On the preparation of dihematoporphyrin ether-free hematoporphyrin derivative

A dihematoporphyrin ether-free hematoporphyrin derivative has been prepared by a base-catalysed dehydration of hematoporphyrin with sodium hydroxide. The identification was performed by HPLC and mass spectroscopy (FD-MS). The reaction of hematoporphyrin with 1 M sodium hydroxide for 24 h yields more than 90% of the monomeric porphyrins.     

Expedient liquid chromatographic method with fluorescence detection for montelukast sodium in micro-samples of plasma

This study describes an expedient assay for the analysis of the asthma medication, montelukast sodium (Singulair, MK-0476), in human plasma samples. After a simple extraction of the plasma, the drug and internal standard, quinine bisulfate, were measured by HPLC. The chromatographic system consisted of a single pump, a refrigerated autosampler, a C₈ 4-μm particle size radial compression cartridge at 40°C and a fluorescence detector with the excitation and emission wavelengths set at 350 and 400 nm, respectively. The mobile phase which was delivered at 1.0 ml/min, was prepared by adding 200 ml of 0.025 M sodium acetate, pH adjusted to 4.0 with acetic acid, to 800 ml of acetonitrile, with 50 μl triethylamine. With a run time of only 10 min per sample, this assay had an overall recovery of >97% with a detection limit of 1 ng/ml. The inter- and intra-run relative standard deviations at 0.05, 0.2 and 1.0 μg/ml were all <9.2%, while the analytical recovery at the same concentrations were within 7.7% of the amount added.     

Some novel N-fatty acyl derivatives of a microbial galactosaminan

Novel seven N-fatty acyl derivatives (degree of substitution 0.78–0.96) of a microbial galactosaminan were prepared in 59–79% yields by its reaction with fatty acid anhydrides in aqueous acetic acid-methanol. N-Acetyl and N-propionyl derivatives were soluble in water, aqueous 2% sodium hydroxide, and aqueous 2% acetic acid, but N-higher fatty acyl (>C6) derivatives were insoluble. Gel was not formed in these react ions     

Composition of cell wall preparations of rice bran and germ

Cell walls of petrol-defatted non-waxy IR32 rice bran and germ were prepared by protein removal with 0.5% SDS—0.6% β-mercaptoethanol, heating the residue to 80°, and destarching with Bacillus licheniformis α-amylase. A waxy rice, IR29, had a similar cell wall composition as IR32. Principal wall sugars were arabinose, xylose, and glucose. The 0.5 M sodium or potassium hydroxide and 8 M urea preferentially extracted arabinose-, xylose- and uronic acid-rich polysaccharides but 6 M sodium hydroxide—0.81 M boric acid extracted mannose-rich polysaccharides. DEAE-cellulose BO₃^3? chromatography of the 0.5 M sodium hydroxide extracts gave fractions of similar arabinose— xylose ratios. Proteins in the cell wall preparations had only 0.4–1.6% hydroxyproline, and were bound mainly to polysaccharides, based on disc gel electrophoresis. The preparations were autofluorescent in UV and rich in phenols, mainly ferulic acid. The cell wall preparations and their 8 M urea fractions had a softening effect on defatted waxy starch aqueous gel at 0.2–2% of the starch.     

Quantification of fluoxetine and norfluoxetine serum levels by reversed-phase high-performance liquid chromatography with ultraviolet detection

A rapid and sensitive high-performance liquid chromatography assay method was developed to determine serum fluoxetine and norfluoxetine levels by single extraction of 0.1 ml of serum with sodium hydroxide. The mobile phase (55% acetonitrile–45% distilled water containing 10 mM aqueous triethylamine) was used to separate fluoxetine and norfluoxetine (25–1000 ng/ml, using clomipramine as the internal standard) by ultraviolet detection at 226 nm. The inter- and intra-day variabilities of fluoxetine and norfluoxetine were 13–18%, and the recoveries of both drugs exceeded 89%. This assay method was applied to a pharmacokinetic disposition study of fluoxetine in mice.     

