Food engineering residues: amino acid composition of hydrolysates and application for the decontamination of metal polluted soils

Several residues of the brewing industry and slaughtering offals were investigated in order to evaluate their potential as raw materials for the hydrolytic preparation of amino acid containing solutions, applicable as extractants in amelioration processes for metal polluted soils. The residues were hydrolysed with 6 mol/L hydrochloric acid and the hydrolysates were analysed for their total nitrogen, TOC, amino acid and heavy metal contents. Then, the leaching capacities of the hydrolysates were examined in a series of batch tests with a contaminated soil.High amino acid yields in relation to the weight of the air-dried raw materials were achieved with blood meal (72.5%) and poultry feather meal (56.6%). The portion of the detected amino acids of the total organic carbon content of the hydrolysates ranged from 38.9% (brewer's spent grain) to 93.6% (blood meal). In extraction tests with hydrolysates adjusted to a total amino acid concentration of 60 mmol/L and to a pH value of 7.0, maximum extraction yields of 50.3% for copper (soil content 279 mg kg^–1) and 38.7% for nickel (soil content 54 mg kg^–1) were reached. An increase of the hydrolysate concentration and of the pH of an amino acid mixture resulted in higher solubilisation of the metals.Dedicated to Prof. Dr. Dieter Klockow on the occasion of his 60th birthday     

The separation of 1-dimethylaminonaphthalene-5-sulfonyl derivatives of peptides by two-dimensional electrophoresis in a thin layer of cellulose

Conclusions 1. A new method for the separation of DNS-peptides has been proposed which is based on the use of two-dimensional electrophoresis in a thin layer of cellulose and which, in combination with photodocumentation, enables clear satisfactorily reducible peptide maps to be obtained with only 2–4×10^–9 mole of protein (peptide) in a time not exceeding 3.5 hr.2. The method described has been used to determine the number of DNS peptides in an incomplete acid hydrolysate of the DNS derivative of the antibiotic A-128-OP (acid).Khimiya Prirodnykh Soedinenii, Vol. 5, No. 6, pp. 535–539, 1969     

Determination of mineral constituents in duplicate portion diets of two university student groups by instrumental neutron activation

Concentrations of 15 elements were determined simultaneously in duplicateportion diets of two university student groups from So Paulo Universityconsisting of nine women (20–23 years) and ten men (20–24 years).Thediet samples were prepared by either freeze-drying or drying in a ventilatedoven. About 100–200 mg of diets were irradiated for 2 minutes and 8hours in the IEA-R1m research reactor and Br, Ca, Cl, Co, Cr, Cs, K, Fe, Mn,Mg, Mo, Na, Rb, Se, and Zn were determined by instrumental neutron activationanalysis (INAA). The average daily intakes found in the women and men groupswere: 2.1 and 4.3 mg of Br, 501 and 707 mg of Ca; 3.1 and 6.0 g of Cl; 12and 25 mg of Co; 15 and 36 µg of Cs; 53 and 63 µg of Cr; 5.1 and10.8 mg of Fe; 1.3 and 2.8 g of K; 134 and 306 mg of Mg; 1.3 and 4.1 mg ofMn; 134 and 302 mg of Mo, 2.0 and 4.1 g of Na; 2.4 and 4.6 mg of Rb; 29 and41 µg of Se; 6.2 and 10.6 mg of Zn, respectively. The daily intakesof Ca, Se and Zn in both groups and Fe in the women groups appeared to bebelow the U.S. RDA recommendations. For the elements Na and Cl the daily intakeswere higher than the recommended values by RDA.     

Evaluating the Antioxidants,Whitening and Antiaging Properties of Rice Protein Hydrolysates

