Sulfate turpentine: a resource of tick repellent compounds.

Compounds with tick (Ixodes ricinus) repellent properties were isolated from sulfate turpentine consisting of Norway spruce (80%) and Scots pine (20%) from southern Sweden. The turpentine was divided into two fractions by distillation under reduced pressure resulting in one monoterpene hydrocarbon fraction and a residual containing higher boiling terpenoids. The monoterpene fraction was further oxidized with SeO to obtain oxygenated monoterpenes with potential tick repellent properties.

N-1-Alkyl-2-oxo-2-aryl amides as novel antagonists of the TRPA1 receptor.

A series of potent antagonists of the ion channel transient receptor potential A1 (TRPA1) was developed by modifying lead structure 16 that was discovered by high-throughput screening. Based on lead compound 16, a SAR was established, showing a narrow region at the nitro-aromatic R(1) moiety and at the warhead, while the R(2) side had a much wider scope including ureas and carbamates. Compound 16 inhibits Ca(2+)-activated TRPA1 currents reversibly in whole cell patch clamp experiments, indicating that under in vivo conditions, it does not react covalently, despite its potentially electrophilic ketone.

Benzyl isothiocyanate, a major component from the roots of Salvadora persica is highly active against Gram-negative bacteria.

Plants produce a number of antimicrobial substances and the roots of the shrub Salvadora persica have been demonstrated to possess antimicrobial activity. Sticks from the roots of S. persica, Miswak sticks, have been used for centuries as a traditional method of cleaning teeth.

Syntheses, characterizations, and biological activities of tetradeca-4,8-dien-1-yl acetates as sex attractants of leaf-mining moth of the genus Phyllonorycter (Lepidoptera: Gracillariidae).

The four possible isomers of tetradeca-4,8-dien-1-yl acetate and corresponding alcohols were synthesized stereoselectively by synthetic routes employing Wittig coupling reaction for the preparation of (Z,E)- and (Z,Z)-isomers, and alkylation of terminal alkynes for the preparation of (E,E)- and (E,Z)-isomers as the key steps. Synthetic products were characterized by 13C- and 1H-NMR spectroscopy as well as mass-spectrometric methods. All four isomers gave distinctive mass spectra where m/z 81 fragments clearly dominated.

Simplified isolation procedure and interconversion of the diastereomers of nepetalactone and nepetalactol.

Three nepetalactones were isolated from Nepeta racemosa (mussinii) by traditional methods. An improved method was developed to isolate nepetalactones from N. faassénii.

Electrophysiological studies and identification of possible sex pheromone components of Brazilian populations of the sugarcane borer, Diatraea saccharalis.

Virgin female gland extracts of sugarcane moth Diatraea saccharalis (Fabricius) (Lepidoptera: Pyralidae), from three locations in Brazil, have been analyzed. By GC-MS analysis and comparison of the chromatographic retention time of the components of the pheromone gland with those retention times of synthetic standards, we observed the presence of (Z)-hexadec-11-enal (1), hexadecanal (2), (9E,11Z)-hexadecadienal (4), (9Z,11Z)-hexadecadienal (5) and (9E,11E)-hexadecadienal (6), as minor components besides the major constituent (9Z,11E)-hexadecadienal (3) already reported. We found no variations in the composition of the gland extracts deriving from the three Brazilian populations and only two compounds, (Z)-hexadec-11-enal (1) and (9Z,11E)-hexadecadienal (3), elicited antennal responses (GC-EAD).

Identification, syntheses, and characterization of the geometric isomers of 9,11-hexadecadienal from female pheromone glands of the sugar cane borer Diatraea saccharalis.

Chemical analysis of the pheromone glands of the sugar cane borer Diatraea saccharalis has shown the presence of the four geometric isomers of 9,11-hexadecadienal (1-4), in addition to hexadecanal and (Z)-hexadec-11-enal. We here report the syntheses and characterization of compounds 1-4. One starting material, 9-decen-1-ol, has been used to obtain all of them via divergent synthetic routes.