Phytochemical profiles, antioxidant and antimicrobial activity of Actinidia polygama and A. arguta fruits and leaves

Plants of two species of Actinidia genus grown in an adverse steppe climate were examined in terms of secondary metabolites’ accumulation, antioxidant potential, and antimicrobial ability. The aim of the work was to reveal whether the introduced plants A. arguta and A. polygama retain their well-known health benefits. Total content of polyphenols (549.2 and 428.1 mg GAE/100 g FW, respectively), flavonoids, and phenolic acids as well as total antioxidant activity and reducing power of the fruit isopropanol extracts were found to be equal or even higher than the reported data on kiwifruit varieties cultivated in China and other regions. Antioxidant potential and phenolic compounds’ content in the fruit peel of both species were higher when compared to pulp, while corresponding indices of leaves exceeded those of the fruit. Disc-diffusion assays showed low to moderate antibacterial activity of A. arguta and A. polygama fruit and leaf extracts against collection Gram-negative and Gram-positive strains. Clinical strains of P. aeruginosa and E. coli resistant to the action of ofloxacin were notably inhibited by A. arguta and A. polygama fruit and leaf crude extracts. Inhibiting effects of plant extracts on clinical strains of K. pneumoniae and A. baumannii were comparable with the effect of ofloxacin. GC-MS assays identified 23 and 36 chemical constituents, respectively in A. arguta and A. polygama fruit isopropanol extracts. The main compounds in both extracts were 2-propenoic acid, pentadecyl ester followed by squalene, 7,9-di-tert-butyl-1-oxaspiro(4,5)deca-6,9-dien-2,8-dione, octadecanoic acid, 2-oxo-methyl ester, ethyl-isoallocholate, and phytol having known bioactivities. Our findings confirmed the preservation of useful properties by the introduced plants and also indicated the rich health-promoting abilities and expedience of cultivating A. arguta and A. polygama in a steppe climate

Some aspects of general characteristic and classification of bacterial β-lactamases

Наведено дані стосовно основних структурних і функціональних груп бактеріальних β-лактамаз, а також сучасні системи класифікації β-лактамаз, які ґрунтуються на спектрах активності, чутливості до інгібіторів і особливостях молекулярної структури. Показано найважливіші властивості β-лактамаз: субстратна специфічність, чутливість до дії інгібіторів, особливості генетичної детермінації. Особливу увагу приділено β-лактамазам грамнегативних бактерій ТEM-, SHV-типу, їх ролі у формуванні стійкості до різних β-лактамів. Приведены данные относительно основных структурных и функциональных групп бактериальных β-лактамаз. Описаны современные системы классификации β-лактамаз, которые базируются на спектрах активности, чувствительности к ингибиторам и особенностях молекулярной струк­туры. Представлены основные свойства β-лактамаз: субстратная специфичность, чувствительность к действию ингибиторов, особенности генетической детерминации. Особое внимание уделяется β-лактамазам грамотрицательных бактерий ТEM-, SHV-типа, их роли в формировании устойчивости к различным β-лактамам. Main structural and functional groups of bacterial β-lactamases are cited in the data review. Modern systems of classification, which was based on spectra of activity, sensitivity to inhibitors and peculiarities of molecular structure are described. The basic properties of β-lactamases are presented: substrate specificity, sensitivity to inhibitors, features of genetic determination. The special attention is given to β-lactamases of gram-negative bacteria TEM-, SHV-type and its role in the development of resistance to different β-lactams

Soluble cuticular wax composition and antimicrobial activity of the fruits of Chaenomeles species and an interspecific hybrid

Plants of the genus Chaenomeles Lindl. (Rosaceae) naturally grow in Southeast Asia and represent the richest resource of biologically active compounds with beneficial properties for humans. Plants of C. japonica (Thunb.) Lindl. and C. speciosa (Sweet) Nakai species, and interspecific hybrid C. × superba (Frahm) Rehder (C. japonica × C. speciosa, Superba group) have been successfully introduced in the steppe zone of Ukraine and bear fruits. In this study, we evaluated chemical composition of fruit cuticular waxes and antimicrobial activity of fruit extracts. The soluble waxes were characterized using gas chromatography-mass spectrometry (GC-MS), and 26–36 compounds, representing 91.7–96.6% of the total soluble cuticular waxes, were identified. Waxes of Chaenomeles fruits belonged to six classes, namely fatty acids, alcohols, aldehydes, esters, ethers and alkanes. Aldehydes 7-hexadecenal and heptacosanal, and alkanes hexatriacontane and tetrapentacontane were the main constituents in the soluble cuticular waxes of C. speciosa and C. × superba fruits, accounting for more than half of the total contents. However, alkane tetrapentacontane, alcohol 8,10-hexadecadien-1-ol and heptacosanal prevailed in C. japonica fruit waxes. Isopropanolic fruit extracts exhibited dose-dependent antimicrobial activity against four Gram-negative bacteria, five Gram-positive bacteria and one fungal strain in the disc diffusion assay. In general, extracts from the Chaenomeles fruits demonstrated higher activity against Gram+ bacteria than Gram- strains. The strongest inhibiting activity was shown against Staphylococcus epidermidis (by the fruit extracts of C. × superba and C. speciosa), Micrococcus lysodeikticus and Candida albicans (both by C. × superba fruit extract). Results of the study confirmed accumulation of the bioactive compounds in the fruit waxes of different Chaenomeles species and antimicrobial ability of Chaenomeles fruits as well. These findings revealed the bioactive compounds in fruit cuticular waxes and suggested health-promoting properties of introduced Chaenomeles species

