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PubMedDate not supplied

[Interaction of peptides with cholesterol].

Interaction of cholesterol with apoproteins A-I and E was studied in absence of phospholipids in vitro. As shown by two methods - ultracentrifugation in density gradient of KBr and an extraction technique - an apoprotein E molecule bound 30-35 molecules of cholesterol and a molecule of A-I bound 17-22 molecules of the sterol. If the primary structure of apoprotein A-I and the fragments of apoprotein E are involved in consideration, the hydrophilic reaction appears to occur between the hydroxyl group of cholesterol and a guanidine group of the protein arginine residues as well as hydrophobic reaction - between side aliphatic chain of the sterol and the branched-chain amino acid, present in the protein at a distance of 4 amino acid residues from the arginine residue. A molecular model, illustrating the cholesterol reaction with polypeptide fragments, is developed. Considering high alpha-spirality of apoproteins E and A-I with specific localization of the charged residues, reaction of the sterol and apoproteins, described in the terms of this model, was possible only after a decrease in order of the protein structure. Dispersion spectra and optical rotation of apoprotein E showed that beta-structures were destroyed and alpha-spiralization was decreased in the protein in presence of cholesterol. The data obtained suggest that amino acid composition and structure of polypeptides are important for their reaction with cholesterol.

Amino Acid Sequence↗
PubMed1984

Conversion of erythro-D-sphinganine to its [1-2H1] and [1-3H1] derivatives.

A convenient chemical synthesis of erythro-D-[1-2H1] sphinganine and erythro-D-[1-3H1]sphinganine is described. The approach utilizes a stereospecific starting material (natural sphinganine prepared from bovine brain sphingomyelin) and applies a sequence of selective protection of functional groups yielding 2-acetamido-3-O-benzoyloctadecan-1-ol. Oxidation of the primary alcohol to an aldehyde followed by NaB2H4 or NaB3H4 reduction and hydrolysis of the protective groups yields erythro-D-[1-2H1]sphinganine or erythro-D-[1-3H1]sphinganine. The synthetic intermediates and isotopically labeled sphinganines are characterized by infrared analysis, 1H-nuclear magnetic resonance, optical rotation, and gas-liquid radiochromatographic and mass spectral fragmentation analyses. The [1-2H1] and [1-3H1] derivatives were obtained with overall yields (and isotope enrichments) of 11% (min. 84 mol% 2H1) and 8% (60 mCi/mmol), respectively.

Animals↗
PubMed1982

Somatic antigens of Pseudomonas aeruginosa. The structure of O-specific polysaccharide chains of P. aeruginosa O:3a, b and O:3a, d lipopolysaccharides.

On mild acid degradation of Pseudomonas aeruginosa O:3a,b and O:3a,d lipopolysaccharides O-specific polysaccharides were isolated. Both polysaccharides were found to contain 2-acetamido-2,6-dideoxy-D-galactose, identified as fucosamine hydrochloride formed after hydrolysis with a very low yield. The other two components of the trisaccharide repeating unit, 2,3-diacetamido-2,3-dideoxy-D-mannuronic acid and 2,3-(1-acetyl-2-methyl-2-imidazolino-5,4)-2,3-dideoxy-D-mannuronic acid, were identified without isolation in their free state directly in the course of structural investigation of the polysaccharides. Both these monosaccharides have never before been found in nature. Solvolysis of either O:3a,b or O:3a,d polysaccharides with liquid hydrogen fluoride resulted in the formation of the same trisaccharide, N-acetylfucosamine residue being the reducing end. The structure of this trisaccharide, which is the repeating unit of both polysaccharides, was deduced from the results of successive chemical modifications and 13C-nuclear magnetic resonance spectra recorded for every oligosaccharide formed. As a result, the acidic diaminosugars were converted into 2,3-diacetamido-2,3-dideoxy-D-mannose indistinguishable from authentic sample. The O-specific polysaccharides O:3a,b and O:3a,d differed in the configuration of the glycosidic bond of N-acetylfucosamine residue only and had the following structures: leads to 4)DManImU(beta 1 leads to 4)DMan(NAc)2U (beta 1 leads to 3)DFucNAc(beta 1- leads to 4)DManImU(beta 1 leads to 4)DMan(NAc)2U (beta 1 leads to 3)DFucNAc(alpha 1- where DManImU = 2.3-(1-acetyl-2-methyl-2-imidazolino-5,4)-2, 3-dideoxy-D-mannuronic acid, DMan(NAc)2U = 2,3-diacetamido-2,3-dideoxy-D-mannuronic acid, DFucNAc = 2-acetamido-2,6-dideoxy-D-galactose. The structures established were in agreement with optical rotations and assignments of all the signals in the 13C-nuclear magnetic resonance spectra of the polysaccharides.

Antigens, Bacterial↗
PubMed1978

Evaluation and characteristics of currently available inulin.

Inulin was not available for clinical testing in the United States between February 1973 and July 1975 because the raw material received in the United States differed from previously manufactured lots in molecular weight, glucose content, optical rotation, melting point, and water solubility. The comparability of the "new" and "old" inulin preparations was assessed in 12 adult male spinal cord injury patients, seven with normal renal function and five with compromised function. The "new" inulin proved to be as accurate and safe an agent for the determination of glomerular filtration rate as the previously available material in both groups of patients, and was made available for general clinical use in the United States in July 1975.

