Solution Equilibrium Study of Divalent Metal Ions with Phenylpropanoid Derivatives and Acetylcysteine Ligands.

Solution equilibrium of divalent metal ions (M=Mn2+, Co2+, Ni2+, Cu2+ and Zn2+) with caffeic acid (ligand C) or dihydrocaffeic acid (ligand D) in binary system, and with acetylcysteine (ligand N) in ternary system were investigated at condition similar to human physiological temperature of 310.15 K and ionic strength of 0.15 mol·dm-3 NaCl. Potentiometry technique was used for the determination of formation constant (log ß) assisted by spectrophotometry technique. The results indicated the formation of [ML], [MLH], [ML2], [ML2H] in binary species and [MLN], [MNLH], [MNLH2] in ternary species, where L represents ligands C or D. It was found that ligand D formed more stable complexes than that of ligand C, which were affected by the presence of double bond in the carboxylate moiety of ligand C. The speciation diagrams were simulated by HySS and discussed briefly, additionally the tendency of ternary complexes was evaluated from parameters Δ log KM and log X.

Facile isolation of purple membrane from Halobacterium salinarum via aqueous-two-phase system.

Purple membrane (PM) is a part of cytoplasmic membrane in certain extreme halophilic microorganisms belonging to Domain Archaea. It transduces light energy to generate proton gradient for ATP synthesis in the microorganisms. Bacteriorhodopsin (BR) is the only protein in PM responsible for the generation of proton gradient. Generally, PM was purified from Halobacterium salinarum via a tedious and lengthy sucrose density gradient ultracentrifugation (SGU). In this work, a facile method based on polyethyleneglycol (PEG)-phosphate aqueous-two- phase extraction system (ATPS) was employed to purify PM from cell lysate of H. salinarum. The results showed that PM could be completely recovered from the interface of PEG-phosphate ATPS with BR purity ca 94.1% as measured by UV-visible absorption spectra. In comparison with PM obtained by SGU, the PM isolated by ATPS could achieve the same level of purity and photocurrent activity (ca 177.2nA/µgBR/cm(2)) as analyzed by SDS-PAGE and photocurrent measurement, respectively. The easily scalable and straightforward ATPS procedure demonstrated that PM can be purified and recovered more cost-effectively with a significantly reduced operation time that should lead to broader range applications of PM possible.

Oil production from Yarrowia lipolytica Po1g using rice bran hydrolysate.

The purpose of this study was to produce microbial oil from Yarrowia lipolytica Po1g grown in defatted rice bran hydrolysate. After removing oil from rice bran by Soxhlet extraction, the bran is subjected to acid hydrolysis with various sulfuric acid concentrations (1-4% v/v), reaction times (1-8 h), and reaction temperatures (60-120°C). The optimal conditions for maximum total sugar production from the hydrolysate were found to be 3% sulfuric acid at 90°C for 6 h. Glucose was the predominant sugar (43.20 ± 0.28 g/L) followed by xylose (4.93 ± 0.03 g/L) and arabinose (2.09 ± 0.01 g/L). The hydrolysate was subsequently detoxified by neutralization to reduce the amount of inhibitors such as 5-hydroxymethylfurfural (HMF) and furfural to increase its potential as a medium for culturing Y. lipolytica Po1g. Dry cell mass and lipid content of Y. lipolytica Po1g grown in detoxified defatted rice bran hydrolysate (DRBH) under optimum conditions were 10.75 g/L and 48.02%, respectively.

Irresolvable complex mixture of hydrocarbons in soybean oil deodorizer distillate.

Aliphatic hydrocarbons (HCs) can be used as a fingerprint of a given seed oil. Only by characterization of aliphatic HCs could contamination by mineral oil in that seed oil be confirmed. During the isolation of squalene from soybean oil deodorizer distillate, a significant amount of unknown HCs, ca. 44 wt%, was obtained. These seemingly-easy-to-identify HCs turned out to be much more difficult to elucidate due to the presence of an irresolvable complex mixture (ICM). The objective of this study was to purify and identify the unknown ICM of aliphatic HCs from soybean oil deodorizer distillate. Purification of the ICM was successfully achieved by using modified Soxhlet extraction, followed by modified preparative column chromatography, and finally by classical preparative column chromatography. FT-IR, TLC, elemental analysis, GC/FID, NMR and GC-MS analyses were then performed on the purified HCs. The GC chromatogram detected the presence of ICM peaks comprising two major peaks and a number of minor peaks. Validation methods such as IR and NMR justified that the unknowns are saturated HCs. This work succeeded in tentatively identifying the two major peaks in the ICM as cycloalkane derivatives.