Plant-derived protein hydrolysates have potential applications in nutrition. Rice protein hydrolysates (RPHs), an excellent source of proteins, have attracted attention for the development of cosmeceuticals. However, few studies have reported the potential application of RPH in analysis, and this study examined their antioxidant activities and the inhibitory activities of skin aging enzymes. The results indicated that the total phenolic and flavonoid concentrations were 2.06 ± 0.13 mg gallic acid equivalent/g RPHs and 25.96 ± 0.52 µg quercetin equivalent/g RPHs, respectively. RPHs demonstrated dose-dependent activity for scavenging free radicals from 1,1-diphenyl-2-picrylhydrazyl [half-maximal inhibitory concentration (IC50) = 42.58 ± 2.1 mg/g RPHs] and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (IC50 = 2.11 ± 0.88 mg/g RPHs), dose-dependent reduction capacity (6.95 ± 1.40 mg vitamin C equivalent/g RPHs) and oxygen radical absorbance capacity (473 µmol Trolox equivalent/g RPHs). The concentrations of the RPH solution required to achieve 50% inhibition of hyaluronidase and tyrosinase activities were determined to be 8.91 and 107.6 mg/mL, respectively. This study demonstrated that RPHs have antioxidant, antihyaluronidase, and antityrosinase activities for future cosmetic applications.     

The energy of the N→O bond in 3-nitroisoxazoline N-oxide

The enthalpy of combustion of 3-nitroisoxazoline has been determined as H _c ^298.15 =–414±0.3 kcal/mole and that of 3-nitroisoxazoline N-oxide as H _c ^298.15 =–406.6±0.5 kcal/mole. From the values for the heats of combustion and evaporation, the standard enthalpies of formation have been calculated and the energy of the NO bond has been evaluated at 64±3 kcal/mole.     

Polysccharides of plant tissue cultures. II. Acid hydrolysis of wastes from a ginseng tissue culture

The conditions of the acid hydrolysis of industrial wastes from a culture of ginseng tissue have been investigated and the optimum conditions — liquor ratio, concentration of acid (HCl and H₂SO₄) and the temperature have been determined. The ratio of monosaccharides has been established with the aid of gas-liquid chromatography. These hydrolysates can be used as nutrient media or additives for them in the microbiological industry.Student O. P. Chernetskaya took part in the work.M. V. Frunze Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 346–350, May–June, 1988.     

Synthesis of the C-end of the tetrapeptide gastrin

Conclusions 1. The carbobenzoxy derivative of the C-terminal tetrapeptide of gastrin—the amide of carbobenzoxytryptophanyl-methionylaspartylphenylalanine—has been synthesized by two different routes.2. In nonnarcotized cats the tetrapeptide obtained causes the secretion of gastric juice with a high content of hydrochloric acid (MR₅₀=11.5 µg/kg).Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 283–287, 1969     

Comparative investigation of the molecular structures of the species-specific proteins of the seeds ofGossypium hirsutum andG. barbadense

The N-terminal amino acids and the amino acid compositions of four species-specific proteins of two species of the cotton plant —Gossypium hirsutum andG. barbadense — have been determined. Peptide maps of tryptic hydrolysates of these proteins have been obtained and compared. Individual tryptic peptides have been isolated and purified. The N-ends, amino acid compositions, and amino acid sequences of individual peptides have been determined. The N-terminal sections of the proteins ofG. hirsutum andG. barbadense as far as the 16th amino acid residue have been sequenced. A comparative analysis has been made of the peptides and proteins of these cottonplant species.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 858–864, November–December, 1997.     

Coupling capacity of solid-phase carboxyl groups

A simple colorimetric procedure for determining the coupling capacity of solid-supported carboxyl groups has been developed. The carboxyl groups of a solid support were coupled to cystamine at pH 4–4.5, using a water soluble carbodiimide 1-ethyl-3-(3-dimethyl-aminopropyl)-carbodiime as the condensing reagent. The solid-phase coupled disulfides were then reduced to sulfhydryl groups by treating the solid phase with dithiothreitol. For every one carboxyl group coupled with cystamine, one solid-phase sulfhydryl is introduced. After removing all of the reducing reagents by extensive washing, the sulfhydryl content, which is equivalent to the carboxyl groups of the gel, was quantified by using 5,5′-dithiobis-(2-nitrobenzoic acid), the Ellman’s reagent.     

Bradykinin-potentiating peptide from venom of the spider Latrodectus tredecimguttatus

A bradykinin-potentiating peptide has been isolated from the venom of the spiderLatrodectus tredecimguttatus. Its physicochemical properties and amino acid composition have been investigated in detail. It has been shown by biological testing on isolated neck of the rat uterus that the peptide increases the contractile effect of bradykinin in in vitro experiments. The potentiating unit is 2 · 10^–3 mg/ml. A 50% increase in the hypotensive effect of bradykinin at a concentration of the bradykinin-potentiating peptide of 15 µg/kg of body weight has been found, the increase in the intensity of the effect being accompanied by a prolongation of its action.A. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 699–703, September–October, 1989.     

