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The aim of the study was to compare two kinds of soluble dietary fibres in a mixture with OSA-starch as wall components of linseed oil capsules. Comparison was made based on emulsion (droplet size, polydispersity index, and viscosity) and powder properties (outer structure, colour, surface oil content, and encapsulation efficiency). Additionally, linseed oil powders were applied to the food model (apple juice) and the colour, physical stability, and volatile compound profile of fortified juice were determined. Although the obtained linseed oil emulsions with different compositions of polysaccharide components showed some variation in droplet size, polydisperse index and viscosity, their encapsulation efficiency by spray-drying was very high (>98%). The powders produced had a similar structure and low surface oil content, and their 2% addition to apple juice did not change its stability and only slightly decreased its colour lightness and yellowness. However, greater differences in the volatile compounds of obtained juices were observed. Overall, the added powders reduced the volatility of aroma compounds typical of apple juice but introduced propanal and hexanal, especially the powders with the highest OSA-starch share. [ABSTRACT FROM AUTHOR]

This study aims to examine the 50/50 polypropylene/polyamide 6 (iPP/PA6) system molded under confined flow conditions, both in its original state and after being modified by two different interfacial agents. This study provides two main insights. Firstly, it focuses on a polymer blend close to phase inversion. Secondly, it investigates the impact of using two different types of interfacial agents (derived from polymer waste) to enhance the compatibility between iPP and PA6. Dynamic Mechanical Analysis (DMA) has been employed to achieve these objectives. It is important to note that the investigation of the 50/50 iPP/PA6 system is a crucial focus predicted in previous studies, where a series of mechanical properties were evaluated using Box–Wilson design of experiments (DOEs) over the whole compositional range on the iPP/PA6 binary system. Thus, two interfacial modifiers, namely succinic anhydride (SA)-grafted atactic polypropylene with terminal, side, and bridge SA grafts (aPP-SASA) and succinyl-fluoresceine (SF) with bridge succinic anhydride grafting atactic polypropylene (aPP-SFSA), were employed. The authors obtained and characterized these agents. The quantity of these agents used in the blend was identified as a critical coordinate in prior studies conducted by the authors. The processing method used, compression molding under confined conditions, was chosen to minimize any orientation effect on the emerging morphology. All characterization procedures were performed on samples processed by contour machining to retain the blend morphologies as they emerged from the processing stage. Results from WAXS and SAXS synchrotron tests concluded there were no changes in the crystal morphology of the iPP or the PA6 in the blends nor any co-crystallization process throughout the compositional range. These findings, and the long period fits on the PP crystalline phase for the fifty/fifty blends we are discussing, will support the present DMA study. Finally, the efficiency of these interfacial modifiers has been concluded, even in this unfavorable scenario. [ABSTRACT FROM AUTHOR]

Fiber-reinforced composites (FRCs) represent a promising class of engineering materials due to their mechanical performance. However, the vast majority of FRCs are currently manufactured using carbon and glass fibers, which raises concerns because of the difficulties in recycling and the reliance on finite fossil resources. On the other hand, the use of natural fibers is still hampered due to the problems such as, e.g., differences in polarity between the reinforcement and the polymer matrix components, leading to a significant decrease in composite durability. In this work, we present a natural fiber-reinforced composite (NFRC), incorporating plasma pre-treated flax fibers as the reinforcing element, thermoplastic polylactic acid (PLA) as a matrix, and a key point of the current study—a thermoset coating based on epoxidized linseed oil for adhesion improvement. Using atmospheric plasma-jet treatment allows for increasing the fiber's surface energy from 20 to 40 mN/m. Furthermore, a thermoset coating layer based on epoxidized linseed oil, in conjunction with dodecyl succinic anhydride (DDSA) as a curing agent and 2,4,6-tris(dimethyl amino methyl) phenol (DMP-30) as a catalyst, has been developed. This coated layer exhibits a decomposition temperature of 350 °C, and there is a substantial increase in the dispersive surface-energy part of the coated flax fibers from 8 to 30 mN/m. The obtained natural fiber-reinforced composite (NFRC) was prepared by belt-pressing with a PLA film, and its mechanical properties were evaluated by tensile testing. The results showed an elastic modulus up to 18.3 GPa, which is relevant in terms of mechanical properties and opens up a new pathway to use natural-based fiber-reinforced bio-based materials as a convenient approach to greener FRCs. [ABSTRACT FROM AUTHOR]

Summary: In order to improve the adsorption properties and stability of porous starch, the porous starch made from ground rice starch was doubly modified by cross‐linking and esterification using sodium trimetaphosphate (STMP) as a cross‐linking agent and octenyl succinic anhydride (OSA) as an esterifying agent. Structural analysis of the samples showed that the phosphate group in STMP formed a new P‐O‐C covalent bond with the hydroxyl group in starch by substitution, OSA combined with the hydroxyl group of starch formed an ester carbonyl group, and all cross‐linking and esterification occurred in the amorphous region of starch. DSC and TG/DTG analysis showed that STMP modification performed better than OSA modification in thermal stability. However, by analysis of the oil absorption properties and freeze–thaw stability, the OSA‐modified porous starch exhibited better oil‐holding rate and freeze–thaw stability. [ABSTRACT FROM AUTHOR]

The fines fraction in mechanical pulp, produced during wood processing can impact the mechanical properties of the resulting paper positively or negatively, making them potential additives for paper strength improvement at the right loading level. To enhance fines' effectiveness as paper strength additives that have heterogeneous surface chemistries, this work employed a regioselective surface esterification method conducted under mild conditions in acetone, with the addition of succinic anhydride and imidazole. This approach converted surface hydroxyl groups of fines into carboxylic acid groups, resulting in a final content of near 0.5 mmol g−1. This modification increased fines' hydrophilicity, as evidenced by enhanced moisture absorption capacity in dynamic vapor sorption analysis. These fines with additional functionality strengthened intermolecular bonding, leading to over 150% enhancement in tensile strength and Young's modulus when cast into thin films. Fines were substituted at 10–20 wt.% concentration to the fiber fraction of softwood thermomechanical pulp (TMP) and bleached chemi-thermomechanical pulp (BCTMP) forming handsheets. It was observed that fines modified with succinic anhydride and imidazole were more effective in enhancing paper strength, including tensile (up to 30%), burst (up to 39%) and tear (up to 4%) indices. This improvement was likely due to enhanced intermolecular bonding between modified fines and the fiber surfaces. By modifying mechanical pulp fines with succinic anhydride and imidazole, we have converted a potential heterogeneous waste product from the industry into a valuable by-product to enhance paper performance. [ABSTRACT FROM AUTHOR]

