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.Bioimaging based on luminescent microscopy represents one of the most powerful analytical techniques in the life sciences because of its high sensitivity accompanied with simplicity and low cost. This visualization procedure can be carried out using water soluble organic and organometallic dyes, their conjugates with polymers and biomolecules 1-3 , as well as with luminescent nanoobjects 4-7 . The growing attention to the latter approach can be explained by well known practice of application of the nanoparticles to construct advanced drug delivery systems, which also make possible easy visualization of drug distribution in cells and tissues. During the last years, such smart combination of diagnostic and therapeutic properties caused enormous interest in biomedical research area.Nowadays, the nanocarriers intended for a creation of drug delivery systems can be both of inorganic 8 and organic nature 9,10 . Among inorganic nanoparticles applied for bioimaging and drug delivery such systems as dye-doped silica 11 , quantum dots 12 , metal nanoclusters 13 , lanthanide-doped nanoparticles 14 , etc. have got a particular attention. The luminescent properties of organic nanocarriers are usually associated with the native material emission characteristics or are the result of their labeling with emissive moieties. In particular, the materials based on photo-luminescent polyacrylonitrile can be mentioned as an example of label-free organic nanoparticles for bioimaging 15 . However, both the covalent labeling of organic nanoparticles or encapsulation of a dye inside the particles 16,17 are the most common approaches. Encapsulation of dyes in a drug-carrying nanoparticle is usually aimed at synchronous release of drug and dye to signal about drug availability in biological ...

No abstract

Naturally coloured cotton is environmentally friendly, since bleaching and chemical dyeing are not needed during textile production. Studying moleculargenetic 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) derivates 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 PAs 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.