Adult↗
PubMed1980

Isolation and characterization of ginsenoside-Rg2, 20R-prosapogenin, 20S-prosapogenin and delta 20-prosapogenin. Chemical studies on saponins of Panax ginseng C. A. Meyer, Third report.

In the course of a chemical study on pure ginsenosides, a ginsenoside-Rg2 was isolated as colorless needles, from the lateral root of Panax ginseng C. A. Meyer. For the characterization of Rg2, a chikusetsusaponin-I (ginsenoide-Rg2) was isolated as colorless needles from rhizome of Panax japonicus C. A. Meyer. The optical rotation value of both saponins were opposite to the published data. On the large scale isolation of ginsenosides, trace amount of ginsenoside-Rg2 was isolated as crystals. Three compounds, A, B and C, were isolated from the reaction mixture on hydrolysis of ginsenoside-Rb1, Rb2 and Rc with 50% aqacetic acid. A was 20R-prosapogenin and it was identical with Rg3. On the other hand, B was found to be 20S-prosapogenin. And C was estimated to be prosagenin dehydrated at C20-OH and named as delta 20-prosapogenin. It was found that an equilibration is present among A, B and C at the earlier stage on acid hydrolysis.

Chemical Phenomena↗
PubMedDate not supplied

[Peculiarities of blood serum albumin transport function during physical exercise].

Physicochemical properties of blood serum albumin were studied in sportsmen during physical exercises. The "carbohydrate and lipid capacity' of blood serum albumin is found to increase under physical loads. Albumin is supposed to incorporate more actively into the transport of carbohydrates or lipids used as source of energy in the muscular work. No noticeable changes in the structure of albumin are found by the optical rotation dispersion technique.

Carbohydrates↗
PubMedDate not supplied

[Isolation and purification of an unspecific component from human serum albumin, typical for pathology].

Albumin from blood serum of healthy persons and from patients with various pathologies and different severity of diseases was characterized using isoelectric focusing in borate-polyol system. In all the pathologies studied a new component occurred, which had an isoelectric point at pH 5.5 and which was not found in fresh albumin preparations isolated from healthy persons. This fraction was isolated and purified. Its isoelectric point was near pH 4.5-4.6 in isoelectrofocusing with ampholines. The divergences were due to complex formation of albumin with ampholines. The modified protein corresponded immunochemically to the human blood serum albumin, did not contain polymers, had a decreased amount of alpha-helix structures as shown by dispersion of optic rotation and its molecular mass was similar to the mass of native albumin.

Clinical Laboratory Techniques↗
PubMed1995

Structures of the O-specific polysaccharide chains of Pectinatus cerevisiiphilus and Pectinatus frisingensis lipopolysaccharides.

Mild acid hydrolysis of the smooth-type lipopolysaccharide (LPS) of Pectinatus frisingensis afforded no polysaccharide but monomeric 6-deoxy-L-altrose (L-6dAlt) which was identified by anion-exchange chromatography in borate buffer, GLC/MS, 1H-NMR spectroscopy, and optical rotation. LPS was degraded with alkali under reductive conditions to give a completely O-deacylated polysaccharide, which was studied by methylation analysis, 1H-NMR and 13C-NMR spectroscopy, including sequential, selective spin-decoupling, two-dimensional correlation spectroscopy (COSY), COSY with relayed coherence transfer, two-dimensional heteronuclear 13C, 1H-COSY, one-dimensional NOE and two-dimensional rotating-frame NOE spectroscopy. It was found that the O-specific polysaccharide chain of P. frisingensis LPS is a homopolymer of 6-deoxy-L-altrofuranose built up of tetrasaccharide-repeating units having the following structure: [sequence: see text] Similarly, mild acid degradation of smooth-type LPS of Pectinatus cerevisiiphilus resulted in depolymerisation of the polysaccharide chain to give a disaccharide consisting of D-glucose and D-fucose. Study of the disaccharide by methylation analysis and alkali-degraded LPS by one-dimensional and two-dimensional 1H-NMR and 13C-NMR spectroscopy showed that the O-specific polysaccharide of P. cerevisiiphilus has the following structure: -->2)-beta-D-Fucf-(1-->2)-alpha-D-Glcp-(1-->.

Bacteria, Anaerobic↗
PubMed1993

[Cortisone Acetate Reference Standard (Control 921) of National Institute of Health Sciences].

The raw material of cortisone acetate was tested for the preparation of "Cortisone Acetate Reference Standard (Control 921)". The quality of the raw material was examined and compared with the previous Cortisone Acetate Reference Standard (Control 743). Analytical data obtained were as follows: loss on drying, 0.06%; melting point, 245.9 degrees C (decomposition); optical rotation, [alpha]20D = +215.5 degrees; UV spectrum, lambda max = 239 nm and specific absorbance E 1%1 cm (239 nm) = 393; infrared spectrum, the same as that of the previous Reference Standard (Control 743); thin-layer chromatography, no impurities were detected up to 100 micrograms; high-performance liquid chromatography (HPLC), three impurities were detected; assay, 100.5% by HPLC. Based on the above results, the raw material was authorized as the Japanese Pharmacopoeia Reference Standard (Control 921).

