title: Synthesis and biological evaluation of a novel baicalein glycoside as an anti-inflammatory agent.
abstract: Baicalein-6-α-glucoside (BG), a glycosylated derivative of baicalein, was synthesized by using sucrose and the amylosucrase of Deinococcus geothermalis and tested for its solubility, chemical stability, and anti-inflammatory activity. BG was 26.3 times more soluble than baicalein and highly stable in buffered solutions and Dulbecco׳s modified Eagle medium containing 10% fetal bovine serum. BG treatment decreased the production of nitric oxide in RAW 264.7 cells treated with lipopolysaccharide (LPS). Luciferase reporter assays, western blots, reverse transcription-polymerase chain reaction, and flow cytometric analyses indicated that BG activated nuclear factor erythroid 2-related factor 2 (Nrf2), an antioxidant transcription factor that confers protection from various inflammatory diseases, induced Nrf2-dependent gene expression, and suppressed the production of reactive oxygen species elicited by LPS more effectively than baicalein. Cellular uptake of BG assessed by confocal microscopy and HPLC analysis of the cell-free extracts of RAW 264.7 cells demonstrated that BG was gradually converted to baicalein inside the cells. These results explain that glycosylation increased the bioavailability of baicalein by helping to protect this vital molecule from chemical or enzymatic oxidation. Therefore, BG, a glycosylated derivative of baicalein, can be an alternative to baicalein as a therapeutic drug.
authors.affiliation: School of Korean Medicine, Pusan National University, Yangsan 626-870, Republic of Korea.
authors.forename: Kyun Ha
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Microbiology, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Young-Don
authors.initials: YD
authors.lastname: Park
authors.affiliation: Department of Microbiology, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Heejin
authors.initials: H
authors.lastname: Park
authors.affiliation: Department of Microbiology, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Keum-Ok
authors.initials: KO
authors.lastname: Moon
authors.affiliation: School of Korean Medicine, Pusan National University, Yangsan 626-870, Republic of Korea.
authors.forename: Ki-Tae
authors.initials: KT
authors.lastname: Ha
authors.affiliation: Graduate School of Biotechnology and Institute of Life Sciences & Resources, Kyung Hee University, Yongin 446-701, Republic of Korea.
authors.forename: Nam-In
authors.initials: NI
authors.lastname: Baek
authors.affiliation: Graduate School of Biotechnology and Institute of Life Sciences & Resources, Kyung Hee University, Yongin 446-701, Republic of Korea.
authors.forename: Cheon-Seok
authors.initials: CS
authors.lastname: Park
authors.affiliation: School of Korean Medicine, Pusan National University, Yangsan 626-870, Republic of Korea. Electronic address: mjoo@pusan.ac.kr.
authors.forename: Myungsoo
authors.initials: M
authors.lastname: Joo
authors.affiliation: Department of Microbiology, Pusan National University, Busan 609-735, Republic of Korea. Electronic address: jhcha@pusan.ac.kr.
authors.forename: Jaeho
authors.initials: J
authors.lastname: Cha
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry* / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology; D002460:Cell Line; D044950:Flavanones / Q000737:chemistry* / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D006027:Glycosides / Q000737:chemistry* / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D044950:Flavanones; D006027:Glycosides; D008070:Lipopolysaccharides; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; C006680:baicalein
keywords: Amylosucrase; Anti-inflammation; Baicalein; Baicalein (PubChem CID: 5281605); Baicalin (PubChem CID: 64982); Glycoside; Nrf2; Transglycosylation