A ketohexose is a ketone-containing hexose. [1] [2] [7] The important ketohexoses are the 2-ketohexoses, and the most important 2-ketose is fructose. Besides the 2-ketoses, there are only the 3-Ketoses, and they do not exist in nature, although at least one 3-ketohexose has been synthesized, with great difficulty.

Ketohexose: A ketose with six carbon atoms is called ketohexose. Ketohexoses exist in eight isomeric forms (2 3 = 8) owing to the presence of three asymmetric carbon atoms (Fig. 2.11). d-isomers are shown in Fig. 2.11.

己糖 （英語： Hexose），又称为 六碳糖，是含有6个碳原子的 单糖， 分子式 为C 6 H 12 O 6. 1位含有醛基的6碳糖称为己醛糖， 2位含有酮基的己糖称为己酮糖。 己糖六個碳原子中有五個碳原子連上了 羥基 (-OH)，餘下的一個碳原子是屬於一個醛基 (-COH)或是酮基 (-CO-)的。 葡萄糖分子的1位碳是屬於一個醛基的，所以葡萄糖是一種 醛糖 Aldose (ALDO=醛)。 而果糖的2位碳則是屬於一酮基的，因此果糖是一種 酮糖 Ketose。 己糖中的醛基或酮基會與 分子内 的 羟基 反应，生 …

2025年1月21日 · Fructose. D-Fructose, also shown in Figure \(\PageIndex{1}\), is the most abundant ketohexose. Note that from the third through the sixth carbon atoms, its structure is the same as that of glucose.

Glucose and galactose are both aldohexoses, while fructose is a ketohexose. D-Glucose, generally referred to as simply glucose, is the most abundant sugar found in nature. Most of the carbohydrates we eat are converted to D-glucose during digestion.

Examples of ketohexoses include fructose, which is a common sugar found in fruits, and psicose, a rare sugar with potential health benefits. Chapter 4 . Carbohydrate polymers are formed from the linear and branched combination of a wide variety of different naturally occurring simple sugars known as monosaccharides.

Monosaccharides can be classified by the number of carbon atoms in the structure and/or the type of carbonyl group they contain (aldose or ketose). Most monosaccharides contain at least one chiral carbon and can form stereoisomers.

Fructose is a keto-hexose crystallising as the β-pyranoid form in white to colourless crystals. Fructose melts in the range of 100–104°C. The specific rotation is [α] 20 D: −91 to −93.5°. It is slightly hygroscopic with an equilibrium humidity of 63% rh (Schiweck 1991a).

2024年4月24日 · Ketohexose features a ketone group, while hexose, a broader category, includes both ketoses and aldoses, distinguished by functional groups. Ketohexose refers specifically to a type of hexose sugar that contains a ketone group on one of its carbon atoms.

Ketohexoses are essential monosaccharides with a six-carbon chain and a ketone group at the second carbon. Fructose, the most common ketohexose, forms a furanose ring structure in its cyclic form, which is crucial for its sweetness and biological activity.