Improving the Selectivity of the C-C Coupled Product Electrosynthesis by Using Molecularly Imprinted Polymer─An Enhanced Route from Phenol to Biphenol.

We developed a procedure for selective 2,4-dimethylphenol, DMPh, direct electro-oxidation to 3,3',5,5'-tetramethyl-2,2'-biphenol, TMBh, a C-C coupled product. For that, we used an electrode coated with a product-selective molecularly imprinted polymer (MIP). The procedure is reasonably selective toward TMBh without requiring harmful additives or elevated temperatures. The TMBh product itself was used as a template for imprinting. We followed the template interaction with various functional monomers (FMs) using density functional theory (DFT) simulations to select optimal FM. On this basis, we used a prepolymerization complex of TMBh with carboxyl-containing FM at a 1:2 TMBh-to-FM molar ratio for MIP fabrication. The template-FM interaction was also followed by using different spectroscopic techniques. Then, we prepared the MIP on the electrode surface in the form of a thin film by the potentiodynamic electropolymerization of the chosen complex and extracted the template. Afterward, we characterized the fabricated films by using electrochemistry, FTIR spectroscopy, and AFM, elucidating their composition and morphology. Ultimately, the DMPh electro-oxidation was performed on the MIP film-coated electrode to obtain the desired TMBh product. The electrosynthesis selectivity was much higher at the electrode coated with MIP film in comparison with the reference nonimprinted polymer (NIP) film-coated or bare electrodes, reaching 39% under optimized conditions. MIP film thickness and electrosynthesis parameters significantly affected the electrosynthesis yield and selectivity. At thicker films, the yield was higher at the expense of selectivity, while the electrosynthesis potential increase enhanced the TMBh product yield. Computer simulations of the imprinted cavity interaction with the substrate molecule demonstrated that the MIP cavity promoted direct coupling of the substrate to form the desired TMBh product.

Newly Discovered Components of Dendrolimus pini Sex Pheromone.

The pine-tree lappet moth, D. pini, is a harmful defoliator of pine forests in Europe and Asia and a potentially invasive species in North America. The lures for trapping D. pini males based on two known components of its sex pheromone appeared weakly attractive to male moths. Identification of all components of the sex pheromone might allow for the development of more effective lures. The pheromone was sampled from virgin females using SPME and analyzed using gas chromatography coupled with mass spectrometry. Four new likely components ((Z5)-dodecenal, (Z5)-dodecen-1-ol, (Z5)-decen-1-yl acetate, (Z5)-tetradecen-1-yl acetate) and two known components ((Z5,E7)-dodecadienal, (Z5,E7)-dodecadien-1-ol) were identified based on comparison against authentic standards, Kováts indices and spectra libraries. The samples also contained several sesquiterpenes. Wind tunnel and field experiments showed that some blends of synthetic pheromone components alone or enriched with Scots pine essential oil (SPEO) were attractive to D. pini males. One component-(Z5)-decen-1-yl acetate-had a repelling effect. The presented knowledge of D. pini sex pheromone provides a basis for developing optimal lures for monitoring or controlling insect populations.

Winter sources of PM2.5 pollution in Podkowa Lesna, a Central-European garden town (Mazovia, Poland).

The paper analyzes PM2.5 aerosol samples collected in Podkowa Lesna, a garden town in Mazovia, Central Poland, for 15 days in winter 2019. We determined the mass concentrations in the air of PM2.5 and PM2.5-bound organic carbon, elemental carbon, levoglucosan, and nine polycyclic aromatic hydrocarbons (PAHs). PM2.5 ranged from 11 to 51 µg m-3 (mean 31 µg m-3) and contained less than 32% organic carbon, 4% elemental carbon, 1% levoglucosan, and 0.12% total PAHs. The analysis based on positive matrix factorization (PMF) indicated two sources of PM2.5 of similar strength - burning vehicle fuels and biomass burning for residential heating. Levoglucosan originated exclusively from biomass burning, while 90% of elemental carbon was from vehicle emissions. About 62% of organic carbon, 85% of benzo(a)anthracene and 55-65% of the remaining PAHs originated from biomass burning. Compared to many worldwide locations, PM2.5, organic carbon, elemental carbon, and levoglucosan in Podkowa were among the lowest. The benzo(a)pyrene concentrations were the highest, while other PAHs were intermediate. However, the mass fractions of PAHs in Podkowa PM2.5 were the highest among the four locations available for comparison. That may indicate the low quality of fuel-burning processes. PAH-related inhalation cancer risk based on PAH carcinogenic potency in Podkowa appeared marginal. This work aims to induce local administrative actions to improve air quality in garden towns.