Acidogenic fermentation of corn stover

Corn stover was fermented by anaerobic acidogenic bacteria to produce volatile (C₂–C₆) organic acids. Mild pretreatment with dilute alkali solutions produced a two-fold increase in fermentability. A mixture of lime and sodium carbonate was found to be a better pretreatment agent than sodium hydroxide. Methane generation was inhibited by low temperature (? 25°C) and high solids [≥ 2.5% (w/v)] fermentation. Volatile acid yields of 0.5–0.55 g acetic acid equiv/g dry ash-free (DAF) stover could be obtained in batch fermentations. Several extractants and extraction solvents for organic acids were found to be nontoxic to acidogenic fermentation. The data show that acidogenic fermentation can produce useful volatile fatty acids in high yields from a complex lignocellulosic feedstock. These fermentations are nonsterile, need no stirring, and are easy to run. Moreover, cellulose, pentosans, and other carbohydrates are directly utilized by acidogenic bacteria. Hence, acidogenic fermentation could be useful in converting biomass to chemical feedstocks and fuel.     

Immobilized enzyme cellulose hollow fibers: I. Immobilization of heparinase

The immobilization of heparinase to tresyl-chloride-activated cellulose hollow fibers for the removal of heparin from the bloodstream was examined. Whole blood can be circulated through cellulose hollow fibers without hemolysis and the tresyl chloride chemistry provides a strong linkage which limits the release of the enzyme from the support. The tresylation and immobilization methods were modified and optimized to improve the heparinase activity retained by cellulose. Pretreatment of the hollow fibers with 0.05/V sodium hydroxide increased the degree of tresylation and the immobilization yield by a factor of five. The use of triethylamine as the organic base in the tresyl chloride activation resulted in threefold greater activity retention by the support than when pyridine was used. Together, sodium hydroxide pretreatment and triethylamine enhanced the activity retained by cellulose to 26.2 +/- 7.0% of that bound to the support. The activity retention was also a function of the technique used for immobilization. The best results were achieved when the enzyme was applied to the activated fibers once every 12 to 24 h for a total of four times. The active enzyme loading on the fibers was 0.3 mg heparin degraded/h cm(2) when 4.5 mug protein/cm(2) was bound to the fibers.     

Preparation of crystalline sodium norcarnitine: an easily handled precursor for the preparation of carnitine analogs and radiolabeled carnitine

A procedure by which crystalline sodium norcarnitine can be prepared in large quantities and high yields has been developed. Carnitine is selectively demethylated by thiophenoxide ion in N,N-dimethylethanolamine. The reactive thiophenoxide ion is generated in situ by addition of thiophenol to this basic reaction solvent. Hence, sodium thiophenoxide, which has been used in similar applications, but is difficult to prepare, can be avoided. Accordingly, reaction of (R,S)-carnitine followed by aqueous azeotropic distillation of byproducts as well as excess starting materials and then by neutralization with sodium hydroxide gave sodium norcarnitine in 89% yield. (R)-Carnitine gave 91% yield of (R)-norcarnitine zwitterion before neutralization. A method for the facile preparation of radiolabeled (R)-carnitine is also described. Thus, methylation of sodium norcarnitine with methyl iodide in methanolic acetone produced carnitine, which precipitated, and sodium iodide, which was soluble.     

Synthesis of some racemicγ-fluoro-α-amino acids

Summary Versatile three-step procedures for syntheses of seven racemi-fluoro-a-amino acids are described. Alkylation oftert-butyl N-(diphenylmethylene) glycinate with 1-bromo-2-fluoroalkanes gave N-protected aminoacid esters both in anhydrous medium using lithium-diisopropylamide as base at low temperature or in a two phase system of 50% aqueous sodium hydroxide and methylene chloride with triethylbenzylammonium chloride as the phase transfer catalyst at room temperature. Subsequent two-step deprotection with citric acid and hydrochloric acid gave the title compounds in 13–33% overall yields.Dedicated to Professor Dr.mult., Dr.h.c. Alois Haas on the occasion of his 65th birthday     

A method for obtaining protein concentrates from microorganisms

In order to isolate proteins from microalgae, yeasts and bacteria, cell disintegration in a special ball-mill was performed. The degree of disintegration of the different microorganisms was compared. The dependence of disintegration on bead size and on the ratio between the volume of suspension and the volume of glass beads was also investigated. Nondisintegrated and disintegrated cells were extracted with sodium hydroxide and the amount of extractable nitrogen and the amount of nitrogen precipitable at pH 4.0 were determined. The dependence of yield on the sodium hydroxide concentration, extraction time, and temperature was studied. When extracting undisintegrated cells, very low yields were obtained and the nitrogen extracted was mostly nonproteinous. For disintegrated cells high yields were obtained. An optimum was found after extraction with 0.3–0.5% sodium hydroxide; at pH 11.0–11.5. The precipitate obtained represented 60–70% of the cell nitrogen. The nitrogen content of the precipitate was 12–14% of the dry weight.     

