C18-UHPLC analysis of retention behavior of newly designed o-alkylated and rostane derivatives in ternary mixture methanol/acetonitrile/water

Different new groups of steroid compounds are the center of attention in a grate number of scientific publications since the majority of compounds are being researched as anticancer drugs. One of the most important feature of potential drug is its lipophilicity. Nowadays, ultra high-performance liquid chromatography (UHPLC) is used as one of the most sophisticated techniques for determination of the retention behavior determination of different biologically active compounds. The series of 18 newly designed O-alkylated androstane derivatives was investigated in reversed phase (RP)-UHPLC system using ternary mixture methanol/acetonitrile/water. A good agreement between experimentally observed and in silico lipophilicity was noticed given that coefficient of determination of 0.8406 was achieved

Chemometric approach to quality characterization of milk-based kombucha beverages

Mliječni kombuča napici su dobiveni fermentacijom mlijeka kombučom. Hijerarhijska klaster analiza (HCA) i analiza glavnih komponenti (PCA) primijenjene su u cilju utvrđivanja razlika između analiziranih uzoraka, kao i identifikacije sličnosti ili različitosti između njih, u prostoru eksperimentalno određenih vrijednosti varijabli. Linearna diskriminantna analiza (LDA) provedena je na neobrađenim podacima u cilju pronalaženja pravila za dodjeljivanje novog uzorka nepoznatog porijekla odgovarajućoj grupi uzoraka. Hijerarhijska klaster analiza pokazala je da je dominantan faktor razlikovanja analiziranih uzoraka kombuča napitaka sadržaj mliječne masti, a zatim slijede sadržaji ukupnih nezasićenih, jednostruko nezasićenih (MUFA) i višestruko nezasićenih (PUFA) masnih kiselina. Uzorci s 0,8 i 1,6 % mliječne masti pripadaju istom klasteru u prostoru analiziranih varijabli zbog sličnosti u njihovoj antioksidativnoj aktivnosti prema DPPH radikalu. Linearnom diskriminantnom analizom utvrđeno je da je najveća razlika u kvaliteti kada se u obzir uzmu vrijednosti pH i antioksidativna aktivnost prema DPPH radikalu između grupa proizvoda sa čajem primorskog vriska i koprivom, dok je najveća sličnost između grupa proizvoda s majčinom dušicom i paprenom metvicom.Milk-based kombucha beverages were obtained conducting kombucha lead fermentation of milk. In order to discriminate the analysed samples and to detect similarities or dissimilarities among them in the space of experimentally determined variables, hierarchical cluster analysis (HCA) and principal component analysis (PCA) were applied. Linear discriminant analysis (LDA) was conducted on the raw data set in order to find a rule for allocating a new sample of unknown origin to the correct group of samples. In the space of the variables analysed by HCA, the dominant discriminating factor for the studied samples of kombucha beverages is the milk fat (MF) content, followed by total unsaturated fatty acids content (TUFA), monounsaturated fatty acids content (MUFA) and polyunsaturated fatty acids content (PUFA). The samples with 0.8 and 1.6% milk fat belong to the same cluster in the space of the analysed variables due to similarities in their AADPPH. It was determined by LDA that there was the biggest difference in quality between the groups of products with winter savoury and stinging nettle, while the highest similarity is between groups of products with wild thyme and peppermint regarding their pH values and antioxidant activity expressed as AADPPH

Retention behavior of novel o-alkylated androstane 3-oximes IN RP(C18)-UHPLC system with methanol/water mobile phase

The retention behavior of newly synthesized O-alkylated androstane 3-oximes has been investigated applying reversed-phase ultra-high performance liquid chromatography (RPUHPLC) with octadecyl stationary phase and methanol/water mobile phase. The set of the analyzed compounds takes into account two groups of steroidal derivatives: 17α-(pyridin-2- yl)methyl and (17E)-(pyridin-2-yl)methylidene derivatives. The retention behavior of the compounds in the applied chromatographic system was determined as logarithm of the capacity factor (logk). Afterwards, the logk values were correlated with in silico lipophilicity (logP) in order to establish the quantitative structure-retention relationship (QSRR) model and to confirm that the obtained retention parameters can be considered chromatographic (anisotropic) lipophilicity parameters. The obtained QSRR model successfully correlates the logk and logP parameters (the strong correlation has been determined). Considering the lipophilicity parameters, the analyzed compounds can be considered from moderately to highly lipophilic

COMPARATIVE CHEMOMETRIC ANALYSIS, RANKING AND SELECTION OF LIPOPHILICITY PARAMETERS OF 6-CHLORO-1,3,5-TRIAZINE DERIVATIVES WITH ACYCLIC AND CYCLIC SUBSTITUENTS

In the present paper, the chemometric analysis, ranking and selection of the most suitable in silico lipophilicity parameters of eight alkyl and cycloalkyl s-triazine derivatives were carried out. The lipophilicity parameters were calculated using various computational approaches and computer programs. The conducted analysis is the basis for further studies aimed to define, compare and examine the influence of alkyl and cycloalkyl substituents, introduced in 6-chloro-1,3,5-triazine-2,4-diamine structure, on molecular lipophilicity and bioactivity. The chemometric methods used in the study are pattern recognition methods, such as hierarchical cluster analysis (HCA) and sum of ranking differences (SRD). The obtained ranking results indicate that the following in silico lipophilicity descriptors can be chosen as the most suitable for interpretation of lipophilicity of the studied series of s-triazine derivatives: AlogP, MlogP, WLOGP, logPKLOP and logPPHYS. The lipophilicity descriptor iLOGP was marked as the least suitable lipophilicity descriptor of the studied series of compounds. The ranking results were validated by 7-fold cross-validation approach and by comparison of ranks by random numbers (CRRN)

Comparative chemometric and quantitative structure-retention relationship analysis of anisotropic lipophilicity of 1-arylsuccinimide derivatives determined in high-performance thin-layer chromatography system with aprotic solvents

Numerous structurally different amides and imides including succinimide derivatives exhibit diverse bioactive potential. The development of new compounds requires rationalization in the design in or- der to provide structural changes that guarantee favorable physico-chemical properties, pharmacological activity and safety. In the present research, a comprehensive study with comparison of the chromato- graphic lipophilicity and other physico-chemical properties of five groups of 1-arylsuccinimide derivatives was conducted. The chemometric analysis of their physico-chemical properties was carried out by us- ing unsupervised (hierarchical cluster analysis and principal component analysis) and supervised pattern recognition methods (linear discriminant analysis), while the correlations between the in silico molecular features and chromatographic lipophilicity were examined applying linear and non-linear Quantitative Structure–Retention Relationship (QSRR) approaches. The main aim of the conducted research was to determine similarities and dissimilarities among the studied 1-arylsuccinimides, to point out the molec- ular features which have significant influence on their lipophilicity, as well as to establish high-quality QSRR models which can be used in prediction of chromatographic lipophilicity of structurally similar 1-arylsuccinimides. This study is a continuation of analysis and determination of the physico-chemical properties of 1-arylsuccinimides which could be important guidelines in further in vitro and eventually in vivo studies of their biological potential