The chromatographic behavior of petanin, petunidin-3-O-[6-O-(4-O-(E)-para-coumaroyl-O-α-rhamnopyranosyl)-β-glucopyranoside]-5-O-β-glucopyranoside, is studied for the first time under conditions of reversed-phase high performance liquid chromatography in mobile phases with different pH values. The relationship between chromatographic behavior (retention time and peak efficiency) and transitions between different forms of anthocyanins is discussed. Analysis of the data obtained in the 2 to 6.5 range of mobile pH phases, the absorption spectra of petanin, and the results from studying the effect of adding tetrabutylammonium bromide to the mobile phase shows that increasing the pH results in the formation of uncharged and anionic forms, in addition to the pseudobase form.
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The selectivity of the separation of some anthocyanins on Diasphere-11-C10CN stationary phase (phase I) is compared with the traditional reversed Symmetry C18 phase (phase II). It is found that, in contrast to phase II, phase I is effective in the separation of isomeric pairs of anthocyanins of 6-hydroxycyanidin-3-rutinoside and delphinidin-3-rutinoside, 6-hydroxypelargonidin-3-rutinoside and cyanidin-3-rutinoside, which ensures the determination of anthocyanins of Alstroemeria flowers. A comparison of separation maps shows that, on phase I, as compared with phase II, retention does not decrease so much, when OH groups are added to the anthocyanidin structure; trend lines for 3-mono-, di-, and triglucosides have a higher slope, and the addition of a glucosidic substituent at position 5 results in a more significant decrease in the retentionof anthocyanins. Different selectivity of the separation of anthocyanins on phase I makes this separation version a good alternative to traditional reversed phase chromatography.
Inhibition of the sodium−glucose cotransporter 2 (SGLT2) by canagliflozin in type 2 diabetes mellitus results in large between-patient variability in clinical response. To better understand this variability, the positron emission tomography (PET) tracer [18F]canagliflozin was developed via a Cu-mediated 18F-fluorination of its boronic ester precursor with a radiochemical yield of 2.0 ± 1.9% and a purity of >95%. The GMP automated synthesis originated [18F]canagliflozin with a yield of 0.5−3% (n = 4) and a purity of >95%. Autoradiography showed [18F]canagliflozin binding in human kidney sections containing SGLT2. Since [18F]canagliflozin is the isotopologue of the extensively characterized drug canagliflozin and thus shares its toxicological and pharmacological characteristics, it enables its immediate use in patients.
