title: The possible presence of natural β-D-glucosidase inhibitors in jujube leaf extract.
abstract: Isoquercitrin is a phenolic compound well-known for having greater health benefits than quercitin, its aglycone derivative, and other related glycosides. However, isoquercitrin is rarely found in nature. Here, we optimized the conditions for the enzymatic transformation of isoquercitrin from rutin that was extracted from jujube leaf using the hesperidinase, enzyme complex containing β-D-glucosidase and α-L-rhamnosidase. The maximum productivity (2.57±0.16mg/mL) was experimentally found under the following conditions: 47.3°C, 52.16h, and pH 5.31, which agreed well with the predicted value (2.65mg/mL). However, the achievement of this maximum yield was due to the absence of β-D-glucosidase activity. Further investigations using a β-D-glucosidase assay and reaction measurements under various conditions revealed that the β-D-glucosidase activity was not blocked by denaturation or known inhibitory factors. Currently, there are no recognized β-D-glucosidase inhibitors present in the jujube leaf; however, our observations strongly suggest that an unidentified β-D-glucosidase inhibitor exists in jujube leaf extract.
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea.
authors.forename: Youngje
authors.initials: Y
authors.lastname: Jo
authors.affiliation: Department of Food Science & Technology, College of Life and Health Science, Hoseo University, Asan, Chungnam 336-759, Republic of Korea.
authors.forename: Seokwon
authors.initials: S
authors.lastname: Lim
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea; Center for Food and Bioconvergence, Seoul National University, Seoul 151-921, Republic of Korea.
authors.forename: Pahn-Shick
authors.initials: PS
authors.lastname: Chang
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea; Center for Food and Bioconvergence, Seoul National University, Seoul 151-921, Republic of Korea; Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Republic of Korea. Electronic address: choiyj@snu.ac.kr.
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Choi
mesh_terms: D005638:Fruit / Q000737:chemistry*; D005959:Glucosidases / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D012431:Rutin / Q000737:chemistry*; D031957:Ziziphus / Q000737:chemistry*
chemical_list: D010636:Phenols; D012431:Rutin; D005959:Glucosidases
keywords: Hesperidinase; Inhibitor; Isoquercitrin; Jujube leaf; β-d-Glucosidase