The Biosynthesis Of Eugenyl α-glucoside By Xanthomonas Campestris BT-112

Clove is an essential oil from the bud of Eugenia aromatica and known as a herb medicine. The main component, accounting for more than 90%, of the clove essential oil is eugenol. Eugenol exhibits a broad biological activities, such as sterilization, narcosisa, ntioxidant, antifebrile, anti-inflammatory, antineoplastic activity and so on. However, the use of eugenol is limited by its liability to sublimate, its extremely low solubility in water and its irritative smell. Therefor its modification of structure is needed.Glycosylation is considered to be an important method of the structural modification of bioactive compounds. Glycosyl conjugation of lipophilic low molecular weight compounds is an efficient tool to enhance water solubility, to improve stability, to decrease the toxicity of xenobiotics, and thereby to increase bioavailability and modify biological activity.In this paper, a bacterium of Xanthomonas campestris BT-112 was isolated and used for the anomer-selective synthesis of eugenyl a-glucoside (a-EG) with maltose as a glucosyl donor. The effects of reaction temperature, shaking speed, pH, eugenol concent ration, and reactant composition were investigated. When the suspension of Xanthomonas campestris BT-112 was incubated at 30℃with 70 mmol/L eugenol and 1.0 mol/L maltose, only one form of eugenyl glucoside was selectively obtained as a product and identified as a-EG by 13C-NMR,1H-NMR. The reaction at pH 8.0 for 72 h under the above conditions, the conversion based on the amount of eugenol supplied reached 63.4%. It has some merits about a-EG of Biosynthesis with Xanthomona campestris BT-112. For example, it has simple rough material; reactionary condition is eary to control; the time of reaction is short; the pureness of a-Arbutin is high; it did not produce toxic organic solvent, and so on. So it has industrialization significance.