title: Polyoxygenated diterpenes from the sponge Phorbas sp.
abstract: Ten new polyoxygenated diterpenes (7-16) along with six known gagunin compounds (1-6) were isolated from the sponge Phorbas sp. collected in the Korean Sea. On the basis of a combination of NMR and mass spectroscopic analyses, the molecular structures of these diterpenes, designated as gagunins H-Q, were determined to be penta- or hexa-oxygenated diterpenes of the 10,13-bis-epi-homoverrucosane class. A new diterpene acid (17) of a bisabolane-related skeletal class was also isolated and structurally defined by the spectroscopic analyses. These compounds exhibited moderate to significant cytotoxicity against the K-562 cell line as well as weak inhibitory activity against isocitrate lyase (ICL).
authors.affiliation: Natural Products Research Institute, College of Pharmacy, Seoul National University, San 56-1, Shilim, Kwanak, Seoul 151-742, Korea.
authors.forename: Kyoung Hwa
authors.initials: KH
authors.lastname: Jang
authors.forename: Ju-eun
authors.initials: JE
authors.lastname: Jeon
authors.forename: Sungkwang
authors.initials: S
authors.lastname: Ryu
authors.forename: Hyi-Seung
authors.initials: HS
authors.lastname: Lee
authors.forename: Ki-Bong
authors.initials: KB
authors.lastname: Oh
authors.forename: Jongheon
authors.initials: J
authors.lastname: Shin
mesh_terms: D000818:Animals; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007522:Isocitrate Lyase / Q000037:antagonists & inhibitors; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010100:Oxygen / Q000737:chemistry*; D011161:Porifera / Q000737:chemistry*
chemical_list: D004224:Diterpenes; D007522:Isocitrate Lyase; D010100:Oxygen