Characterization of anacardic acids by micellar electrokinetic chromatography and mass spectrometry

A possibility of using capillary electrophoresis for separation of anacardic acids (6-alkylsalicylic acids) has been studied. Conventional micellar electrokinetic chromatography (MEKC) in non-coated fused silica capillaries and reversed-flow micellar electrokinetic chromatography (RF-MEKC) in capillaries coated with polydimethylacrylamide was applied for separation of anacardic acids extracted from cashew nuts. Influence of the composition of background electrolyte on the resolution of anacardic acid isomers was evaluated. Separations were performed using sodium dodecyl sulphate (SDS) micelles and mixed micelles of SDS and polyoxyethylene lauryl ether as a pseudostationary phase. To further improve the separation in RF-MEKC, beta-cyclodextrin and a dual cyclodextrin system of beta-cyclodextrin with heptakis-6-sulphato-beta-cyclodextrin was added to the working electrolyte. Best separation of anacardic acids were achieved in the polydimethylacrylamide-coated capillary using 10 mM phosphate background electrolyte pH 6.5 with addition of 1 M urea, 20% acetonitrile, 10 mM of beta-cyclodextrin and 1 mM of heptakis-6-sulfo-beta-cyclodextrin. Mass spectrometry was used for the identification of anacardic acids in the extract from cashew nuts in single and tandem mode using Q-TOF instrument. Nine anacardic acids were identified in the extract form the cashew nuts.

6-Alkylsalicylic Acids and 6-Alkylresorcylic Acids from Ants in the Genus Crematogaster from Brunei

The defensive chemistry of two species of ants from Brunei in the genus Crematogaster (Physocrema group) has been investigated. Ants in this group release a white secretion from hypertrophied metapleural glands on their thorax when they are disturbed. Previously, one species in this group has been shown to produce alkylphenols and alkylresorcinols. In the present investigation, similar compounds along with salicylic acids and resorcylic acids that are anacardic acid and olivetolic acid homologs, respectively, are described from two species. The structures of these compounds were suggested by their spectroscopic data and confirmed by direct comparison with synthetic samples. Some of these compounds occur in lichens and have well documented physiological activities.