Unique Polybrominated Hydrocarbons from the Australian Endemic Red Alga Ptilonia australasica.

Abstract

The red alga Ptilonia australasica is endemic to Australian temperate waters. Chemical investigation of P. australasica led to the identification of four new polybrominated compounds, ptilones A-C (1-3) and australasol A (4). Their planar structures were established by extensive NMR and MS analyses. The low H/C ratio and the presence of a large number of heteroatoms made the structure elucidation challenging. The absolute configurations of 1, 2, and 4 were determined by quantum chemical ECD calculations employing time-dependent density functional theory. Ptilones A-C (1-3) show unique 4-ethyl-5-methylenecyclopent-2-enone (1 and 2) and 2-methyl-6-vinyl-4H-pyran-4-one (3) skeletons not previously reported in algal metabolites. Ptilone A displayed the most potent cytotoxicity against the human prostate cancer PC3 cells with an IC50 value of 0.44 μM and induced the PC3 cell cycle arrest in the G0/G1 phase.

• Authors: Trong D Tran, Ngoc B Pham, Ronald J Quinn
• Journal: Journal of natural products (J Nat Prod) Vol. 79 Issue 3 Pg. 570-7 (Mar 25 2016) ISSN: 1520-6025 [Electronic] United States
• PMID: 26904921 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents
• Hydrocarbons, Brominated
• australasol A
• ptilone A
• ptilone B
• ptilone C

Topics

• Antineoplastic Agents (chemistry, isolation & purification, pharmacology)
• Australia
• Cell Cycle
• Drug Screening Assays, Antitumor
• G1 Phase
• Humans
• Hydrocarbons, Brominated (chemistry, isolation & purification, pharmacology)
• Inhibitory Concentration 50
• Male
• Molecular Structure
• Nuclear Magnetic Resonance, Biomolecular
• Prostatic Neoplasms (drug therapy)
• Rhodophyta (chemistry)