Bioactive Hydrolysates from Chlorella vulgaris: Optimal Process and Bioactive Properties

Microalgae have been described as a source of bioactive compounds, such as peptides. Microalgae are easy to produce, making them a sustainable resource for extracting active ingredients for industrial applications. Several microalgae species have interesting protein content, such as Chlorella vulgaris with around 52.2% of protein, making it promising for peptide hydrolysate production. Therefore, this work focused on the production of water-soluble hydrolysates rich in proteins/peptides from the microalgae C. vulgaris and studied bioactive properties. For that, a design of experiments (DOE) was performed to establish the optimal conditions to produce hydrolysates with higher levels of protein, as well as antioxidant and antihypertensive properties. Four experimental factors were considered (cellulase percentage, protease percentage, hydrolysis temperature, and hydrolysis duration) for three responses (protein content, antioxidant activity, and antihypertensive activity). The optimal conditions determined by the DOE allowed producing a scaled-up hydrolysate with 45% protein, with antioxidant activity, measured by oxygen radical absorbance capacity assay, of 1035 µmol TE/g protein, IC₅₀ for angiotensin-converting enzyme inhibition activity of 286 µg protein/mL, and α-glucosidase inhibition of 31% (30 mg hydrolysate/mL). The obtained hydrolysates can be used as functional ingredients for food and nutraceuticals due to their antioxidant, antihypertensive, and antidiabetic potential. Moreover, the antioxidant potential of the extracts may be relevant for the cosmetic industry, especially in antiaging formulations.     

Physicochemical analysis of a protein with nerve growth activity from the muscle tissue of Rana ridibunda

A protein nerve growth factor has been isolated in the pure form from the muscles of the lake frogRana ridibunda. The individuality of the substance obtained has been shown, its molecular mass (106.0–110.0 kDa) and pI value (9.2–9.4) have been determined, and lysine and valine have been found as the N- and C-terminal amino acid residues of its polypeptide chain. In view of the detection of the presence of sugars (about 1%), the substance has been identified as a glycoprotein. Its absorption spectra in the UV region has been obtained and the amino acid composition of the isolated protein has been determined. Information on the amino acid composition of various proteins with nerve growth activity has been subjected to comparative analysis with the aid of computer programs, and on this base their phylogenetic tree has been constructed.Institute of Biochemistry, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 251–257, March–April, 1992.     

Effect of high pressure on the rate constant of the Diels-Alder reaction between furan and maleic anhydride

The effect of high pressure (up to 700 MPa) on the rate of the Diels-Alder reaction between furan and maleic anhydride has been investigated in deuterated acetone at 20C. The volume effect of the reaction at atmospheric pressure is found to be V₀=–28.0 cm³/mole. The rate constants for the formation, decomposition and isomerization of the products have been found by numerical integration. The volume of activation V in the pressure range studied has been determined from the observed dependence of log k upon P by spline approximation and was found to be –30.5 cm³/mole at atmospheric pressure, close to the volume change in the reaction, which is consistent with the assumption of a conjugated cyclic transition state.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 525–529, March, 1990.     

Esterification of C2−C16 dicarboxylic acids to n-butyl esters in aqueous solutions for their gas chromatographic analysis

Summary C₂–C₁₆ dicarboxylic acids were esterified in aqueous solution in the presence of sulfuric acid. Esterification in water/n-butanol mixtures with mole ratios between 0.02 and 2.53 can be utilized for the quantitative determination of the dicarboxylic acids by gas chromatography. The presence of water does not interfere at water/n-butanol mole ratios below 0.27. For mole ratios above 0.27 anhydrous sodium sulfate has been used for binding the water. The mole ratio range was 0.25–0.75 for anhydrous sodium sulfate/water, and 0.32–1.3 for sulfuric acid/anhydrous sodium sulfate.     

