Green Gold from Down Under

Bioprospecting for Phytopharmaceuticals

from Tropical North Queensland, Australia

Australia has a unique and distinctive flora. A long period of isolation has led to a high proportion of endemic species and genera. Our research has concentrated on the rainforests of the wet tropics of north-eastern Queensland. This region, stretching from Townsville north to Cooktown, contains the largest area of extant rainforest in Australia and consists of coastal plains as well as several mountain ranges and tablelands.

Daintree River, far north Queensland	Daintree National Park, far north Queensland
Paluma Rainforest	Iron Range National Park, Cape York Penninsula

Some recent publications describing our work in north Queensland:

Setzer, W.N., M.C. Setzer, R.B. Bates, P. Nakkiew, B.R. Jackes, L. Chen, M.B. McFerrin, and E.J. Meehan. 1999. Antibacterial Hydroxycinnamyl Esters from Piper caninum from Paluma, North Queensland, Australia. The Crystal and Molecular Structure of (+)-Bornyl Coumarate. Planta Medica 65: 747-749.

The crude chloroform bark extract of Piper caninum (Piperaceae) exhibits antibacterial activity against the Gram-positive bacteria, Bacillus cereus, Staphylococcus aureus, and Streptococcus pneumoniae. The antibacterial agents in this extract have been isolated using bioactivity-directed chromatographic techniques and identified by NMR spectroscopy as (+)-bornyl p-coumarate and bornyl caffeate. A single-crystal X-ray structure has been carried out on (+)-bornyl p-coumarate. The compound crystallizes in the orthorhombic space group P2₁2₁2₁ (#19) with a = 12.659(4), b = 13.281(4), and c = 10.177(3) Å. Full-matrix least-squares refinement converged at R = 0.047, and R_w = 0.058.

Piper caninum	Bornyl coumarate

Setzer, W.N., M.C. Setzer, R.B. Bates, and B.R. Jackes. 2000. Biologically Active Triterpenoids of Syncarpia glomulifera Bark Extract from Paluma, North Queensland, Australia. Planta Medica 66: 176-177.

The crude chloroform bark extract of Syncarpia glomulifera (Myrtaceae) shows antibacterial and cytotoxic activity. Bioactivity-directed separation led to the isolation of oleanolic acid-3-acetate, ursolic acid-3-acetate and betulinic acid. The relatively large abundance (10% of the crude extract) and high degree of activity of betulinic acid are responsible for the bioactivity of the crude bark extract.

Syncarpia glomulifera	Betulinic acid

The crude dichloromethane bark extract of Pilidiostigma tropicum (Myrtaceae) from north Queensland, Australia, shows antibacterial and cytotoxic activity. Bioactivity-directed separation led to the isolation of rhodomyrtoxin B and ursolic acid-3-p-coumarate as the biologically active materials. The structures of these compounds were elucidated on the basis of spectral analysis.

Pilidiostigma tropicum	Rhodomyrtoxin B

Setzer, W.N., M.C. Setzer, R.L. Peppers, M.B. McFerrin, E.J. Meehan, L. Chen, R.B. Bates, P. Nakkiew, and B.R. Jackes. Triterpenoid Constituents in the Bark of Balanops australiana from Paluma, North Queensland, Australia. Submitted.

Two new triterpenoid natural products (friedelane-3a,21a-diol and friedelane-3a,28,29-triol) have been isolated from the chloroform bark extract of Balanops australiana from Paluma, north Queensland, Australia. The known triterpenoids betulinic acid, friedelin, canophyllol, zeylanol, and 21a-hydroxyfriedelan-3-one, were also isolated. The structures of the compounds were elucidated on the basis of spectral analysis. A single-crystal X-ray structural analysis has been carried out on 21a-hydroxyfriedelan-3-one.

Balanops australiana	21a-hydroxyfriedelan-3-one

Related Web Pages:

Cooperative Research Centre for Tropical Rainforest Ecology and Management

Department of Tropical Plant Science, James Cook University of North Queensland

Australian Floral Biodiversity

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August, 2000