Respective Molar Ratios Research Articles

Extraction, Structural Characterization, and Physicochemical and Biological Properties of Water-Soluble Polysaccharides from Adlay Bran.

Adlay bran, often discarded or used as animal feed, holds untapped potential. This study explores the beneficial properties of water-soluble polysaccharides (ABPs), extracted using a hot water method, with the aim of transforming what is commonly regarded as waste into a valuable resource. The response surface methodology (RSM) was employed to fine-tune the extraction parameters, establishing conditions at 80.0 °C, 2.5 h, and a water-to-material ratio of 31.6 mL/g. Structural studies showed that ABPs consist of different monosaccharides, including rhamnose, arabinose, glucosamine, glucose, galactose, xylose, mannose, and glucuronic acid, with respective molar ratios of 2.12%, 2.40%, 0.52%, 77.12%, 7.94%, 3.51%, 2.55%, and 3.82%. The primary component of these polysaccharides has a molecular weight averaging 12.88 kDa. The polysaccharides feature eight distinct linkage types: →3,4)-Rhap-(1→ at 5.52%, →4)-Glcp-(1→ at 25.64%, Glcp-(1→ at 9.70%, →3,4)-Glcp-(1→ at 19.11%, →4)-Xylp-(1→ at 7.05%, →3)-Glcp-(1→ at 13.23%, →3,4)-Galp-(1→ at 9.26%), and →4,6)-Gclp-(1→ at 12.49%. The semi-crystalline properties of ABPs and their shear-thinning characteristics were validated by X-ray diffraction and rheology tests. In vitro assays highlighted the strong antioxidant activities of ABPs, as evidenced by DPPH and ABTS hydroxyl radical scavenging tests, along with significant metal chelating and reducing powers. Additionally, ABPs showed significant inhibition of α-glucosidase and α-amylase, making them attractive as versatile additives or as agents with antioxidant and blood-sugar-lowering properties in both the food and pharmaceutical sectors. These findings support the utilization of adlay bran for higher-value applications, harnessing its bioactive components for health-related benefits.

Flocculation Performance of Industrial Sugarcane Juice by Acrylamide-Based Anionic Flocculant

Despite the widespread use of ionic polymer flocculants in sugar refineries, there is still insufficient knowledge on the relationship between the polymer properties and the efficiency of flocculation. This paper describes the performance of poly(sodium acrylate-co-acrylamide) (poly(SA-co-AAm)) as an anionic flocculant in the flocculation–coagulation of sugarcane juice from the sugar factory Gempolkrep PTPN X Mojokerto. Poly(SA-co-AAm) was successfully prepared via free radical polymerization of sodium acrylate and acrylamide with respective molar ratios of 40:60, 50:50, and 60:40, and compared with the commercial flocculant Accofloc. It was found that the mud height of the sugarcane decreased with increasing SA:AAm ratio. However, mud height increase was observed with further increasing SA:AAm ratio. Furthermore, increasing the flocculant dosage did not induce any significant change in the mud height and pH. The total dissolved solids (TDS) significantly decreased when the ratio of sodium acrylate:acrylamide was changed from 40:60 to 50:50, whereas a further change to 60:40 increased the TDS value again. It is also noticed that the tendency of turbidity is consistent with the TDS value. These results demonstrate that poly(SA-co-AAm) is a feasible alternative to the commercial flocculant owing to its good flocculation–coagulation performance with an optimum SA:AAm ratio of 50:50.

Electronic properties of BZT nano-ceramic grades at low frequency region

BZT ceramics was prepared by using fine powder mixture of BaCO3, TiO2 and ZrO2 in the respective molar ratio to form Ba(Zr0.10Ti0.90)O3 via solid state reaction at elevated temperature. The prepared BZT was milled in the planetary ball mill from 0-120 min to achieve different powder grades from micron to nano-sized particles. After the powder characterization by XRD and SEM the samples were pressed in disc shape and sintered at different temperatures from 1100-1350?C in the air. The sintered samples were characterized by SEM and their density and average grain size was determined and presented vs. sintering temperature and powder grades (milling time). After that the silver epoxy electrodes were deposited on sintered disc samples. The disc samples capacity and resistivity were measured at low frequency region from 1 Hz to 200 kHz using low frequency impedance analyzer. The sintering temperatures and powder grades were used as parameters. Finally the specific resistance ?, dielectric constant (?' + j?") and tg? where determined from the impedance measurements. The behavior of electronic properties where analyzed e.g. the relaxation effect of the space charge (inter-granular electric charges) vs. sintering temperature and ceramic grades. The results obtained were compared with best literature data for the losses in BZT ceramics at low frequencies.

