Chiral building blocks for amphotericin B

1986 ◽  
Vol 64 (9) ◽  
pp. 1800-1809 ◽  
Author(s):  
David Liang ◽  
Henry W. Pauls ◽  
Bert Fraser-Reid ◽  
Michael Georges ◽  
Azeez M. Mubarak ◽  
...  
Keyword(s):  
Family Member ◽  
Amphotericin B ◽  
Absolute Configuration ◽  
Building Blocks ◽  
Carbon Chain ◽  
Polyene Macrolides ◽  
General Plan ◽  
Chiral Component

A general plan is outlined for disconnection of the polyene macrolides, which is aimed at achieving their syntheses, as well as facilitating the determination of their absolute configurations. The plan is exemplified by amphotericin B, I, the only family member of known absolute configuration. The major chiral component is a 20-carbon chain, III, which upon further retrosynthetic disconnection leads to three subunits, two of which correspond to the dideoxy hexoses IV and V. Although these are formally mirror images, they are best represented as the 3,4-dideoxyhexopyranoside, 1, and the 3,5-dideoxyfuranose, 2. Syntheses of 1 and 2 from readily available starting materials are described.

scholarly journals Rapid Organocatalytic Chirality Analysis of Amines, Amino Acids, Alcohols, Amino Alcohols and Diols with Achiral Iso(thio)cyanate Probes

2021 ◽  
Author(s):  
Eryn Nelson ◽  
Jeffrey S. S. K. Formen ◽  
Christian Wolf
Keyword(s):  
Amino Acids ◽  
Absolute Configuration ◽  
Rapid Determination ◽  
Amino Alcohols ◽  
Enantioselective Synthesis ◽  
Widespread Occurrence ◽  
Chiral Compounds ◽  
New Methods ◽  
The Absolute

The widespread occurrence and significance of chiral compounds does not only require new methods for their enantioselective synthesis but also efficient tools that allow rapid determination of the absolute configuration,...

scholarly journals Preparative-scale HPLC Resolution of Metallacyclic η3-Allyltricarbonyliron Complexes and Determination of the Absolute Configuration by X-Ray Crystal Structure Analysis

1999 ◽  
Vol 23 (9) ◽  
pp. 578-579
Author(s):  
Rainer Schobert ◽  
Hermann Pfab ◽  
Jutta Böhmer ◽  
Frank Hampel ◽  
Andreas Werner
Keyword(s):  
Crystal Structure ◽  
Silica Gel ◽  
Structure Analysis ◽  
Absolute Configuration ◽  
Crystal Structure Analysis ◽  
Preparative Scale ◽  
X Ray ◽  
The Absolute

Racemates of (η3-allyl)tricarbonyliron lactone complex Fe(CO)3{η1:η3-C(O)XCH2CHCMeCH2} 1a (X = O) and (η3-allyl)tricarbonyliron lactam complex 2a (X = NMe) are resolved on a preparative scale by HPLC on cellulose tris(3,5-dimethylphenyl)carbamate/silica gel RP-8 and the absolute configuration of (-)-2a is determined by X-ray crystal structure analysis.

scholarly journals Quantitative Determination of the Effects of He-Ne Laser Irradiation on Seed Thermodynamics, Germination Attributes and Metabolites of Safflower (Carthamus tinctorius L.) in Relation with the Activities of Germination Enzymes

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1411
Author(s):  
Rashida Perveen ◽  
Xiukang Wang ◽  
Yasir Jamil ◽  
Qasim Ali ◽  
Shafaqat Ali ◽  
...  
Keyword(s):  
Seed Germination ◽  
Energy Levels ◽  
Soluble Sugars ◽  
Building Blocks ◽  
Carthamus Tinctorius ◽  
Fast Decline ◽  
Seed Irradiation ◽  
Seed Reserves ◽  
Positive Correlations

The present investigation was undertaken to assess the effects of different doses (100, 300, and 500 mJ) of low power He–Ne laser (632.8 nm) irradiation on seed germination and thermodynamics attributes and activities of potential germinating enzymes in relation with changes in seed metabolites. He–Ne laser seed irradiation increased the amylase (Amy), protease (Pro) and glucosidase (Gluco) activities, with a significant improvement in seed thermodynamics and seed germination attributes. A fast increase was found in free fatty acids (FFA), free amino acids (FAA), chlorophyll (Chl), carotenoids (Car), total soluble sugars (TSS) and reducing sugars (RS) in laser treated seeds in parallel with fast decline in seed oil contents and total soluble proteins (TSP). Significant positive correlations were recorded in laser-induced enhanced seed energy levels, germination, activities of germination enzymes with levels of FAA, FFA, Chl, TSS and RS, but a negative correlation with the levels of TSP and oil. In conclusion, the seed treatment with 100 and 300 mJ He–Ne laser was more effective to improve the seed germination potential associated with an improvement in seed energy levels due to increased activities of germination enzymes due to the speedy breakdown of seed reserves to simple metabolites as building blocks.

Asymmetric Total Synthesis and Determination of the Absolute Configuration of (+)-Srilankenyne via Sequence-Sensitive Halogenations Guided by Conformational Analysis

2021 ◽  
Vol 23 (4) ◽  
pp. 1321-1326
Author(s):  
Hongjun Jang ◽  
Soo Yeon Kwak ◽  
Dongjoo Lee ◽  
Juan V. Alegre-Requena ◽  
Hyoungsu Kim ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Conformational Analysis ◽  
Absolute Configuration ◽  
Asymmetric Total Synthesis ◽  
The Absolute
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