L-Xylose: Sweet Messenger L-(-) 木糖：甜蜜使者

Today, as modern technology and life intertwine, more and more functional chemicals are coming into our view, and L-(-) xylose is one of them. As an important pharmaceutical intermediate, food additive and chemical raw material, L-(-) xylose has become a sweet messenger connecting health and life with its unique properties and wide application fields. This article will take you to appreciate the wonderful world of this chemical substance.

The “business card” of L- xylose

L-(-) xylose, chemically called L-xylose, is a monosaccharide of the aldehyde pentose type with a left-handed structure. It is a white fine crystal or powder with a molecular formula of C₅H₁₀O₅ and a molecular weight of 150.13.

The "health magic" of L- xylose

■ The "sugar reduction" pioneer in the food industry

As people pay more and more attention to healthy eating, low-sugar and sugar-free foods have become the new favorites in the market. L- xylose has become an ideal sweetener choice due to its low sweetness and almost no calories. It not only satisfies people's desire for sweetness, but also avoids the health problems caused by excessive sugar intake.

■ The "guardian" of intestinal health

L- xylose has a high proliferation effect on bifidobacteria in the human intestine. Bifidobacteria are a kind of beneficial intestinal flora that can help the human body better digest and absorb food, enhance immunity, and inhibit the growth of harmful bacteria. By consuming L- xylose, the intestinal microenvironment can be improved, intestinal health can be promoted, and thus the overall immune ability of the body can be improved.

■ The "little expert" of anti-oxidation

L- xylose has a strong antioxidant effect, which can effectively resist the invasion of free radicals, protect human cells from oxidative damage, help delay aging, and prevent the occurrence of various chronic diseases.

The “multiple applications” of L- xylose

■ "All-rounder" in the field of food processing

In addition to being a sweetener, L-xylose is also widely used in food processing. It has good hygroscopicity and water retention, which can improve the texture and taste of food and extend the shelf life of food. For example, adding L-xylose to baked goods can make bread, cakes, etc. softer and more moist; in meat products, it can also be used as a flavor modifier to increase the delicious taste of meat and help maintain the tenderness of meat. In addition, L-xylose can also be used to prepare meat flavors, high-grade soy sauce colors, etc., adding unique flavor and color to food.

■ "Potential stock" in the pharmaceutical field

In the pharmaceutical industry, L-xylose is an important pharmaceutical intermediate that can be used to synthesize a series of anti-cancer, anti-AIDS, anti-hepatitis C virus and other drugs. Its unique metabolic pathways and physiological functions have also attracted much attention in the research of adjuvants for diabetes treatment. By regulating the balance of intestinal flora, L- xylose can improve the insulin resistance of diabetic patients and lower blood sugar levels. At the same time, it also has the effects of promoting intestinal mucosal repair and enhancing immune function, which is of great significance for improving the overall health of diabetic patients.

■ "New favorite" of the chemical industry

L- xylose also has certain uses in light industry and chemical industry. For example, in cosmetics, it can be used as a moisturizer and antioxidant to provide moisture and protection for the skin; in daily necessities, L- xylose can be used to produce products such as sugar-free chewing gum to meet the needs of different consumers.

The "production mystery" of L-(-) xylose

L-xylose is not a naturally occurring compound and can only be obtained through synthesis, including chemical synthesis and biotransformation.

▷ The earliest chemical synthesis method was reported in 1950 by patent US2584129A.

▷In 1955, Courtois and Le Dizet reported the synthesis of L-xylose by a two-step method of oxidation followed by hydrolysis using 2,4-O-benzylene-D-sorbitol as raw material. The disadvantage of this method is that the catalytic oxidant used is extremely unstable and particularly easy to decompose, and the reaction process is difficult to control.

▷ In 2003, US Patent 20030097029 reported the use of L-xylose acid to generate L-xylose by hydrogenation reduction under the action of ruthenium catalyst, with a reaction pressure of 5MPa and a reaction time of 18h. However, under these conditions, L-xylose will continue to be over-reduced to generate xylitol.

▷ In 2017, Chinese patent CN108276455A reported that an acid catalyst can be used to convert 2,4-O-benzylene-L-xylose into L-xylose. The reaction time is short, the conditions are mild, and the product yield is high.

▷ There are fewer reports on bioconversion methods. In 2002, Yadav et al. reported that galactose oxidase can synthesize L-xylose in a biological carrier.

▷ In 2005, Granstrom et al. reported that xylitol can be used to obtain L-xylose under the action of gene 701B strain and L-rhamnose isomerase.

▷ In 2012, Usvalampi et al. reported that xylulose can be used to selectively generate L-xylose under the action of Escherichia coli-L-fucose isomerase.

▷ In 2017, Chinese patent CN108165591A reported that 2-keto-L-gulonic acid was converted into L-xylose under the action of pyruvate decarboxylase.

Conclusion

L- xylose is a multifunctional sugar with optical activity for medical use. A large number of pharmaceutical application research and market applications have been carried out on L-xylose abroad, and the domestic market demand for it has also increased rapidly. In the future, with the continuous advancement of technology and the continuous expansion of the market, L-(-) xylose will show its unique value and charm in more fields. We expect L-xylose to bring more benefits and surprises to human health and life.