title: Inhibition of HIV-1 reverse transcriptase and protease by phlorotannins from the brown alga Ecklonia cava.
abstract: The bioassay-directed isolation of a marine brown alga, Ecklonia cava, afforded four phlorotannin derivatives, eckol (1), 8,8'-bieckol (2), 8,4"'-dieckol (3), and phlorofucofuroeckol A (4). Among these compounds, 2 and 3 exhibited an inhibitory effect on human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) and protease. Specifically, they inhibited the RT more potently than the protease. The inhibitory activity of compound 2 (IC(50), 0.51 microM) against HIV-1 RT was comparable to that of nevirapine (IC(50), 0.28 microM), a reference compound. An enzyme kinetic assay showed that this compound inhibited the RNA-dependent DNA synthesis activity of HIV-1 RT noncompetitively against dUTP/dTTP with a K(i) value of 0.78 microM. With respect to the homopolymeric template/primer, (rA)n(dT)15, 8,8'-bieckol (2) displayed an uncompetitive type of inhibition (K(i), 0.23 microM).
authors.affiliation: College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-752, Korea.
authors.forename: Mi-Jeong
authors.initials: MJ
authors.lastname: Ahn
authors.forename: Kee-Dong
authors.initials: KD
authors.lastname: Yoon
authors.forename: So-Young
authors.initials: SY
authors.lastname: Min
authors.forename: Ji Suk
authors.initials: JS
authors.lastname: Lee
authors.forename: Jeong Ha
authors.initials: JH
authors.lastname: Kim
authors.forename: Tae Gyun
authors.initials: TG
authors.lastname: Kim
authors.forename: Seung Hee
authors.initials: SH
authors.lastname: Kim
authors.forename: Nam-Gil
authors.initials: NG
authors.lastname: Kim
authors.forename: Hoon
authors.initials: H
authors.lastname: Huh
authors.forename: Jinwoong
authors.initials: J
authors.lastname: Kim
mesh_terms: D016333:HIV Protease / Q000737:chemistry*; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors* / Q000737:chemistry; D000459:Phaeophyceae / Q000737:chemistry*; D011480:Protease Inhibitors / Q000737:chemistry*; D012194:RNA-Directed DNA Polymerase / Q000302:isolation & purification; D018894:Reverse Transcriptase Inhibitors / Q000737:chemistry*; D013634:Tannins / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D011480:Protease Inhibitors; D018894:Reverse Transcriptase Inhibitors; D013634:Tannins; D054303:HIV Reverse Transcriptase; D012194:RNA-Directed DNA Polymerase; D016333:HIV Protease