関: red

WordNet

of a color at the end of the color spectrum (next to orange); resembling the color of blood or cherries or tomatoes or rubies (同)reddish, ruddy, blood-red, carmine, cerise, cherry, cherry-red, crimson, ruby, ruby-red, scarlet
red color or pigment; the chromatic color resembling the hue of blood (同)redness
the process of producing red blood cells by the stem cells in the bone marrow

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〈U〉〈C〉『赤,』『赤色;』赤い絵の具(染料) / 〈U〉赤い服 / 〈C〉《しばしば『R-』》《話》《時に軽べつして》アカ,共産主義者;過激論(主義)者 / 〈U〉《通例the ~》(会計の)赤字,負債 / 『赤い』,赤色の / (顔・目などが)赤くなった;血に染った / 赤い服を着た;赤毛の / 《しばしば『R-』》《話》《軽べつして》共産主義の;過激な

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2017/06/05 10:21:07」(JST)

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Diastereomers that are also epimers


D-Threose	D-Erythrose

Diastereomers (sometimes called diastereoisomers) are a type of a stereoisomer.^[1] Diastereomerism occurs when two or more stereoisomers of a compound have different configurations at one or more (but not all) of the equivalent (related) stereocenters and are not mirror images of each other.^[2] When two diastereoisomers differ from each other at only one stereocenter they are epimers. Each stereocenter gives rise to two different configurations and thus increases the number of stereoisomers by a factor of two.

Diastereomers differ from enantiomers in that the latter are pairs of stereoisomers that differ in all stereocenters and are therefore mirror images of one another.^[3] Enantiomers of a compound with more than one stereocenter are also diastereomers of the other stereoisomers of that compound that are not their mirror image. Diastereomers have different physical properties (unlike enantiomers) and different chemical reactivity. Diastereoselectivity is the preference for the formation of one or more than one diastereomer over the other in an organic reaction.

Syn / anti

When the single bond between the two centres is free to rotate, cis/trans descriptors become invalid. Two widely accepted prefixes used to distinguish diastereomers on sp³-hybridised bonds in an open-chain molecule are syn and anti. Masamune proposed the descriptors which work even if the groups are not on adjacent carbons. It also works regardless of CIP priorities. Syn describes groups on the same face while anti describes groups on opposite faces. The concept applies only to the Zigzag projection. The descriptors only describe relative stereochemistry rather than absolute stereochemistry.

Erythro / threo

Two older prefixes still commonly used to distinguish diastereomers are threo and erythro. In the case of carbohydrates, when drawn in the Fischer projection the erythro isomer has two identical substituents on the same side and the threo isomer has them on opposite sides.^[4] When drawn as a zig-zag chain, the erythro isomer has two identical substituents on different sides of the plane (anti). The names are derived from the diastereomeric aldoses erythrose (a syrup) and threose (melting point 126 °C). These prefixes are not recommended for use outside of the realm of carbohydrates because their definitions can lead to conflicting interpretations.^[5]

Another threo compound is threonine, one of the essential amino acids. The erythro diastereomer is called allo-threonine.


L-Threonine (2S,3R) and D-Threonine (2R,3S)

L-allo-Threonine (2S,3S) and D-allo-Threonine (2R,3R)

Multiple stereocenters

If a molecule contains two asymmetric carbons, there are up to 4 possible configurations, and they cannot all be non-superimposable mirror images of each other. The possibilities continue to multiply as there are more asymmetric centers in a molecule. In general, the number of configurational isomers of a molecule can be determined by calculating 2ⁿ, where n = the number of chiral centers in the molecule. This holds true except in cases where the molecule has meso forms.

For n = 3, there are eight stereoisomers. There are four pairs of enantiomers: R,R,R and S,S,S; R,R,S and S,S,R; R,S,S and S,R,R; and R,S,R and S,R,S. There are four diastereomers, because each of the pairs of enantiomers is a diastereomer with respect to the other three. For n = 4, there are sixteen stereoisomers, or eight pairs of enantiomers. The four aldopentoses and the eight aldohexoses (subsets of the five- and six-carbon sugars) are examples of sets of compounds that differ in this way.

Example

Tartaric acid contains two asymmetric centers, but two of the "isomers" are equivalent and together are called a meso compound. This configuration is not optically active, while the remaining two isomers are D- and L- mirror images, i.e., enantiomers. The meso form is a diastereomer of the other forms.


(natural) tartaric acid L-(+)-tartaric acid dextrotartaric acid	D-(−)-tartaric acid levotartaric acid	mesotartaric acid
(1:1) DL-tartaric acid "racemic acid"

The families of 4, 5 and 6 carbon carbohydrates contain many diastereomers because of the large numbers of asymmetric centres in these molecules.