Structural characterization and in vitro evaluation of the prebiotic potential of an exopolysaccharide produced by Bacillus thuringiensis during fermentation

Microbial extracellular polysaccharides possess various beneficial characteristics and are potential prebiotic candidates. The extracellular polysaccharide BPS-1 was isolated from Bacillus thuringiensis (its production being optimized by response surface methodology) and subjected to high-cell-density fermentation. BPS-1 is a heteropolysaccharide (molecular weight 35.6 kDa) composed of rhamnose, arabinose, glucosamine, galactose, glucose, and mannose in respective molar ratios 3.7:1.7:4.5:1:3.1:1.1. Its functional groups and structural features were characterized by FT-IR and NMR. The cytotoxicity of BPS-1 was evaluated against HcoEpiC and LoVo cell lines. BPS-1 was also evaluated for its potential effects on human gut microbiota in an in vitro fermentation model. During 48 h of anaerobic fermentation by healthy human fecal bacteria, BPS-1 significantly enhanced the production of short-chain fatty acids and increased the relative abundance of beneficial bacterial genera. This is the first report of the prebiotic potential of BPS-1 produced by Bacillus thuringiensis and provides a basis for its application in the food industry.

Solubility of Piperine and Its Inclusion Complexes in Biorelevant Media and Their Effect on Attenuating Mouse Ileum Contractions.

This study evaluated the solubility of piperine (PP) in biorelevant media and the effect of its ground mixtures (GMs) and coprecipitates (CPs) on intestinal contractions when presented in inclusion complexes with α-, β-, and γ-cyclodextrins (CDs). In the powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) measurements, CP (PP/αCD) and CP (PP/γCD) suggest the formation of inclusion complexes. The 1H-nuclear magnetic resonance (NMR) analysis showed the integrated intensity ratios of CP (PP/αCD) and CP (PP/γCD) protons to be 1/2 and 1/1, the same as the respective molar ratios in the respective GM inclusion complexes. The intestinal contraction test confirmed that the intestinal contraction rate of carbachol (CCh) in the presence of 2.0 × 10–5 M PP was comparable to that in the absence of PP. On the other hand, CP (PP/αCD), GM (PP/αCD = 1/2), and GM (PP/βCD = 1/1) formed inclusion complexes that significantly suppressed the intestinal contractility at PP 1.0 × 10–8 M. No significant differences were observed between CP and GM. The solubility of the PP/αCD inclusion complex was 6–7 times higher than that of PP in the fasted-state-simulated intestinal fluid (FaSSIF, pH 6.5). PP functioned to suppress intestinal contraction by forming an inclusion complex. Based on this result, PP/αCD might be expected to be effective as an antidiarrheal.

Molar ratios of dietary phytate to minerals and iron status of female residential students in University of Dhaka, Bangladesh.

Female undergraduate students may undergo many health implications due to the transition from secondary to undergraduate level. The study was aimed to assess molar ratios of phytate to minerals (calcium, zinc, and iron) in the diets, and to measure the iron status of resident female students at Dhaka University. In total, 180 female students between 18-26 years of age from 3 dormitories of Dhaka University were selected for the study. Dietary intake information was collected over three consecutive days. Multiple-Pass 24-hour recall. Blood hemoglobin and serum ferritin levels were analyzed for sub-sample (20 participants from each dormitory). The mean dietary intake of phytate, calcium, zinc, and iron were estimated at 347.11, 181.04, 6.59, and 7.14 mg/day, and hemoglobin and serum ferritin at 11.34 g/dl, and 18.48 ng/ml, respectively. The respective molar ratios of phytate: calcium, phytate: zinc, phytate: iron and phytate × calcium: zinc were 0.13, 5.27, 4.20, and 21.26 in the diet of the respondents. The prevalence of anemia, iron deficiency and iron deficiency anemia among the respondents was found to be 51.7%, 48.4%, and 28.3%, respectively. Linear regression analysis showed that only zinc intake had positive association with hemoglobin, while iron and zinc intake had a significant positive, and phytate:iron molar ratio had a significant negative association with serum ferritin concentration (p < 0.05). After adjusting all significant determinants of serum ferritin, no predictors have found significant. Larger and more specific research is needed to clearly understand the mechanism behind anemia and iron deficiency among female residential students.