Facile synthesis of superparamagnetic thiamine/Fe3O4 with enhanced adsorptivity toward divalent copper ions.

The development of environmentally friendly adsorbents has been extensively carried out to overcome the detrimental effects of heavy metal accumulation, which has persistently become a global ecological problem. In pursuit of generating eco-friendly adsorbents, a green method for synthesizing thiamine functionalized-Fe3O4 (FT) was developed in this study. A one-step chemical oxidation and functionalization technique was used to prepare FT using the ammonia-containing solvent. A molar ratio of ammonia:Fe:thiamine of 15:1:1 was shown to produce FT15 with high yield, adsorptivity, and purity. XRD, XPS, FTIR, SEM, and SQUID characterization of FT15 revealed the formation of superparamagnetic thiamine functionalized Fe3O4 in their particles. This superparamagneticity facilitates the easy recovery of FT15 particles from the waste-containing solution by using an external magnetic force. The batch adsorption of Cu(II) onto FT15 showed the best fit with the Sips adsorption isotherm model with a maximum adsorption capacity of 426.076 mg g-1, which is 5.69-fold higher capacity than the control unmodified Fe3O4 (F15). After five adsorption-desorption cycles, the FT15 can maintain up to 1.95-fold higher capacity than the freshly synthesized F15. Observation on the physicochemical properties of the post-adsorption materials showed the contribution of an amine group, pyrimidine ring, and the thiazolium group of thiamine in boosting its adsorption capacity. This study provides important findings to advance the adsorptivity of magnetic adsorbents with promising recoverability from aqueous solution by employing naturally available and environmentally friendly compounds such as thiamine.

A review on rice bran protein: its properties and extraction methods.

Rice bran protein has been found to be of high quality and of importance for food and pharmaceutical applications. It is a plant protein that can be derived from rice bran, an abundant and cheap agricultural byproduct. The protein content in rice bran is about 10-15% and it consists of 37% water-soluble, 31% salt-soluble, 2% alcohol-soluble, and 27% alkali-soluble storage proteins. Its unique property as being hypoallergenic and having anti-cancer activity makes it a superior cereal protein that may find a wide range of applications. There were already reports on the extraction of rice bran protein several decades ago. However, as of now, commercial rice bran protein is still unavailable in the market. This review is aimed at providing valuable discussions on rice bran protein, that is, storage protein, its various properties, and extraction methods for the development of an effective processing scheme. Also, an update on the current processing methods is also included.

Nanocelluloses: Sources, Pretreatment, Isolations, Modification, and Its Application as the Drug Carriers.

The 'Back-to-nature' concept has currently been adopted intensively in various industries, especially the pharmaceutical industry. In the past few decades, the overuse of synthetic chemicals has caused severe damage to the environment and ecosystem. One class of natural materials developed to substitute artificial chemicals in the pharmaceutical industries is the natural polymers, including cellulose and its derivatives. The development of nanocelluloses as nanocarriers in drug delivery systems has reached an advanced stage. Cellulose nanofiber (CNF), nanocrystal cellulose (NCC), and bacterial nanocellulose (BC) are the most common nanocellulose used as nanocarriers in drug delivery systems. Modification and functionalization using various processes and chemicals have been carried out to increase the adsorption and drug delivery performance of nanocellulose. Nanocellulose may be attached to the drug by physical interaction or chemical functionalization for covalent drug binding. Current development of nanocarrier formulations such as surfactant nanocellulose, ultra-lightweight porous materials, hydrogel, polyelectrolytes, and inorganic hybridizations has advanced to enable the construction of stimuli-responsive and specific recognition characteristics. Thus, an opportunity has emerged to develop a new generation of nanocellulose-based carriers that can modulate the drug conveyance for diverse drug characteristics. This review provides insights into selecting appropriate nanocellulose-based hybrid materials and the available modification routes to achieve satisfactory carrier performance and briefly discusses the essential criteria to achieve high-quality nanocellulose.