Formation of uniform silver particles from bis (1,2-ethanediamine)silver(I) complex

Uniform spherical silver particles were produced by decomposing the bis(1,2-ethanediamine)silver(I) complex, by aging a solution of 1.0×10^–3 mole dm^–3 in silver (I) nitrate, 1.0 mole dm^–3 in 1,2-ethanediamine, and 2.5×10^–1 mole dm^–3 in nitric acid (basic solution) at 100°C for 42 min. The average modal diameter was estimated to be 0.52 m with a relative standard deviation of 0.10. A moderately oxygenrich layer, 40 Å thick, on the surface of the particles was detected by means of photoelectron surface microanalysis (XPS). The silver particles grew through a polynuclear-layer mechanism, as judged from the concentration change in soluble silver(I) species in the supernatant solution. The particles' point of zero charge (PZC) was estimated at pH 6.5 by potentiometric titration.     

Amplification method for the titrimetric determination of L-rhamnose by periodate oxidation

The stoichiometry of the oxidation of rhamnose by periodate has been studied using a method based on the determination of iodate. Conditions have been found under which one mole of rhamnose stoichiometrically reduces six moles of periodate. An amplification method for the titrimetric determination of rhamnose is proposed in which one mole of rhamnose reacts with 6 moles of periodate with the formation of six moles of iodate, which is equivalent to 18 moles of triiodide, in the titration of which 36 gram-equivalents of sodium thiosulfate are consumed. The method is distinguished by high sensitivity and accuracy. The relative standard deviation in the determination of 2–3.5 mg of rhamnose does not exceed 0.5–1%.Biokhimreaktiv Scientific Production Association. All-Union Scientific-Research Institute of Applied Biochemistry, Olaine. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 21–24, January–February, 1984.     

Some characteristics of the alkali-soluble protein from the red alga Furcellaria fastigiata

Summary From the red agar-bearing alga furcellaria we have isolated an alkali-soluble protein. Its aminoacid composition and N-terminal acid — arginine — have been determined. It has been shown to belong to the group of glycoproteins. One of the possible types of carbohydrate — protein bonds is a O-glycosidic bond.Odeassa Institute of Building Engineering. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 400–404, May–June, 1975.     

Application of Lanthanide-Sensitised Chemiluminescence to the Determination of Levofloxacin, Moxifloxacin and Trovafloxacin in Tablets

A flow injection method including chemiluminescence detection has been developed and applied to the determination of fluoroquinolones levofloxacin, moxifloxacin and trovafloxacin in tablets. The proposed method is based on the luminescent properties of the system Ce(IV)–sulphite–fluoroquinolone and the addition of a trivalent lanthanide ion as emission-sensitizer. The optimum conditions for chemiluminescence emission were investigated for each fluoroquinolone. The best results were achieved when employing Eu(III) as lanthanide cation for levofloxacin and moxifloxacin, and Tb(III) for trovafloxacin. These fluoroquinolones were determined over the concentration range of 0.5–3.5µgmL^–1, 0.2–3.0µgmL^–1 and 0.008–0.400µgmL^–1, with detection limits of 0.100, 0.035 and 0.008µgmL^–1, respectively. The relative standard deviations were in the range of 1.0–2.5% for all three cases. The method was applied to the determination of three fluoroquinolones in their respective pharmaceutical preparations and compared with an independent UV-spectrophotometric method. The results were satisfactory.     

An NMR study of proton exchange in the system p-nitrosophenol—p-quinone monooxime

The solvent used was dimethylformamide at neutral and alkaline pH. The equilibrium constants are determined by spectrophotometry. The rate of proton exchange has been measured as a function of temperature and concentration. The rate constants and activation energies have been measured; for uncatalyzed exchange k_n=(1.5±0.5) ·· 10³ M^–1 sec^–1, E=8±1 kcal/mole, while base-catalyzed exchange has k=(0.3±0.1) · 10⁶ M^–1 sec^–1 and E=6±1 kcal/mole.We are indebted to A. I. Brodskii for assistance in this work, and to V. I. Oshkaderov and L. A. Kichakova for recording the NMR spectra.     

Some functional properties of cotton protein hydrolysates

A comparative study of the solubility and emulsifying properties of cotton protein hydrolysates produced by the enzyme preparation Pektofoetidin has shown that the optimum functional properties are possessed by hydrolysates with a degree of proteolysis of 8–13%.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 520–524, July–August, 1990.