Application of chemometrics for identification of chemical constituents of essential oils of importance for biological activities of selected aromatic lamiaceae species

Essential oils (EOs) extracted from natural products are made up of large number of chemical constituents. Being natural mixtures of very complex nature, essential oils may consist of about 20-60 components at quite different concentrations. Essential oils are characterized by two or three major components being present at fairly high concentrations (20-70%) in comparison to other components that are present in trace amounts. From that reason one plant can provide a pool of chemical ingredients that cause a whole range of activities. The present paper analyzes the activities in the space of the chemical constituents of EOs of 7 medicinal plants from Lamiaceae family known as peppermint, oregano, thyme, rosemary, sage, basil and lemon balm. The hierarchical clustering analysis (HCA) was applied to explore the similarities and dissimilarities between the 7 Lamiaceae herbs, and chemical constituents of their EOs together with their antioxidant and antibacterial activity. More in-depth examination of the data was achieved by color map. HCA indicated the uniqueness of each essential oil considered. The high content of certain compounds, as well as the unique presence of other chemical constituents were identified for each EO. HCA grouped the studied EOs into two clusters: one with peppermint, oregano and thyme, and the other with rosemary and sage, while basil and lemon balm were non-clustered

Correlation between retention constants obtained in reversed-phase liquid chromatography and partition coefficients of some benzimidazole derivatives

Several calculation procedures for log P values based on the fragmental and atomic contributions are compared with experimental reversed-phase liquid chromatography (RPLC) retention constants of benzimidazole derivatives. The RPLC experiments were performed on HPLC comerrcially available LiChrosorb RP(-18 column with binary solvent mixtures of methanol-phosphate buffer (pH 7) as mobile phase. Retention constant log k0 was determined by the extrapolation method. Good correlaton was found between the retention constants log k0 and log P, as well as m and log P of the compounds investigated

Chemometric analysis of lipophilicity parameters of newly synthesized spiro hydantoin derivatives determined by RP-TLC and protic solvents

Predmet ovog rada je ispitivanje lipofilnosti novosintetisanih derivata cikloalkilspiro-5-hidantoina. Parametri lipofilnosti (RM0) za ispitivana jedinjenja dobijeni su primenom reversno fazne hromatografije na tankom sloju C-18 modifikovanog slikagela. Kao pokretne faze korišćene su dvokomponentne smeše vode i protičnih organskih rastvarača (metanola, etanola, n-propanola, i-propanola i t-butanola). Linearna zavisnost između RM vrednosti i zapreminskog udela organskog modifikatora u pokretnoj fazi, φ, omogućava izračunavanje RM0 ispitivanih jedinjenja. Uticaj supstituenata, kao modifikatora pokretne faze na RM0 vrednosti procenjen je primenom hemometrijskih metoda, hijerarhijske kalster analize (HCA) i analize glavnih komponenata (PCA). Ove metode omogućavaju grupisanje ispitivanih derivata spirohidantoina, kao i primenjenih pokretnih faza prema njihovoj polarnosti.The subjects of this paper are newly synthesized derivatives of cycloalkylspiro-5- hydantoins and the analysis of their lipophilicity. The parameters of lipophilicity (RM0) were determined by reverse phase thin layer chromatography on C-18 modified silica gel. Mobile phases were two-component mixtures of water and protic organic solvents (i.e. methanol, ethanol, n-propanol, i-propanol and t-butanol). Linear relationship between RM values and volume fraction of organic solvent, φ, allows calculation of RM0 for investigated compounds. The effect of the substituents in the molecule as well as mobile phase modifier on RM0 value was assessed using chemometric methods, hierarchical cluster analysis (HCA) and principal component analysis (PCA). This allows clustering of spiro hydantoin derivatives as well as applied mobile phases according to their polarity