Summary: The synthesis of octenyl succinic anhydride‐modified starch was achieved through a fluidised bed activated by jet milling with graded revolution rates of 1200, 1800, 2400, 3000, and 3600 rpm. This study investigated the changes in the structural, physicochemical, and application properties of modified starch after jet milling. The results showed that modified starch can be synthesised using a one‐step jet milling process. The degree of substitution increased with a decrease in the starch particle size, resulting in a rough granule morphology. Structural analysis revealed that crystalline areas were destroyed in the modified starches. In the Fourier‐infrared spectrum, typical peaks appeared at 1724 and 1573 cm−1 upon introduction of the octenyl succinic anhydride group, whereas a new sodium peak appeared in the XPS spectrogram. The 1H‐NMR spectrum indicated that the esterification reaction mainly occurred on OH2 groups. The emulsification properties of the modified starch were significantly enhanced and increased with the crushing strength. The octenyl succinic anhydride‐modified starch has potential as a wall material for microcapsules, with good embedding rate and thermal stability. This novel synthesis method represents an innovative method for the synthesis of OSA‐starches. [ABSTRACT FROM AUTHOR]

Ecological nutrition aims to unravel the extensive web of nutritional links that drives animals in their interactions with their ecological environments. Nutrition plays a key role in the success of European wild rabbit (Oryctolagus cuniculus) and could be affected by the breeding status of the animals and reflected in the metabolome of this species. As nutritional needs are considerably increased during pregnancy and lactation, the main objective of this work was to determine how the breeding status (pregnant and lactating) of European wild rabbit does affects nutritional requirements and their metabolome (using targeted and untargeted metabolomics), aiming to find a useful biomarker of breeding status and for monitoring nutritional requirements. To address this gap, 60 wild European rabbits were studied. Animals were divided according to their breeding status and only pregnant (n = 18) and lactating (n = 11) rabbit does were used (n = 29 in total). The body weight and length of each animal were analyzed. The relative and absolute chemical composition of the gastric content and whole blood sample were taken, and targeted and untargeted metabolomics were analyzed. As a main result, there were no differences in biometric measurements, gastric content, and targeted metabolomics, except for live weight and nonesterified fatty acids (NEFA), as pregnant animals showed higher live weight (+12%; p = 0.0234) and lower NEFA acid levels (−46%; p = 0.0262) than lactating females. Regarding untargeted metabolomics, a good differentiation of the metabolome of the two breeding groups was confirmed, and it was proven that pregnant animals showed higher plasmatic levels of succinic anhydride (3.48 more times; p = 0.0236), succinic acid (succinate) (3.1 more times; p = 0.0068) and propionic acid (3.98 more times; p = 0.0121) than lactating animals. However, lactating animals showed higher levels of N‐[(3a,5b,7b)‐7‐hydroxy‐24‐oxo‐3‐(sulfoxide) cholan‐24‐yl]‐Glycine (cholestadien) (2.4 more times; p < 0.0420), 4‐maleyl‐acetoacetate (MAA) (3.2 more times; p < 0.0364) and irilone (2.2 more times; p = 0.0451) than pregnant animals, any of these metabolites could be used as a potential biomarker. From these results, it can be concluded that the most notable changes were observed in the metabolome of individuals, with most of the changes observed being due to energy and protein mobilisation. [ABSTRACT FROM AUTHOR]

Simple Summary: Substances that are absent in the biosphere, but have been synthesized by humans in recent decades, are called xenobiotics. They are released into the environment in large volumes and can actively affect invertebrates and their intestinal parasites or commensals. Such an influence of xenobiotics on parasite–host relationships remained poorly studied until recently. In this article, the host–parasite system "larva of Tenebrio molitor—Gregarina polymorpha" under the influence of 24 organic compounds is investigated. We found that several substances increase the mortality of T. molitor larvae, and substances such as diphenyl ether, benzyl alcohol, catechol, and 3-aminobenzoic acid, on the contrary, reduce the number of parasites (G. polymorpha) without significantly affecting host insects (larva of T. molitor). Thus, various xenobiotics can destroy the parasite–host relationship, having a greater effect on the host in some cases and on the parasite in other cases. Environmental contamination with xenobiotics affects organisms and the symbiotic relations between them. A convenient object to study relationships between parasites and their hosts is the host–parasite system "Tenebrio molitor Linnaeus, 1758 (Coleoptera, Tenebrionidae)—Gregarina polymorpha (Hammerschmidt, 1838) Stein, 1848 (Eugregarinorida, Gregarinidae)". For this experiment, we took 390 T. molitor larvae and 24 organic compounds. Groups of mealworms, 15 in each, were subjected to those compounds for 10 days. Then, we recorded the vitality of both the larvae of T. molitor and G. polymorpha. To assess how G. polymorpha had affected the hosts' wellbeing, we looked for changes in the larvae's body mass and compared them to the number of gregarines in their intestines. The vitality of the larvae was inhibited by cyclopentanol and 2-naphthol. The intensity of gregarine invasion was reduced by diphenyl ether, benzyl alcohol, catechol, and 3-aminobenzoic acid. No effect on the number of gregarines was produced by 3,4,5-trihydroxybenzoic acid, cyclohexanemethanol, phenol, benzalkonium chloride, maleic anhydride, cyclohexanol, resorcin, benzoic acid, 2-methylfuran, terpinen-4-ol, 1-phenylethylamine, dibutyl phthalate, 3-furancarboxylic acid, 5-methyl furfural, 6-aminohexanoic acid, succinic anhydride, o-xylene, and benzaldehyde. In the infected T. molitor individuals, the mean number of G. polymorpha equaled 45 specimens per host. The groups of smaller mealworms had fewer gregarines. Positive correlation was seen between growth rates of T. molitor larvae and the intensity of invasion by gregarines. [ABSTRACT FROM AUTHOR]

Pig liver is a high-quality source of animal protein, but natural pig liver protein is poorly emulsified. To improve its properties and enhance the added value of pig liver processing, this experiment prepared pig liver protein solution, measured the index of acylation, and investigated the effects on the emulsification properties, protein particle state, and molecular structure of pig liver protein with the addition amount of succinic anhydride as the variable. Results showed that with the increase of succinic anhydride addition, the acylation degree and emulsification activity of porcine liver protein showed an overall increasing trend, the emulsion zeta potential and the protein adsorption on the surface of emulsion oil droplets showed an increasing trend and then a decreasing trend, the emulsion particle size and protein surface hydrophobicity showed a decreasing trend, and the advanced structure of the protein were changed. The optimal addition of succinic anhydride for acylation treatment of porcine liver protein solution (10 mg/mL of concentration) was 0.10 g/g Pro. The emulsification activity of the porcine liver protein increased from 9.550 m²/g to 64.135 m²/g under this condition. Succinic anhydride reacted with porcine liver protein through covalent binding, causing changes in protein structure and significantly improving the emulsifying activity of the porcine liver protein. [ABSTRACT FROM AUTHOR]