Detection of Fungi and Oomycetes by Volatiles Using E-Nose and SPME-GC/MS Platforms.

Fungi and oomycetes release volatiles into their environment which could be used for olfactory detection and identification of these organisms by electronic-nose (e-nose). The aim of this study was to survey volatile compound emission using an e-nose device and to identify released molecules through solid phase microextraction-gas chromatography/mass spectrometry (SPME-GC/MS) analysis to ultimately develop a detection system for fungi and fungi-like organisms. To this end, cultures of eight fungi (Armillaria gallica, Armillaria ostoyae, Fusarium avenaceum, Fusarium culmorum, Fusarium oxysporum, Fusarium poae, Rhizoctonia solani, Trichoderma asperellum) and four oomycetes (Phytophthora cactorum, P. cinnamomi, P. plurivora, P. ramorum) were tested with the e-nose system and investigated by means of SPME-GC/MS. Strains of F. poae, R. solani and T. asperellum appeared to be the most odoriferous. All investigated fungal species (except R. solani) produced sesquiterpenes in variable amounts, in contrast to the tested oomycetes strains. Other molecules such as aliphatic hydrocarbons, alcohols, aldehydes, esters and benzene derivatives were found in all samples. The results suggested that the major differences between respective VOC emission ranges of the tested species lie in sesquiterpene production, with fungi emitting some while oomycetes released none or smaller amounts of such molecules. Our e-nose system could discriminate between the odors emitted by P. ramorum, F. poae, T. asperellum and R. solani, which accounted for over 88% of the PCA variance. These preliminary results of fungal and oomycete detection make the e-nose device suitable for further sensor design as a potential tool for forest managers, other plant managers, as well as regulatory agencies such as quarantine services.

Analysis of cerium oxide and copper oxide nanoparticles bioaccessibility from radish using SP-ICP-MS.

BACKGROUND: The transformation of nanoparticles (NPs) internalized in plant tissues is the human digestive system that can provide a better understanding of the impact of NPs on the human system. The presented methodology was developed to study the bioaccessibility of cerium oxide (CeO2 ) and copper oxide (CuO) NPs from radish after the in vitro simulation of gastrointestinal digestion using single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS). RESULTS: Radish plants were cultivated hydroponically in a growth medium containing: (i) CeO2 NPs and (ii) CuO NPs. Both cerium (Ce) and copper (Cu) were found in all organs of the radish plants after analysis by standalone ICP-MS. This confirms the bioaccumulation of CeO2 and CuO NPs and the translocation of their Ce and Cu to the aerial parts of the plant. Less Ce (4.095 µg g-1 ) has been detected in leaves than in roots (1.156 mg g-1 ) while Cu content in leaves was 5.245 µg g-1 and in roots was 10.41 µg g-1 . Analysis of the digestive extracts obtained after the in vitro simulation of gastro (pepsin) and gastrointestinal (pancreatin) digestion showed that Ce has easy access to human system at least by 73%. CONCLUSION: The size of CeO2 NPs in digestive extracts showed no significant changes. However, the results obtained for CuO NPs digestion were variable and suggested that CuO NPs dissolved during the digestion process. The CuO NPs were observed in roots after the gastrointestinal digestion concluding that CuO NPs recovered after the initial dissolution. © 2020 Society of Chemical Industry.

Identification of Flavonoids and Bufadienolides and Cytotoxic Effects of Kalanchoe daigremontiana Extracts on Human Cancer Cell Lines.