Complexes of carbohydrates with aluminate ion. Aldose-ketose interconversion on anion-exchange resin (aluminate and hydroxide forms)

Kinetic parameters for aldose and ketose transformations in the d-glucose-d-mannose-d-fructose system at 27° on aluminate resin and hydroxide resin were obtained. On both resins, hydroxide ion functions as the catalyst for isomerization. By forming a complex with d-fructose, resin-bound aluminate ion stabilizes the ketose and permits high yields (up to 72%) of d-fructose from d-glucose. The effect of temperature on d-glucose-to-d-fructose conversion was studied; lower temperatures give the higher maximum yields. Maltose is converted into maltulose in moderately high yield (63%) at 24° on aluminate resin; higher yields are not possible at this temperature because of a marked tendency for maltulose to undergo elimination of d-glucose at C-4.     

Organosolv fractionation process with various catalysts for improving bioconversion of triploid poplar

Triploid poplar (Populus tomentosa Carr.) was fractionated with mild organosolv process, and the effects of varying catalysts (formic acid, triethylamine and sodium hydroxide) and solvents (methanol, ethanol, n-propanol and n-butanol) on the substrate's physicochemical characteristics were examined. The data showed that neither the degree of polymerization (DP), nor the relative crystallinity was significantly influenced under the seven runs. In comparison, the addition of NaOH was more efficient on hemicelluloses dissolution, resulting in lower yields and higher glucose content of the cellulosic fractions than formic acid and triethylamine. Correspondingly, the final ethanol concentration was significantly increased from 1.83 g/L to 3.86–5.09 g/L. Besides, a certain amount of xylose (704.4–962.8 mg/L) was released in the hydrolyzates during the simultaneous saccharification and fermentation (SSF), which could be further isolated to improve the multiple utilization of raw material. This research provided some useful data for the application of mild organosolv fractionation on the utilization of whole biomass, especially for the recovery of hemicellulosic components.     

Effect of ferric tartrate/sodium hydroxide solvent pretreatment on enzyme hydrolysis of cellulose in corn residue

Lignocellulose containing 62% cellulose was prepared from corn residue by dilute acid hydrolysis using 5% H(2)SO(4) at 90 degrees C. The lignocellulose was then treated with a cellulose solvent consisting of a ferric sodium tartrate complex in 1.5N sodium hydroxide at levels ranging from 4:1 to 12:1 (solvent volume: corn residue lignocellulose) or a 1.5N sodium hydroxide solution alone. Subsequent hydrolysis with cellulase enzymes from Trichoderma reesei gave cellulose conversions which were two to three times higher than untreated lignocellulose (30%) and approached 90% conversion after 24 h in the best cases. It was found that increasing cellulase enzyme levels from 3.74 lU/g lignocellulose to 7.71 lU/g lignocellulose increased cellulose conversion by 50% at all pretreatment conditions, while an increase from 7.71 to 10.1 lU/g gave only an additional 5-10% increase. Pretreatment with sodium hydroxide resulted in 5-25% lower conversions than observed for cellulose treated with the solvent, depending on enzyme levels and treatment levels. At high enzyme levels, sodium hydroxide pretreatment is almost as effective in enhancing cellulose conversion after 24 h as is pretreatment using the cellulose solvent.     

Microwave‐based alkali pretreatment of switchgrass and coastal bermudagrass for bioethanol production

