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A new bromotyrosine-derived alkaloid, (+)-aplysinillin (1), together with seven known compounds, was isolated from the crude organic extract of the marine sponge Aplysinella sp. collected from the Federated States of Micronesia. The structure of 1 was deduced by NMR and mass spectral techniques. Compounds 1-8 were evaluated for their inhibitory activity with the hyphae formation inhibition assay in Streptomyces 85E. Compounds 1 and 8 exhibited antiproliferative activities against the human breast adenocarcinoma cancer cell line MCF-7.

A novel screening method for antimycobacterial agents using Mycobacterium marinum was developed. M. marinum was selected as a model organism because it has a close phylogenetic relationship to M. tuberculosis, a relatively rapid doubling time, similar drug susceptibilities to M. tuberculosis, and less stringent safety requirements. More than 1000 crude marine and plant extracts were screened against M. marinum in a Zone of Inhibition (ZOI) assay, and twenty-one target extracts were identified. The crude organic extract of the marine sponge, Haliclona sp.10, was chosen for further investigation as it yielded a ZOI of 20 mm at a concentration of 80 microg/disk. Following bioassay-guided fractionation, (-)-papuamine was isolated, and yielded a 15 mm ZOI at a concentration of 25 microg/disk. In standard assays using M. marinum, (-)-papuamine exhibited both an MIC and an MBC95 of 6.25 microg/mL. This is the first report of antimycobacterial activity for (-)-papuamine. In addition, when (-)-papuamine and other natural product extracts were tested for activity against both M. marinum and M. tuberculosis, activity was comparable between the two species. These data indicate that (-)-papuamine is a promising lead for the development of new antimycobacterial agents and that M. marinum is a useful surrogate for the screening of antimycobacterial compounds.

A new dolabellane diterpenoid, 7(S)-hydroperoxy-13-keto-(1S,11R)-dolabella-3(E),8(17),12(18)-triene (1), and two known compounds, 7(S),8(S)epoxy-13-keto-1(S),11(R)-dolabella-3(E),12 (18)-diene (2) and 13-keto-1(S),11(R)-dolabella-3(E),7(E),12(18)-triene (3), were isolated from the marine sponge Eunicea calyculata. The structure of 1 was elucidated by 1D (1)H- and (13)C-NMR spectra and 2D HMQC, HMBC, and the relative stereochemistry was established by analysis of coupling constants and NOESY spectra. In addition, an X-ray crystallographic analysis on a single crystal of 2 was carried out. Compounds 1 and 2 were inactive in the hyphae formation inhibition assay (HFI) in Streptomyces 85E while compound 3 showed inhibitory activity at a concentration of 20 microg/20 microL in the HFI assay.

A new quassinoid, yadanziolide S (1), was isolated from the seeds of the traditional Chinese medicinal herb, Brucea javanica, along with ten known compounds, flazin, bruceine D, yadanziolide B, bruceoside A, yadanziolide S, yadanzigan, glycerol 1,3-bisoleate, azelaic acid, (+/-)-8-hydroxyhexadecanoic acid, and vanillin. Compound 1 is the first quassinoid to have been isolated from B. javanica without a methyleneoxy bridge between C-8 and C-13, and its structure was determined using spectroscopic methods, and confirmed by single-crystal X-ray diffraction. All isolates were evaluated for their potential to induce human promyelocytic leukemia (HL-60) cell differentiation, and to inhibit cyclooxygenase-1 (COX-1), -2 (COX-2), and 7,12-dimethylbenz[a]anthracene (DMBA)-induced lesions in a mouse mammary organ culture model.