Kalanchoe species are well-known medicinal plants used in traditional medicine as anti-inflammatory and analgesic remedies. Recently, it has been reported that Kalanchoe plants have cytotoxic properties; however, data on traditional use of these plants in tumor treatment are extremely limited. Kalanchoe daigremontiana is one of the most popular species cultivated in Europe, and it is used, among other things, as a remedy in treating skin injuries and wounds. Studies on the biological activity of this species are scarce, and there is a lack of data on the cytotoxic activity of K. daigremontiana extracts on epithelial cancer cells in the literature. In our present study, we analyzed the phytochemical composition of K. daigremontiana ethanol extract and fractions-water and dichloromethane-by the HPLC-DAD-ESI-MS method and estimated cytotoxic activity of the extracts on human adenocarcinoma (HeLa), ovarian (SKOV-3), breast (MCF-7), and melanoma (A375) cell lines by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, real-time cell analyzer (RTCA), and flow cytometry. We identified 6 bufadienolide compounds and 19 flavonoids, mostly kaempferol, quercetin, isorhamnetin, and myricetin glycosides, of which only 3 flavonoids have been identified in K. daigremontiana to date. Other flavonoids that were characterized in our study have not yet been found in this plant. The ethanol extract and water fraction of K. daigremontiana did not show significant cytotoxic activity on the tested cell lines. In contrast, the dichloromethane fraction showed the strongest activity against all cell lines with IC50 values of ≤ 10 µg/mL. The results indicated that this activity is mainly due to the presence of bersaldegenin-1,3,5-orthoacetate.

Uptake, translocation, size characterization and localization of cerium oxide nanoparticles in radish (Raphanus sativus L.).

Due to their unique physical and chemical properties, the production and use of cerium oxide nanoparticles (CeO2 NPs) in different areas, especially in automotive industry, is rapidly increasing, causing their presence in the environment. Released CeO2 NPs can undergo different transformations and interact with the soil and hence with plants, providing a potential pathway for human exposure and leading to serious concerns about their impact on the ecosystem and human organism. This study investigates the uptake, bioaccumulation, possible translocation and localization of CeO2 NPs in a model plant (Raphanus sativus L.), whose edible part is in direct contact with the soil where contamination is more likely to happen. The stability of CeO2 NPs in plant growth medium as well as after applying a standard enzymatic digestion procedure was tested by single particle ICP-MS (SP-ICP-MS) showing that CeO2 NPs can remain intact after enzymatic digestion; however, an agglomeration process was observed in the growth medium already after one day of cultivation. An enzymatic digestion method was next used in order to extract intact nanoparticles from the tissues of plants cultivated from the stage of seeds, followed by size characterization by SP-ICP-MS. The results obtained by SP-ICP-MS showed a narrower size distribution in the case of roots suggesting preferential uptake of smaller nanoparticles which led to the conclusion that plants do not take up the CeO2 NPs agglomerates present in the medium. However, nanoparticles at higher diameters were observed after analysis of leaves plus stems. Additionally, a small degree of dissolution was observed in the case of roots. Finally, after CeO2 NPs treatment of adult plants, the spatial distribution of intact CeO2 NPs in the radish roots was studied by laser ablation ICP-MS (LA-ICP-MS) and the ability of NPs to enter and be accumulated in root tissues was confirmed.

Complexation of tropane alkaloids by cyclodextrins.

Complexes of atropine, homatropine, scopolamine, and ipratropium with cyclodextrins were investigated by NMR and capillary electrophoresis. It has been demonstrated that tropane alkaloids form complexes with ß- and γ-cyclodextrins of 1:1 stoichiometry. NMR measurements indicate the formation of complexes where both aliphatic and aromatic parts of tropane alkaloids interact with ß-cyclodextrin. The stability constants of the investigated alkaloids with ß- and γ-cyclodextrins were determined by capillary electrophoresis. It has been found that ß-cyclodextrin forms ten times more stable complexes than γ-cyclodextrin. Moreover, the analysis of the obtained crystal structure of ß-cyclodextrin/(-)-hyoscyamine complex reveals that two molecules of (-)-hyoscyamine oriented in head-to-tail mode are tightly fitted inside head-to-head ß-cyclodextrin dimer. Conformation of (-)-hyoscyamine as well as scopolamine changes substantially upon complexation adapting to the cavity of ß-cyclodextrin as shown by X-ray analysis, NMR and DFT calculations data.

Titanium Dioxide Nanoparticle Circulation in an Aquatic Ecosystem.

Nanotechnology is a dynamically developing field of scientific and industrial interest across the entire world, and the commercialization of nanoparticles (NPs) is rapidly expanding. Incorporation of nanotechnologies into a range of manufactured goods results in increasing concern regarding the subsequent release of engineered NPs into the environment. One of the biggest threats of using NPs is the transfer and magnification of these particles in the trophic chain. The aim of the studies was the evaluation of the distribution of TiO2 NP contamination in the aquatic ecosystem under laboratory conditions. Bioaccumulation of TiO2 NPs by plants (Elodea canadensis) and fish (Danio rerio) in the source of contamination was investigated. The studies were focused on the consequences of short-term water contamination with TiO2 NPs and the secondary contamination of the components of the investigated model ecosystem (plants, sediments). It was found that in the fish and the plants exposed to NP contamination, the amount of Ti was higher than in the control, indicating an effective bioaccumulation of NPs or ions originating from NPs. It was clearly shown that the NPs present in the sediments are available to plants and fish. Additionally, the aquatic plants, an important trophic level in the food chain, can accumulate NPs and be a source of NPs for higher organisms. It was concluded that even an incidental contamination of water by NPs may result in long-term consequences induced by the release of NPs.