This article discusses alternatives for modifying native starch through pre-treatments, with a focus on environmentally friendly methods, in order to assess how the type of modification affects the stability of Pickering emulsions. The affinity of native starch granules for aqueous and oily phases is impaired due to low steric repulsion, causing droplets to tend to aggregate. Therefore, it is essential to study the mechanisms governing the interface of emulsions. Waxy starches are the most commonly used for Pickering emulsion stabilization due to their high amylopectin content and, consequently, high crystallinity. Most of the modified starches presented in the literature in the last 5 years for Pickering emulsion stabilization involve chemical treatment with organic acids, such as octenyl succinic anhydride (OSA), which may, however, leave toxic and harmful acidic residues that are harmful to health. In this context, the article aims to broaden horizons by highlighting emerging physical techniques (thermal and non-thermal) applied in a simple and combined manner for starch modification. The use of modified starch aims to facilitate interactions between the aqueous and oily phases, thereby improving stability through enhanced interfacial and steric interactions. From future perspectives, enzymatic modification routes of native starch deserve special attention, as they are selective in attacking the amorphous zones of starch, while also respecting green chemistry. [ABSTRACT FROM AUTHOR]

This study aimed to improve the physicochemical and functional properties of chickpea starch through chemical modification with octenyl succinic anhydride (OSA). Starch was extracted from chickpeas and chemically modified by OSA with a maximum degree of substitution (0.0152) in 5 h (reaction time). The characteristics of OSA-chickpea starch were compared to those of native chickpea starch, corn starch, and wheat starch. The chemical composition values demonstrated that the extracted chickpea starch was pure, and the isolation technique was very effective for legume starch isolation. OSA-chickpea starch with a higher absolute value of zeta-potential illustrated greater turbidity, oil absorption capacity (OAC), water holding capacity (WHC), emulsion stability, and freeze–thaw stability than native starches during storage. The foaming problem and gel syneresis of OSA-chickpea starch were significantly (p < 0.05) lower than native starches. The highest swelling powers and solubility indexes were detected for chickpea and OSA-chickpea starches at 85 °C and for corn and wheat starches at 95 °C. The results of texture analysis (compression and puncture tests) showed that the OSA-chickpea starch produced a more stable gel texture with less breaking force than the other starches. The FTIR spectra indicated that the OSA-modification was successfully done, and this process could alter the starch from hydrophilic to dual hydrophobic-hydrophilic molecules and improve the physicochemical and functional characteristics of chickpea starch. [ABSTRACT FROM AUTHOR]

The importance of protecting valuable phenolic compounds causes the need for coatings with greater resistance, for which chemical modification is used. Encapsulation of jujube extract in sodium alginate/whey protein isolate (WPI) and modified sodium alginate/whey protein isolate beads (modified with Octenyl Succinic Anhydride (OSA)) was studied. Total phenolic compounds of the jujube extract, some physical and structural properties of the beads were measured. The highest content of total phenol in modified beads at ambient temperature was 91.2 mg/l (first day). The highest efficiency was observed in the alginate/WPI beads stored at ambient temperature on the 14th day which was 14.91%. The hardness of the beads was also affected by the modification (from 0.99 to 1.26 N). The higher Tg which ensures higher stability in thermal procedure was revealed in the modified beads (77.23°C). FTIR revealed hydroxyl groups related to the jujube extract, gum and whey protein-induced intramolecular beta-sheets. These results are very important in the construction of protective systems and delivery of biological compounds of jujube extract for use in the production of novel functional foods and beverages. [ABSTRACT FROM AUTHOR]

Curcumin (Cur) is a phytochemical with various beneficial properties, including antioxidant, anti-inflammatory, and anticancer activities. However, its hydrophobicity, poor bioavailability, and stability limit its application in many biological approaches. In this study, a novel amphiphilic chitosan wall material was synthesized. The process was carried out via grafting chitosan with succinic anhydride (SA) as a hydrophilic group and deoxycholic acid (DA) as a hydrophobic group; 1H-NMR, FTIR, and XRD were employed to characterize the amphiphilic chitosan (CS—SA—DA). Using a low-cost, inorganic solvent-based procedure, CS—SA—DA was self-assembled to load Cur nanomicelles. This amphiphilic polymer formed self-assembled micelles with a core–shell structure and a critical micelle concentration (CMC) of 0.093 mg·mL−1. Cur-loaded nanomicelles were prepared by self-assembly and characterized by the Nano Particle Size Potential Analyzer and transmission electron microscopy (TEM). The mean particle size of the spherical Cur-loaded micelles was 770 nm. The drug entrapment efficiency and loading capacities were up to 80.80 ± 0.99% and 19.02 ± 0.46%, respectively. The in vitro release profiles of curcumin from micelles showed a constant release of the active drug molecule. Cytotoxicity studies and toxicity tests for zebrafish exhibited the comparable efficacy and safety of this delivery system. Moreover, the results showed that the entrapment of curcumin in micelles improves its stability, antioxidant, and anti-inflammatory activity. [ABSTRACT FROM AUTHOR]

The esterification of starches with octenyl succinic anhydride (OSA) under alkaline conditions is a modification process that takes a long time. Ultrasound-assisted esterification was investigated as an alternative for obtaining esterified starches with higher degree of substitution (DS) and reaction efficiency (RE), which could have more possibilities of application. Andean native potato starches were subjected to a conventional esterification process (OSA) and esterification with ultrasound-assisted treatment (US-OSA). The morphological and size distribution of granules, molecular features (infrared spectroscopy and X-ray diffraction), thermal, and rheological characteristics were assessed. The DS and RE for US-OSA starches were higher than those for OSA ones. Modified starches showed some peeled granules with a few pores in their surfaces, and also, span values of US-OSA starches were lower than OSA ones. Molecular studies showed that both starches, OSA and US-OSA, did not exhibit notable differences. Enthalpy of gelatinization for US-OSA starches was lower than of OSA ones. Hence, the results suggest that the esterification process of starches can be facilitated with a green technology such as ultrasound-assisted treatment, which is fast-paced and does not change the esterified starch characteristics. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, clove essential oil (CL), eugenol (EU), and cinnamaldehyde (CI) were immobilized in starch sodium octenyl succinate (SSO) using an emulsification method. The main characteristics, stability, and biological properties of the prepared emulsions were established. Particle size analyses using dynamic light scattering showed that the smaller droplets were characteristic of emulsions containing CI (205–218 nm) and EU (181–236 nm), while the largest droplets were determined for CL emulsions (293–348 nm). Moreover, the highest antioxidant activity was determined for CL (79–83%) and EU (80–88%) emulsions, while CI emulsions showed the greatest antibacterial activity. The obtained emulsions were applied to the paper sheets and the bioactive properties of coated paper were studied. Evaluation of antioxidant properties revealed that high antioxidant activity reaching 76–92% and 87–91% was characteristic of coatings containing CL and EU, respectively. Meanwhile, coatings containing CI showed quite low antioxidant activity (4–9%) but demonstrated the greatest antimicrobial effect on Gram-negative and Gram-positive bacteria as well as yeasts. Hence, CL and EU emulsions could be used as effective natural antioxidants, whereas CI emulsions could be applied as an antimicrobial agent on cellulose-based substrates for a wide range of human health protection applications. [ABSTRACT FROM AUTHOR]

