title: Synthesis and evaluation of bioactive naphthoquinones from the Brazilian medicinal plant, Tabebuia avellanedae.
abstract: A series of naphthoquinones based on the naphtho[2,3-b]furan-4,9-dione skeleton such as (-)-5-hydroxy-2-(1'-hydoxyethyl)naphtho[2,3-b]furan-4,9-dione (1) and its positional isomer, (-)-8-hydroxy-2-(1'-hydoxyethyl)naphtho[2,3-b]furan-4,9-dione (2), which are secondary metabolites found in the inner bark of Tabebuia avellanedae, were stereoselectively synthesized and their biological activities were evaluated in conjunction with those of their corresponding enantiomers. Compound 1 exhibited potent antiproliferative effect against several human tumor cell lines, but its effect against some human normal cell lines was much lower than that of mitomycin. On the other hand, its enantiomer (R)-1 was less active toward the above tumor cell lines than 1. The antiproliferative effect of 2 against all tumor cell lines was significantly reduced. These results indicated the presence of the phenolic hydroxy group at C-5 is of great important for increasing antiproliferative effect. In addition, 1 also showed higher cancer chemopreventive activity than 2, while there were no significant differences between 1 and 2 in antimicrobial activity. Both compounds displayed modest antifungal and antibacterial activity (gram-positive bacteria), whereas they were inactive against gram-negative bacteria.
authors.affiliation: Faculty of Pharmacy, Takasaki University of Health and Welfare, Nakaorui-machi, Takasaki 370-0033, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Yamashita
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kaneko
authors.forename: Harukuni
authors.initials: H
authors.lastname: Tokuda
authors.forename: Katsumi
authors.initials: K
authors.lastname: Nishimura
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kumeda
authors.forename: Akira
authors.initials: A
authors.lastname: Iida
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D005260:Female; D006801:Humans; D051379:Mice; D008826:Microbial Sensitivity Tests; D009285:Naphthoquinones / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D010946:Plants, Medicinal / Q000737:chemistry; D013237:Stereoisomerism; D029663:Tabebuia / Q000737:chemistry*
chemical_list: D000890:Anti-Infective Agents; D000972:Antineoplastic Agents, Phytogenic; D009285:Naphthoquinones