title: Anti-tyrosinase, antioxidant, and antibacterial activities of novel 5-hydroxy-4-acetyl-2,3-dihydronaphtho[1,2-b]furans.
abstract: Novel 5-hydroxy-4-acetyl-2,3-dihydronaphtho[1,2-b]furans (7a-k) were synthesized using ceric ammonium nitrate (CAN)-catalyzed formal [3 + 2] cycloaddition. Synthesized compounds were evaluated for their tyrosinase inhibitory, antioxidant, and antibacterial activities. A modified spectrophotometric method using l-DOPA as substrate was used to determine tyrosinase inhibitory activities, and a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay was used to evaluate antioxidant properties. Antibacterial activities against gram-negative Escherichia coli (KCTC-1924) and gram-positive Staphylococcus aureus (KCTC-1916) were evaluated using the disc diffusion technique. Of the synthesized compounds, 7b with a 4-acetyl and an electron-enriched dihydronaphthofuran ring showed the highest tyrosinase-inhibition activity (IC50 = 8.91 μg/mL), which was comparable with that of standard kojic acid (IC50 = 10.16 μg/mL), potent antioxidant activity (IC50 = 3.33 μg/mL), which was comparable with that of BHT (IC50 = 34.67 μg/mL), and excellent antibacterial activities (MICs: 0.50 μg/mL against E. coli and S. aureus strains). A mechanistic analysis of 7b demonstrated that its tyrosinase inhibitory activity was reversible and competitive. Compounds 7c and 7d showed potent antioxidant activities (IC50: 6.30 and 5.01 μg/mL), and compound 7d also exhibited potent inhibitory activity against E. coli with a MIC of 0.5 μg/mL. Furthermore, compounds 7a, 7e, 7f, and 7i showed potent antibacterial activities against S. aureus with MICs of 0.5 μg/mL, which was comparable to that of ampicillin (MIC = 0.5 μg/mL).
authors.affiliation: School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749, Republic of Korea.
authors.forename: Likai
authors.initials: L
authors.lastname: Xia
authors.affiliation: School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749, Republic of Korea.
authors.forename: Akber
authors.initials: A
authors.lastname: Idhayadhulla
authors.affiliation: School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749, Republic of Korea. Electronic address: yrlee@yu.ac.kr.
authors.forename: Yong Rok
authors.initials: YR
authors.lastname: Lee
authors.affiliation: Department of Food Science and Technology, Yeungnam University, Gyeongsan 712-749, Republic of Korea.
authors.forename: Young-Jung
authors.initials: YJ
authors.lastname: Wee
authors.affiliation: Analysis Research Division, Daegu Center, Korea Basic Science Institute, Daegu 702-701, Republic of Korea.
authors.forename: Sung Hong
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000363:Agaricales / Q000201:enzymology / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects*; D005663:Furans / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013211:Staphylococcus aureus / Q000187:drug effects*; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D004791:Enzyme Inhibitors; D005663:Furans; D014442:Monophenol Monooxygenase
keywords: Anti-tyrosinase; Antibacterial; Antioxidant; CAN; Dihydronaphtho[1,2-b]furans; Formal [3 + 2] cycloaddition