One-step synthesis of nitrogen-grafted copper-gallic acid for enhanced methylene blue removal.

Nitrogen-grafting through the addition of glycine (Gly) was performed on a metal- phenolic network (MPN) of copper (Cu2+) and gallic acid (GA) to increase its adsorption capacity. Herein, we reported a one-step synthesis method of MPN, which was developed according to the metal-ligand complexation principle. The nitrogen grafted CuGA (Ng-CuGA) MPN was obtained by reacting Cu2+, GA, and Gly in an aqueous solution at a molar ratio of 1:1:1 and a pH of 8. Several physicochemical measurements, such as Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), N2 sorption, X-ray diffraction (XRD), and thermal gravimetry analysis (TGA), were done on Ng-CuGA to elucidate its characteristics. The analysis revealed that the Ng-CuGA has non-uniform spherical shaped morphology with a pore volume of 0.56 cc/g, a pore size of 23.25 nm, and thermal stability up to 205 °C. The applicational potential of the Ng-CuGA was determined based on its adsorption capacity against methylene blue (MB). The Ng-CuGA was able to adsorb 190.81 mg MB per g adsorbent at a pH of 6 and temperature of 30 °C, which is 1.53 times higher than the non-grafted CuGA. Detailed assessment of Ng-CuGA adsorption properties revealed their pH- and temperature-dependent nature. The adsorption capacity and affinity were found to decrease at a higher temperature, demonstrating the exothermic adsorption behavior.

Bioactivity Studies of Hesperidin and XAV939.

The present work aimed to evaluate the reactivity of natural bioflavonoid hesperidin (HSP) and synthetically derived XAV939 (XAV) against human hepatocellular carcinoma (HepG2), human breast cancer (MDA-MB231) cancer cell lines, and related molecular and pathological profiles. Data recorded revealed that the cytotoxic potential of the tested products was found to be cell type- and concentration-dependent. The half-maximal inhibitory concentration (IC50) value of the HSP-XAV mixture against MDA-MB231 was significantly decreased in the case of using the HSP-XAV mixture against the HepG2 cell line. Also, there was a significant upregulation of the phosphotumor suppressor protein gene (P53) and proapoptotic genes such as B-cell lymphoma-associated X-protein (Bax, CK, and Caspase-3), while antiapoptotic gene B-cell lymphoma (Bcl-2) was significantly downregulated compared with the untreated cell control. The cell cycle analysis demonstrated that DNA accumulation was detected mainly during the G2/M phase of the cell cycle accompanied with the elevated reactive oxygen species level in the treatment of HepG2 and MDA-MB231 cell lines by the HSP-XAV mixture, more significantly than that in the case of cell control. Finally, our finding suggests that both HSP and XAV939 and their mixture may offer an alternative in human liver and breast cancer therapy.

Fabrication of cellulose carbamate hydrogel-dressing with rarasaponin surfactant for enhancing adsorption of silver nanoparticles and antibacterial activity.

Bacterial contamination on external wounds is known to be a factor that prevents wound healing and triggers tissue damage. Hydrogel-dressings with antibacterial activity is a useful medical device to avoid this contamination, wherein the antibacterial activity can be provided via incorporation of silver nanoparticles (AgNPs). Contrary to the conventional two-step preparation of an AgNPs-loaded hydrogel (AgNPs@hydrogel), this work aims to establish a new and facile synthesis method employing the adsorption principle. Once AgNO3 adsorbed into active sites of the hydrogels, in situ reductions using NaBH4 was employed to produce AgNPs@hydrogel. The effect of surfactant addition on the AgNO3 loading and the antibacterial activity of the resulting hydrogel dressing was investigated. The outcome of this work indicates that the addition of rarasaponin not only can increase the loading of AgNPs on cellulose carbamate hydrogel (CCH) but also significantly enhance the antibacterial activity of the resulted hydrogel-dressing. Superior to the other studied surfactant, the loading capacity (LC) of AgNPs is found to be 10.15, 9.94, and 7.53 mg/g for CCH modified with rarasaponin, CTAB, and Tween80, respectively. These findings conclude that the addition of surfactant, especially rarasaponin, can effectively improve the loading of AgNPs onto hydrogel-dressing via adsorption and promote the antibacterial activity. Furthermore, the cytotoxic test shows that the hydrogel-dressings have good biocompatibility toward skin fibroblast cells.

