Enzymatic Synthesis of Four Stereoisomers of 7-0xo-biopterin and Determination of the Absolute Structure of Ichthyopterin

Pteridines ◽  
1990 ◽  
Vol 2 (3) ◽  
pp. 151-156 ◽  
Author(s):  
Shin Ichiro Takikawa ◽  
Sadao Matsuura
Keyword(s):  
Enzymatic Synthesis ◽  
Side Chain ◽  
Side Chains ◽  
Enzymatic Conversion ◽  
Cd Spectra ◽  
The Absolute ◽  
Chiral Centers ◽  
Absolute Structure

Summary Enzymatic conversion of stereoisomers of biopterin (3a-d) to the 7-oxo-biopterin isomers (4a-d) was performed with a new pterin 7-oxidase extracted from carp skin. The chiral centers of the 6-side chains of biopterin isomers were preserved during the conversion, and the four possible stereoisomers of 7-oxo-biopterin (4a-d) were obtained from the corresponding biopterin isomers (3a-d). HPLC and CD spectra studies showed that natural ichthyopterin is 2-amino-6-(L-erythro-1',2' -dihydroxypropyl)-4, 7(3H,8H)-pteridinedione (4a) which has the same L-erythro structure at the side chain as natural biopterin (3a). This fact suggests that ichthyopterin is biologically derived from biopterin in these fishes.

scholarly journals Absolute structure determination of compounds with axial and planar chirality using the crystalline sponge method

2015 ◽  
Vol 6 (7) ◽  
pp. 3765-3768 ◽  
Author(s):  
Shota Yoshioka ◽  
Yasuhide Inokuma ◽  
Manabu Hoshino ◽  
Takashi Sato ◽  
Makoto Fujita
Keyword(s):  
Structure Determination ◽  
Asymmetric Syntheses ◽  
Planar Chirality ◽  
The Absolute ◽  
Absolute Structure

The absolute structure determination of compounds with axial and planar chirality obtained by recently developed asymmetric syntheses was achieved using the crystalline sponge method without using any reference compounds or synthetic modifications.

Chiral Crystalline Sponges for the Absolute Structure Determination of Chiral Guests

2017 ◽  
Vol 139 (33) ◽  
pp. 11341-11344 ◽  
Author(s):  
KaKing Yan ◽  
Ritesh Dubey ◽  
Tatsuhiko Arai ◽  
Yasuhide Inokuma ◽  
Makoto Fujita
Keyword(s):  
Structure Determination ◽  
The Absolute ◽  
Absolute Structure

The First Total Synthesis of Cochleamycin A and Determination of the Absolute Structure.

ChemInform ◽  
2003 ◽  
Vol 34 (48) ◽  
Author(s):  
Kuniaki Tatsuta ◽  
Fumie Narazaki ◽  
Nobusuke Kashiki ◽  
Jun-Ichiro Yamamoto ◽  
Satoshi Nakano
Keyword(s):  
Total Synthesis ◽  
The Absolute ◽  
Absolute Structure

scholarly journals The First Total Synthesis of Cochleamycin A and Determination of the Absolute Structure

2003 ◽  
Vol 56 (6) ◽  
pp. 584-590 ◽  
Author(s):  
KUNIAKI TATSUTA ◽  
FUMIE NARAZAKI ◽  
NOBUSUKE KASHIKI ◽  
JUN-ICHIRO YAMAMOTO ◽  
SATOSHI NAKANO
Keyword(s):  
Total Synthesis ◽  
The Absolute ◽  
Absolute Structure

Determination of the Absolute Structure of (+)-Cystothiazole B.

ChemInform ◽  
2004 ◽  
Vol 35 (47) ◽  
Author(s):  
Takamitsu Sasaki ◽  
Keisuke Kato ◽  
Hiroyuki Akita
Keyword(s):  
The Absolute ◽  
Absolute Structure

scholarly journals Redetermination of β-Ba(PO3)2

2014 ◽  
Vol 70 (2) ◽  
pp. i7-i7 ◽  
Author(s):  
Matthias Weil
Keyword(s):  
Bond Length ◽  
Coordination Polyhedron ◽  
Structure Determination ◽  
Length Distribution ◽  
Anisotropic Displacement Parameters ◽  
The Absolute ◽  
Bond Length Distribution ◽  
Absolute Structure ◽  
Atomic Coordinates

In comparison with the previous structure determination of the β-modification of bariumcatena-polyphosphate that was based on Weissenberg film data [Grenieret al.(1967).Bull. Soc. Fr. Minéral. Cristallogr.90, 24–31], the current CCD-data-based redetermination reveals all atoms with anisotropic displacement parameters, standard uncertainties for the atomic coordinates, and the determination of the absolute structure. Moreover, a much higher accuracy in terms of the bond-length distribution for the polyphosphate chain, with two shorter and two longer P—O distances, was achieved. The structure consists of polyphosphate chains extending parallel to [100] with a periodicity of two PO4tetrahedra. The Ba2+cations are located between the chains and are surrounded by ten O atoms in the form of a distorted coordination polyhedron, with Ba—O distances ranging from 2.765 (3) to 3.143 (3) Å, also reflecting the higher precision of the current redetermination.

The use of Mo Kα radiation in the assignment of the absolute configuration of light-atom molecules; the importance of high-resolution data

2014 ◽  
Vol 70 (4) ◽  
pp. 660-668 ◽  
Author(s):  
Eduardo C. Escudero-Adán ◽  
Jordi Benet-Buchholz ◽  
Pablo Ballester
Keyword(s):  
High Resolution ◽  
Crystal Structures ◽  
Structure Determination ◽  
Great Majority ◽  
Data Sets ◽  
Light Atom ◽  
High Resolution Data ◽  
The Absolute ◽  
Absolute Structure

Recent studies have confirmed the usefulness of the Hooft and Parsons methodologies for determination of the absolute crystal structures of enantiopure light-atom compounds using CuKα radiation. While many single-crystal diffractometers used for small-molecule structure determination are equipped with molybdenum anodes, use of data from such instruments for the absolute structure determination of light-atom crystal structures is rarely documented and has often been found to be unsuccessful. The Hooft and Parsons methodologies have been applied to 44 data sets obtained from single crystals containing light-atom molecules of known chirality using Mo Kαradiation. Several factors influencing the calculation of accurate and precise values for the Hooft and Parsons parameters obtained from these data sets have been identified, the inclusion of high-resolution diffraction data being particularly important. The correct absolute structure was obtained in all cases, with the standard uncertainties of the final absolute structure parameters below 0.1 for the great majority.

Sign in / Sign up

Export Citation Format

Share Document