Mycoextraction of radiolabeled cesium and strontium by Pleurotus eryngii mycelia in the presence of alumina nanoparticles: Sorption and accumulation studies.

Widespread use of products based on nanomaterials results in the release of nanoparticles into the environment. Nanoparticles can be taken up by organisms, but they can also coexist with other substances such as radionuclides, thus affecting their uptake or toxicity. In contrast, the sorption capacity of nanoparticles is exploited in water purification. The aim of the study was to investigate: (i) bioaccumulation of cesium and strontium by Pleurotus eryngii mycelia in the presence of alumina nanoparticles (Al2O3 NPs); and (ii) sorption of radionuclides on the surface of nanoparticles. For the experiments, living and dried mycelia were used to permit distinguishing between active uptake and passive sorption of the NPs by P. eryngii. The results are discussed from the perspective of the use of P. eryngii in the mycoextraction of radionuclides. The sorption capacity of Al2O3 NPs and the accumulation by P. eryngii mycelia differ for the applied radioisotopes. The efficiency of Cs and Sr sorption by alumina nanoparticles is 20% and 40%, respectively. Mycelia of P. eryngii have the ability to accumulate 30% of both radioisotopes from the medium. More than 60% of strontium can be removed accumulated from water by P. eryngii mycelia in coexistence with Al2O3 NPs, while the efficiency of cesium removal accumulation is negligible. It was found that alumina nanoparticles do not enhance uptake of radionuclides by P. eryngii mycelia; mycoextraction of radionuclides by mycelia and sorption by Al2O3 NPs are concurrent processes. There was no difference between live or dried mycelia uptake.

Accumulation of Platinum Nanoparticles by Sinapis alba and Lepidium sativum Plants.

Nanoparticles (NPs) are commonly used, and concerns about their possible adverse effects are being voiced as well. However, little is known about the fates of NPs released to the environment. The aim of the study was to (i) evaluate the ability of Sinapis alba and Lepidium sativum plants to take up platinum nanoparticles (Pt-NPs) and translocate them to aboveground organs, (ii) compare the accumulation efficiency of different forms of platinum and (iii) identify the forms in which platinum is stored in plant tissues. Plants were cultivated on medium supplemented with different concentrations of Pt-NPs and [Pt(NH3)4](NO3)2. Platinum content in plants was determined using inductively coupled plasma mass spectrometry. For the identification of the presence of Pt-NPs in plant tissues, gamma spectrometry following iron irradiation was applied. It was found that L. sativum and S. alba are tolerant to applied concentrations of Pt-NPs and have an ability to take up platinum from the medium and translocate it to aboveground organs. The highest concentration of platinum was observed in plant roots (reaching 8.7 g kg-1 for S. alba). We tentatively conclude that platinum is accumulated as nanoparticles. The obtained results suggest future application of plants for phytoremediation and recovery of noble metal nanoparticles.

Toxic effect of silver and platinum nanoparticles toward the freshwater microalga Pseudokirchneriella subcapitata.

The growing use of nanoparticles in a wide range of products has resulted in their release into the aquatic environment; therefore, an understanding of the toxic effects of nanoparticles on aquatic organisms is of permanent importance. The aim of this study was to evaluate the toxicity of silver and platinum nanoparticles toward the freshwater microalga, Pseudokirchneriella subcapitata. Algal growth and photosynthetic pigments were determined to quantitate the effects of varying concentrations of Ag and Pt nanoparticles. The silver nanoparticles were much more toxic than the platinum ones. The concentrations causing total inhibition of algal growth were 5.0 and 22.2 mg L(-1), respectively. Similar results were obtained by analyzing the concentration of photosynthetic pigments in P. subcapitata exposed to nanoparticles. Thus, simple spectrophotometric determination of chlorophyll is a convenient tool for the analysis of nanoparticle toxicity to algae.