Switchgrass and coastal bermudagrass are promising lignocellulosic feedstocks for bioethanol production. However, pretreatment of lignocelluloses is required to improve production of fermentable sugars from enzymatic hydrolysis. Microwave‐based alkali pretreatment of switchgrass and coastal bermudagrass was investigated in this study. Pretreatments were carried out by immersing the biomass in dilute alkali reagents and exposing the slurry to microwave radiation at 250 W for residence times ranging from 5 to 20 min. Simons' stain method was used to quantify changes in biomass porosity as a result of the pretreatment. Pretreatments were evaluated based on yields of total reducing sugars, glucose, and xylose. An evaluation of different alkalis identified sodium hydroxide as the most effective alkali reagent for microwave‐based pretreatment of switchgrass and coastal bermudagrass. 82% glucose and 63% xylose yields were achieved for switchgrass and 87% glucose and 59% xylose yields were achieved for coastal bermudagrass following enzymatic hydrolysis of biomass pretreated under optimal conditions. Dielectric properties for dilute sodium hydroxide solutions were measured and compared with solid losses, lignin reduction, and reducing sugar levels in hydrolyzates. Results indicate that dielectric loss tangent of alkali solutions is a potential indicator of the severity of microwave‐based pretreatments. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010     

Effect of hydrolysing and oxidizing agents on the composition and degradation of wheat straw monosaccharides

Summary Wheat straw (WS) was treated with 5% sodium hydroxide, ozone and 5% sulfur dioxide at 70°C for 72 h, and the effect of treatments on monosaccharide composition and in vitro degradability by rumen microorganisms was studied. The major sugars, glucose and xylose, comprising about 90% of the total monosaccharides in the untreated WS were mainly confined to the cell walls. SO₂ exerted the greatest solubilizing effect, followed by ozone and NaOH; the respective values for the solubilized cell wall polysaccharides were: 26, 12 and 4.4%. One third of the total phenolics was oxidized by ozone, whereas, SO₂ exerted mostly a solubilizing effect on this fraction, converting 75% of it into soluble phenolics. In the NaOH treated WS 41% of the total phenolics were soluble, as compared to 22% in the untreated. The in vitro digestibility of monosaccharides in the untreated WS were initially high: 50% and 58% for xylose and glucose, respectively and 63% to 80% for the minor sugars. The SO₂ treatment resulted in an overall increase in digestibility of monosaccharides with values lying in the range of 90%. Sodium hydroxide was more efficient than ozone in enhancing the degradability of xylan and total sugars. The digestibility of cell wall sugars was increased from 52.4% to 84.4%, 63.4% and 72.3% by SO₂, O₃ and NaOH treatments respectively. Based on the present findings, it appears that wheat straw cell wall components are more sensitive to hydrolytic than to oxidative processes aimed at increasing its degradability by rumen microorganisms. SO₂ exerted on WS a multi-effect which was particularly suitable for increasing the digestibility of monosaccharides.     

A new facile methylation method for cell-wall polysaccharides

A new methylation method involving powdered sodium hydroxide and methyl iodide has been developed for the facile methylation of cell-wall polysaccharides. Commercial cellulose powder, wood cellulose, and unbleached kraft pulp in solution in SO₂-diethylamine-methyl sulfoxide could be completely methylated. Suspensions of holocelluloses, prepared from spruce and beech wood-meals and containing <5% of lignin, and cell-wall polysaccharides containing relatively large amounts of uronic acid and isolated from midrib of Nicotiana tabacum (CWM), were almost completely methylated in one step. Some decarboxylation occurred with the latter polymers.     

Integrated biodiesel production: a comparison of different homogeneous catalysts systems

The most common catalysts for biodiesel production are homogeneous basic catalysts. In the present paper, a comparison is made of different basic catalysts (sodium methoxide, potassium methoxide, sodium hydroxide and potassium hydroxide) for methanolysis of sunflower oil. All the reactions were carried out under the same experimental conditions in a batch stirred reactor and the subsequent separation and purification stages in a decanter. The analytical methods included gas chromatography and the determination of fat and oil conventional parameters. The biodiesel purity was near 100 wt.% for all catalysts. However, near 100 wt.% biodiesel yields were only obtained with the methoxide catalysts. According to the material balance of the process, yield losses were due to triglyceride saponification and methyl ester dissolution in glycerol. Obtained biodiesel met the measured specifications, except for the iodine value, according to the German and EU draft standards. Although all the transesterification reactions were quite rapid and the biodiesel layers achieved nearly 100% methyl ester concentrations, the reactions using sodium hydroxide turned out the fastest.     

