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【答案】应助回帖
★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ andong668: 金币+30, ★★★很有帮助, 谢谢 2015-03-04 09:25:43
Recently, a study from Divakar's group has shown that L-isoleucyl-D-glucose, L-histidyl-D- fructose, L-diphenylborinate-D-mannose, L-phenylalanyl-D-glucose have interesting properties, such as good emulsification, dispersion, solubilization properties, which can form a porous lipidic coating [algal lipid membrane??] on the skin surface, and keep skin moisturized. These amino sugar esters can be used as a good skin lubricants and moisturizing ingredients.
Currently, these sugar esters were mainly manufactured by chemical synthesis using acids as a catalyst, usually under hush reaction conditions such as high temperature and high pressure. It has issues like [saturated products?? I dont understand the meaning in a scientific sense, it is only applicable to saturated fatty chains?], low selectivity, reaction byproducts, and may cause environmental pollution. In recent years, the production of surface-active molecules of biological origin through bioprocesses as well as enzymatic synthesis have been reported[10-12]. Lipases, which hydrolyze acyl-glycerides, have been widely used in organic synthesis due to the fact that they can accept a wide range of substrates and their activities are quite stable in nonaqueous environment in organic solvents. The another advantages using enzymes as catalysts include the lack of formation of byproducts , excellent chemo-regioselectivity and mild reaction conditions. It has been exploited in the field of carbohydrate research[ I suggest that you delete this sentence]. So far a variety of lipases have been successfully used to catalyze the coupling reaction between sugar and fatty acids, including the synthesis of glucose esters. However, the highcost of lipases often prevents their widespread industrial uses. |
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