ABSTRACT
Application of chemometric methods in the study of the retention indices of thirteen 5-arylidene-2,4- thiazolidinediones in two low polarity high-performance thin-layer chromatographic (HPTLC) stationary phases (RP-18 and RP-CN) and six aqueous mobile phases. Principal component analysis classified chromatographic systems into four specific groups while one system remained non-classified. Hierarchical clustering analysis enabled grouping of the chromatographic systems into three clusters, and the studied compounds into three main classes. The color map enabled more in-depth interpretation of the relationships between the studied compounds and HPTLC systems applied.
Subject(s)
Chromatography, Thin Layer/methods , Thiazolidinediones/isolation & purification , Cluster Analysis , Principal Component Analysis , Thiazolidinediones/chemistryABSTRACT
The small millipede Callipodella fasciata secretes an earthy smell when disturbed. This secretion was obtained by CH(2) Cl(2) extraction from specimens of both sexes and was identified by GC/MS analyses to be composed of p-cresol (96.5%), phenol (3.5%), and p-ethylphenol (traces). This is the first identification of these compounds in an epigean European callipodidan species and the first report of intergeneric differences in the chemical composition of defensive secretions in callipodidans. These compounds have repellent, antimicrobial, and antifungal properties.
Subject(s)
Arthropods/chemistry , Cresols/isolation & purification , Phenols/isolation & purification , Animals , Anti-Infective Agents/isolation & purification , Female , Gas Chromatography-Mass Spectrometry , Insecticides/isolation & purification , MaleABSTRACT
Nine compounds were detected in three different millipede species: Polydesmus complanatus (L.), Brachydesmus (Stylobrachydesmus) avalae Curcic & Makarov, and Brachydesmus (Stylobrachydesmus) dadayi Verhoeff. Benzaldehyde, benzyl alcohol, benzoylnitrile, benzyl methyl ketone, benzoic acid, benzyl ethyl ketone, mandelonitrile, and mandelonitrile benzoate were identified by GC-FID and GC-MS analyses. Hydrogen cyanide was detected qualitatively by the picric acid test. Benzyl ethyl ketone, benzyl methyl ketone, and benzyl alcohol were detected for the first time in polydesmidan millipedes. Benzoylnitrile was the major component in all three hexane extracts. These compounds are suspected to be active in the defensive secretions of these millipede species.
Subject(s)
Arthropods/metabolism , Organic Chemicals/metabolism , Animals , Arthropods/physiology , Female , Gas Chromatography-Mass Spectrometry , Male , Organic Chemicals/analysis , Organic Chemicals/isolation & purification , Species SpecificityABSTRACT
OBJECTIVE: In this study 14 newly synthesized s-triazine derivatives were investigated by means of reversed-phase thin-layer chromatography (TLC) on C-18 stationary and five different mobile phases: acetone-water, acetonitrile-water, methanol-water, 2-propanol-water, and tetrahydrofuran-water. METHODS: Principal component analysis (PCA) was performed to explore and visualize similarities and differences among the compounds and among the mobile phases. Observations from the PCA were supported using hierarchical cluster analysis (HCA). RESULTS: Physicochemical parameters that are significant for activity, that is, absorption, distribution, and bonding for different receptors in target tissues were calculated. CONCLUSION: Highly predictive models, describing quantitative relationships between chromatographic retention and parameters that influence activity, were obtained using partial least squares (PLS) method.