In the current research, basmati rice starch (BRS) has been modified with octenyl succinic anhydride (OSA). The properties of BRS and modified basmati rice starch (MBRS) were evaluated, and subsequently, the effect of their addition to polyvinyl alcohol (PVA) in two different ratios (70/30 and 30/70) to prepare blend films was studied. The degree of substitution of MBRS was 0.00483%, which was found within the permitted range of Food and Drug Administration guidelines. The pH (6.1 vs. 5.8) and viscosity average molecular weight (1.5 x 104 and 1.275 x 104 Da) were found to be lower for MBRS, solubility (11.52 vs. 13.60%), swelling power (11.5 vs. 13.60 g/g), and oil absorption (2.4 vs. 3.2 g/g) capacities were higher. FTIR and XRD studies revealed minor differences in the MBRS spectra owing to the low substitution. The blend films cast with PVA and MBRS showed higher film thickness, hydration characteristics, transparency, and UV-blocking efficiency. [ABSTRACT FROM AUTHOR]

Copyright of Ingeniería y Competitividad is the property of Universidad del Valle and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, we investigated the structural properties and digestibility of wheat starch treated with octenyl succinic anhydride (OSA). For the experiment, the samples were reacted with 2, 4, 6, 8, and 10% OSA (pH 8.5–9.0) for 2 h. A light micrograph showed that there was no difference in the morphology and Maltese cross between native and OSA-treated starch. The X-ray diffraction (XRD) patterns of the native and OSA-treated starches showed typical A-type diffraction. In addition, the Fourier transform infrared (FT-IR) spectrum showed a distinct carbonyl peak at approximately 1730 cm−1, indicating the stretching vibration of the C=O bond of the ester group. The degree of substitution (DS) and content of resistant starch (RS) increased with increasing concentrations of treated OSA because of the increase in ester bonds. In particular, RS was thermostable compared to the RS content in uncooked and cooked starch. Blood glucose levels and response in vivo decreased as the OSA concentration increased. Treatment of wheat starch with 8% OSA concentration produced 35.6% heat-stable resistant starch. These results suggest that starch modified with OSA can be used to produce functional foods for diabetes. [ABSTRACT FROM AUTHOR]

This present work investigated the influence of black rice anthocyanins as antioxidants on the oxidation stability of oil. Malonic acid, succinic acid and succinic anhydride were grafted on black rice anthocyanins through acylation method to improve their antioxidant activity in oil. The results from fourier transform infrared spectroscopy (FTIR) showed new absorption peaks near 1744 cm-1 and 1514 cm-1, which implied that malonic acid, succinic acid and succinic anhydride grafted on the -OH of glucoside and rutinoside through esterification reaction and resulted that the polarity of these were reduced. Total content of anthocyanin (TAC) decreased to 166. 3 mg/g, 163.7 mg/g and 150.2 mg/g, respectively after modification with succinic acid, malonic acid and succinic anhydride. Compared with native anthocyanins, the acylation of black rice anthocyanins partially reduced its antioxidant activity. In addition, DPPH clearance of molecular modified anthocyanins decreased to 62.6% (San-An). As revealed in the oil stability through the determination of primary oxidation products (PV) and secondary oxidation products (p-AV), Sa-An, Ma-An and San-An showed stronger antioxidant activity in Schaal oven accelerated oxidation test during 12 days than native black rice anthocyanin in both corn oil and flaxseed oil. Molecular modified black rice anthocyanins are expected to be used as colorants, antioxidants, etc. in oil-rich food. [ABSTRACT FROM AUTHOR]

Summary: Rice glutelin is poorly soluble which restricts its potential food application. Succinylation is a chemical modification that improves the solubility of proteins by derivatising the ɛ‐amino group of lysine residues. In this study, rice glutelin was modified by succinic anhydride at different succinic anhydride concentrations (10%, 20%, 30%, 40%, and 50%). The succinylated rice glutelin samples showed enhanced solubility, reduced particle size, and increased absolute zeta potential values. The emulsifying and foaming properties of succinylated rice glutelin were also significantly improved. Moreover, SEM revealed that the surface of succinylated rice glutelin had small pits and protrusions. These results suggest that succinylation can effectively improve the functional properties of rice glutelin, which will facilitate its application in the food industry. [ABSTRACT FROM AUTHOR]

This work aims to prepare new poly(ionic liquid)s (PILs) and use them for crude oil emulsion separation (EES). PILs were synthesized by an opening ring reaction of hexadecylsuccinic anhydride (HAS) using polyethyleneimine branched MW 600 (PEI) and triethylenetetramine (TTA) in a one-step procedure, obtaining PILs, HSPI-PIL, and HSTA-PIL, respectively. Chemical structure, interfacial tension, aggregate size, and thermal behavior were verified using several techniques. The efficiency of HSPI-PIL and HSTA-PIL toward EES was explored using different parameters, including water content (WC), demulsifier concentration, temperature, and pH value. The results indicated that EES proportionally increased with increased WC and temperature. The data also revealed that increased demulsifier concentration improved EES at low WC, for example, 10% and 30%; however, this parameter showed no significant effect with crude oil emulsion containing high WC, for example, 50%. Furthermore, HSPI-PIL and HSTA-PIL gave the maximum EES values at a pH of 7, while they decreased in acidic and basic mediums. [ABSTRACT FROM AUTHOR]

A novel inorganic-monosaccharide nanohybrid synthesized through coating the nickel–zinc ferrite (NZF) core by silica and subsequent functionalization with galactose (Ni0.4Zn0.6Fe2O4@SiO2/galactose) and characterized by FT-IR, FESEM, EDAX, XRD, XRF, BET, TGA, and VSM techniques. Its catalytic efficacy examined in some domino four-component reactions to obtain various classes of phthalazine derivatives at 90 °C under solvent-free conditions: (i) the reaction of phthalic anhydride (PA), hydrazine hydrate, dimedone, and different aldehydes to get 3,3-dimethyl-13-(aryl)-3,4-dihydro-1H-indazolo[1,2-b]phthalazine-1,6,11(2H,13H)-triones; (ii) the reaction of phthalic anhydride/phthalimide, hydrazine hydrate, malononitrile, and different aldehydes to obtain 3-amino-5,10-dioxo-1-(aryl)-5,10-dihydro-1H-pyrazolo[1,2-b]phthalazine-2-carbonitriles; and (iii) the reaction of succinic anhydride, hydrazine hydrate, dimedone, and different aldehydes to prepare 3,3-dimethyl-11-(aryl)-3,4,7,8-tetrahydro-1H-pyridazino[1,2-a]indazole-1,6,9(2H,11H)-triones. In addition, the recovery and reusability of the Ni0.4Zn0.6Fe2O4@SiO2/galactose determined successfully, and the reused nanocomposite identified through FESEM and EDAX techniques. [ABSTRACT FROM AUTHOR]