Thermophysical, Cohesive Energy Density and Molar Heat Capacity of Surfactant-Based Low-Transition-Temperature Mixtures

The present investigation deals with the synthesis and thermophysical evaluation of six natural low-transition-temperature mixtures (NALTTMs) with surfactants as suitable hydrogen bond donors (HBDs) and ammonium salts as hydrogen bond acceptors (HBAs). Thermophysical evaluation of these NALTTMs reveals the linear relationship of density and refractive index and nonlinear relation of conductivity and viscosity with temperature. The obtained results are associated with temperature by binary model equations. Additionally, the molar heat capacity and cohesive energy density manifest close dependence on the corresponding molar mass and follow a linear relation with increasing temperature. It could be concluded from the data that the choice of HBA and HBD with their respective molar ratio has a major influence on the extraction ability and thermophysical properties of NALTTM.

Mesoporous x[Cu(II)O] nanoclusters dispersed and immobilized on y$$[\text {SiO}_{2}]$$ matrix: structure and effective controlled biocidal activity against Pseudomonas aeruginosa and Bacillus subtilis

Herein we report the synthesis of mesoporous nanostructures comprising copper (II) oxide $$\{x[\mathrm{Cu(II)O}]\}$$ immobilized on silica $${ y}[\mathrm{SiO}_{2}]$$ template for release of copper ions by precipitation via sol–gel technique. Three different specimens with increasing amount of Cu in the matrix with amount of Si being the same in all the samples, viz. ‘6Cu:5Si’, ‘4.5Cu:5Si’ and ‘3Cu:5Si’ where the numbers refer to the respective molar ratios of their respective domains, were prepared. Increase of crystallinity in the mesoporous material with increase in incorporation of copper domains consisting of CuO in $$\text {SiO}_{2}$$ matrix has been established. The average size of the CuO nanoparticle (NP) (domain) is 20–30 nm. The BET surface area has been found to be 276–390 $$\text {m}^{2}\ \text {g}^{-1}$$ and Langmuir surface area has been found to be 422–605.9 $$\text {m}^{2}\ \text {g}^{-1}$$ for the samples 5Si:3Cu–5Si:6Cu, respectively, having pore size of 4–6.5 nm. The cytotoxicity data show that the NPs are less toxic below concentration of $$125\ \upmu \text {g ml}^{-1}$$ . A steady increase in percentage of bacterial-‘Escherichia coli’, ‘Pseudomonas aeruginosa’ and ‘Bacillus subtilis’ cell death (indicated by decrease in optical density) due to increase in concentrations of NPs after incubation for 14 h, showing sensitivity even at very low concentrations (5–20 $$\upmu $$ g), has been observed. A comparative antibacterial activity test among the three prepared specimens has been reported, which shows better antibacterial activity with the lowest copper concentration. Better antibacterial sensitivity when compared with equivalent amount of commercial CuO is established.

Adsorption Assisted Photocatalytic Removal of Methyl Orange by MgAl2O4-Sb2S3 Composite Material.

