title: Novel diterpenes with cytotoxic, anti-malarial and anti-tuberculosis activities from a brown alga Dictyota sp.
abstract: Two new diterpenes, (1E,2R*,3R*,4S*,6E,18S*)-4,18-dihydroxydictyolactone (1) and 8alpha,11-dihydroxypachydictyol A (2), together with fucoxanthin (3) and a known diterpene 4alpha-hydroxycrenulatane (4) were isolated from the methanol extract of the brown alga Dictyota sp. collected from Bangsaen Beach, Thailand. Their structures were determined by spectroscopic data. The relative stereochemistry of 1 was established by NOE difference and NOESY experiments. Compound 1 showed weak anti-tuberculosis activity while 2 displayed strong cytotoxicity against the NCI-H187 cell line, and potent anti-malarial activity. In addition, 3 was active against HSV-1 and malarial parasites.
authors.affiliation: Department of Chemistry, Faculty of Science, Burapha University, Bangsaen, Chonburi, Thailand. jongkoln@buu.ac.th
authors.forename: J
authors.initials: J
authors.lastname: Jongaramruong
authors.forename: N
authors.initials: N
authors.lastname: Kongkam
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D000995:Antitubercular Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D000459:Phaeophyceae / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000962:Antimalarials; D000995:Antitubercular Agents; D004224:Diterpenes