Propolis is one of the most used natural products known for centuries for its beneficial effects. Due to significant differences in chemical composition of samples originating from different geographic and climatic zones it is crucial to characterize reliably each type of propolis. This article comprises the latest findings concerning the poplar type propolis, i.e. it gives a cross section of chemical composition, botanical origin and biological activity of poplar type propolis in order to encourage further investigations that would indicate its beneficial effects.

Honey is a precious natural product that is marketed with a wide range of nutritional and medicinal properties. However, it is also a product subjected to frequent adulteration through mislabeling and mixing with cheaper and lower-quality honeys and various sugar syrups. In that sense, honey authentication regarding its genuine botanical and geographical origins, as well as the detection of any adulteration, is essential in order to protect consumer health and to avoid competition that could create a destabilized market. Various analytical techniques have been developed to detect adulterations in honey, including measuring the ratios of stable isotopes (mostly ¹³C/¹²C) and the use of different spectroscopic, chromatographic, and electrochemical methods. This review aims to provide a cross-section of contemporary analytical methods used for the determination of honey authenticity in order to help the scientific community engaged in the field of honey chemistry make appropriate choices and select the best applications that should lead to improvements in the detection and elimination of fraudulent practices in honey manufacturing.

Needs for fast, yet reliable means of assessing the lipophilicities of diverse compounds resulted in the development of various in silico and chromatographic approaches that are faster, cheaper, and greener compared to the traditional shake-flask method. However, at present no accepted "standard" approach exists for their comparison and selection of the most appropriate one(s). This is of utmost importance when it comes to the development of new lipophilicity indices, or the assessment of the lipophilicity of newly synthesized compounds. In this study, 50 well-known, diverse compounds of significant pharmaceutical and environmental importance have been selected and examined. Octanol-water partition coefficients have been measured with the shake-flask method for most of them. Their retentions have been studied in typical reversed thin-layer chromatographic systems, involving the most frequently employed stationary phases (octadecyl- and cyano-modified silica), and acetonitrile and methanol as mobile phase constituents. Twelve computationally estimated logP-s and twenty chromatographic indices together with the shake-flask octanol-water partition coefficient have been investigated with classical chemometric approaches-such as principal component analysis (PCA), hierarchical cluster analysis (HCA), Pearson's and Spearman's correlation matrices, as well as novel non-parametric methods: sum of ranking differences (SRD) and generalized pairwise correlation method (GPCM). Novel SRD and GPCM methods have been introduced based on the Comparisons with One VAriable (lipophilicity metric) at a Time (COVAT). For the visualization of COVAT results, a heatmap format was introduced. Analysis of variance (ANOVA) was applied to reveal the dominant factors between computational logPs and various chromatographic measures. In consensus-based comparisons, the shake-flask method performed the best, closely followed by computational estimates, while the chromatographic estimates often overlap with in silico assessments, mostly with methods involving octadecyl-modified silica stationary phases. The ones that employ cyano-modified silica perform generally worse. The introduction of alternative coloring schemes for the covariance matrices and SRD/GPCM heatmaps enables the discovery of intrinsic relationships among lipophilicity scales and the selection of best/worst measures. Closest to the recommended logKOW values are ClogP and the first principal component scores obtained on octadecyl-silica stationary phase in combination with methanol-water mobile phase, while the usage of slopes derived from Soczewinski-Matyisik equation should be avoided.