The current article is about the water treatment in which colored water contaminated by methyl orange has been used for adsorption assisted photocatalysis. Coupling of photocatalysis with the traditional water treatment processes has been in practice since last couple of years for the improvement of degradation efficiencies, for example, photocatalysis coupled with ultrafilteration, adsorption, flocculation, biological methods, photolysis, membrane distillation, etc. Among all these coupling approaches, adsorption assisted photocatalysis being a very simple and highly efficient approach is suffering from few drawbacks on the account of high cost, low stability and surface area of the adsorbent support. The present study is a contribution towards improvement in this coupling approach. A low cost, highly stable spinel magnesium aluminate (MgAl2O4) material synthesized at nanoscale is used for composite formation with antimony sulphide (Sb2S3) material having high absorption coefficient in the visible light of solar spectrum. A review of recent patents shows that the field of photoctalysis is dominated by the traditional TiO2 catalyst. The modification of TiO2 by either composite formation or by doping is the main focus. Coprecipitation method is used for the synthesis of spinel in which the desired precursors in the respective molar ratios were mixed and annealing of the resulting precipitates was carried out at 800oC for 8 h. Sb2S3 was synthesized by the hydrothermal method in which the required molar solution of precursors was mixed with urea solution and the whole mixture was maintained at 105oC for 6 hrs in a Teflon lined autoclave. The resulting suspension was then annealed at 37oC for 3 hours. The composite of Sb2S3 and MgAl2O4 has been synthesized by mixing both the materials in 1:1 and heat treated in an oven at a temperature of 200oC. Peaks in X-ray diffraction pattern correspond to both the Sb2S3 and spinel phase. All the peaks corresponding to the Sb2S3 and spinel phase were found to be shifted to higher d-spacing values. This indicates the expansion of unit cells of the Sb2S3 and MgAl2O4 phases. Thermal studies show that only 3% weight loss is observed at a temperature of 200-1000oC which may be due to the loss of surface water from the sample. Surface area, pore volume and pore size obtained from N2 adsorption were 143m2/g, 0.21cc/g and 23.26Å, respectively. The removal efficiency of 0.1g catalyst for methyl orange solution of 5mg/L concentration after reaction in dark conditions for the time of one hour was calculated to be 24% owing to the adsorption. The visible light degradation efficiency of the 0.1g catalyst for 1, 5, 19, 25 and 50 mg/L concentrations of MO solutions were 97, 93, 75, 72 and 62% respectively. The dosage of the catalyst was found to have a direct relationship with the degradation efficiency. Lower pH was found suitable for the degradation owing to better interaction of catalyst surface and the adsorbed dye. Percent degradation increased with the increase in the time and temperature of reaction. The degradation kinetics followed pseudo first order rate equation; the calculated value of rate constant was 0.0102 min-1. The mechanism involves the excitation of electrons in the valence band of Sb2S3 to the conduction band by the absorption of visible and UV light. The electrons and holes participate in the surface reactions resulting in the formation of superoxide and hydroxyl radicals which degrade the targeted polluted. Lower concentration of MO solutions, acidic pH, higher catalyst dosage and greater reaction times were found suitable for the degradation efficiency.

Microwave-assisted catalytic esterification of α-glucoisosaccharino-1,4-lactone with tall oil fatty acids

Carbohydrates-rich materials are partly degraded during alkaline kraft pulping into a complex mixture of aliphatic carboxylic acids consisting of α-glucoisosaccharinic acid as one of the main acids. On the other hand, crude tall oil, containing significant amounts fatty acids, is obtained as a by-product from kraft pulping. One interesting novel approach is to utilize chemically both these side-streams by producing renewable surfactants from aliphatic carboxylic acids and fatty acids via esterification. In this paper, lauric (C12:0) and oleic (C18:1) acids as well as a mixture of tall oil fatty acids were esterified with α-glucoisosaccharino-1,4-lactone in a microwave-assisted batch reactor using a respective molar ratio of 3:1 in the presence of p-toluenesulfonic acid as a catalyst to obtain a mixture of the corresponding mono- and diesters (nonionic surfactants) at 70–100 °C for 6–24 h. The total yields varied in the range of 40–62 % and the mass ratio of monoesters to diesters (0.4–2.7) was greatly dependent on the fatty acid feedstock. It seems that relatively high yields of mono- and diesters of typical fatty acids can be obtained when they are esterified with one of the most significant lactones (α-glucoisosaccharino-1,4-lactone) in black liquor from kraft pulping. These esters are potential surfactants based on renewable feedstocks.

