Microbial resolution of DL-N-benzyloxycarbonyl-p-hydroxyphenylglycine by Streptomyces zaomyceticus

1984 ◽  
Vol 30 (10) ◽  
pp. 1301-1304 ◽  
Author(s):  
Yasuji Suhara ◽  
Sayuri Itoh ◽  
Kazuteru Yokose ◽  
Rieko Ninomiya ◽  
Kimihiro Watanabe ◽  
...  
Keyword(s):  
Optically Active ◽  
Crystalline Form ◽  
Soil Organism ◽  
Unique Type

Using DL-p-hydroxyphenylglycine umbelliferone carbamate as the probe, screening from soil was carried out for microbes capable of hydrolysing urethane-type derivatives. Out of 71 strains positive for umbelliferone liberation (fluorescent), 8 strains were able to hydrolyze DL-N-benzyloxycarbonyl-4-hydroxyphenylglycinc (I). One of such soil organism identified as Streptomyces zaomyceticus carried out this reaction in an enantio-selective manner. Optically active, pure D-N-benzyloxycarbonyl-4-hydroxyphenylglycine and L-4-hydroxyphenylglycine were obtained in crystalline form in 83 and 80% yields, respectively, after a 5-day incubation of the substrate (300 mg/100 mL) with this organism. In contrast to conventional L-acylase (EC 3.5.1.14) which can hydrolyze N-pbenylacetyl-4-hydroxyphenylglycine but not I, the enzymes responsible for the above resolution could cleave both substrates, indicating that they represent a unique type of amidohydrolase.

A Study on the Kinetically Controlled Cyclization of 6-Deoxy-3-O-methyl-6-nitro-D-glucose and-L-idose, and the Preparation of Optically Active Nitroinositol Derivatives

1973 ◽  
Vol 51 (17) ◽  
pp. 2836-2842 ◽  
Author(s):  
Jan Kovář ◽  
Hans H. Baer
Keyword(s):  
Slow Rate ◽  
Optically Active ◽  
Crystalline Form ◽  
Kinetic Control ◽  
Active Compounds ◽  
Controlled Processes ◽  
Primary Products ◽  
Kinetically Controlled

The cyclization (internal Henry addition) of 6-deoxy-3-O-methyl-6-nitro-D-glucose (1) and-L-idose (2) was investigated with respect to the sequence in which stereoisomeric deoxynitroinositol methyl ethers are formed from each. It was found that, under conditions of kinetic control, the primary products generated from 1 are the nitronate 4′ (that corresponds to the epimeric deoxynitroinositols 4 and 5 having the epi-3 and muco-3 configurations, respectively) and the nitronate D-6′ of optically active 1-deoxy-4-O-methyl-1-nitro-L-myo-inositol (L-6). They are formed in approximately equal proportions. Ensuing thermodynamically controlled processes lead to racemization of L-6 and formation of the scyllo isomer 3 at a relatively slow rate. The cyclization of 2, found to be faster than that of 1, gave as primary products the enantiomeric nitronate D-6′ and the nitronate 3′ in a ratio of about 4:1. The nitronate 4′ arose by subsequent epimerization. The optically active compounds D-6 and L-6 were isolated in pure, crystalline form.

Preparation and Properties of Human Prothrombin Complex

1970 ◽  
Vol 24 (03/04) ◽  
pp. 325-333 ◽  
Author(s):  
G. H Tishkoff ◽  
L. C Williams ◽  
D. M Brown
Keyword(s):  
Molecular Weight ◽  
Proteolytic Enzyme ◽  
Enzyme Inhibitor ◽  
Specific Activity ◽  
Crystalline Form ◽  
Sedimentation Equilibrium ◽  
Crystalline Complex ◽  
Interaction Product ◽  
Proteolytic Enzyme Inhibitor ◽  
Purification Scheme

SummaryAs a corollary to our previous studies with bovine prothrombin, we have initiated a study of human prothrombin complex. This product has been isolated in crystalline form as a barium glycoprotein interaction product. Product yields were reduced compared to bovine product due to the increased solubility of the barium glycoprotein interaction product. On occasion the crystalline complex exhibited good yields. The specific activity of the crystalline complex was 1851 Iowa u/mg. Further purification of human prothrombin complex was made by removal of barium and by chromatography on Sephadex G-100 gels. The final product evidenced multiple procoagulant activities (II, VII, IX and X). The monomeric molecular weight determined by sedimentation equilibrium in a solvent of 6 M guanidine-HCl and 0.5% mercaptoethanol was 70,191 ± 3,057 and was homogeneous with respect to molecular weight. This product was characterized in regard to physical constants and chemical composition. In general, the molecular properties of human prothrombin complex are very similar to the comparable bovine product. In some preparations a reversible proteolytic enzyme inhibitor (p-aminophenylarsonic acid) was employed in the ultrafiltration step of the purification scheme to inhibit protein degradation.