Chromatography, High Pressure Liquid↗
PubMed1993

[Riboflavin Reference Standard (Control 921) of National Institute of Health Sciences].

The raw material for riboflavin was tested for preparation of the "Riboflavin Reference Standard (Control 921)". Analytical data obtained were as follows: melting point, 283.8 degrees C (decomposition); specific absorbance, E1%1 cm = 852 (267 nm), 275 (373 nm), 325 (446 nm); infrared spectrum, the same as that of JP Riboflavin Reference Standard; optical rotation [alpha]20D = 138.5 degrees; thin-layer chromatography, no impurities were detected up to 6 micrograms; high-performance liquid chromatography, a small amount of 9 impurities were detected; loss on drying, 0.16%; assay, 100.3% by spectrophotometry. Based on the above results, the raw material was authorized as the Japanese Pharmacopoeia Reference Standard (Control 921).

Chromatography, High Pressure Liquid↗
PubMed1993

[Cholecalciferol Reference Standard (Control 921) of National Institute of Health Sciences].

The raw material for cholecalciferol was tested for preparation of the "Cholecalciferol Reference Standard (Control 921)". Analytical data obtained were as follows: melting point, 89.9 degrees C; UV and infrared spectra, the same as those for JP Cholecalciferol Reference Standard (Control 901), respectively; specific absorbance at 265 nm E1%1 cm = 472.2; optical rotation, [alpha]20D = 107.1 degrees; thin-layer chromatography and high-performance liquid chromatography (HPLC), no impurities were detected; assay, 99.97% by HPLC. Based on the above results, the raw material was authorized as the Japanese Pharmacopoeia Reference Standard (Control 921).

Cholecalciferol↗
PubMed1994

Activation of a cryptic gene encoding a kinase for L-xylulose opens a new pathway for the utilization of L-lyxose by Escherichia coli.

A silent gene encoding a kinase that specifically phosphorylates L-xylulose was activated and rendered constitutive in mutant cells of Escherichia coli. L-Xylulose kinase was purified to homogeneity and found to be a dimer of two subunits of 55 kDa, highly specific for L-xylulose with a Km of 0.8 mM, a Vmax of 33 mumol/min/mg, and an optimum pH of 8.4. Physical (thin layer chromatography) and spectroscopic (nuclear magnetic resonance and optical rotation) characterization of the product of L-xylulose kinase indicated that the enzyme phosphorylated the sugar at position 5. The gene encoding L-xylulose kinase was mapped in the 80.2 min region of the chromosome by conjugation and transduction. Cloning and comparison of the restriction map with the Kohara map (Kohara, Y., Akiyame, K., and Isono, K. (1987) Cell 50, 495-501) located the gene between positions 3963 and 3965 kilobases. The molecular and functional features of L-xylulose kinase together with the location of the corresponding gene indicate that this enzyme did not derive from mutation of any other known kinase. The new kinase opens a route for the utilization of L-lyxose through the action of rhamnose permease, rhamnose isomerase, and the phosphorylation of the L-xylulose formed to L-xylulose 5-phosphate, which is then introduced into the pentose phosphate pathway for subsequent metabolism.

Cloning, Molecular↗
PubMed1994

[Veratrum alkaloids. I].

Alkaloids represent an important group of therapeutically significant secondary metabolites. The plants of the genus Veratrum contain alkaloids with an antihypertensive effect. Also the genera Schoenocaulon and Zygadenus are sources of veratrum alkaloids. The present paper presents a survey of isolated alkaloids from the underground and aerial parts of 17 species of the genus Veratrum. The alkaloids occur as glycosides, aglycones or in the form of esters with various acids. In conformity with the IUPAC regulations for the nomenclature of steroids, Veratrum alkaloids were divided into 7 groups. The present paper lists the compounds of the first two groups, i.e. (1) alkaloids of the jervanine and veratranine types (I-XXIII), and (2) alkaloids with the cevanine skeleton (XXIV-XXXV). The individual compounds are characterized by their physico-chemical constants (melting point, optical rotation).

Veratrum Alkaloids↗
PubMedDate not supplied

Isolation of chromomycin A3 from a new subspecies of Streptomyces.

A streptomycete contaminant in a marine fungal culture was found to exhibit antibiotic activity against gram-positive bacteria and mycobacteria. The active principle was determined to be a mixture of as many as 12 components which exhibited properties characteristic of the aureolic acid group of antibiotics. Chromatographic comparisons using reference materials revealed the major and second components of the antibiotic mixture to be indistinguishable from chromomycins A3 and A2, respectively. The major component was isolated using a series of column chromatographic and preparative tlc separations. Confirmation of the identity of the major antibiotic as chromomycin A3 was based on elemental analysis, optical rotation, spectral (uv, ir and nmr) characteristics, and properties of an acetate derivative.

Anti-Bacterial Agents↗