- 16.10% for SG-plasticized films with increasing plasticizer concentrations of the film samples. Varying plasticizer concentrations exhibited a minor effect on the S-plasticized film's thermal properties. Significant decrement in the glass transition temperatures of Dioscorea hispida starch films was observed when the plasticizer contents were raised from 30% to 60%. Significantly, the present work has shown that plasticized Dioscorea hispida starch can be considered a promising biopolymer for the applications of biodegradable films.

Biocatalytic Approach for Direct Esterification of Ibuprofen with Sorbitol in Biphasic Media.

Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) introduced in the 1960s and widely used as an analgesic, anti-inflammatory, and antipyretic. In its acid form, the solubility of 21 mg/L greatly limits its bioavailability. Since the bioavailability of a drug product plays a critical role in the design of oral administration dosage, this study investigated the enzymatic esterification of ibuprofen as a strategy for hydrophilization. This work proposes an enzymatic strategy for the covalent attack of highly hydrophilic molecules using acidic functions of commercially available bioactive compounds. The poorly water-soluble drug ibuprofen was esterified in a hexane/water biphasic system by direct esterification with sorbitol using the cheap biocatalyst porcine pancreas lipase (PPL), which demonstrated itself to be a suitable enzyme for the effective production of the IBU-sorbitol ester. This work reports the optimization of the esterification reaction.

Osmolytes Can Destabilize Proteins in Cells by Modulating Electrostatics and Quinary Interactions.

Although numerous in vitro studies have shown that osmolytes are capable of stabilizing proteins, their effect on protein folding in vivo has been less understood. In this work, we investigated the effect of osmolytes, including glycerol, sorbitol, betaine, and taurine, on the folding of a protein GB3 variant in E. coli cells using NMR spectroscopy. 400 mM osmolytes were added to E. coli cells; only glycerol stabilizes the folded protein, whereas betaine and taurine considerably destabilize the protein through modulating folding and unfolding rates. Further investigation indicates that betaine and taurine can enhance the quinary interaction between the protein and cellular environment and manifestly weaken the electrostatic attraction in protein salt bridges. The combination of the two factors causes destabilization of the protein in E. coli cells. These factors counteract the preferential exclusion mechanism that is adopted by osmolytes to stabilize proteins.

Kinetically Equivalent Functionality and Reactivity of Commonly Used Biocompatible Polyurethane Crosslinking Agents.

In this paper, the kinetics of the reaction of phenyl isocyanate with crosslinking agents such as sucrose, sorbitol, and glycerol are reported. Crosslinking agents were used in high molar excess to isocyanate to obtain pseudo-first-order rate dependencies, and the reaction products were separated by high-performance liquid chromatography and detected by UV spectroscopy and mass spectrometry. It was found that the glycerol's primary hydroxyl groups were approximately four times reactive than the secondary ones. However, in the case of sorbitol, the two primary OH groups were found to be the most reactive, and the reactivity of hydroxyl groups decreased in the order of kOH(6)(8.43) > kOH(1)(6.91) > kOH(5)(1.19) > kOH(2)(0.98) > kOH(3)(0.93) > kOH(4)(0.64), where the numbers in the subscript and in the brackets denote the position of OH groups and the pseudo-first-order rate constants, respectively. The Atomic Polar Tenzor (APT) charges of OH groups and dipole moments of monosubstituted sorbitol derivatives calculated by density functional theory (DFT) also confirmed the experimental results. On the other hand, the reactions of phenyl isocyanate with crosslinking agents were also performed using high excess isocyanate in order to determine the number of OH-groups participating effectively in the crosslinking process. However, due to the huge number of derivatives likely formed in these latter reactions, a simplified reaction scheme was introduced to describe the resulting product versus reaction time distributions detected by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). Based on the results, the kinetically equivalent functionality (fk) of each crosslinking agent was determined and found to be 2.26, 2.6, and 2.96 for glycerol, sorbitol, and sucrose, respectively.

Investigations of Dianhydro-D-glucitol adsorbed on AuNPs surface: In silico and in vitro approach based on anticancer activity studies against A549 lung cancer cell lines.

The adsorption behavior of a lung cancer agent, Dianhydro-D-glucitol (DIS) on gold nanoparticles (AuNPs) was studied using surface-enhanced Raman scattering techniques. The stabilized geometry, inter- and intra-molecular hydrogen bond, and harmonic vibrational wavenumbers of DIS and DIS adsorbed on AuNPs (DISA) surface have been investigated with the help of the density functional theory (DFT) method. The stability of the molecules arising from stereoelectronic interactions, leading to its bioactivity, has been confirmed using natural bond orbital (NBO) analysis, which was further substantiated by the narrow HOMO LUMO energy gap obtained for DISA, from frontier molecular orbital analysis as well as electronic spectral analysis. The molecular electrostatic potential analysis along with local and global reactivity descriptors predicts the reactive site of the molecules. Molecular docking study was performed to obtain information about protein-ligand reactions for DIS and DISA, with different cancer proteins. This study enlightens the potential of SERS agents for targeted drug delivery and photothermal. The in vitro cytotoxic effects of DPH and DPHA molecules on lung cancer cell lines were analyzed using the MTT assay and the SERS method.

Characterization of the sorbitol dehydrogenase SmoS from Sinorhizobium meliloti 1021.

Sinorhizobium meliloti 1021 is a Gram-negative alphaproteobacterium with a robust capacity for carbohydrate metabolism. The enzymes that facilitate these reactions assist in the survival of the bacterium across a range of environmental niches, and they may also be suitable for use in industrial processes. SmoS is a dehydrogenase that catalyzes the oxidation of the commonly occurring sugar alcohols sorbitol and galactitol to fructose and tagatose, respectively, using NAD+ as a cofactor. The main objective of this study was to evaluate SmoS using biochemical techniques. The nucleotide sequence was codon-optimized for heterologous expression in Escherichia coli BL21 (DE3) Gold cells and the protein was subsequently overexpressed and purified. Size-exclusion chromatography and X-ray diffraction experiments suggest that SmoS is a tetramer. SmoS was crystallized, and crystals obtained in the absence of substrate diffracted to 2.1 Šresolution and those of a complex with sorbitol diffracted to 2.0 Šresolution. SmoS was characterized kinetically and shown to have a preference for sorbitol despite having a higher affinity for galactitol. Computational ligand-docking experiments suggest that tagatose binds the protein in a more energetically favourable complex than fructose, which is retained in the active site over a longer time frame following oxidation and reduces the rate of the reaction. These results supplement the inventory of biomolecules with potential for industrial applications and enhance the understanding of metabolism in the model organism S. meliloti.