Hesperidin, which is called vitamin P, is a flavonoid compound abundantly occulting in citrus fruit peel. This material is well known to decrease capillary fragility and permeability. In addition, hesperidin is reported to have various physiological activities. Therefore, it has attracted attention as a multifunctional food ingredient. However, the use of this flavonoid in the field of foods has been limited because of its low water solubility. To solve this problem, we developed a soluble derivative of hesperidin, glucosyl hesperidin, which was synthesized by regioselective transglycosylation with cyclodextrin glucanotransferase from Bacillus stearothermophilus . Glucosyl hesperidin was very soluble in water, and its solubility was about 100, 000 times greater than that of conventional hesperidin. Moreover, the metabolic fate of this glucoside was investigated. As a result, it was verified that orally administered glucosyl hesperidin was hydrolyzed?to?hesperidin by small intestinal α-glucosidases, and that released hesperidin was hydrolyzed to hesperetin by β-glucosidases from intestinal bacteria before absorption. Glucosyl hesperidin was also confirmed to exhibit such physiological activities as improvement effect on microcirculation, antihypertensive effect and decrease of serum triglyceride level.?From these findings, glucosyl hesperidin is considered to be available effectively as a soluble vitamin P supplement in the field of functional foods.