Enantioselective Extraction System Containing Binary Chiral Selectors and Chromatographic Enantioseparation Method for Determination of the Absolute Configuration of Enantiomers of Cyclopentolate.

The distribution coefficients and enantioseparation of cyclopentolate were studied in an extraction system containing d-tartaric acid ditertbutyl ester in organic phase and 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD) in aqueous phase. Various parameters involved in the enantioseparation such as the type and the concentration of chiral selectors, pH value and a wide range of organic solvents were investigated. The maximum enantioselectivity (α = 2.13) and optimum distribution coefficients (KR = 0.85, KS = 0.40) were obtained under the following conditions: 0.10 mol/L HP-ß-CD in aqueous phase and 0.20 mol/L d-tartaric acid ditertbutyl ester in decanol as organic phase. Cyclopentolate is present as a racemic mixture to the aqueous phase. The potentially different biological activities of cyclopentolate enantiomers have not been examined yet. Two chiral liquid chromatography methods have been developed for the direct separation of the enantiomers of cyclopentolate. First method was used for the quantification analysis of cyclopentolate enantiomers in aqueous phase. Second method used two chiroptical detectors: electronic circular dichroism (ECD) and optical rotation (OR) for the identification of individual cyclopentolate enantiomers from the organic phase enriched with (R)-enantiomer. The absolute stereochemistry was determined by means of the comparison of the experimental and computed ECD spectra and signs of OR. The ECD spectra of chiral analytes were measured on-line using HPLC-ECD technique.

Interactions with ß-cyclodextrin as a way for encapsulation and separation of camphene and fenchene.

The separation of isomeric monoterpenes, camphene and fenchene by complexation with ß-cyclodextrin is presented. Both of the monoterpenes form complexes with ß-cyclodextrin (as shown by both gas chromatography and (1)H NMR) with similar stability constants nevertheless it is possible to separate them by re-crystallization. The crystal structure of ß-cyclodextrin with fenchene was also studied by X-ray diffraction.

Effect of acetylsalicylic acid on the current-voltage characteristics of planar lipid membranes.

Monitoring of influence of acetylsalicylic acid (ASA) on lipid bilayer conductance may contribute to better understanding of molecular mechanisms underlying passage of ASA into cells. This paper presents effects of increasing sweeping potential on stability of egg yolk phosphatidylcholine planar bilayer lipid membranes (BLM) without or with cholesterol incubated in the presence of ASA. We demonstrated that current flow through bilayer membranes generated fluctuating pores in their structure. Presence of cholesterol in the membrane caused an increase in the value of the breakdown potential, thus confirming that cholesterol had a stabilizing effect on BLM. Otherwise, ASA significantly reduced these values regardless of cholesterol concentration. Overall, by destabilizing the lipid bilayer, ASA contributed to the formation of metastable single pores, which facilitated ASA diffusion through a bilayer. Our data point out that ASA transport across the lipid bilayer takes place predominantly via the process of passive diffusion. In conclusion, the effects of ASA on lipid bilayer stability may contribute to drug transport through membrane lipid bilayers.

Determination of diastereomerization barrier of some flavanones by high-performance liquid chromatography methods.

The rate constants and activation energy barriers DeltaG# of diastereomerization reaction of flavanones: naringin, narirutin, hesperidin and neohesperidin were determined. The stopped-flow HPLC (SFM-HPLC), dynamic HPLC (D-HPLC) and enantioselective HPLC combined with the classical kinetic method were applied for determination of these parameters. It was found that the rate constants of diastereomerization were about eight times higher for naringin and narirutin (1.9 x 10(-5) s(-1)) than for hesperidin and neohesperidin (2.4 x 10(-6) s(-1)). No significant differences in the rate of diastereomerization were found between neohesperidosides and corresponding rutinosides.

The phytochemical and genetic survey of common and dwarf juniper (Juniperus communis and Juniperus nana) identifies chemical races and close taxonomic identity of the species.