Effect of Cooking Temperature on Mineral Content and Anti-nutritional Factors of Yam and Taro Grown in Southern Ethiopia

Abstract This study aimed to determine the mineral composition and anti-nutritional factors, oxalate and phytate, of yam and taro grown in southern Ethiopia. In addition, the effect of cooking at different temperatures on the mineral compositions and anti-nutritional factors together with respective molar ratios Ca:oxalate, Zn:phytate, Ca:phytate and (Ca × phytate):Zn was determined. The mineral compositions were found to be: 21.8–15.7, Ca; 11.4–12.1, Na; 7.02–7.24, Mg; 6.47–14.14, Zn; 2.04–4.3, Fe; 0.26–0.88, Mn; 0.50–0.60, Cu; 0.57–0.82, Co; and 0.20–2.15, Ni in mg/100 g in the raw yam samples and 41–53, Ca; 6.21–7.21, Na; 7.32–7.58, Mg; 42–50, Zn; 1.93–3.25, Fe; 1.71–5.88, Mn; 0.46–0.51, Cu; 0.65–0.95, Co; and 0.18–0.68 Ni in mg/100 g of raw taro samples. Mineral content decreased by cooking except Fe and Ca in one variety of taro where they show a bit increment. The anti-nutritional factor to mineral ratio tends to imply that the relative bioavailability of the minerals after cooking was found to be increased except for that of Fe. These tubers may present health hazard potential, which in turn demands proper processing before consumption to eliminate the toxic effects of anti-nutritional factors.

ChemInform Abstract: Cotemplating Synthesis of a Rare Borate Ni(en)3·Hen· [B9O13(OH)4]·H2O with a Chiral Polyanonic Chain Constructed from Two Different Clusters.

AbstractThe title compound is prepared by solvothermal treatment of a mixture of H3BO3, NiCl2, DMF, en, and 3‐nitrophenylboronic acid in the respective molar ratio of 7.7:0.5:25.9:44.9:0.8 under the co‐templating effect of [Ni(en)3]2+ and Hen+ cations (autoclave, 128 °C, 7 d; 34% yield).

Optimized one-step preparation of a bioactive natural product, guaiazulene-2,9-dione

We previously isolated a natural product, namely guaiazulene-2,9-dione showing strong antibacterial activity against Vibrio anguillarum, from a gorgonian Muriceides collaris collected in South China Sea. In this experiment, guaiazulene-2,9-dione was quantitatively synthesized with an optimized one-step bromine oxidation method using guaiazulene as the raw material. The key reaction condition including reaction time and temperature, drop rate of bromine, concentration of aqueous THF solution, respective molar ratio of guaiazulene to bromine and acetic acid, and concentration of guaiazulene in aqueous THF solution, were investigated individually at five levels each for optimization. Combined with the verification test to show the absolute yield of each optimization step, the final optimal condition was determined as: when a solution of 0.025 mmol mL−1 guaiazulene in 80% aqueous THF was treated with four volumes of bromine at a drop rate of 0.1 mL min−1 and four volumes of acetic acid at −5°C for three hours, the yield of guaiazulene-2,9-dione was 23.72%. This was the first report concerning optimized one-step synthesis to provide a convenient method for the large preparation of guaiazulene-2,9-dione.

Preparation and characterization of stable nanoliposomal formulation of fluoxetine as a potential adjuvant therapy for drug-resistant tumors.

Chemotherapy research highly prioritizes overcoming the multidrug resistance (MDR) in human tumors. Liposomal formulation of fluoxetine, as a fourth generation chemosensitizer, was constructed and characterized for percent entrapment, release profile, morphology, particle size, zeta potential and stability. Liposomes were prepared using different active loading techniques. The influence of different formulation variables such as loading methodology, type of main lipid, addition of PEGylated lipid and cholesterol percentage was evaluated to achieve required entrapment efficiency, in vitro release behavior and stability. The studied parameters had significant effect on physicochemical characteristics of the nanocarriers. High fluoxetine encapsulation efficiency (83% ± 3%) and appropriate particle size (101 ± 12 nm) and zeta potential (-9 ± 2 mv) were achieved for PEGylation liposomes composed of DSPE-PEG, DSPC and cholesterol at respective molar ratio of 5:70:25. An in vitro fluoxetine release of about 20% in 48 h was observed from optimum formulation. Atomic force microscopy (AFM) studies confirmed homogeneous distribution of particles and spherical shape with smooth surface. The optimum formulation was stable for 9 days when incubated at 37 °C. The results of this study are very encouraging for application of the developed fluoxetine liposomal formulation in drug-resistant tumor models.

