title: Polyketides from the cultured lichen mycobiont of a Vietnamese Pyrenula sp.
abstract: A spore-derived mycobiont of a crustose Pyrenula sp. lichen collected in Vietnam was cultivated on a malt-yeast extract medium supplemented with 10% sucrose. Chemical investigation of the cultivated colonies led to the isolation of eight new alkylated decalin-type polyketides (1-8) along with three known compounds. The structures of these compounds were elucidated by spectroscopic and chemical means. This is the first instance of this type of polyketide being isolated from a cultured lichen mycobiont. The isolated polyketides 1 and 7 exhibited inhibitory activities against mammalian DNA polymerases α and β with IC50 values ranging from 8.1 to 19.5 μM. Compound 1 showed cytotoxic effects against the HCT116 human colon carcinoma cultured cell line with an IC50 value of 6.4 ± 0.7 μM.
authors.affiliation: Kobe Pharmaceutical University , Kobe 658-8558, Japan.
authors.forename: Duy Hoang
authors.initials: DH
authors.lastname: Le
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Takenaka
authors.forename: Nobuo
authors.initials: N
authors.lastname: Hamada
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Mizushina
authors.forename: Takao
authors.initials: T
authors.lastname: Tanahashi
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004256:DNA Polymerase I / Q000037:antagonists & inhibitors; D019951:DNA Polymerase beta / Q000037:antagonists & inhibitors; D004354:Drug Screening Assays, Antitumor; D045325:HCT116 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D008011:Lichens / Q000737:chemistry*; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry; D024301:Plant Bark / Q000737:chemistry; D061065:Polyketides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D014744:Vietnam
chemical_list: D000970:Antineoplastic Agents; D009281:Naphthalenes; D061065:Polyketides; C000590857:pyrenulic acid A; C000590858:pyrenulic acid G; C007229:decalin; D004256:DNA Polymerase I; D019951:DNA Polymerase beta