A new species of Ranunculus (Ranunculaceae) from Western Pamir-Alay, Uzbekistan

New data on the phylogeny of four rare and endemic species of RanunculusL.sect.Ranunculastrum DC. of western Pamir-Alai, one of which is new to science, have been obtained. Ranunculustojibaevii sp. nov., from the Baysuntau Mountains, Western Hissar Range of Uzbekistan, is described. The new species is closely related to R.botschantzevii Ovcz., R.convexiusculus Kovalevsk. and R.alpigenus Kom., but differs in the blade of the radical leaves, which is rounded-reniform, segments 3-5-dissected, each 2-5-partite with elongated, rounded apical lobes. A phylogenetic analysis, using both the nuclear ribosomal internal transcribed spacer (ITS) and cpDNA (matK, rbcL, trnL-trnF), was informative in placing R.tojibaevii in context with its most closely-related species. Discussion on the geographic distribution, updated identification key, a detailed description, insights about its habitat and illustrations are provided.

Physico-Chemical and Antioxidant Properties of Skimmed Varenets (Slavic Baked Milk Yogurt) Mixed with Enzyme-Modified Potato Starches

The present studies have examined the effect of potato starches treated with amylase B.licheformis (Bl) (laboratory sample) or Amylosubtilin® (AM) (Berdsk Factory of Biological Preparations (now: Sibbiofarm), Russia) in different concentrations on the quality of Slavic skim milk drink Varenets made from baked milk. The baked milk is milk heated to 98 °C for 3 hours, it has a sweet aroma and taste and creamy hue. The presence of enzyme-modified potato starches (Bl or AM) has been found to promote the activation of lactic acid fermentation, the accumulation of exopolysaccharides, and such stabilized products have a higher viscosity, a lower percentage of syneresis compared to the control sample. The antioxidant capacity of the Varents samples after fermentation was evaluated by two assays: analysis of radical capture activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH •); and the ability to restore Fe + 3 (Iron Reduction Antioxidant Ability Assay, FRAP). All Varentz samples showed different values for DPPH, FRAP assays depending on the starches used. The Introduction of pre-fermented starches into defatted jam promotes formation of enhanced antioxidant properties of milk product. The use of starches modified with enzymes improves sensory characteristics, in particular, as a fat imitator, formsfull taste of the drink.

Inventory of some Tulipa species from Uzbekistan using DNA barcoding

Climate fluctuations in the Quaternary period in significantly influenced the evolution and distribution of plants, which caused to a serious genetic effects and speciation activity [1]. Thus, Central Asia is distinguished by a wide variety of flora, including 9520 species, while 20% are endemics [2]. Great phenotypic diversity of the wild flora in Uzbekistan, numbering about 4400 species of vascular plants is determined by the peculiar climatic conditions, a variety of zoning, altitudinal zones [3]. At the same time, being one of the centers of early diversification of monocotyledonous geophytes, taxonomically complex representatives of this group are not sufficiently involved in phylogenetic studies. This study is a pilot study of the flora of Uzbekistan using DNA barcoding method, that based on sequencing of phylogenetically significant sequences. Four plastid (rbcL, psbA-trnH, matK, trnL-F) and one nuclear (ITS) markers were used for species identification of the genus Tulipa. The results of molecular phylogenetic analysis for 15 species of Tulipa (Liliaceae) using the marker sequence encoding ITS fragment are presented. The successful usefulness of DNA technology for genetic inventory has been demonstrated.