Juniperus communis L. (= J. communis var. communis) and Juniperus nana Willd. (= J. communis var. SAXATILIS) are subspecies of juniper. J. communis grows widely in both hemispheres, primarily in lower elevations while J. nana is mainly observed in high mountains. Although they can be distinguished by morphological features, it is not known whether they are genetically and phytochemically distinct entities. We aimed to check whether it is possible to distinguish these two plants (i) by pharmaceutically important chemical traits and (ii) on the basis of intraspecifically highly polymorphic fragment of chloroplast DNA. We used GC with achiral as well as with enantioselective stationary phase columns to identify the main monoterpenes of the essential oil. Sequence analysis of the TRNL (UAA)- TRNF (GAA) intergenic spacer of the chloroplast genome was used as a genetic marker of taxonomic identity between these two subspecies. The chromatographic analysis showed the existence of three chemical races - the alpha-pinene type, the sabinene type and one with intermediate contents of these terpenes among both J. communis and J. nana. Surprisingly, sequence analysis of TRNL (UAA)- TRNF (GAA) revealed 100 % similarity between the common and the dwarf juniper. Thus, the monoterpene pattern is related to geographical origin, and not to the species identity. We suggest that the three chemical races identified in the present study should be considered as separate sources of pharmaceutical raw material. Our results demonstrate that the contents of alpha-pinene and sabinene may be applied as a quick diagnostic test for preliminary evaluation of plant material.

Thermodynamic studies of complexation and enantiorecognition processes of monoterpenoids by alpha- and beta-cyclodextrin in gas chromatography.

Gas-liquid chromatography was applied in thermodynamic investigations of processes of complexation and enantioseparation by alpha- and [-cyclodextrins of chiral monoterpenoids. The distribution constants, stability constants and thermodynamic parameters enthalpy, entropy and free energy of the complexation processes were determined. It has been found that enantioseparation of monoterpenes by alpha- and beta-cyclodextrins is the result of formation of 1:2 stoichiometric complexes. When 1:1 stoichiometric complexes are formed, enantioselectivity is not observed. All investigated processes of complexation are enthalpy-driven regardless of the stoichiometry of the formed complexes. -deltaH, -TdeltaS and -deltaG of complexation process have higher values for bicyclic than for monocyclic monoterpenoids as well as for alpha-CD than for beta-CD. The first or second step of complexation may be responsible for enantioselectivity.

Chiral recognition ability of alpha-cyclodextrin with regard to some monoterpenoids under gas-liquid chromatographic conditions.

Gas-liquid chromatography was applied to investigate the mechanism of alpha-cyclodextrin (alpha-CD) complexation processes with some chiral monoterpenoids differing from each other in chemical properties and structure. They were chosen from hydrocarbons, alcohols, aldehydes and ketones of acyclic, monocyclic and bicyclic structure. The relationships between the retention factor, k, of a guest solute (G) and alpha-CD concentration were studied. The obtained data enabled the stoichiometry, the stability of individual complexes and the separation factor of enantiomers to be determined. It was found that almost all the investigated monoterpenoids, apart from the acyclic ones, form inclusion complexes with alpha-CD. Straight-line relations (r vs. [alpha-CD]) were observed for monocyclic alcohols and pulegone, without any trace of enantioselectivity. This behaviour indicates that the 1:1 stoichiometry of the G-CD complexes does not lead to chiral recognition. Parabolic relations arising from 1:2 stoichiometry were found for limonene, alpha-phellandrene, some monocycylic ketones and all the investigated bicyclic terpenoids. It appeared that only the second step of complexation displayed marked enantioselectivity. However, a loss of efficiency resulting from slower equilibration is then noticeable. Attempts are made to rationalize the chromatographic results with respect to the structure of the investigated compounds.

Separation of some chiral flavanones by micellar electrokinetic chromatography.

Micellar electrokinetic chromatography (MEKC) was applied for enantioseparation of selected flavanones, including naringin, hesperidin, neohesperidin, naringenin, hesperetin, pinostrobin, isosakuranetin, eriodictyol, and homoeriodictyol. gamma-Cyclodextrin (gamma-CD) and sodium cholate (SCh) were used as chiral modifiers inducing enantioselectivity to the background electrolyte. From among many investigated selectors only these two appeared to possess the best enantioselective properties in respect to studied flavanones. The mechanisms of their action are a little different; SCh used above critical micelle point concentration forms chiral micelles itself while gamma-CD is deprived of this property and requires addition of surfactants as, e.g., sodium dodecyl sulfate. It was found that SCh enables separation of flavanone glycosides diastereomers while separation of enantiomers of flavanone aglycones may be achieved with gamma-CD. Consideration of structural relation led to the suggestion that interaction of sugar moiety of glycosides with SCh micelles give rise to chiral recognition. MEKC appeared to be a suitable and efficient analytical tool to follow enantiomeric composition of flavanones.