The α-chymotrypsin is widely present in the digestive system of prokaryotes and eukaryotes that helps in the digestion by the hydrolysis of the peptide bond. It is serine protease enzyme (E.C. 3.4.21.1) and involves in many biological processes as well as in pancreatic disorders. In the previous study, marine red alga namely Jolyna laminariodes was used for the isolation of succinylanthranilic acid ester (2). Further, analogues were synthesised from anthranilic acid by using succinic anhydride, maleic anhydride and glutaric anhydride into corresponding dicarboxylic acids and further into acid ester including succinylanthranilic acid (1), succinylanthranilic acid ester (2), maleinylanthranilic acid (3), maleinylanthranilic acid ester (4), glutarnylanthranilic acid (5) and glutarnylanthranilic acid ester (6). For all natural products analogues percent inhibition against α-chymotrypsin have been calculated. In this study, molecular docking is used to estimate the binding energy of natural product analogues against α-chymotrypsin enzyme. The docking energies are in good agreement with experimental findings. [ABSTRACT FROM AUTHOR]

New polysilsesquioxane (PSQ)-based CO2 separation membranes with succinic anhydride and monoalkylurea units as thermally degradable CO2-philic units were prepared by the copolymerization of a 1:1 mixture of [3-(triethoxysilyl)propyl]succinic anhydride (TESPS) or [3-(triethoxysilyl)propyl]urea (TESPU) and bis(triethoxysilyl)ethane (BTESE). The succinic anhydride and monoalkylurea units underwent thermal degradation to form ester and dialkylurea units, respectively, with the liberation of small molecules (e.g., CO2 and NH3) under N2 atmosphere. The effects of thermal degradation on the performance of the obtained membranes were investigated. The TESPS-BTESE- and TESPU-BTESE-based membranes calcined at 250 °C and 200 °C exhibited good CO2/N2 permselectivities of 20.2 and 14.4, respectively, with CO2 permeances of 7.7 × 10−8 and 7.9 × 10−8 mol m−2·s−1·Pa−1, respectively. When the membranes were further calcined at elevated temperatures of 350 °C and 300 °C, respectively, to promote the thermal degradation of the organic units, the CO2 permeances increased to 1.3 × 10−7 and 1.2 × 10−6 mol m−2·s−1·Pa−1 (3.9 × 102 and 3.6 × 103 GPU), although the CO2/N2 permselectivities decreased to 19.5 and 8.4, respectively. These data indicate that the controlled thermal degradation of the organic units provides a new methodology for possible tuning of the CO2 separation performance of PSQ membranes. [ABSTRACT FROM AUTHOR]

A silicone carrying combined functionalities of different mechanisms and physiochemical properties is synthesized as a strategy for faster and broader bacterial eliminations. Briefly, ring‐opening alcoholysis of succinic anhydride with 2‐dimethylaminoethanol and subsequent esterification of the alcoholysis product with 5‐(4‐hydroxyphenyl)imidazolidine‐2,4‐dione produced a structure with one tertiary amine and two hydantoinyl NH bonds. The tertiary amine was quaternized with 3‐chloro‐1‐propanol whose OH was then alcoholyzed with SiH of poly(methylhydrosiloxane). The polymeric product was interpenetrated into cotton at 30 MPa and 50°C in supercritical CO2 and treated with tert‐butyl hypochlorite to chlorinate its hydantoinyl NH bonds, forming a 78 nm biocidal layer of silicone with quaternized hydantoin‐based N‐chloramines. Antibacterial tests showed that the quaternary ammonium salt and two hydantoin‐based N‐chloramines act synergistically due to their complementary features, killing both Staphylococcus aureus and Escherichia coli much more efficiently than each functionality. More importantly, the ratio of N‐chloramine to quaternary ammonium salt of 2:1 herein also provided higher efficacy than a reported counterpart with a 1:1 ratio. Biocidability of the modified cotton had promising stability and rechargeability, which indicates that supercritical interpenetration produced a durable interfacial layer without the necessity of chemical bonding. [ABSTRACT FROM AUTHOR]

Chitosan (CS) is a polysaccharide obtainable by the deacetylation of chitin, which is highly available in nature and is consequently low-cost. Chitosan is already used in the biomedical field (e.g., guides for nerve reconstruction) and has been proposed as a biomaterial for tissue regeneration in different body districts, including bone tissue. The interest in chitosan as a biomaterial stems from its ease of functionalization due to the presence of reactive groups, its antibacterial properties, its ease of processing to obtain porous matrices, and its inherent similarity to polysaccharides that constitute the human extracellular matrix, such as hyaluronic acid (HA). Here, chitosan was made to react with succinic anhydride to develop a negatively charged chitosan (SCS) that better mimics HA. FT-IR and NMR analyses confirmed the presence of the carboxylic groups in the modified polymer. Four different electrospun matrices were prepared: CS, SCS, a layer-by-layer matrix (LBL), and a matrix with both CS and SCS simultaneously electrospun (HYB). All the matrices containing SCS showed increased human osteoblast proliferation, mineralization, and gene expression, with the best results obtained with HYB compared to the control (CS). Moreover, the antibacterial potential of CS was preserved in all the SCS-containing matrices, and the pure SCS matrix demonstrated a significant reduction in bacterial proliferation of both S. aureus and E. coli. [ABSTRACT FROM AUTHOR]

In this study, asymmetric Al2O3-SiO2 Janus nanoparticles with a dumbbell-like structure were synthesized by a facile chemical process in the aqueous phase. Prior to synthesis, Al2O3 nanoparticles in hydrosol were amino-modified using 3-aminopropyl triethoxysilane (KH550) and then carboxyl acid-functionalized using a ring-opening reaction of the amine functions with succinic anhydride, imparting unique anionic properties to the Al2O3 end. SiO2 nanoparticles were rendered hydrophobic through modification with hexamethyldisilazane (HMDS) and further functionalized with 3-chloropropyl triethoxysilane (KH230). The two nanoparticle hydrosols were then mixed, and the asymmetric Al2O3-SiO2 Janus nanoparticles were synthesized via the reaction between the –NH2 and −CH2Cl groups. The prepared Janus nanoparticles were primarily characterized by dynamic light scattering (DLS), Zeta potential (ZP), and transmission electron microscopy (TEM). The results indicated that about 90% of the modified Al2O3 and SiO2 nanoparticles were covalently coupled in a one-to-one manner to form the dominant dumbbell-like structure. These Janus nanoparticles exhibit amphiphilic properties, making them highly promising surfactants for emulsifying oil–water mixtures. [ABSTRACT FROM AUTHOR]

