The preparation of zaragozic acid A analogues by directed biosynthesis.

Zaragozic acid A analogues are produced by an unidentified sterile fungus when it is exogenously supplied with 2-thiophenecarboxylic acid, 3-thiophenecarboxylic acid, 2-furoic acid, 2-fluorobenzoic acid, 3-fluorobenzoic acid, or 4-fluorobenzoic acid. The analogues carry 2-thiophenyl, 3-thiophenyl, 2-furyl, o-fluorophenyl, m-fluorophenyl, or p-fluorophenyl group, respectively, at C-6' of the C-1 alkyl side chain replacing the phenyl group of natural zaragozic acid A. All the new analogues of zaragozic acid A possess picomolar inhibitory activity against squalene synthase in vitro.

Caste-specific compounds in male carpenter ants.

Three caste-specific substances new to arthropod glandular secretions occur in the mandibular glands of male ants of five species in the genus Camponotus. These volatile compounds, which are not found in alate females or workers, have been identified as methyl 6-methyl salicylate, 2,4-dimethyl-2-hexenoic acid, and methyl anthranilate. The free acid has not been described previously.

Antibacterial activity of venom alkaloids from the imported fire ant, Solenopsis invicta Buren.

The antibacterial properties of synthetic fire ant venom alkaloids were tested by disc-diffusion procedures against a variety of bacteria and by doubling concentrations in broth cultures of Staphylococcus aureus and Escherichia coli. Gram-positive bacteria were inhibited by lower concentrations of trans-2-methyl-6-n-undecylpiperidine, trans-2-methyl-6-n-tridecylpiperidine, and trans-2-methyl-6-n-pentadecylpiperidine than were gram-negative bacteria. A fourth alkaloid, trans-2-methyl-6-(cis-6-pentadecenyl)piperidine, which was available in minute quantity and was tested by disc-diffusion only, was ineffective against all organisms.

Alkaloid from fire ant venom: identification and synthesis.

An alkaloid, trans-2-methyl-6-n-undecylpiperidine (solenopsin A), has been isolated from the venom of the fire ant Solenopsis saevissima. The structure has been confirmed by an unambiguous synthesis.