Determination of the quinidine analog, 7′-trifluoromethyldihydrocinchonidine-2HCl in plasma and urine by high-performance liquid chromatography

A rapid and specific high-performance liquid chromatographic (HPLC) assay was developed for the determination of the antiarrhythmic quinidine analog, 7′-trifluoromethyldihydrocinchonidine-2HCl ([I]-2HCl) in plasma and urine. The overall recovery of [I] from plasma was 86 ± 9% with a sensitivity limit of detection of 0.2 μg/ml.The assay involves extraction of [I] into benzene-methylene chloride (9:1) from plasma or urine made alkaline with 0.1 N sodium hydroxide (pH 13) and saturated sodium chloride, the residue of which is dissolved in methylene chloride, an aliquot of which is analyzed by HPLC using adsorption chromatography on silica gel with UV detection at 254 nm. The mobile phase composed of methylene chloride-methanol-conc. ammonium hydroxide (95.5:4:0.5) yields baseline resolution of quinidine used as the internal (reference) standard, compound [I] and dihydroquinidine, a common contaminant in quinidine.The assay was applied to the analysis of plasma and urine samples taken from a dog administered a single 20 mg/kg dose via intravenous and oral routes. The stability of [I] in human plasma for up to 37 days of storage at ?17°C was also demonstrated.     

The effect of calcium and sodium hydroxides and of sodium acrylate on the fermentation and digestibility in vitro of ensiled whole-crop wheat and barley harvested at different stages of maturity

Whole-crop wheat and barley were each harvested at the soft-, medium- and hard-dough stages of grain development. Material from each harvest was ensiled in polythene bag silos without additive or after the addition of calcium hydroxide, sodium hydroxide or sodium acrylate at 50, 50 and 12.5 g kg_?1 of the crop dry matter (DM), respectively. All silages were opened after 60 days.With advancing maturity there was an increase in the content of DM, starch and insoluble-nitrogen, but a reduction in water-soluble carbohydrates (WSC) and ash.When crops were ensiled without additives, only medium-dough barley fermented to give butyric acid. However, the addition of calcium hydroxide to crops of low DM (soft-dough) and medium DM (medium-dough) promoted the activity of clostridial bacteria giving rise to the production of butyric acid, but this did not occur with crops of high DM (hard-dough). Sodium hydroxide gave rise to butyric acid only at low DM, and to restricted fermentation at high DM content. Sodium acrylate restricted fermentation and prevented butyric acid production in all silages.Ensiling led to an average reduction of 5 percentage units in the digestible organic matter (DOM) of the control silages compared to that of the crops. Addition of calcium hydroxide and sodium acrylate gave values similar to the control silages. Only sodium hydroxide consistently increased DOM, the effect becoming more marked as the crops matured. The increases over the control silages were 10, 18 and 26 units for wheat and 15, 21 and 20 units for barley at low, medium and high DM, respectively.     

Ammonia and sodium hydroxide treatment of wheat straw in diets for fattening steers

The effects of treating Neepawa wheat straw with anhydrous ammonia (35 kg t^?1), sodium hydroxide (50 kg t^?1) and pelleting were evaluated in two experiments. The diets consisted of 51% rolled barley, 40% straw, 4% rapeseed meal, 2% tallow, plus minerals and a vitamin supplement. Straw was treated as follows: (1) shredded into 2.0-cm lengths; (2) shredded into 0.64-cm lengths and pelleted; (3) ammoniated and shredded; (4) ammoniated and pelleted; (5) sodium hydroxide and pelleted; (6) ammoniated, sodium hydroxide and pelleted.Apparent digestibility was measured with six steers per treatment. Pelleting had no effect on organic matter (OM) digestibility, but decreased neutral detergent fibre (NDF) and cellulose digestion. Respective increases for OM and NDF digestibility following chemical treatment of the straw were as follows: ammoniation — 15 and 17%; sodium hydroxide — 4 and 13%.The six diets were given to 144 Hereford steers (240 kg) for 92 days in the second experiment. Feed consumption ranged from 8.51 to 10.39 kg day^?1 for diets 1 and 4, and body weight gains ranged from 0.83 to 1.26 kg day^?1 for diets 1 and 6, respectively. Respective increases for intake, gain and feed efficiency compared to untreated shredded straw were as follows: pelleting — 11, 34 and 17%; ammoniation — 12, 36 and 17%. Sodium hydroxide treatment prior to pelleting improved intake, gain and feed efficiency by 5, 10 and 5%, respectively. There was no evidence of additive effects between ammoniation and either pelleting or alkali treatment, though treatment with sodium hydroxide prior to pelleting did result in the highest gains and feed efficiency.