Antioxidant properties, betalain profiles and biochemical composition were studied in table beets with maroon and yellow root colors. Features of dynamic changes during the growing season were described. Significant differences in antioxidant activity were found in table beet accessions with differently colored roots. Negative dynamics of antioxidant activity were observed in all accessions. Statistically significant differences were registered among the accessions in the total amounts of phenolic compounds, chlorophylls, and betalains. The group of maroon accessions demonstrated strong positive correlations between their antioxidant activity and total phenolics (r = 0.91), antioxidant activity and betacyanins (r = 0.80), and between betacyanins and phenolics (r = 0.90). The antioxidant activity in the accessions with yellow roots was associated with chlorophyll b (r = 0.85), ascorbic acid (r = 0.83), and total phenolics (r = 0.83). The data are presented on the structure of betalains in two table beet groups contrasting in their root color. The results of the study made it possible to identify key components in the biochemical profile of differently colored beetroots, associated with their high antioxidant activity. Dynamic changes were shown for the antioxidant activity and fractional composition of betalains in table beet during its growing season, and a conclusion was made concerning the higher nutritional value of maroon cultivars.

Table beet (Beta vulgaris L.) is a source of the natural red-colored food dye (E162), highly demanded for the broad spectrum of its biological activity. The relevance of this study is dictated by the lack of knowledge about the dynamics of changes in the crop’s betalain content during the growing season, which impedes identifying the optimal timing of harvesting in order to obtain the dye. This paper presents the results of research into betacyanins (BC) and betaxanthins (BX), separately in the peel and flesh of roots, in 15 differently colored table beet accessions from the collection of the N.I. Vavilov Institute (VIR). There was no statistically significant accumulation of betalains in beets during the growing season. The pigment’s significant fluctuations associated with abiotic environmental factors were shown. The ratio of BC/BX in red-colored accessions was measured: 2.65 in the peel and 2.9 in the flesh. Strong positive relationships were found between BC and BX in the peel (r = 0.97) and flesh (r = 0.79) of red-colored biotypes, which stably persisted throughout the growing season. The beetroot peel was more sensitive to temperature changes, in contrast to the flesh. The negative effect of a temperature increase on betalains in red-colored beetroots intensified on the second or third day. The pigment composition of the flesh was less susceptible to the negative impact of increased temperatures, but reacted negatively to rainfall, becoming more expressed on the second or third day. A conclusion was made about the morphotype with high betalain content. Recommended cultivars are mid-ripening, with rounded and medium-sized roots, a large number of narrow leaf blades, and short and thin petioles.

The growing attention to the luminescent nanocarriers is strongly stimulated by their potential application as drug delivery systems and by the necessity to monitor their distribution in cells and tissues. In this communication we report on the synthesis of amphiphilic polypeptides bearing C-terminal phosphorescent label together with preparation of nanoparticles using the polypeptides obtained. The approach suggested is based on a unique and highly technological process where the new phosphorescent Pt-cysteine complex serves as initiator of the ring-opening polymerization of α-amino acid N-carboxyanhydrides to obtain the polypeptides bearing intact the platinum chromophore covalently bound to the polymer chain. It was established that the luminescent label retains unchanged its emission characteristics not only in the polypeptides but also in more complicated nanoaggregates such as the polymer derived amphiphilic block-copolymers and self-assembled nanoparticles. The phosphorescent nanoparticles display no cytotoxicity and hemolytic activity in the tested range of concentrations and easily internalize into living cells that makes possible in vivo cell visualization, including prospective application in time resolved imaging and drug delivery monitoring.

Naturally coloured cotton is environmentally friendly, since bleaching and chemical dyeing are not needed during textile production. Studying molecular-genetic mechanisms underpinning pigment production may facilitate breeding cotton with coloured fibre. In the current review we summarize the known data on structural and regulatory genes involved in biosynthesis of flavonoid pigments proanthocyanidins (PAs) in brown and caffeic acid (CA) in green fibre. The first chapter considers the first studies on fibre cotton inheritance, from the beginning of the last century. Then, we briefly review the biochemical and physico-chemical methods proving the presence of PAs in brown fibre and derivatives of CA in green cotton fibre. The biochemical analysis of coloured cotton fibre was followed by genetic studies of structural genes coding for enzymes participating in PA and CA biosynthesis, transport and oxidation processes. We summarize the data on the genes coding for transcription factors from the MBW (MYB-bHLH-WD40) regulatory complex, which controls flavonoid biosynthesis in coloured cotton fibre. The regulatory gene most interesting as a target for markers-assisted breeding and genome editing is GhTT2-3A. brown fibre, caffeic acid, flavonoids, green fibre, Gossypium, MBW regulatory complex, proanthocyanidins

The intensively pigmented legumes belonging to Phaseolus and Vigna spp. are valued as an essential component of healthy nutrition due to their high content of flavonoids. In this context, we used the accessions of Vigna unguiculata with different colors of seed coats from the N.I. Vavilov All-Russian Institute of Plant Genetic Resources collection as the main object of this research. We applied confocal laser scanning microscopy, biochemical analysis, and wide in silico and molecular genetic analyses to study the main candidate genes for anthocyanin pigmentation within the MYB cluster on chromosome 5. We performed statistical data processing. The anthocyanin content ranged from 2.96 mg/100 g DW in reddish-brown-seeded cowpea accessions to 175.16 mg/100 g DW in black-seeded ones. Laser microscopy showed that the autofluorescence in cowpea seeds was mainly caused by phenolic compounds. The maximum fluorescence was observed in the seed coat, while its dark color, due to the highest level of red fluorescence, pointed to the presence of anthocyanins and anthocyanidins. Genes of the MYB cluster on chromosome 5 demonstrated a high homology and were segregated into a separate clade. However, amplification products were not obtained for all genes because of the truncation of some genes. Statistical analysis showed a clear correlation between the high content of anthocyanins in cowpea seeds and the presence of PCR products with primers Vigun05g0393-300-1.

The development of biomaterials with gradient surface modification capable of spatially controlled cell adhesion and migration is of great importance for tissue engineering and regeneration. In this study, we proposed a method for the covalent modification of PLA-based materials with a cationic polypeptide (polylysine, PLys) via a thiol-ene click reaction carried out under a light gradient. With this aim, PLA-based films were fabricated and modified with 2–aminoethyl methacrylate (AEMA) as a double bond source. The latter was introduced by reacting pre-formed and activated surface carboxyl groups with the amino group of AEMA. The success of the modification was confirmed by ¹H NMR, Raman and X-ray photoelectron spectroscopy data. A further photoinduced thiol-ene click reaction in the presence of a photosensitive initiator as a radical source was further optimized using cysteine. For grafting of PLys via the thiol-ene click reaction, PLys with a terminal thiol group was synthesized by ring-opening polymerization using Cys(Acm) as an amine initiator. Deprotection of the polypeptide resulted in the formation of free thiol groups of Cys-PLys. Successful gradient grafting of Cys-PLys was evidenced by covalent staining with the fluorescent dye Cy3-NHS. In addition, PLys gradient-dependent adhesion and migration of HEK 293 cells on PLys-PLA-based surfaces was confirmed.