Phytochemical profiles and antimicrobial activity of the inflorescences of Sorbus domestica, S. aucuparia, and S. torminalis

The genus Sorbus L. is known for its extremely complex taxonomical relationships and health-promoting phytochemicals included in the composition of its floral constituents. The inflorescences of three Sorbus species (rowans), characterized by distinct molecular-genetic traits, were studied in order to examine the possible chemotaxonomic and antimicrobial value of their metabolites. GC–MS profiling of the hexane extracts of S. domestica, S. aucuparia, and S. torminalis inflorescences identified a total of 87 components, which represented six chemical classes (hydrocarbons, alcohols, esters, fatty acid, aldehydes, and ketones) and miscellaneous minor floral constituents (1-methylinosine, 5-amino tetrazole, 1,4-dimethylbenzene, 3,5-bis(1,1-dimethylethyl)-phenol, 3-acetoxy-7,8-epoxylanostan-11-ol, cycloeucalenol acetate, etc.). Principal component analysis (PCA) of the qualitative and quantitative heterogeneity of the floral metabolites determined 1-hentetracontanol, nonacosane, pentadecyl acrylate, 1-methylhexacosane, cycloeucalenol acetate, butyl acetate, and urs-12-ene as the main components which contributed to the differences between S. domestica, S. aucuparia and S. torminalis and resulted in the distinction between the rowan species. Disc-diffusion assays showed variability in activity of inflorescence extracts against Gram-negative (Enterobacter dissolvens, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae) and Gram-positive (Micrococcus lysodeikticus, Staphylococcus aureus, and S. epidermidis) bacterial and clinical fungal (Candida albicans) strains. The effect of S. torminalis was high against S. epidermidis and P. aeruginosa, while it was at its lowest against clinical C. albicans strains. Inflorescences of S. domestica showed the highest inhibition of P. aeruginosa, and moderate effects against S. epidermidis and C. albicans. Inflorescences of S. aucuparia caused low to moderate growth inhibition of both Gram-positive and Gram-negative bacterial strains, while it showed the highest effect on C. albicans. Antimicrobial properties of rowan inflorescences may be attributed to oleic, linoleic, arachidic, hexadecanoic, and pentadecanoic acids, 24-norursa-3,12-diene, hexahydrofarnesyl acetone, cycloeucalenol acetate, and other compounds which have known bioactivity. These findings indicated rowan inflorescences as a rich source of valuable secondary metabolites and allow us to assume an application of the floral constituents as chemotaxonomic markers of the genus Sorbus species

Strains of soil microorganisms promising for the creation of a complex plant protection product against mycoses and harmful insects

We evaluated the antagonistic activity of 23 strains of Bacillus spр. against phytopathogenic fungi Fusarium oxysporum, F. culmorum, F. moniliforme, Cladosporium herbarum, Alternaria alternata and Aspergillus niger. The antagonistic activity was tested by agar diffusion (the method of blocks). For determining the influence of bacteria on barley plants , ardent seeds were treated by cultural liquid (dilution 1 : 10) for 2 hours and germinated in Petri dishes on moist filter paper. The fungistatic effect of Bacillus sрp. separately and in combination with entomopathogens (in equal ratio) was determined by the level of inhibition of the fungi Fusarium spp. on a solid nutrient medium with 5% of the culture liquid. Insecticidal activity of microorganisms was determined in the model experiments by the percentage of death of the caterpillar Archips podana Scop. Strains of Bacillus sp. KMB-3 and Bacillus sp. KMB-6 inhibited the growth of all test cultures (zones of growth inhibition 11.4–30.6 and 11.5–29.4 mm, respectively). We established the absence of antagonism between selected strains and entomopathogenic bacteria Bacillus thuringiensis IMB-7186, fungi Beauveria bassiana IMB-F-100043. We found that treatment of barley seeds with culture liquids of Bacillus sp. KMB-3 and Bacillus sp. KMB-6 didn’t have a negative effect on the morphometric indices and dry weight of seedlings. We established that the highest percentage of growth inhibition of F. culmorum IMB-F-50716 was provided by a complex of Bacillus sp. KMB-3, B. bassiana IMB-F-100043 and B. thuringiensis IMB-7186, whose action was at the same level as the action of monoculture Bacillus sp. KMB-3 (85.4% and 84.7%, respectively). The highest percentage inhibition of growth of F. oxysporum ІМВ-F-54201 was provided by a complex of strains of Bacillus sp. KMB-3 and B. bassiana IMB-F-100043, whose effect was slightly inferior to that of the monoculture Bacillus sp. KMB-3 (68.4% and 75.1%, respectively). The insecticidal activity of complexes Bacillus sp. KMB-3, B. bassiana IMB-F-100043, B. thuringiensis IMB-7186 or Bacillus sp. KMB-6, B. bassiana IMB-F-100043, B. thuringiensis IMB-7186 insignificantly differed from that of the complex entomopathogens B. bassiana IMB-F-100043 and B. thuringiensis IMB-7186 (71.1%, 73.3% death versus 80.0%). The selected microbial complexes can be considered as promising for the development of a preparation for the protection of plants against fungal diseases and harmful insects