Applications

As stated, two diastereomers will not have identical chemical properties. This knowledge is harnessed in chiral synthesis to separate a mixture of enantiomers. This is the principle behind chiral resolution. After preparing the diastereomers, they are separated by chromatography or recrystallization. Note also the example of the stereochemistry of ketonization of enols and enolates.

References

^ IUPAC "Gold Book" diastereoisomerism doi:10.1351/goldbook.D01679
^ Garrett, R.H.; Grisham, C.M. (2005), Biochemistry 3rd ed., Belmont CA: Thomson, p. 205, ISBN 0-534-41020-0 .
^ IUPAC "Gold Book" enantiomer doi:10.1351/goldbook.E02069
^ Modern physical organic chemistry Eric V. Anslyn,Dennis A. Dougherty 2006
^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "erythro, threo".

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English Journal

DNA-templated silver nanoclusters based label-free fluorescent molecular beacon for the detection of adenosine deaminase.

Zhang K, Wang K, Xie M, Zhu X, Xu L, Yang R, Huang B, Zhu X.Author information Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu 214063, China; Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, China.AbstractA general and reliable fluorescent molecular beacon is proposed in this work utilizing DNA-templated silver nanoclusters (AgNCs). The fluorescent molecular beacon has been employed for sensitive determination of the concentration of adenosine deaminase (ADA) and its inhibition. A well-designed oligonucleotide containing three functional regions (an aptamer region for adenosine assembly, a sequence complementary to the region of the adenosine aptamer, and an inserted six bases cytosine-loop) is adopted as the core element in the strategy. The enzymatic reaction of adenosine catalyzed by ADA plays a key role as well in the regulation of the synthesis of the DNA-templated AgNCs, i.e. the signal indicator. The intensity of the fluorescence signal may thereby determine the concentration of the enzyme and its inhibitor. The detection limit of the ADA can be lowered to 0.05 UL(-1). Also, 100 fM of a known inhibitor erythro-9-(2-hydroxy-3-nonyl) adenine hydrochloride (EHNA) is enough to present distinguishable fluorescence emission. Moreover, since the fluorescent signal indicator is not required to be bound with the oligonucleotide, this fluorescent molecular beacon may integrate the advantages of both the label-free and signal-on strategies.
Biosensors & bioelectronics.Biosens Bioelectron.2014 Feb 15;52:124-8. doi: 10.1016/j.bios.2013.08.049. Epub 2013 Aug 30.
A general and reliable fluorescent molecular beacon is proposed in this work utilizing DNA-templated silver nanoclusters (AgNCs). The fluorescent molecular beacon has been employed for sensitive determination of the concentration of adenosine deaminase (ADA) and its inhibition. A well-designed oligo
PMID 24035856

DMS triggers apoptosis associated with the inhibition of SPHK1/NF-κB activation and increase in intracellular Ca2+ concentration in human cancer cells.

Chen K, Pan Q, Gao Y, Yang X, Wang S, Peppelenbosch MP, Kong X.Author information Bio-X Center, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, P.R. China.AbstractN,N-Dimethyl-D-erythro-sphingosine (DMS) is known to induce cell apoptosis by specifically inhibiting sphingosine kinase 1 (SPHK1) and modulating the activity of cellular ceramide levels. The present study investigated the effects and the mechanism(s) of action of DMS in human lung cancer cells. We found that DMS dose-dependently suppressed cell proliferation and induced cell apoptosis in the human lung cancer cell line, A549. Mechanistically, treatment with DMS suppressed the activation of SPHK1 and nuclear factor-κB (NF-κB) p65, but increased intracellular [Ca2+]i in A549 cells. This study demonstrates that DMS triggers the apoptosis of human lung cancer cells through the modulation of SPHK1, NF-κB and calcium signaling. These molecules may represent targets for anticancer drug design.
International journal of molecular medicine.Int J Mol Med.2014 Jan;33(1):17-24. doi: 10.3892/ijmm.2013.1541. Epub 2013 Oct 30.
N,N-Dimethyl-D-erythro-sphingosine (DMS) is known to induce cell apoptosis by specifically inhibiting sphingosine kinase 1 (SPHK1) and modulating the activity of cellular ceramide levels. The present study investigated the effects and the mechanism(s) of action of DMS in human lung cancer cells. We
PMID 24173614

In vitro Characterization of LmbK and LmbO: Identification of GDP-D-erythro-α-D-gluco-octose as a Key Intermediate in Lincomycin A Biosynthesis.

