Svetlana S. Aleksenko

Разработана методика определения низких концентраций пинаколилового спирта (3,3-диметилбутан-2-ола) и хлорпикрина (трихлорнитрометана) на основе анализа равновесной паровой фазы с использованием газовой хроматографии с масс-спектрометрическим детектированием (ГХ-МС). Оптимизированы условия определения указанных веществ, изучено влияние температуры, времени термостатирования, фазового соотношения (b), присутствия высаливателя на степень извлечения соединений. Показано, что равновесие в системе конденсированная фаза-пар устанавливается в течение 5 минут в интервале температур от 60 до 95 °С. Повысить чувствительность определения хлорпикрина в значительной степени позволяет варьирование фазовым соотношением: уменьшение b с 19,0 до 1,0 приводит к увеличению площади пика хлорпикрина в 13 раз, а чувствительность определения пинаколилового спирта в водных средах (>3 раз) - процедура высаливания. Линейная градуировочная зависимость получена для растворов пинаколилового спирта в интервале концентраций от 0,005 до 1,0 мг/л и хлорпикрина от 0,005 до 0,5 мг/л с коэффициентами корреляции 0,9988 и 0,9971, соответственно. Пределы обнаружения в воде составили: для пинаколилового спирта - 0,5 нг/мл, для хлорпикрина - 2,0 нг/мл. Метод применен для определения соединений в природных матрицах (почве, воде, снеге), косметических (масле для тела) и антисептических (санитайзере)...

The methodological developments and applications of CE related to studying biotransformations of metal‐based nanoscale particles of impending medicinal use are overviewed. This is an update to a previous review article (Aleksenko, S. S., Shmykov, A. Y., Oszwałdowski, S., Timerbaev, A. R., Metallomics 2012, 4, 1141–1148) and it covers the research papers published within the last five years. As was anticipated in that review, CE can now be seen as a customary technique in the analysis of biomolecular interactions that exert an impact on the mechanism of action of nanoparticles, comprising metabolism, delivery, cell processing, and targeting. Different ways by which the CE method is applied for such monitoring, including conjugation mode, sample preparation, separation, and detection, are critically assessed. Special emphasis is put on examinations using inductively coupled plasma MS detection recent advent of which to the area made CE a versatile speciation tool for biomedical studies of nanomaterials containing metals.

Determination of the DNA-binding reactivity and affinity is an important part of a successful program for the selection of metallodrug candidates. For such assaying, a range of complementary analytical techniques was proposed and tested here using one of few anticancer metal-based drugs that are currently in clinical trials, indazolium trans-[tetrachloridobis(1H-indazole)ruthenate(III), and a DNA oligonucleotide. A high reactivity of the Ru drug was confirmed in affinity capillary electrophoresis (CE) mode, where adduct formation takes place in situ (i.e., in the capillary filled with an oligonucleotide-containing electrolyte). To further characterize the binding kinetics, a drug–oligonucleotide mixture was incubated for a different period of time, followed by ultrafiltration separation into two different in molecular weight fractions (>3 and <3 kDa). The time-dependent distribution profiles of the Ru drug were then assessed by CE-inductively coupled plasma mass spectrometry (ICP-MS), revealing that at least two DNA adducts exist at equilibrium conditions. Using standalone ICP-MS, dominant equilibrium amount of the bound ruthenium was found to occur in a fraction of 5–10 kDa, which includes the oligonucleotide (ca. 6 kDa). Importantly, in all three assays, the drug was used for the first time in in-vitro studies, not in the intact form but as its active species released from the transferrin adduct at simulated cancer cytosolic conditions. This circumstance makes the established analytical platform promising to provide a detailed view on metallodrug targeting, including other possible biomolecules and ex vivo samples.

As metallic nanoparticles are growing in importance as analytes in CE, increases an interest in appropriate detection methods for their quantification in various samples. For gold nanoparticles (AuNPs), the most common UV detection poses intricacy of inadequate sensitivity that hinders the applicability of CE. With the objective of resolving this challenge, UV detection was compared with C⁴D and ICP‐MS as alternative modes of detection for AuNPs. A C⁴D detector, applied under pressure‐driven conditions, exhibited better sensitivity than a UV detector. However, C⁴D turned to be unsatisfactory to differentiate the signal of AuNPs at common CE conditions despite varying the nature of BGE and detection conditions. Due to intrinsic sensitivity and low background levels typical to Au, ICP‐MS greatly surpasses UV detection. After optimization trials, CE‐ICP‐MS gained the LOD of AuNPs as low as 2 × 10^–15 M, as well as an excellent performance in terms of signal stability and linearity. Also importantly, the optimized BGE appears to be well matched to explore the behavior of AuNPs in biologically relevant systems. This was demonstrated by probing the interaction between AuNPs and the main blood‐transporting protein, HSA.

The mechanism by which the most relevant ruthenium anticancer drugs are activated in tumors to commence their tumor-inhibiting action remains one of t

The antioxidant activity of buckwheat and barley extracts by reaction with 1,1-diphenyl-2-picrylhydrazyl and the total of phenolic compounds have been determined using the Folin-Ciocalteu reagent. It has been found that water-ethanol extracts of buckwheat are characterized by higher antioxidant activity (6.2 ± 0.5 μM-eq. of Trolox/g) and concentration of phenolic compounds (4.41 ± 0.07 mg-eq. of rutin/g) compared to barley extracts (4.2 ± 0.3 μM-eq. of Trolox/g and 2.4 ± 0.1 mg-eq. of rutin/g, respectively). A series of phenolic compounds have been identified by HPLC with UV detection and mass spectrometric detection with electrospray ionization. The main phenolic compounds-antioxidants in buckwheat extracts are rutin, catechin and epicatechin, 1-O-caffeoyl-O-rutinoside (m/z 487), and epicatechin-O-3,4-dimethylgallate (m/z 469), and in the barley extract, catechin, prodelphinidin B3 (m/z 593), procyanidin B3 (m/z 577), and procyanidin C2 (m/z 865).

A method based on combining inductively coupled plasma mass spectrometry (ICP-MS) with capillary electrophoresis (CE) or an ultrafiltration step was d