In order to further improve the emulsion stability and the intrinsic performance of self-emulsified epoxy resin, a novel amphipathic resin was synthesized from dodecylsuccinic anhydride (DDSA), methoxypolyethylene glycols and bisphenol-A epoxy. Similar systems based on different anhydrides including methyl hexahydrophthalic anhydride (MHHPA) as well as phthalic anhydride (PA) were prepared simultaneously for comparison. The stabilities of various emulsions were evaluated according to particle diameter, centrifugal stability and surface tension tests. Meanwhile, the curing behaviors, thermal resistances and interface properties between resins and diverse reinforcement fibers were also investigated. The results showed that introducing of DDSA could effectively enhance the stability of emulsion with the surface tension reducing to 37.22 mN/m. The microdebonding strength between the self-emulsifying resin system and carbon fiber is poor, but its interfacial strength with ultra-high molecular weight polyethylene fibers is better than that of the MHHPA and PA systems, and it has excellent overall performance. [ABSTRACT FROM AUTHOR]

Starch-based Pickering emulsions have received much attention recently due to their low cost, biodegradability, and green characteristics. To investigate the effect of acid heat treatment on the physicochemical properties of octenyl succinic anhydride starch (OSAS) and the stability of Pickering emulsion, acid heat treatment of esterified starch with hydrochloric acid was performed to obtain samples with different degrees of treatment and to make Pickering emulsion. The structure of starch particles before and after acid heating treatment was analyzed using scanning electron microscopy and Fourier transform infrared spectroscopy. The stability of the emulsions was evaluated using the emulsion index, droplet size, and zeta potential. The results showed that compared to natural starch, acid heat treatment of esterified starch resulted in increased solubility, darker coloration, greater exposure of reducing ends leading to higher reducing sugar content, and reduced starch orderliness. However, the original granular morphology was still retained. Additionally, based on the emulsification index, droplet size, etc., it can be concluded that acid heat treatment OSAS is more suitable as a Pickering emulsion stabilizer compared to untreated OSAS. [ABSTRACT FROM AUTHOR]

The employment of 2-deoxyribose-5-phosphate aldolase (DERA) stands as a prevalent biocatalytic route for synthesizing statin side chains. The main problem with this pathway is the low stability of the enzyme. In this study, mesocellular silica foam (MCF) with different pore sizes was used as a carrier for the covalent immobilization of DERA. Different functionalizing and activating agents were tested and kinetic modeling was subsequently performed. The use of succinic anhydride as an activating agent resulted in an enzyme hyperactivation of approx. 140%, and the stability almost doubled compared to that of the free enzyme. It was also shown that the pore size of MCF has a decisive influence on the stability of the DERA enzyme. [ABSTRACT FROM AUTHOR]

Biopolymers, especially cellulose, are vital to transitioning to a circular economy and reducing our reliance on fossil fuels. However, for many applications a high degree of cellulose hydroxyl modification is necessary. The challenge is that the chemical features of the hydroxyls of cellulose and water are similar. Therefore, chemical modification of cellulose is often explored under non‐aqueous conditions with systems that result in high hydroxyl accessibility and reduce cellulose aggregation. Unfortunately, these systems depend on hazardous and complex solvents from fossil resources, which diverge from the initial sustainability objectives. To address this, we developed three new betaine‐based ionic liquids that are fully bio‐based, scalable, and green. We found that a specific ionic liquid had the perfect chemical features for the chemical activation of cellulose without disturbing its crystalline ordering. The high activation in heterogeneous conditions was exemplified by reacting cellulose with succinic anhydride, resulting in more than 30 % conversion of all hydroxyls on cellulose. Overall, this work opens new perspectives for the derivatization of cellulosic materials while simultaneously "keeping it green". [ABSTRACT FROM AUTHOR]

Two ferrocene derivatives, namely, 1,2-(tetramethylene)-ferrocene and 1,2,1′,2′-bis(tetramethylene)-ferrocene, were synthesized in a four-step reaction sequence starting from ferrocene. Friedel–Crafts acylation of ferrocene using succinic anhydride gave mono- or bis(3-carboxypropinoyl)-ferrocene depending on the stoichiometry of succinic anhydride. The reduction of the keto groups to methylene followed by ring-closing using trifluoroacetic anhydride gave 1,2-(α-ketotetramethylene)-ferrocene or 1,2,1′,2′-bis(α-ketotetramethylene)-ferrocene. The diastereomeric mixture of the latter diketones was separated using column chromatography, characterized via single-crystal X-ray analysis, and assigned its stereochemistry. Reduction of the keto groups to methylene under Clemmensen conditions gave homoannular mono- or bis(tetramethylene)-ferrocene derivatives. The molecular structure of 1,2-(tetramethylene)-ferrocene revealed that the ipso carbon atoms of the cyclopentadienyl group are 0.023(3) Å farther away from Fe(II) compared to the remaining three carbon atoms. Both complexes exhibit lower half-wave oxidation potentials than ferrocene, possibly due to the electron-releasing effects of the tetramethylene bridges. [ABSTRACT FROM AUTHOR]

BACKGROUND: In the present study, the insoluble fraction of Persian gum (IFPG) was modified with octenyl succinic anhydride (OSA) and its various properties were assessed. In addition, the effect of OSA‐IFPG on the rheological and textural properties of dairy cream was investigated. RESULTS: Suitable conditions for achieving a degree of substitution (DS) of 0.023 were found at pH 9, IFPG concentration 4 wt%, OSA concentration 10 wt% and a temperature of 40 °C, within 120 min. The carbonyl group attachment in OSA‐IFPG was also confirmed via Fourier transform infrared and H‐nuclear magnetic resonance spectroscopy (1H‐NMR). While the X‐ray diffraction test indicated no significant changes in the structure of the IFPG after modification with OSA, esterification increased the negative charge density, decreased thermal decomposition temperature and increased the emulsifying capacity to 100%, which was obtained for the first time. The use of OSA‐modified IFPG in creams augmented the complex viscosity, loss and storage modulus, while also demonstrating the creation of a pseudo‐gel network. The hardness and adhesiveness of the texture increased, which can be explained by the formation of a compact structure and reduced particle size. CONCLUSION: Overall, OSA‐IFPG with hydrophilic and hydrophobic sections may function as an emulsifier and be recommended as a safe source of hydrocolloids for emulsion stability. It can also provide a positive physical structure when added to dairy cream, even if the fat concentration is lower than usual. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

We describe the synthesis and characterisation of four organic Lewis acids based on fluorophosphoniums, with tetracarbonyl cobaltate as the counter-anion: [R3PF]+[Co(CO)4]− (with R = o-Tol, Cy, iPr, and tBu). Their catalytic activity was investigated for the carbonylation of β-lactones to succinic anhydrides. In the presence of [tBu3PF]+[Co(CO)4]− IV (3 mol%), 90% of succinic anhydride was afforded from β-propiolactone after 16 h at 80 °C, at a very mild pressure of 2 bar of carbon monoxide. Our study sets the first example of the use of a main-group cation as a Lewis acidic partner in the cobalt-catalyzed carbonylation of β-lactones. [ABSTRACT FROM AUTHOR]

