The isolation and structure elucidation of three new secondary metabolites, chaetoglobosin-510 (1), -540 (2), and -542 (3), are described. These compounds were produced by cultures of the marine-derived fungus Phomopsis asparagi, challenged with the known F-actin inhibitor jasplakinolide. Chaetoglobosin-542 (3) displayed antimicrofilament activity and was cytotoxic toward murine colon and leukemia cancer cell lines.

Extracts of the fruit of Clusia havetiodes var. stenocarpa have yielded three new prenylated benzophenone derivatives, 28,29-epoxyplukenetione A (1), 33-hydroperoxyisoplukenetione C (2), and 15,16-dihydro-16-hydroperoxyplukenetione F (3), as well as four which have been previously described, plukenetiones C, F, and G and sampsonione G.

Antibiotics are the primary drugs for combating Neisseria gonorrhoeae infections, but with evolving antibiotic resistance of this bacterium, new druggable molecules are needed to stem the tide of this impending public health crisis. Propolis has long been recognized for its antimicrobial properties, being composed of secondary metabolites with antibacterial potential. We herein describe the evaluation of a Jamaican multifloral propolis for antibacterial activity against N. gonorrhoeae. The bioassay-guided evaluation of the ethyl acetate extract yielded (+)-medicarpin ( 1 ), whose final structure was elucidated based on spectral analysis and comparison with the known metabolites. Compound ( 1 ) selectively inhibited N. gonorrhoeae with a minimum inhibitory concentration value of 0.25 mg/mL, showing an additive effect against N. gonorrhoeae when combined with vancomycin.

Dedicated to Prof. Wilfred R. Chan for his inspiration and dedication to natural products chemistry. The roots of Hypericum hypericoides (Clusiaceae) have yielded five prenylated benzophenone derivatives. Three of these are new: 18-hydroxy-7-epi-clusianone, 18-hydroxyclusianone, isolated as the acetate, and 18-hydroxyhyperibone K. The known compounds obtained were 7-epi-clusianone and clusianone.

The absolute configuration of 3-benzoyl-4-hy­droxy-6,6-dimethyl-1,5,7-tris­(3-methyl­but-2-en­yl)bicyclo­[3.3.1]non-3-ene-2,9-dione, C33H42O4, isolated from Hypericum hypericoides, has been determined. The previous study [Xiao et al. (2007 ▶). J. Nat. Prod. 70, 1779–1782] gave only the established relative configuration. The three stereogenic centers are now established as 1R, 5R and 7S on the basis of the refinement of the Flack absolute structure parameter against Cu Kα data and correspond to a specific rotation of [α]D 20 = +66°. The enol–hy­droxy group forms an intra­molecular O—H⋯O hydrogen bond to close an S(6) ring.

Biopesticides are generally considered a safer and more environmentally friendly alternative to conventional pesticides. Plant metabolites display a range of pest specific activity ranging from antimicrobial to larvicidal and nematocidal. We herein describe the evaluation of a Guyanese collection of Vismia guianensis (Clusiaceae) for anthelmintic activity. The bioassay-guided evaluation of the hexane extract yielded the new prenylated benzophenone 8,9-epoxyvismiaphenone F (1). The final structures were elucidated based on spectral analysis and comparison to the known metabolite. To evaluate the anthelmintic efficacy of these compounds, Caenorhabditis elegans were exposed to the compounds via a ring assay model. Post-exposure, the numbers of live C. elegans in the compound (middle), bacteria ring were recorded for 3 d, as well as the total number of live worms for each plate. Compound 1 reduced C. elegans’ overall growth and reproduction, suggesting that these prenylated benzophenones may hold some promise as natural pesticides.

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