Biomedical subjects

A S Muhammad Sofian

Publications and source records attributed to A S Muhammad Sofian.

4 recordsLinked to original sources

PubMed2002

Regioselective sulfonylation of 6,1',6'-tri-O-tritylsucrose through dibutylstannylation: synthesis of 4'-O-sulfonyl derivatives of sucrose.

3-O-Mesyl-1,6-di-O-trityl-beta-D-fructofuranosyl-(2-->1)-6-O-trityl-alpha-D-glucopyranoside (3) was synthesized via stannylation of 6,1',6'-tri-O-tritylsucrose with dibutyltin oxide in benzene, followed by treatment of the crude product with methanesulfonyl chloride in the presence of triethylamine in dichloromethane at 0 degrees C. A similar treatment of the tri-tritylsucrose in toluene, instead of benzene, yielded 4-O-mesyl-1,6-di-O-trityl-beta-D-fructofuranosyl-(2-->1)-6-O-trityl-alpha-D-glucopyranoside (4) as the major product. The X-ray crystal structure of the corresponding acetyl derivative, 3-O-acetyl-4-O-mesyl-1,6-di-O-trityl-beta-D-fructofuranosyl-(2-->1)-2,3,4-tri-O-acetyl-6-O-trityl-alpha-D-glucopyranoside (5), confirms the position and stereochemistry of the methanesulfonyl group at C-4 of the fructofuranosyl ring.

Crystallography, X-Ray↗

PubMed2002

2,3,3',6-Tetra-O-acetyl-4,1',6'-trichloro-4,1',4',6'-tetradeoxygalactosucrose.

At 160 K, one of the Cl atoms in the furanoid moiety of 3-O-acetyl-1,6-dichloro-1,4,6-trideoxy-beta-D-fructofuranosyl 2,3,6-tri-O-acetyl-4-chloro-4-deoxy-alpha-D-galactopyranoside, C(20)H(27)Cl(3)O(11), is disordered over two orientations, which differ by a rotation of about 107 degrees about the parent C-C bond. The conformation of the core of the molecule is very similar to that of 3-O-acetyl-1,4,6-trichloro-1,4,6-trideoxy-beta-D-tagatofuranosyl 2,3,6-tri-O-acetyl-4-chloro-4-deoxy-alpha-D-galactopyranoside, particularly with regard to the conformation about the glycosidic linkage.

Journal Article↗

PubMed2002

4,1',6'-Trichloro-4,1',6'-trideoxysucrose monohydrate.

At 160 K, the glucopyranosyl ring in 1,6-dichloro-1,6-dideoxy-beta-D-fructofuranosyl 4-chloro-4-deoxy-alpha-D-glucopyranoside monohydrate, C(12)H(19)Cl(3)O(8).H(2)O, has a near ideal (4)C(1) chair conformation, while the fructofuranosyl ring has a (4)T(3) conformation. The conformation of the sugar molecule is quite different to that of sucralose, particularly in the conformation about the glycosidic linkage, which affects the observed pattern of intramolecular hydrogen bonds. A complex series of intermolecular hydrogen bonds links the sugar and water molecules into an infinite three-dimensional framework.

Journal Article↗

PubMed2001

Two halodeoxy sucrose analogues.

At 160 K, the structure of 4-bromo-4-deoxysucrose, C(12)H(21)BrO(10), is very similar to that of sucrose, particularly with respect to the conformation of the glycosidic linkage. As in sucrose, an intramolecular hydrogen bond exists between the glucopyranosyl and the fructofuranosyl rings. Conversely, the structure of 1',6'-dibromo-4-fluoro-4,1',6'-trideoxysucrose monohydrate, C(12)H(19)Br(2)FO(8) x H(2)O, shows large conformational differences when compared with the structures of both sucrose and sucralose. This compound does not exhibit any intramolecular hydrogen bonds. In each compound, a complex series of intermolecular hydrogen bonds link the molecules into an infinite three-dimensional framework. The absolute configuration of each molecule has been determined.

Crystallography, X-Ray↗