Release of phenolic acids from defatted rice bran by subcritical water treatment.

BACKGROUND: Oil production from rice bran, an undervalued by-product of rice milling, produces defatted rice bran (DRB) as a waste material. Although it is considered a less valuable product, DRB still contains useful substances such as phenolic compounds with antioxidant, UV-B-protecting and anti-tumour activities. In this study the phenolic acids in DRB were extracted with subcritical water at temperatures of 125, 150, 175 and 200 °C. RESULTS: Analysis of total phenolics using Folin-Ciocalteu reagent showed about 2-20 g gallic acid equivalent kg(-1) bran in the extracts. High-performance liquid chromatography analysis showed low contents of phenolic acids (about 0.4-2 g kg(-1) bran). Ferulic, p-coumaric, gallic and caffeic acids were the major phenolic acids identified in the extracts. Thermal analysis of the phenolic acids was also done. The thermogravimetric curves showed that p-coumaric, caffeic and ferulic acids started to decompose at about 170 °C, while gallic acid did not start to decompose until about 200 °C. CONCLUSION: Subcritical water can be used to hydrolyse rice bran and release phenolic compounds, but the high temperatures used in the extraction can also cause the decomposition of phenolic acids.

Enhanced Lipid Production in Yarrowia lipolytica Po1g by Over-expressing lro1 Gene under Two Different Promoters.

Yarrowia lipolytica is a well-known oleaginous yeast that naturally accumulates lipids to more than 20% of their dry cell weight. Due to its brief doubling time and Generally Recognized as Safe (GRAS) properties, Y. lipolytica has been exploited for the production of commercially valuable lipids. Among the genes related to the lipid synthesis, the gene YALI0E16797g (LRO1) encoding a major triacylglycerol synthase of Y. lipolytica shows a significant impact during the acylation process. Thus, in the present work, we explore the contributions of hp4d or TEFintron promoters to the response of LRO1 expression on lipid accumulation by molecular cloning technology. Results showed that over-expression of LRO1 led to higher lipid content as well as lipid yield. The one with the hp4d promoter showed the highest lipid content of 12% wt. However, such an enhancement also caused a growth defect of cells. On the other hand, the lipid content of the cells over-expressing LRO1 with TEFintron promoter revealed only a modest increase in lipid content, but it promoted cell growth. Therefore, all things considered the one with the TEFintron promoter showed the highest lipid yield.

Protonation Equilibria of N-Acetylcysteine.

The acid base protonation equilibria of N-acetylcysteine (Nac) and its equilibrium constants in water solutions were determined by the Hyperquad 2008 software assessment from the pH potentiometry data, which provides a diversity of statistics presentations. The effect of a number of organic solvents on the acid base protonation processes was also examined. The solution equilibria of N-acetylcysteine (Nac) were studied at T = 298.15 K in water (w 1) + organic liquid mixtures [100 w 2 = 0, 20, 40, 60, and 80%] with an ionic strength of I = 0.16 mol·dm-3 NaNO3. Also, the organic solvent's influence was studied based on the Kamlet-Taft linear solvation energy relationship. The experimental results were compared with theoretical ones obtained via the Gaussian 09 calculation computer program. The protonation equilibria of Nac were found to be important in the progress of separation systems in aqueous and non-aqueous ionic solutions. Nac showed a likely good metal dibasic chelating bioligand as the DFT calculations proved two binding sites. Spectrophotometry evaluation was also done for N-acetylcysteine bioligands at various pH values in water solutions then its absorbance ratio was measured.

Hydrophobic Cetyltrimethylammonium Bromide-Pillared Bentonite as an Effective Palm Oil Bleaching Agent.

