Chromatographic Analysis of Orchid Extracts and Quantum Chemical Calculations of Individual Components Interaction with Silica

The most common phenolic components of sixteen orchid extracts were identified using high performance liquid chromatography and laser desorption/ionization mass spectrometry. The interaction between these compounds and silica silanol groups was studied using quantum chemical calculations. Results show that the strength of the interaction of phenols with silica increased in the following order: ferullic, feruloylquinic and fertaric acids < kaempferol, apingenin << сhlorogenic and caffeic acids, rhamnetin, quercetin, luteolin, epicatechin gallate. The common feature of compounds characterized by the strongest interaction with silanol groups is the presence of phenol ring with two neighbouring hydroxyl groups

Assessment of the molecular cytogenetic, morphometric and biochemical parameters of Deschampsia antarctica from its southern range limit in maritime Antarctic

Different chromosomal forms of Deschampsia antarctica Desv. (Poaceae), including diploids (2n=26), hypotriploid (2n=36–38) and a genotype with an occasional occurrence of B chromosome (2n=26+0-1B) that originated from southern marginal populations (Argentine Islands region, maritime Antarctic) were studied using molecular cytogenetic, morphometric and biochemical methods. FISH analysis revealed variations in the number of rDNA sites between the diploid and hypotriploid plants. The genome size varied among plants with a different chromosome number and was on average 10.88 pg/2C for diploids and 16.46 pg/2C for hypotriploid. The mean values of leaf length of plants grown in vitro varied within a range of 5.23–9.56 cm. The total phenolic content ranged from 51.10 to 105.40 mg/g, and the total flavonoid content ranged from 1.22 to 4.67 mg/g. The amount of phenolic compounds did not differ significantly between the genotypes, while a variation in the flavonoid content was observed for L59 and DAR12. The diploids did not differ significantly among each other in terms of the number of rDNA loci, but differed slightly in their genome size. The individuals of DAR12 carrying B chromosome were similar to other diploids in terms of their genome size, but statistically differed in leaf length. The hypotriploid had both a greater number of rDNA sites and a larger genome size. No statistical correlations were observed between the genome size and leaf length or genome size and accumulation of phenolic and flavonoid compounds. The results of this study suggest that D. antarctica plants from the southern edge of the range are characterised by the heterogeneity of the studied parameters

In vitro propagation of Cattleya Lindl. and Laelia Lindl. species

Nowadays many wild species of South American’s orchids are under threat of extinction from over-col- lection and habitat destruction. Many tropical native orchid species were propagated in the National Botanical Garden of National Academy of Sciences of Ukraine through a range of asymbiotic seed germi- nation techniques and tissue culture procedures aimed to preserve a number of individuals under artificial conditions in glasshouses in the temperate zone, with the aim to protect these species from complete extinc- tion. Our orchid collection includes plants of Cattleya and Laelia species. Some of these species are rare in the wild. To protect them from extinction the meth- ods of propagation should be developed. Nowadays many wild species of South American’s orchids are under threat of extinction from over-col- lection and habitat destruction. Many tropical native orchid species were propagated in the National Botanical Garden of National Academy of Sciences of Ukraine through a range of asymbiotic seed germi- nation techniques and tissue culture procedures aimed to preserve a number of individuals under artificial conditions in glasshouses in the temperate zone, with the aim to protect these species from complete extinc- tion. Our orchid collection includes plants of Cattleya and Laelia species. Some of these species are rare in the wild. To protect them from extinction the meth- ods of propagation should be developed.

Chromatographic and mass spectrometric analysis of secondary metabolites of <i>Deschampsia antarctica</i> from Galindez Island, Argentine Islands

The aim of this work was to study the polyphenolic composition of Deschampsia antarctica È. Desv. plants grown at natural conditions on different locations on the Galindez Island, Argentine Islands, the maritime Antarctic. The plants were collected during the summer season of the 26th Ukrainian Antarctic Expedition (2020–2022). The extracts of 21 plants were obtained and the composition of the extracts was analyzed by means of high-performance liquid chromatography and matrix-assisted laser desorption/ionization mass spectrometry. The antioxidant properties of the extracts were characterized using the DPPH (2,2-diphenyl-1-picrylhydrazyl) test. The extracts were found to contain large amount of polyphenolic compounds, with flavonoids and phenolic acids, as well as their derivatives, being the most common classes of the phenols. Using the HPLC data the content of various phenols in the plants was systematic studied. It has been found that in all plants the most abundant phenols are flavonoids/flavonoid derivatives (on average about 75% of total mass of phenols). Among the flavonoids, luteolin derivatives predominate (86–94% of the total mass of flavonoids), and, among luteolin derivatives, the main compounds are orientin, orientin 2&quot;- O-β-arabinopyranoside and isoswertiajaponin 2&quot;- O-β-arabinopyranoside (67–83% of the total mass of luteolin derivatives). It has been also found that all the extracts possess the high activity in inhibition of DPPH radicals and that the antioxidant activity of the extracts correlates with total content of phenols in the samples. Thus, Deschampsia antarctica É. Desv. plants are a valuable source of natural phenolic antioxidants, and the most common antioxidants in the extracts are orientin, orientin 2&quot;- O-β-arabinopyranoside and isoswertiajaponin 2&quot;- O-β-arabinopyranoside

