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In bio-organic chemistry, a hexose is a monosaccharide with six carbon atoms, having the chemical formula C6H12O6. Hexoses are classified by functional group, with aldohexoses having an aldehyde at position 1, and ketohexoses having a ketone at position 2. ==Aldohexoses== The aldohexoses have four chiral centres for a total of 16 possible aldohexose stereoisomers (24). The D/L configuration is based on the orientation of the hydroxyl at position 5, and does not refer to the direction of optical activity. The eight D-aldohexoses are: File:DAllose Fischer.svg | D-Allose File:DAltrose Fischer.svg | D-Altrose File:DGlucose Fischer.svg | D-Glucose File:Mannose.svg | D-Mannose File:DGulose Fischer.svg | D-Gulose File:DIdose Fischer.svg | D-Idose File:DGalactose Fischer.svg | D-Galactose File:DTalose Fischer.svg | D-Talose Of these D-isomers, all except D-altrose are naturally occurring. L-Altrose, however, has been isolated from strains of the bacterium ''Butyrivibrio fibrisolvens''. A mnemonic for the aldohexoses is "All Altruists Gladly Make Gum in Gallon Tanks": allose, altrose, glucose, mannose, gulose, idose, galactose, talose. When drawn in this order, the Fischer projections of the D-aldohexoses follow a pattern. Allose has all four hydroxyl groups on the right. At carbon 2, the hydroxyl groups alternate right-left. At carbon 3, the first two are on the right, the next two are on the left, and so on. At carbon 4, the first four are on the right and the rest are on the left. At carbon 5, all eight D-aldohexoses have the hydroxyl group on the right. This can be seen as binary counting to seven, where 0 stands for hydroxyl and 1 for hydrogen. So 0000 stands for D-Allose, 0001 stands for D-Altrose, 0010 stands for D-Glucose, 0011 stands for D-Mannose, 0100 stands for D-Gulose, 0101 stands for D-Idose, 0110 stands for D-Galactose and 0111 stands for D-Talose. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「hexose」の詳細全文を読む スポンサード リンク
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