Seven new compounds (1-6 and 10) with a unique carbon skeleton have been isolated from the sponge Hamigera tarangaensis, and the structure of a previously reported metabolite has been revised from 12 to 8. The structures have been assigned from extensive NMR examination. Compounds 3-6 showed moderate in-vitro cytotoxicity against P-388, while 3 showed 100% in-vitro virus inhibition against both the Herpes and Polio viruses, with only slight cytotoxicity.

The sponge Hamigera tarangaensis has yielded eight new compounds and we report here the structure of one of these compounds, hamigeran A, C(20)H(25)BrO(5), or methyl 7-bromo-4beta,6-dihydroxy-1beta-isopropyl-3aalpha,8-dimethyl-5-oxo-1a,3a,4,5-tetrahydrocyclopenta[a]naphthalene-4-carboxylate, and the decomposition product of hamigeran D, C(21)H(28)BrNO(4), namely 2-(8-bromo-2beta,7-dimethyl-4-oxo-1,3alpha-benzoxazan-5-yl)-3-isopropylcyclopentylacetic acid.

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Floribundal (1), the first example of a nonglycosidic bisiridoid has been isolated from the heartwood of Scaevola floribunda and its structure and relative stereochemistry determined by NMR spectroscopy and molecular modeling. The aglycon 2 of loganin was also isolated. A mixture of six novel δ-amyrin fatty esters with C20−C30 acid moieties (7−12) were isolated from the bark of S. floribunda and their structures elucidated by NMR and HRMS of the parent compounds and their hydrolysis products. The bark also contains the triterpenes δ-amyrin (13) and δ-amyrin acetate (14), and ursolic acid acetate, betulinic acid, and betulin.