Multiple fold increase in activity of ferroxidase–apoferritin complex by silver and gold nanoparticles

The effect of silver (Ag) and gold (Au) nanoparticles on the ferroxidase activity of apoferritin showed a 110-fold increase in specific activity and a 9-fold increase over the control at the respective molar ratios of Au-apoferritin and Ag-apoferritin nanoparticles (NPs) of 500:1 and 1000:1. Typical color change, from pale yellow to brown, occurred when apoferritin was mixed with AgNO3 or AuCl3 followed by sodium borohydride to afford respective metal-apoferritin NP complexes in a ratio of between 250:1 and 4000:1. These complexes were characterized by ultraviolet-visible inductively coupled plasma–optical emission spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and energy-dispersive x-ray spectroscopy. Transmission electron microscopy revealed that the size of NPs increased as the molar ratio of metal to apoferritin increased, with an average size of 3–6 nm generated with Au-to-apoferritin and/or Ag-to-apoferritin molar ratios of 250:1 to 4000:1. Fourier transform infrared spectrometry showed no structural changes of apoferritin when the NPs were attached to the protein. From the Clinical EditorIn this paper the utility of gold and silver nanoparticles in augmenting the activity of the ferroxidase-apoferritin complex is described. Both NPs dramatically increased the ferroxidase activity.

Structure of the O-antigen polysaccharide present in the lipopolysaccharide ofCronobacter dublinensis(subspecieslactaridiorlausannensis) HPB 3169

Cronobacter dublinensis (formerly Enterobacter sakazakii) HPB 3169 is a pathogenic Gram-negative bacterium that produces a smooth-type lipopolysaccharide in which the antigenic O-polysaccharide component was determined to be a repeating pentasaccharide unit composed of L-rhamnose; 2-acetamido-2-deoxy-D-glucose; 3,6-dideoxy-3-(R)-3-hydroxybutyramido-D-glucose; and 3-deoxy-manno-oct-2-ulosonic acid in the respective molar ratio 2:1:1:1. Chemical and 2D NMR analyses of the O-polysaccharide and a pentasaccharide derived by the mild acid hydrolysis of the ketosyl linkage of the Kdo (3-deoxy-D-manno-2-octulosonic acid) residue in the O-polysaccharide established that the O-antigen is a high molecular mass unbranched polymer of a repeating pentasaccharide unit and has the structure [see formula in text] where Bu is a (R)-3-hydroxybutanoyl substituent. The O-antigen is structurally similar to that of the recently reported Cronobacter sakazakii strain G706 (designated as serotype O5), except that in strain G706 the d-Qui3N is in its N-acetyl form, in contrast to its presence as a 3-deoxy-3-(R)-3-hydroxybutyramido derivative in the C. sakazakii HPB 3169 strain O-antigen.

Bi-component hydrogel of perylene-3,4,9,10-tetracarboxylic potassium salt andl-tyrosine

Potassium perylene-3,4,9,10-tetracarboxylate (P) and L-tyrosine (T) produces supramolecular PT complexes viz.PT11, PT12, PT13 and PT14 where the numbers indicate respective molar ratios. PT11 does not produce a hydrogel but the other three produce hydrogels with a minimum gelation concentration of 1.30% (w/v). All PT gels exhibit a fibrillar morphology and the gel melting temperature follows the order PT14 > PT13 > PT12. The frequency independent G′ (G′ > G′′) for PT12, PT13 and PT14 systems characterize them as a gel and the critical yield stress values are 6.0, 3.18 and 0.76 Pa for PT14, PT13 and PT12, respectively. The presence of H-bonding and electrostatic interactions in PT complexes is evident from the FTIR spectra. NMR spectra suggest π–π stacking in both gels and in the PT11 complex, however, there is less π-stacking in the latter. The red shift of the absorption peaks of PT gels compared to that of P is attributed to the J-aggregate formation. The emission peaks also show red shifts and the emission intensity increases significantly. The average life time value decreases in the gels. With increasing temperature, PL-intensity gradually decreases due to the de-stacking of the J-aggregates but the emission peak position shows a step like increase due to batch-wise slipping of PT motifs from J-aggregates.

Composition and antioxidant activity of water-soluble polysaccharides from Tuber indicum.