Lin CI, Sasaki E, Zhong A, Liu HW.AbstractLincomycin A is a clinically useful antibiotic isolated from Streptomyces lincolnensis. It contains an unusual methylmercapto-substituted octose, methylthiolincosamide (MTL). While it has been demonstrated that the C8 backbone of MTL moiety is derived from D-fructose 6-phosphate and D-ribose 5-phosphate via a transaldol reaction catalyzed by LmbR, the subsequent enzymatic transformations leading to the MTL moiety remain elusive. Here, we report the identification of GDP-D-erythro-α-D-gluco-octose (GDP-D-α-D-octose) as a key intermediate in the MTL biosynthetic pathway. Our data show that the putative octose 1,8-bisphosphate intermediate is first converted to octose 1-phosphate by a phosphatase, LmbK. The subsequent conversion of the octose 1-phosphate to GDP-D-α-D-octose is catalyzed by the octose 1-phosphate guanylyltransferase, LmbO. These results provide significant insight into the lincomycin biosynthetic pathway because the activated octose likely serves as the acceptor for the installation of the C1 sulfur appendage of MTL.
Journal of the American Chemical Society.J Am Chem Soc.2013 Dec 31. [Epub ahead of print]
Lincomycin A is a clinically useful antibiotic isolated from Streptomyces lincolnensis. It contains an unusual methylmercapto-substituted octose, methylthiolincosamide (MTL). While it has been demonstrated that the C8 backbone of MTL moiety is derived from D-fructose 6-phosphate and D-ribose 5-phosp
PMID 24380627

Japanese Journal

Crucial role of 4-deoxy-L-erythro-5-hexoseulose uronate reductase for alginate utilization revealed by adaptive evolution in engineered Saccharomyces cerevisiae

Scientific Reports 7, 2017-06-23
NAID 120006313614

Identification of 2-keto-3-deoxy-D-Gluconate Kinase and 2-keto-3-deoxy-D-Phosphogluconate Aldolase in an Alginate-Assimilating Bacterium, Flavobacterium sp Strain UMI-01

Marine drugs 15(2), 37, 2017-02
NAID 120006309132

SYNTHESIS OF BENZYL TETRA-O-ACETYL-α-L-GLUCOPYRANOSIDE FROM BENZYL 2,3-DIDEOXY-β-D-ERYTHRO-HEX-2-ENOPYRANOSIDE (Dedicated to Professor Dr. Masakatsu Shibasaki on the occasion of his 70th birthday)

Heterocycles : an international journal for reviews and communications in heterocyclic chemistry 95(2), 862-871, 2017-01-25
NAID 40021211306

Related Pictures

★リンクテーブル★

リンク元	「red」「赤」
拡張検索	「erythropoietic」「erythroblastotic」「erythropoiesis stimulating agent」

「red」

　　[★]

adj.

赤色の、赤、赤い

関: erythro

「赤」

　　[★]

英: red、erythro
関: エリスロ、赤色、赤い

「erythropoietic」

　　[★]

adj.

赤血球新生の、赤血球形成の

関: erythropoiesis

「erythroblastotic」

　　[★]

赤芽球症の

関: erythroblastosis

「erythropoiesis stimulating agent」

　　[★] エリスロポエチン製剤

[1] IUPAC "Gold Book" diastereoisomerism doi:10.1351/goldbook.D01679

[2] Garrett, R.H.; Grisham, C.M. (2005), Biochemistry 3rd ed., Belmont CA: Thomson, p. 205, ISBN 0-534-41020-0 .

[3] IUPAC "Gold Book" enantiomer doi:10.1351/goldbook.E02069

[4] Modern physical organic chemistry Eric V. Anslyn,Dennis A. Dougherty 2006

[5] IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "erythro, threo".

v t e Concepts in asymmetric synthesis
Chirality types	Chirality Stereocenter Planar chirality Chiral ligand Axial chirality Supramolecular chirality Inherent chirality
Chiral molecules	Stereoisomer Enantiomer Diastereomer meso compound racemic mixture Enantiomeric excess (ee) Diastereomeric excess (de)
Analysis	Optical rotation Chiral derivatizing agents NMR spectroscopy of stereoisomers Ultraviolet-visible spectroscopy of stereoisomers
Chiral resolution	Recrystallization Kinetic resolution Chiral column chromatography Diastereomeric recrystallization
Reactions	Asymmetric induction Chiral pool synthesis Chiral auxiliaries Asymmetric catalysis Organocatalysis Biocatalysis

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erythro