Yeast Sup35 Prion Structure: Two Types, Four Parts, Many Variants

The yeast [PSI+] prion, formed by the Sup35 (eRF3) protein, has multiple structural variants differing in the strength of nonsense suppressor phenotype. Structure of [PSI+] and its variation are characterized poorly. Here, we mapped Sup35 amyloid cores of 26 [PSI+] ex vivo prions of different origin using proteinase K digestion and mass spectrometric identification of resistant peptides. In all [PSI+] variants the Sup35 amino acid residues 2–32 were fully resistant and the region up to residue 72 was partially resistant. Proteinase K-resistant structures were also found within regions 73–124, 125–153, and 154–221, but their presence differed between [PSI+] isolates. Two distinct digestion patterns were observed for region 2–72, which always correlated with the “strong” and “weak” [PSI+] nonsense suppressor phenotypes. Also, all [PSI+] with a weak pattern were eliminated by multicopy HSP104 gene and were not toxic when combined with multicopy SUP35. [PSI+] with a strong pattern showed opposite properties, being resistant to multicopy HSP104 and lethal with multicopy SUP35. Thus, Sup35 prion cores can be composed of up to four elements. [PSI+] variants can be divided into two classes reliably distinguishable basing on structure of the first element and the described assays

Antioxidant properties of some plant extracts and effect of their addition on the oxidation stability of biodiesel

The extracts from the leaves of Deschampsia antarctica É. Desv., Camelina sativa (L.) Crantz, and Camellia japonica L. plants, as well as from defatted Camelina sativa and Silybum marianum seedcakes were investigated as potential additives for improvement of biodiesel stability against oxidation. Composition of the extracts was studied by means of HPLC, and antioxidant properties were evaluated using the Folin-Ciocalteu assay and the DPPH test. The oxidation of biodiesel was monitored during the accelerated procedure at 43C, with the changes in the acid number of biodiesel samples being the criteria of this process. In spite of significant distinctions in the content of various phenolic compounds, all the extracts were found to possess high antioxidant activity and decelerate biodiesel oxidation by 9-26%. The data did not reveal a directly proportional relationship between the antioxidants content in the extract, on the one hand, and the enhancement in biodiesel stability, on the other hand; various extracts had different influence on the behaviour of biodiesel from rape and Camelina seed oils. The results obtained are consistent with the assumption that there is no universal stabilizer for different types of biodiesel and indicate the prospects on searching for novel antioxidants of natural origin to inhibit oxidative processes

Development, integrative study and research prospects of <i>Deschampsia antarctica</i> collection

This review presents the results of multi-year efforts for the development and integral investigation of the collection of Deschampsia antarctica É. Desv. plants originated from the maritime Antarctic. To create the collection, we have optimized the procedures and conditions for germination of seeds and generation of aseptic plants in vitro together with their subsequent clonal propagation, long-term in vitro culture, and acclimatization of plants to pot culture, and finally produced fertile plants able to set viable seeds. The collection of plants cultivated in vitro and in pots is consisted of clones of 22 different genotypes originated from eight island populations from the Argentine Islands – Kyiv Peninsula region. Some of these clones have been successfully cultured for more than ten years and were found to be genetically stable over this period. The collection was shown to be heterogeneous in a number of variables. The morphological and anatomical characteristics of the plants, as well as the data of karyological, molecular cytogenetic, molecular genetics, and biochemical analysis are presented. The created collection of D. antarctica plants can provide a valuable plant material with well-studied characteristics grown under controlled conditions to perform experimental research on the mechanisms for plant adaptation and resistance to various abiotic factors of Antarctic environment. Furthermore, development of the collection and its comprehensive characterization form the basis for further biotechnological developments focused on the use of this Antarctic plant as a source of biologically active substances, which can potentially be used for therapeutic and prophylactic purposes