Optical analysis of ink and other contaminants in process waters

TAPPI Journal ◽  
2012 ◽  
Vol 11 (8) ◽  
pp. 51-58
Author(s):  
ANTTI HAAPALA ◽  
MIKA KÖRKKÖ ◽  
ELISA KOIVURANTA ◽  
JOUKO NIINIMÄKI
Keyword(s):  
Optically Active ◽  
Process Water ◽  
Paper Machine ◽  
Optical Analysis ◽  
Direct Process ◽  
Active Components ◽  
Water Contaminants ◽  
Dependent Measurement ◽  
Measurement Methodology

Analysis methods developed specifically to determine the presence of ink and other optically active components in paper machine white waters or other process effluents are not available. It is generally more interest¬ing to quantify the effect of circulation water contaminants on end products. This study compares optical techniques to quantify the dirt in process water by two methods for test media preparation and measurement: direct process water filtration on a membrane foil and low-grammage sheet formation. The results show that ink content values obtained from various analyses cannot be directly compared because of fundamental issues involving test media preparation and the varied methodologies used to formulate the results, which may be based on different sets of assumptions. The use of brightness, luminosity, and reflectance and the role of scattering measurements as a part of ink content analysis are discussed, along with fine materials retention and measurement media selection. The study concludes with practical tips for case-dependent measurement methodology selection.

Microscopic Structure of Er-Related Optically Active Centers in Si

2003 ◽  
Vol 770 ◽  
Author(s):  
H. Przybylinska ◽  
N. Q. Vinh ◽  
B.A. Andreev ◽  
Z. F. Krasil'nik ◽  
T. Gregorkiewicz
Keyword(s):  
Ground State ◽  
Photoluminescence Spectrum ◽  
Zeeman Effect ◽  
Optically Active ◽  
Single Type ◽  
Active Centers ◽  
Mbe Growth ◽  
Spectral Components ◽  
Er Doped ◽  
Successful Observation

AbstractA successful observation and analysis of the Zeeman effect on the near 1.54 μm photoluminescence spectrum in Er-doped crystalline MBE-grown silicon are reported. A clearly resolved splitting of 5 major spectral components was observed in magnetic fields up to 5.5 T. Based on the analysis of the data the symmetry of the dominant optically active center was conclusively established as orthorhombic I (C2v), with g‼≈18.4 and g⊥≈0 in the ground state. The fact that g⊥≈0 explains why EPR detection of Er-related optically active centers in silicon may be difficult. Preferential generation of a single type of an optically active Er-related center in MBE growth confirmed in this study is essential for photonic applications of Si:Er.

Lanoconazole and Its Related Optically Active Compound NND-502: Novel Antifungal Imidazoles with a Ketene Dithioacetal Structure

2003 ◽  
Vol 2 (2) ◽  
pp. 147-160 ◽  
Author(s):  
Yoshimi Niwano ◽  
Tetsuto Ohmi ◽  
Akira Seo ◽  
Hiroki Kodama ◽  
Hiroyasu Koga ◽  
...  
Keyword(s):  
Active Compound ◽  
Optically Active ◽  
Ketene Dithioacetal

Biological Production of (S)-acetoin: A State-of-the-Art Review

2019 ◽  
Vol 19 (25) ◽  
pp. 2348-2356 ◽  
Author(s):  
Neng-Zhong Xie ◽  
Jian-Xiu Li ◽  
Ri-Bo Huang
Keyword(s):  
Side Effects ◽  
Chemical Synthesis ◽  
State Of The Art ◽  
Optically Active ◽  
Considerable Progress ◽  
Future Prospects ◽  
Chiral Compound ◽  
Biological Production ◽  
Acetoin Production ◽  
Made In

Acetoin is an important four-carbon compound that has many applications in foods, chemical synthesis, cosmetics, cigarettes, soaps, and detergents. Its stereoisomer (S)-acetoin, a high-value chiral compound, can also be used to synthesize optically active drugs, which could enhance targeting properties and reduce side effects. Recently, considerable progress has been made in the development of biotechnological routes for (S)-acetoin production. In this review, various strategies for biological (S)- acetoin production are summarized, and their constraints and possible solutions are described. Furthermore, future prospects of biological production of (S)-acetoin are discussed.

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