Pyrroloacridine alkaloids from Plakortis quasiamphiaster: structures and bioactivity.
A re-collection of Plakortis quasiamphiaster from Vanuatu in 2003 resulted in the isolation of three known compounds, plakinidine A (1) and amphiasterins B1 (6) and B2 (7). Also isolated was a new bis-oxygenated pyrroloacridine alkaloid, plakinidine E (8), with a unique O-substitution versus N-substitution at position C-12 in 1. The biological evaluation of the active compounds in two assays provided complementary data. Plakinidine A (1) exhibited cytotoxicity against human colon H-116 cells with an IC50 of 0.23 microg/mL, but there were no effects against the yeast Saccharomyces cerevisiae diploid homozygous deletion strain of topoisomerase I (top1Delta). By contrast, 8 was inactive against H-116 cells but was potent in the yeast halo screen.
Ralifo
Paul
P
Department of Chemistry and Biochemistry, Institute of Marine Sciences, University of California, Santa Cruz, California 95064, USA.
Sanchez
Laura
L
Gassner
Nadine C
NC
Tenney
Karen
K
Lokey
R Scott
RS
Holman
Theodore R
TR
Valeriote
Frederick A
FA
Crews
Phillip
P
D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D047229:Plakortis / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000187:drug effects; D009514:Vanuatu
D000470:Alkaloids; D000970:Antineoplastic Agents