Thiacalixarene based quaternary ammonium salts as promising antibacterial agents

The search for new antibacterial and antiseptic drugs is an urgent problem due to the resistance of microorganisms to existing drugs. In this work, for the first time, the design of antibacterial and bactericidal agents based on quaternary ammonium compounds on thiacalixarene macrocyclic platform was proposed and implemented. A series of tetrasubstituted quaternary ammonium salts with different nature and length of the substituent (-N⁺(CH₃)₂R, R = CH₂Ph, C_nH_2n+1, n = 1, 4, 8, 10) based on p-tert-butylthiacalix[4]arene in cone and 1,3-alternate conformations was obtained with excellent yields. The obtained compounds have a high antibacterial effect against Gram-positive (S. aureus, S. epidermidis, B. subtilis) bacteria comparable with commercial antiseptics chlorhexidine, miramistin and benzalkonium chloride. It was found that quaternary ammonium derivatives of thiacalix[4]arene in 1,3-alternate conformation more effectively inhibit the growth of the tested bacterial strains in comparison with compounds in cone conformation. Cytotoxicity studies on human skin fibroblast (HSF) cells demonstrated that all compounds were less toxic compared to reference drugs. The different type of interaction of the studied compounds with model DPPC lipid membranes explains different antibacterial activity and cytotoxicity of compounds. The compounds in cone conformation are adsorbed on the DPPC vesicles membrane surface, while the incorporation of lipophilic alkyl fragments of macrocycles in 1,3-alternate conformation into the membrane leads to "clumping" of DPPC vesicles. It was shown the saving of antibacterial activity of thiacalixarene derivatives in 1,3-alternate conformation on Gram-positive clinical strains. The obtained results allow viewing the described thiacalixarene based quaternary ammonium compounds as promising molecules in the development of the new antibacterial agents.

Novel Bis-Ammonium Salts of Pyridoxine: Synthesis and Antimicrobial Properties

A series of 108 novel quaternary bis-ammonium pyridoxine derivatives carrying various substituents at the quaternary nitrogen’s and acetal carbon was synthesized. Thirteen compounds exhibited antibacterial and antifungal activity (minimum inhibitory concentration (MIC) 0.25–16 µg/mL) comparable or superior than miramistin, benzalkonium chloride, and chlorhexidine. A strong correlation between the lipophilicity and antibacterial activity was found. The most active compounds had logP values in the range of 1–3, while compounds with logP > 6 and logP < 0 were almost inactive. All active compounds demonstrated cytotoxicity comparable with miramistin and chlorhexidine on HEK-293 cells and were three-fold less toxic when compared to benzalkonium chloride. The antibacterial activity of leading compound 5c₁₂ on biofilm-embedded Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli or Pseudomonas aeruginosa was comparable or even higher than that of the benzalkonium chloride. In vivo 5c₁₂ was considerably less toxic (LD₅₀ 1705 mg/kg) than benzalkonium chloride, miramistine, and chlorhexidine at oral administration on CD-1 mice. An aqueous solution of 5c₁₂ (0.2%) was shown to be comparable to reference drugs efficiency on the rat’s skin model. The molecular target of 5c₁₂ seems to be a cellular membrane as other quaternary ammonium salts. The obtained results make the described quaternary bis-ammonium pyridoxine derivatives promising and lead molecules in the development of the new antiseptics with a broad spectrum of antimicrobial activity.

Antibacterial activity profile of miramistin in in vitro and in vivo models

BACKGROUND

Miramistin is a widely used antiseptic, disinfectant and preservative, and one of the most popular antimicrobial agents on pharmaceutical market of the Russian Federation (http://www.dsm.ru/en/news/385/). However, there is a lack of reported systematic data on antibacterial efficacy of this agent obtained in accordance with the international standards.

AIM

This paper represents a systematic study of antibacterial properties of miramistin. Another objective of this work is to evaluate and compare the exploratory performance of in vitro and in vivo protocols of antiseptics' efficacy testing using miramistin as the reference antiseptic.

METHODS

Antibacterial activity of 0.1% and 0.2% aqueous solutions of miramistin against two museum strains of S. aureus (ATCC 209p) and E. coli (CDC F-50) was studied. Three standard in vitro laboratory tests (microdilution test, suspension test, and metal surface test), and one in vivo test (on rat's skin) were used. The study was conducted in accordance with the international regulatory documents.

RESULTS

Miramistin showed high bactericidal activity against the studied bacterial pathogens in the standard in vitro tests. Thus, in the microdilution test it showed expressed activity against S. aureus (MIC 8 μg/ml, MBC 16 μg/ml) and E. coli (MIC 32 μg/ml, MBC 128 μg/ml). In the suspension test, miramistin decreased the amount of colony forming units by at least 6 log10 units for S. aureus, and by at least 4.5 log10 units for E. coli. Transition to the metal surface test led to significant decrease of antibacterial activity by 1-3 log10 units as compared to the suspension test. Further dramatic reduction of antiseptic activity (by 3-4 log10 units) was observed in in vivo rat skin test. Addition of a protein contaminant (bovine serum albumin) led to a general decrease in the effectiveness of miramistin against the test pathogens (typically, by 1-2 log10 units). An interesting effect of exposure time-dependent reversal of miramistin's specificity to the studied Gram-positive S. aureus and the Gram-negative E. coli organisms was observed in the metal surface test.

