Dihydrotestosterone with an Ammonium Centre in the Position 16β

1997 ◽  
Vol 62 (4) ◽  
pp. 656-664 ◽  
Author(s):  
Barbora Slavíková ◽  
Alexander Kasal ◽  
Miloš Buděšínský
Keyword(s):  
Quaternary Ammonium ◽  
Water Soluble ◽  
High Yield ◽  
Partial Hydrolysis ◽  
Amino Group ◽  
Alternative Synthesis ◽  
Group Participation ◽  
Neighbouring Group Participation ◽  
Hydrolysis Of

In an alternative synthesis of 17β-hydroxy-16β-(piperidin-1-yl)-5α-androstan-3-one (4), neighbouring group participation between a 17β-carbonyloxy group and the 16β-amino group was used and a high yield partial hydrolysis of 3β,17β-diacetoxy-16β-(piperidin-1-yl)-5α-androstane (11) was developed. Interference of the neighbouring group participation was also apparent in another 17β-acetoxy derivative - in oxidation of compound 12 to 13. Compound 4 was converted into water-soluble derivatives, i.e. quaternary ammonium derivatives 17 to 20.

CHARACTERIZATION OF THREE HEMICELLULOSES FROM THE WOOD OF AMABILIS FIR (ABIES AMABILIS)

1963 ◽  
Vol 41 (6) ◽  
pp. 1381-1388 ◽  
Author(s):  
E. C. A. Schwarz ◽  
T. E. Timell
Keyword(s):  
Periodate Oxidation ◽  
Specific Rotation ◽  
Water Soluble ◽  
Partial Hydrolysis ◽  
Abies Amabilis ◽  
A Value ◽  
Linear Framework ◽  
Molecular Rotations ◽  
Hydrolysis Of

An arabino-4-O-methylglucuronoxylan (10:14:76), a water-soluble galactoglucomannan (1:1:3), and an alkali-soluble galactoglucomannan (0.1:1:3) have been isolated in yields of 7, 4, and 8% from the wood of amabilis fir (Abies amabilis). The structure of the polysaccharides was established by methylation and periodate oxidation techniques. The xylan ([Formula: see text]) contained side chains of (1 → 2)-linked 4-O-methyl-α-D-glucuronic acid and (1 → 3)-linked α-L-arabinofuranose residues, both attached directly to a linear framework of (1 → 4)-linked β-D-xylose residues. The galactoglucomannans ([Formula: see text] 76 and 95) contained (1 → 6)-linked α-D-galactopyranosyl residues attached directly to a backbone of (1 → 4)-linked β-D-mannose and β-D-glucose residues. Partial hydrolysis of the two hexosans yielded 10 and 13 oligosaccharides, respectively, containing (1 → 4)-β-D-mannose, (1 → 4)-β-D-glucose, and (1 → 6)-α-D-galactopyranose residues. The molecular rotations of a series of mannooligosaccharides corresponded to a value of −54° for the specific rotation of an infinitely long mannan. It is concluded that the main hemicelluloses in amabilis fir wood are the same as those occurring in the wood of gymnosperms from other genera. The same three hemicelluloses are also present in the bark of this species.

CONSTITUTION OF THREE HEMICELLULOSES FROM THE WOOD OF ENGELMANN SPRUCE (PICEA ENGELMANNI)

1963 ◽  
Vol 41 (6) ◽  
pp. 1389-1395 ◽  
Author(s):  
A. R. Mills ◽  
T. E. Timell
Keyword(s):  
Glucuronic Acid ◽  
Water Soluble ◽  
Partial Hydrolysis ◽  
Side Chains ◽  
Engelmann Spruce ◽  
Linear Framework ◽  
Single Side ◽  
Hydrolysis Of ◽  
Picea Engelmanni

An arabino-4-O-methylglucuronoxylan (10:70:12), a water-soluble galactoglucomannan (1:1:3), and an alkali-soluble galactoglucomannan (0.2:1:3) have been isolated in yields of 8.0, 1.0, and 8.1% from the wood of Engelmann spruce (Picea engelmanni). The xylan consisted of a linear framework of (1 → 4)-linked β-D-xylose residues to which were directly attached single side chains of (1 → 2)-linked 4-O-methyl-α-D-glucuronic acid and (1 → 3)-linked α-L-arabinofuranose residues. The galactoglucomannans were both composed of a backbone of (1 → 4)-linked β-D-mannose and β-D-glucose residues, some of which carried directly attached side chains of (1 → 6)-linked α-D-galactopyranose residues. Partial hydrolysis of the water-soluble galactoglucomannan yielded, among other oligosaccharides, a trisaccharide composed of galactose, glucose, and mannose residues. It is concluded that the main polysaccharides in the wood of Engelmann spruce are the same as those in most other gymnosperms. In the bark of this tree, the water-soluble galactoglucomannan is replaced by one or several polysaccharides of an entirely different composition.

CONSTITUTION OF THE GALACTOMANNAN FROM THE KERNEL OF GREEN PALMYRA PALM NUT (BORASSUS FLABELLIFER LINN.)

1961 ◽  
Vol 39 (7) ◽  
pp. 1408-1418 ◽  
Author(s):  
A. K. Mukherjee ◽  
D. Choudhury ◽  
P. Bagchi
Keyword(s):  
Periodate Oxidation ◽  
Structural Formula ◽  
Water Soluble ◽  
Molar Ratio ◽  
Partial Hydrolysis ◽  
Soluble Polysaccharide ◽  
Hydrolysis Of

The water-soluble polysaccharide extracted from the kernel of green palmyra palm nut (Borassusflabellifer Linn.) was shown to be composed of D-galactose and D-mannose in the proportion of 1:2.4. Hydrolysis of the fully methylated galactomannan yielded 2,3,4,6-tetra-O-methyl-D-galactose, 2,3,6-tri-O-methyl-D-mannose, and 2,3-di-O-methyl-D-mannose in the molar ratio of 1:1.4:0.95. Partial hydrolysis of the galactomannan afforded 4-O-β-D-mannopyranosyl-D-mannose, 6-O-α-D-galactopyranosyl-D-mannose, and two trisaccharides. Based on these results a structural formula for the galactomannan has been proposed, additional evidence for which was adduced from periodate-oxidation studies.

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