Микробиологические аспекты пробиотических препаратов

The main stages of the beginning and development of probiotic preparations, the general characteristics of modern probiotics, the scope of their use in medicine and veterinary are presented. The characteristics of microorganisms (bifidus bacteria, lactobacteria and Bacillus bacteria) used in the production of probiotics, the basic requirements that should be met by these organisms, as well as prospects for the development of probiotics are shown. Розглянуто основні етапи виникнення та розвитку пробіотичних препаратів, загальну характеристику сучасних пробіотиків, сфери їх використання в медицині та ветеринарії. Наведено характеристику мікроорганізмів (біфідобактерій, лактобактерій, бактерій роду Bacillus), які використовуються у виробництві пробіотиків, основні вимоги, яким повинні відповідати ці мікроорганізми, а також перспективи розвитку застосування пробіотиків.Рассмотрены основные этапы возникновения и развития пробиотических препаратов, общая характеристика современных пробиотиков, сферы их использования в медицине и ветеринарии. Дана характеристика микроорганизмов (бифидобактерий, лактобактерий, бактерий рода Bacillus), используемых в производстве пробиотиков, основные требования, которым должны отвечать эти микроорганизмы, а также перспективы развития применения пробиотиков.

Mechanical, Electrical and Magnetic Properties of Ferrogels with Embedded Iron Oxide Nanoparticles Obtained by Laser Target Evaporation: Focus on Multifunctional Biosensor Applications

Hydrogels are biomimetic materials widely used in the area of biomedical engineering and biosensing. Ferrogels (FG) are magnetic composites capable of functioning as magnetic field sensitive transformers and field assisted drug deliverers. FG can be prepared by incorporating magnetic nanoparticles (MNPs) into chemically crosslinked hydrogels. The properties of biomimetic ferrogels for multifunctional biosensor applications can be set up by synthesis. The properties of these biomimetic ferrogels can be thoroughly controlled in a physical experiment environment which is much less demanding than biotests. Two series of ferrogels (soft and dense) based on polyacrylamide (PAAm) with different chemical network densities were synthesized by free-radical polymerization in aqueous solution with N, N'-methylene-diacrylamide as a cross-linker and maghemite Fe2O3 MNPs fabricated by laser target evaporation as a filler. Their mechanical, electrical and magnetic properties were comparatively analyzed. We developed a giant magnetoimpedance (MI) sensor prototype with multilayered FeNi-based sensitive elements deposited onto glass or polymer substrates adapted for FG studies. The MI measurements in the initial state and in the presence of FG with different concentrations of MNPs at a frequency range of 1-300 MHz allowed a precise characterization of the stray fields of the MNPs present in the FG. We proposed an electrodynamic model to describe the MI in multilayered film with a FG layer based on the solution of linearized Maxwell equations for the electromagnetic fields coupled with the Landau-Lifshitz equation for the magnetization dynamics.This work was supported in part within the framework of the state task of the Ministry of Education and Science of Russia 3.6121.2017/8.9; RFBR grants 16-08-00609-a, 18-08-00178, and by the ACTIMAT ELKARTEK grant of the Basque Country Government. Selected studies were made at SGIKER Common Services of UPV-EHU and URFU Common Services. We thank I.V. Beketov, A.A. Chlenova, S.O. Volchkov, V.N. Lepalovskij, A.M. Murzakaev and A.A. Svalova for special support

Transformations of substituted cyanoiminooctahydroquinazolines under oxidation conditions

Substituted quinazolines of various degrees of saturation and functionalization possess a wide spectrum of biological activity, in particular, anticancer activity, which predetermines the importance of obtaining new representatives of this type of compounds and studying their practically useful properties. Methods for the preparation of 2-cyanoiminoquinazolines are poorly described in the literature, while their properties and oxidation reactions have not been studied at all. We have analyzed the stability of tautomeric forms of 2-cyanoiminoquinazolines, determined the activation energy of their formation using quantum-chemical calculations, studied their transformation under the action of strong oxidants (CrO3/AcOH, NaNO2/AcOH). Selective aromatization of the azoheterocycle and hydrolysis of the -CN-group to form 2-aminocarbamoylquinazoline occurred during oxidation. An increase in temperature from 120 to 160° C (using CrO3) resulted in the formation of 2-nitrosoquinazoline. The structure of our new obtained substances was established by spectral methods (IR, 1H, 13C NMR, HSQC, NOESY), a scheme of their formation has been proposed