Glucuronoxylans have been considered as an alternative polymer for petroleum polymers in coatings, films, emulsifiers, and other industries. In this study, different molecule weight glucuronoxylans were obtained through xylanase hydrolysis. Dodecenyl succinic anhydride (DDSA) was used as a modifying agent to functionalize glucuronoxylans. At the same degree of substitution (DS), higher molecule weight glucuronoxylans led to better emulsifying properties and emulsion stability. Higher molecule weight DDSA modified glucuronoxylans showed smaller droplets size, lower zeta potential, higher EA (emulsifying activity) and better emulsion stability. These results suggested that molecule weight has positive impact on the emulsifying properties of DDSA modified glucuronoxylans. Furthermore, DS had positive impact on the emulsifying properties of DDSA modified glucuronoxylans. [ABSTRACT FROM AUTHOR]

In this study, guar gum (GG) was chemically modified to its carboxymethyl derivative, which was then esterified with octenyl succinic anhydride (OSA) using a nucleophilic catalyst 4-dimethylaminopyridine (DMAP) to render the derivative amphiphilic characteristics. The carboxymethyl guar gum (CMGG) and succinoylated CMGG was characterized using Fourier transform infrared spectroscopy (FTIR) spectroscopy. The amphiphilic CMGG synthesized using DMAP/OSA ratio of 0.5:1 (CMGGOSA-I), was found to be non-toxic. The amphiphilic guar gum self-assembled in water to form nanocarriers with mean diameter of 430 ​nm and zeta potential of −19.0 ​mV. Transmittance electron microscope (TEM) image showed spherical nature of the developed CMGGOSA-I nanocarriers. In presence of amphiphilic CMGG, the aqueous solubility of glimepiride was enhanced by about 67-fold. The nanocarriers released glimepiride in simulated gastrointestinal fluids for a period of more than 24 ​h, following Higuchi's kinetics. Korsmeyer-Peppas modeling of the drug release data revealed that a combination of swelling and diffusion mechanism was operative in the event of drug release. In streptozotocin-induced diabetic rat model, the nanocarriers outperformed pure drug suspensions in terms of anti-diabetic activity, which lasted up to 24 ​h. Overall; the newly synthesized amphiphilic CMGG nanocarriers demonstrated controlled drug release properties and showed promise for controlling type-2 diabetes.

Light-triggered antimicrobial cellulose surfaces were obtained by the immobilization of a photosensitive phenosafranin dye (PSF) in a hybrid organic–inorganic silsesquioxane polymer applied on handsheets prepared from a standard bleached softwood pulp. These coatings were deposited by polycondensation of methyltriethoxysilane and an alkoxysilyl derivative of phenosafranin (TESPSF) obtained by the thiolene addition reaction and coupling of the succinic anhydride derivative with a primary amine group of PSF. TESPSF and coatings were characterized by advanced techniques in terms of chemical structure (1H, 13C, 29Si NMR, MS, ATR-IR), surface properties (SEM, EDX, water contact angles), and optical properties (UV, reflection light intensity, ISO brightness). The light-induced antimicrobial activity of sheets of paper coated with new materials showed the inhibition of the growth of the bacteria Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 8739. The cytotoxicity studies of modified cellulose surfaces were performed using erythrocyte lysis assays under both dark and light conditions exhibited no toxicity on erythrocytes. Thus, the new material did not reveal harmful effects on erythrocytes, regardless of the presence and absence of light. [ABSTRACT FROM AUTHOR]

A procedure has been developed for the preparation of Bombyx mori N-succinyl chitosan in a dimethyl sulfoxide medium for 24 h at 22 ºC, pH = 7 and a ratio of chitosan/succinic anhydride = 1:1 mol. It was found that, under the chosen synthesis conditions, the functionalization of chitosan occurs due to the substitution of the H (C2) atoms of the amino group of chitosan by the succinyl group up to 41.6%. The formation of –NH–CO– groups is indicated by IR, NMR spectral, conductometric methods. Was established a decrease in the content of total nitrogen and –NH2 groups in the original chitosan and synthesized samples of succinyl chitosan from 8.5 to 6.2% and from 87 to 45.4%, respectively. According to the results of 1H-NMR spectroscopy, it was found that the spectra of chitosan and N-SCS have specific absorption regions at 2672 ppm and 2589 ppm, respectively. It has been shown that the IR and NMR spectra of N-succinyl chitosan samples exhibit absorption bands characteristic of –NH–CO– groups. An increase in the particle size and degree of polydispersity in solutions of N-succinyl chitosan in comparison with chitosan indicates an increase in the probability of intra- and intermolecular interactions of macromolecules of its derivative. It was found that solutions of N-succinyl chitosan have the highest fungicidal activity in comparison with chitosan and the reference fungicide preparation—Bahor, forming an inhibitory zone of 34 ± 2 mm. The results obtained are of interest in the creation of a biodegradable, non-toxic and effective fungicide for the agro-industrial complex. [ABSTRACT FROM AUTHOR]

Succinic acid diamides containing two pharmacophoric fragments, one of which is 2amino-pyrimidine, and the other, N-methylpiperazine, 2-aminopyrimidine, or substituted aniline moiety, were synthesized in two steps. The synthetic scheme included acylation of substituted (pyrimidin-2-ylamino)aniline or pyrimidin-2-amine with succinic anhydride and the subsequent acylation of another heterocyclic or aromatic amine with the resulting pyrimidine-substituted succinic acid monoamide. The key intermediate products in the synthesis are succinic acid anilides. The acylation heterocyclic or aromatic amines with substituted succinic acid monochloride or amidation of succinic acid benzotriazolyl ester gave the corresponding succinic acid diamides as potential inhibitors of enzymes mediating tumorigenic processes. [ABSTRACT FROM AUTHOR]

Alternative sources for polymeric materials have been sought in the past few years to reduce our dependence on fossil feedstock. We report the catalytic carbonylation of acrylic acid, a platform chemical that can be bio‐sourced, as a new pathway toward the formation of a useful monomer to polyesters, namely succinic anhydride. The novel system reported herein tackles the difficult carbonylation of unsaturated carboxylic acids through the utilization of an Earth‐abundant metal catalyst, [Co2(CO)8], in presence of a bidentate ligand, 1,2‐bis(dicyclohexylphosphino)ethane (dcpe), and H2. We investigated the influence of the reaction conditions through the variations of metal, ligand, temperature, pressure, and gas composition. The carbonylative ring‐closure of acrylic acid was successfully obtained in high yield and selectivity toward the formation of succinic anhydride using mild conditions (90 °C and 16 bar of CO/H2 95 : 5). [ABSTRACT FROM AUTHOR]