To promote a minimal use of acid in the activation of bentonite and to maintain oil quality during refinery and storage, a new class of bleaching agent, cetyltrimethylammonium bromide (CTAB)-pillared bentonite (CTAB@Bent), is fabricated. The influences of three independent intercalation variables, including temperature T (40, 50, and 60 °C), time t (2, 4, and 6 h), and CTAB loading m c (0.2, 0.25, 0.33, 0.50, and 1.00%, w/w), on the ß-carotene removal rate are studied. The multilevel factorial design combined with the response surface methodology and three-way analysis of variance is employed to design and optimize experiments in regard to the three independent variables. Based on the optimization results, the highest ß-carotene removal rate is monitored at 71.04% (w/w) using CTAB@Bent obtained at optimum intercalation conditions (CTAB@Ben-Opt): T = 40 °C, t = 3.2 h, m c = 1.00% (w/w). The mechanism study shows that the adsorption of ß-carotene onto CTAB@Bent-Opt is spontaneous and endothermic, with the governing steps of physical interaction and ion exchange between ß-carotene and the cationic head of CTAB. CTAB@Bent-Opt also exhibits characteristics superior to those of commercial raw bentonite and acid-activated bentonite, indicating that a more efficient ß-carotene removal can be achieved using this new bleaching agent.

Studies on the performance of bentonite and its composite as phosphate adsorbent and phosphate supplementation for plant.

Organo-bentonite (OrB) was prepared by modifying bentonite with chitosan, and natural surfactant extracted from Sapindus rarak fruit. The physical alteration post-modification, performance of phosphates (Pi) adsorption, and possibility as a Pi-supplementation for plants of OrB were assessed and compared to acid-activated bentonite (AAB). The physical alteration due to modification of bentonite was characterized. SEM images were not indicating significant morphology differences between OrB and AAB. Existence of chitosan layers in OrB causes a decrease in basal spacing as characterized using XRD. The BET surface area of OrB was decreased compared to AAB due to pore coverage by chitosan. Adsorption studies reveal that OrB has a higher adsorption capacity towards Pi than AAB, which is 97.608 and 131.685 mg/g at 323 K for AAB and OrB, respectively. The H-shape isotherm curve indicates that chemisorption is dominantly controlling the adsorption. The isotherm and kinetics adsorption were well fitted to Langmuir and Pseudo-second order models, respectively. Performance of AAB and OrB as Pi-supplementation was assessed based on growth phenotypes of Arabidopsis thaliana; seedlings show that supplementation of Pi@AAB and Pi@OrB (at half doses) can promote primary root extension. These results also demonstrate the safety of direct disposal of the materials into the soil.

Aqueous synthesis of highly adsorptive copper-gallic acid metal-organic framework.

A greener route to synthesize mesoporous copper-gallic acid metal-organic framework (CuGA MOF) than the conventional method using harmful DMF solvent was proposed in this study. Various synthesis attempts were conducted by modifying the synthesis conditions to produce CuGA MOF with comparable physical properties to a reference material (DMF-synthesized CuGA NMOF). The independent variables investigated include the molar ratio of NaOH to GA (1.1 to 4.4) and the synthesis temperature (30, 60, 90 °C). It was found that proper NaOH addition was crucial for suppressing the generation of copper oxide while maximizing the formation of CuGA MOF. On the other hand, the reaction temperature mainly affected the stability and adsorption potential of CuGA MOF. Reacting Cu, GA, and NaOH at a molar ratio of 1:1:2.2 and a temperature of 90 °C, produced mesoporous MOF (CuGA 90-2.2) with a surface area of 198.22 m2/g, a pore diameter of 8.6 nm, and a thermal stability of 219 °C. This MOF exhibited an excellent adsorption capacity for the removal of methylene blue (124.64 mg/g) and congo red (344.54 mg/g). The potential usage of CuGA 90-2.2 as a reusable adsorbent was demonstrated by its high adsorption efficiency (> 90%) after 5 adsorption-desorption cycles.

Equilibrium and kinetic studies in adsorption of heavy metals using biosorbent: a summary of recent studies.

