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Anthocyanins of basil leaves

The anthocyanin composition of five purple leaves cultivars of Ocimum basilicum L. was investigated by reversed-phase HPLC with mass-spectrometric detection by ESI mode with ion partial fragmentation as well as preparation of dried differently colored forms of anthocyanins encapsulated into maltodextrinmatrix. Analysis of the mass spectra revealed that according to the chromatographic profile the set of basil cultivar anthocyanins under investigation may be divided into two groups with the common feature being ahigh level of acylation with (mainly) p-coumaric, ferulic and malonic acids of the same base: cyanidin-3-dihexoside-5-hexoside. The presence of acylation with substituted cinnamic acids permits us to obtain solutions not only with a red color (the property of the flavylium form) but also with blue shades of coloration due to quinonoid and negatively charged quinonoid forms. All forms except that of flavylium are not stable in solution but stable enough to prepare dried encapsulated forms by lyophilization. Although the loss of anthocyaninswith drying is not negligible, the final product is characterized with high stability for storage in a refrigerator.

Chromatographic behavior of anthocyanins on a C10CN stationary phase

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.

Green extraction of anthocyanins with natural deep eutectic solvents

Natural Deep Eutectic Solvents (NADES) represent a green chemistry alternative to utilization of common hazardous organic solvents. They were introduced by Abbott et al. [1], and were found to have a wide range of compositions and favorable properties. NADES are typically obtained by mixing hydrogen-bond acceptors (HBA), with hydrogen bond donors (HBD), leading to a significant depression of the melting point. The availability of components, simple preparation, biodegradability, safety, re usability and low cost are the significant advantages that call for research on their analytical applications. Three methods are most commonly used for preparing NADES: a) heating and stirring: the mixture until a clear liquid is formed; b) evaporating solvent from components solution with a rotatory evaporator; c) freeze drying of aqueous solutions.The common solvents for the extraction of anthocyanins are acidified mixtures of water with ethanol, methanol, or acetone. The anthocyanins extracts are susceptible to degradation due to high temperature, and the solvent properties (e.g. high pH) and the whole process can often be time-consuming. Extraction of anthocyanins from red cabbage by four NADES was investigated. It was demonstrated that NADES have comparable extraction efficiencies with conventional method with 0.1 M water solution of HCl. This indicates a possibility of utilization the Green chemistry extraction processes as a promising new green-extraction technology with low cost efficiency and environment friendly technology for production of safe food additives.

Chromatographic behavior of petanin in reversed-phase HPLC in mobile phases with a wide range of pH

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.

Photovoltaic efficiency of anthocyanins in dye-sensitized solar cells (DSSCs)

Using Karapet’yants comparative analysis in chromatography

Karapet’yants comparative analysis is applied to anthocyanin retention using the example of an extract of Adonis aestivalis petals. The attribution of anthocyanin peaks according to the comparative analysis is confirmed by the parameters of the mass spectra. A set of purple maize anthocyanins is used as a referencesample.