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Four new sesquiterpenoid nitrobenzoyl esters (1–4) have been isolated from organic extracts of the culture broth and mycelia of Aspergillus versicolor, a fungus isolated from the surface of the Caribbean green alga Penicillus capitatus. The structures of the four compounds were determined through extensive analysis of 1H NMR, 13C NMR, HMQC, and HMBC data. 9α, 14-Dihydroxy-6β-p-nitrobenzoylcinnamolide (1) displayed significant cytotoxicity against HCT-116 human colon carcinoma cells in vitro and exhibited moderately selective cytotoxicity toward a panel of renal tumor cell lines.

Two new cyclic hexadepsipeptides, exumolides A ( 1 ) and B ( 2 ) were produced by a marine fungus, identified as a Scytalidium sp., collected in the Bahamas. Two dimensional NMR methods, coupled with tandem mass spectrometry (MS-MS), were used to establish the structures of the new compounds. The exumolides exhibit antimicroalgal activity against the unicellular chlorophyte Dunaliella sp. at 20 μg ml −1 in liquid media cell growth assays.

Three novel sesterterpenes, neomangicols A−C (1−3) were isolated from the mycelial extract of a marine fungus belonging within the genus Fusarium. The carbon skeleton of the neomangicols is undescribed and constitutes a new class of C25 rearranged sesterterpenes. The structures of the new metabolites were determined by 1D and 2D NMR methods, and the absolute configuration of 3 was determined by Mosher ester analysis of a diacetonide derivative. The configurations of the three stereocenters in the side-chain were assigned on the basis of molecular modeling and NOESY NMR correlations observed for several diacetonide derivatives of 3. Neomangicols A and B are cytotoxic against HCT-116 human colon carcinoma in in vitro evaluation, while neomangicol B inhibits the growth of the Gram-positive bacterium Bacillus subtilus with a potency similar to that of the antibiotic gentamycin.

[structure: see text] The stereoselectivity of N-methylputrescine (3) oxidation to pyrrolinium ion 4 in Erythroxylum coca during cocaine (1) biosynthesis was studied. The remote isotope method was used to advantage. Each enantiomer of 4-monodeuterated N-methylputrescine served as a precursor for plant feeding. To facilitate mass-spectrometric analysis of products, a 2H3 13C-methyl group was also incorporated into the 4-deuterio-N-methylputrescines. Oxidative deamination of N-methylputrescine was found to be stereoselective; the pro-S hydrogen atom is removed with 6-10:1 selectivity.

A marine fungal isolate, tentatively identified as Fusarium heterosporum, has been found to produce a series of structurally novel sesterterpene polyols, the mangicols A-G (4-10). The structures of the new compounds, including the stereochemistry of mangicol A, were assigned by interpretation of spectral data derived from both natural products and synthetic derivatives. The mangicols, which possess unprecedented spirotricyclic skeletal components, show only weak to modest cytotoxicities toward a variety of cancer cell lines in in vitro testing. Mangicols A and B, however, showed significant antiinflammatory activity in the PMA (phorbol myristate acetate)-induced mouse ear edema model. A biosynthetic pathway for the neomangicol and mangicol carbon skeletons is proposed on the basis of the incorporation of appropriate radiolabeled precursors.