Distinctive adsorption equilibria and kinetic models are of extensive use in explaining the biosorption of heavy metals, denoting the need to highlight and summarize their essential issues, which is the main purpose of this paper. As a general trend, up until now, most studies on the biosorption of heavy metal ions by miscellaneous biosorbent types have been directed toward the uptake of single metal in preference to multicomponent systems. In particular, Langmuir and Freundlich models are the most common isotherms for correlating biosorption experimental data though other isotherms, which were initially established for gas phase applications, can also be extended onto biosorption system. In kinetic modeling, the pseudo-first and -second order equations are considered as the most celebrated models.

An environment-friendly composite as an adsorbent for removal Cu (II) ions.

The low-cost composite film was prepared by incorporating chitosan, berry soap fruit extract (rarasaponin), and bentonite as the raw materials. The produced chitosan/rarasaponin/bentonite (CRB) composite exhibits outstanding adsorption capability toward copper metal ions (Cu(II)). A series of static adsorption experiments were carried out to determine the isotherm and kinetic properties of CRB composite in the adsorption process. The adsorption equilibrium shows a good fit with the Langmuir isotherm model; the CRB composite has maximum uptake of Cu (II) of 412.70 mg/g; the kinetic adsorption data exhibit a good fit with the pseudo-second-order model. The thermodynamic parameters, ΔH°, ΔG°, and ΔS°, obtained from the isotherm data indicate that the uptake of copper ions by CRB composite is more favored at low temperatures. This study shows that physicochemical modified adsorbent, namely CRB composite, can remove Cu (II) better than pristine adsorbent of AAB and chitosan. The CRB composite also shows potential reusability.

Isolation and characterization of starch from Limnophila aromatica.

Starch is one of the digestible natural polymers found in vascular plants. This natural polymer is the primary source of polysaccharides to produce energy for humans. In this work, starch was extracted from the defatted and dephenolated Limnophila aromatica (DFPLA) by using the alkaline method. The DFPLA contains starch with a purity of 70.43 % where 55.1 % of it is the resistant starch. Physicochemical properties of the DFPLA starch such as solubility, morphology, swelling power, crystallinity, gelatinization, retrogradation, decomposition temperature, pasting profile, and surface functional groups were evaluated. The DFPLA starch possesses a medium-amylose content of 23.78 %, and the particle diameters of the starch were varied from 3 to 6 µm. The swelling power and solubility of the DFPLA starch are increasing as the temperature increased, where at 90 °C the swelling power and solubility of the starch is 13.73 g/g and 7.26%, respectively. Starch from DFPLA has a high total dietary fiber (76.28%) which is comparable to that of starch extracted from staple foods. The results indicate that starch from DFPLA possesses good physicochemical properties; this alternative starch may have potential application as a new feedstock for food industries.

Highly adsorptive chitosan/saponin-bentonite composite film for removal of methyl orange and Cr(VI).

Robust and simple composite films for the removal of methyl orange (MO) and Cr(VI) have been prepared by combining chitosan, saponin, and bentonite at a specific ratio. There are several composite films (chitosan-saponin-bentonite (CSB)) prepared; among them, the composite films CSB2:3 and CSB1:1 have the highest removal efficiency toward MO and Cr(VI) where the maximum removal is 70.4% (pH 4.80) and 92.3% (pH 5.30), respectively. It was found that different types of adsorbate have different thermodynamic properties of the adsorption process; the adsorption of MO onto CSB2:3, chitosan, and acid-activated bentonite (AAB) proceeded endothermically, while the adsorption of Cr(VI) onto CSB1:1, chitosan, and AAB proceeded exothermically. The parameters of the adsorption were modeled by using isotherm and kinetic equations. The models of Langmuir, Freundlich, Redlich-Peterson, Sips, and Toth were used for fitting the adsorption isotherm data at a temperature of 30, 45, and 60 °C; all of the isotherm models could represent the data well. The result indicates that CSB2:3 has the highest adsorption capacity toward MO with qm of 360.90 mg g-1 at 60 °C; meanwhile, CSB1:1 has the highest adsorption capacity toward Cr(VI) with qm 641.99 mg g-1 at 30 °C. The pseudo-second-order model could represent the adsorption kinetics data better than the pseudo-first-order equation. The adsorption mechanism was proposed, and the thermodynamic properties of the adsorption were also studied.