Water-in-oil-in-water (W/O/W) crystallizable double emulsions stabilized with a mixture of octenyl succinic anhydride starch (OSA starch) and xanthan gum (XG) were formulated. These systems were proposed as modules for the release of chlortetracycline (CTC). The characterization results indicated that the stability, the average diameter of the globules, and the apparent viscosity of the double emulsions formulated depend on OSA starch and XG concentrations, and on their ratio in the outer water phase. In addition, emulsions exhibited good creaming stability during 40 days of rest at 25 C and 40 C. However, samples prepared with 0.25%/0.5% and 0.5%/0.5% of OSA starch/XG mixture were found more stable. Also, it was noticed that the encapsulation efficiency (EE) and the release rate of CTC incorporated in the inner water phase strongly depend on the polymer concentrations in the outer water phase. Furthermore, the increase in the concentration of biopolymer results in a slowing down of the drug encapsulation and an improvement in the EE. Moreover, the Korsmeyer-Peppas model was tested to represent the kinetics of CTC release; the release mechanism was found as a simple diffusion type. [ABSTRACT FROM AUTHOR]

Recently, polyetheretherketone (PEEK) has shown promising dental applications. Surface treatment is essential for dental applications owing to its poor surface energy and wettability; however, no consensus on an effective treatment method has been achieved. In this study, we attempted to carboxylate PEEK sample surfaces via Friedel–Crafts acylation using succinic anhydride and AlBr3. The possibility of further chemical modifications using carboxyl groups was examined. The samples were subjected to dehydration–condensation reactions with 1H,1H-pentadecafluorooctylamine and N,N'-dicyclohexylcarbodiimide. Furthermore, the sample's surface properties at each reaction stage were evaluated. An absorption band in the 3300–3500 cm−1 wavenumber region was observed. Additionally, peak suggestive of COOH was observed in the sample spectra. Secondary modification diminished the absorption band in 3300–3500 cm−1 and a clear F1s signal was observed. Thus, Friedel–Crafts acylation with succinic anhydride produced carboxyl groups on the PEEK sample surfaces. Further chemical modification of the carboxyl groups by dehydration-condensation reactions is also possible. Thus, a series of reactions can be employed to impart desired chemical structures to PEEK surfaces. [ABSTRACT FROM AUTHOR]

Although amphiphilic chitosan has been widely studied as a drug carrier for drug delivery, fewer studies have been conducted on the antimicrobial activity of amphiphilic chitosan. In this study, we successfully synthesized deoxycholic acid-modified chitosan (CS-DA) by grafting deoxycholic acid (DA) onto chitosan C2-NH2, followed by grafting succinic anhydride, to prepare a novel amphiphilic chitosan (CS-DA-SA). The substitution degree was 23.93% for deoxycholic acid and 29.25% for succinic anhydride. Both CS-DA and CS-DA-SA showed good blood compatibility. Notably, the synthesized CS-DA-SA can self-assemble to form nanomicelles at low concentrations in an aqueous environment. The results of CS, CS-DA, and CS-DA-SA against Escherichia coli and Staphylococcus aureus showed that CS-DA and CS-DA-SA exhibited stronger antimicrobial effects than CS. CS-DA-SA may exert its antimicrobial effect by disrupting cell membranes or forming a membrane on the cell surface. Overall, the novel CS-DA-SA biomaterials have a promising future in antibacterial therapy. [ABSTRACT FROM AUTHOR]

The aim of this study is to prepare redox-sensitive nanophotosensitizers for the targeted delivery of chlorin e6 (Ce6) against cervical cancer. For this purpose, Ce6 was conjugated with β-cyclodextrin (bCD) via a disulfide bond, creating nanophotosensitizers that were fabricated for the redox-sensitive delivery of Ce6 against cancer cells. bCD was treated with succinic anhydride to synthesize succinylated bCD (bCDsu). After that, cystamine was attached to the carboxylic end of bCDsu (bCDsu-ss), and the amine end group of bCDsu-ss was conjugated with Ce6 (bCDsu-ss-Ce6). The chemical composition of bCDsu-ss-Ce6 was confirmed with 1H and 13C NMR spectra. bCDsu-ss-Ce6 nanophotosensitizers were fabricated by a dialysis procedure. They formed small particles with an average particle size of 152.0 ± 23.2 nm. The Ce6 release rate from the bCDsu-ss-Ce6 nanophotosensitizers was accelerated by the addition of glutathione (GSH), indicating that the bCDsu-ss-Ce6 nanophotosensitizers have a redox-sensitive photosensitizer delivery capacity. The bCDsu-ss-Ce6 nanophotosensitizers have a low intrinsic cytotoxicity against CCD986Sk human skin fibroblast cells as well as Ce6 alone. However, the bCDsu-ss-Ce6 nanophotosensitizers showed an improved Ce6 uptake ratio, higher reactive oxygen species (ROS) production, and phototoxicity compared to those of Ce6 alone. GSH addition resulted in a higher Ce6 uptake ratio, ROS generation, and phototoxicity than Ce6 alone, indicating that the bCDsu-ss-Ce6 nanophotosensitizers have a redox-sensitive biological activity in vitro against HeLa human cervical cancer cells. In a tumor xenograft model using HeLa cells, the bCDsu-ss-Ce6 nanophotosensitizers efficiently accumulated in the tumor rather than in normal organs. In other words, the fluorescence intensity in tumor tissues was significantly higher than that of other organs, while Ce6 alone did not specifically target tumor tissue. These results indicated a higher anticancer activity of bCDsu-ss-Ce6 nanophotosensitizers, as demonstrated by their efficient inhibition of the growth of tumors in an in vivo animal tumor xenograft study. [ABSTRACT FROM AUTHOR]

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In this study, we investigated the structural properties and digestibility of wheat starch treated with octenyl succinic anhydride (OSA). For the experiment, the samples were reacted with 2, 4, 6, 8, and 10% OSA (pH 8.5–9.0) for 2 h. A light micrograph showed that there was no difference in the morphology and Maltese cross between native and OSA-treated starch. The X-ray diffraction (XRD) patterns of the native and OSA-treated starches showed typical A-type diffraction. In addition, the Fourier transform infrared (FT-IR) spectrum showed a distinct carbonyl peak at approximately 1730 cm−1, indicating the stretching vibration of the C=O bond of the ester group. The degree of substitution (DS) and content of resistant starch (RS) increased with increasing concentrations of treated OSA because of the increase in ester bonds. In particular, RS was thermostable compared to the RS content in uncooked and cooked starch. Blood glucose levels and response in vivo decreased as the OSA concentration increased. Treatment of wheat starch with 8% OSA concentration produced 35.6% heat-stable resistant starch. These results suggest that starch modified with OSA can be used to produce functional foods for diabetes.