title: Chemical synthesis and tyrosinase inhibitory activity of rhododendrol glycosides.
abstract: The concise synthesis of rhododendrol glycosides 3-8, which are novel derivatives of (+)-epirhododendrin (1) and (-)-rhododendrin (2), has been achieved in six steps from benzaldehyde 9. The key reactions include aldol condensation and trichloroacetimidate glycosylation. From biological studies, it has been determined that synthetic derivatives of 1 and 2 possess potent tyrosinase inhibitory activity. Particularly, the inhibitory activity of cellobioside 8 (IC50=1.51μM) is six times higher than that of kojic acid. The R-epimers (4, 6, and 8) possessed more potent activity than the corresponding S-epimers (3, 5, and 7), indicating that tyrosinase inhibitory activity is significantly governed by stereochemistry of rhododendrol glycosides.
authors: Department of Applied Life Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan.
authors: Takehiro
authors: T
authors: Iwadate
authors: Green Center, Fuji Steel Industry, Tochigi 328-0204, Japan.
authors: Yutaka
authors: Y
authors: Kashiwakura
authors: Department of Life Science, Faculty of Science, Okayama University of Science, Okayama 700-0005, Japan.
authors: Noriyoshi
authors: N
authors: Masuoka
authors: Department of Chemistry, Faculty of Education, Utsunomiya University, Tochigi 321-0943, Japan.
authors: Yoichi
authors: Y
authors: Yamada
authors: Department of Applied Life Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan; Department of Applied Biological Chemistry, Faculty of Agriculture, Utsunomiya University, Tochigi 321-0943, Japan. Electronic address: nihei98@cc.utsunomiya-u.ac.jp.
authors: Ken-Ichi
authors: K
authors: Nihei
mesh_terms: D000440:Butanols / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D006027:Glycosides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D015394:Molecular Structure; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D000440:Butanols; D004791:Enzyme Inhibitors; D006027:Glycosides; C115945:rhododendrol; D014442:Monophenol Monooxygenase
keywords: Aldol condensation; Glycosylation; Rhododendrol glycoside; Tyrosinase inhibitor