Crude water-soluble Chinese truffle Tuber indicum polysaccharide (TIP) was extracted from the fruiting bodies with water and then successively purified by DEAE-cellulose 52 and Sephadex G-100 column chromatography, yielding two major polysaccharide fractions: TIP1-1 and TIP2-1. High-performance gel permeation chromatography analysis showed that the average molecular sizes of TIP1-1 and TIP2-1 were approximately 1.75×10(4) Da and 5.73×10(3) Da, respectively. Monosaccharide component analysis by gas chromatography indicated that TIP1-1 was composed of mannose, glucose, galactose, and rhamannose in the respective molar ratio of 3.93:1.24:0.75:1.26 and that TIP2-1 contained mannose, glucose, and arabinose in the respective molar ratio of 5.27:1.44:0.43. The antioxidant activity analyses revealed that TIP1-1 and TIP2-1 possessed considerable antioxidant activity. Compared with TIP1-1, which has a higher molecular weight and contains no uronic acid, TIP2-1 exhibited a protective effect on PC12 cells injured by H(2)O(2) and a higher scavenging activity against free radicals. The relative effects of the lower molecular size, the presence of uronic acid, and the antioxidant activity of TIP2-1 appear to be significant. Accordingly, the Chinese truffle T. indicum might serve as an effective antioxidative healthcare food and source of natural antioxidants.

Bicomponent Hydrogels of Lumichrome and Melamine: Photoluminescence Property and Its Dependency on pH and Temperature

Lumichrome (L) and melamine (M) produce thermoreversible hydrogels in LM31 and LM11 compositions, but LM13 composition does not produce hydrogel (the numbers indicate the respective molar ratio of the components). The formation of thermoreversible gels is confirmed from morphology, DSC, and rheological experiments where LM13 system does not meet the required characteristics of thermoreversible gels. FTIR spectra suggest that H-bonding between L and M produces the supramolecular complex, and (1)H NMR spectra suggest that pi-stacking of the complex produce fibrillar network structure entrapping a large amount of water producing the hydrogels. The nonplanar structure of LM13 complex probably causes difficulty in pi-stacking, prohibiting the gel formation. The UV-vis spectra show a blue shift of the pi-pi* transition band (354 nm) indicating H-aggregate formation but the pi-pi* band coupled with n-pi* transition (386 nm) shows a constant red shift by 7 nm, indicating independency of pi-stacking on the n-pi* transition in the different LM systems. The PL intensities of LM11 and LM31 gels become more quenched than the intensity of pure L due to formation of nonfluorescent complex (static quenching) in the gels. In the LM13 sol the degree of quenching is less than that of the gels because of absence of energy transfer through the junction points of gels. The increased lifetime values of LM gels compared to that of pure L is also indicative of H-aggregate formation. The PL intensity increases linearly with increase of temperature due to thinning of the fibers decreasing the exciton energy transfer. The emission peak shows a red shift with rise in temperature, indicating H- to J-aggregate transformation, and at the melting temperature it shows a sharp decrease. With both increase and decrease of pH from the neutral pH 7, the gels exhibit higher PL intensity because of sol formation.

Titrimetric assay of lisinopril in aqueous and non-aqueous media

Four simple titrimetric procedures are described for the determination of lisinopril (LNP) in bulk and in pharmaceuticals based on the neutralization of basic-amino and acidic carboxylic acid groups present in LNP. Method A is based on the neutralization of basic amino groups using perchloric acid as titrant in anhydrous acetic acid medium. Method B, method C and method D are based on neutralization of carboxylic acid group using NaOH, sodium methoxide and methanolic KOH, as titrants, respectively. Method A is applicable over 2.0-20.0 mg range and the calculations are based in the molar ratio of 1:2 (LNP:HClO4). Method B, method C and method D are applicable over 2.0-20.0 mg, 1.0-10.0 mg and 5.0-15.0 mg range, respectively, and their respective molar ratios are 1:1 (LNP:NaOH), 1:2 (LNP:CH3ONa) and 1:1 (LNP:KOH). Intraday and inter day accuracy and precision of the methods were evaluated and the results showed intra- and inter-day precision less than 2.7% (RSD), and accuracy of &lt; 2.5% (RE). The developed methods were applied to determine LNP in tablets and the results were validated statistically by comparing the results with those of the reference method by applying the Student’s t-test and F-test.