CONCLUSIONS

The results of this work provide systematic data on antibacterial efficacy of miramistin. They also underscore the need in relevant in vivo models for evaluation of antiseptics' efficacy. While the existing in vitro methods can be successfully applied at the discovery stages, it is necessary to use more realistic in vivo models at more advanced development stages. The observed selectivity reversal effect should be taken into account when carrying out the antiseptics' efficacy testing and surface disinfection procedures.

Comment on "An unexpected formation of the novel 7-oxa-2-azabicyclo[2.2.1]hept-5-ene skeleton during the reaction of furfurylamine with maleimides and their bioprospection using a zebrafish embryo model" by C. E. Puerto Galvis and V. V. Kouznetsov, Org. Biomol. Chem., 2013, 11, 407

It has been proved that the reaction between furfuryl amines and N-R-maleimides leads to the formation of aza-Michael addition products - 3-(furylmethylamino)-N-R-pyrrolidine-2,5-diones, instead of 7-oxa-2-azabicyclo[2.2.1]hept-5-enes, as this journal reported previously.

[Distribution and physiology of microorganisms in petrochemical oily sludge of plant]

The occurrence, vertical distribution, and the physiological state of microorganisms in a petrochemical oily sludge deposit were studied. The total number and the number of viable microbial cells at depths of 0.2 and 3 m were about 10 and 10(8) cells/g dry wt. sludge. Most microbial cells taken from the middle (1 m deep) and the bottom (3 m deep) sludge horizons showed a delayed colony-forming ability, which suggested that the cells occurred in a hypometabolic state. The relative number of microaerobic denitrifying microorganisms steeply increased with depth. The amount of microorganisms tolerant to 3, 5, and 10% NaCl and capable of growing at 7 and 40 degrees C varied from 10(2) to 10(8) CFU/g dry wt. sludge. Petrochemical oily sludge was found to maintain the growth of heterotrophs, among which the degraders of oily sludge and ten different individual polycyclic aromatic hydrocarbons were detected. The occurrence of highly adaptable microorganisms with an adequate metabolic potential in the petrochemical oily sludge deposit implies that its bioremediation is possible without introducing special microorganisms.

[Alternative pathways of the initial transformation of 2,4,6-trinitrotoluene by yeasts]

A new model for the initial transformation of 2,4,6-trinitrotoluene (TNT) by facultatively anaerobic and aerobic yeasts is presented. The model is based on the data that Saccharomyces sp. ZS-A1 was able to reduce the nitrogroups of TNT with the formation of 2- and 4-hydroxyaminodinitrotoluenes (2-HADNT and 4-HADNT) as the major early TNT metabolites (the molar HADNT/TNT ratio reached 0.81), whereas aminodinitrotoluenes (ADNTs) and the hydride-Meisenheimer complex of TNT (H-TNT) were the minor products. Candida sp. AN-L13 almost completely transformed TNT into H-TNT through the reduction of the aromatic ring. Candida sp. AN-L14 transformed TNT through a combination of the two mechanisms described. Aeration stimulated the production of HADNT from TNT, whereas yeast incubation under stationary conditions promoted the formation of HADNT. The transformation of TNT into HADNT led to a tenfold increase in the acute toxicity of the TNT preparation with respect to Paramecium caudatum, whereas the increase in the toxicity was about twofold in the case of the alternative attack at the aromatic ring.

[Basic approaches to medical, forensic, and biomechanical studies in expert evaluation of a car injury]

Modern approaches to forensic medical expert evaluation of car injuries are discussed. Many problems remain unsolved after examination of injuries in victims inside the car, which negatively tells on the versions suggested during criminal investigation of car accidents. The experts often neglect the most sensitive methods for evaluation of these injuries and many fundamental approaches to the problem: differential diagnosis of primary and secondary injuries; basic medical and biomechanical methods and studies of the clues; fundamentals of total systems evaluation of the results of forensic medical expert evaluation.

Physiological mechanisms of the "arousal response" in animals in a state of hypobiosis

In a state of hypobiosis in white rats it was found that the previously described [4, 6] "arousal response" is characterized by a flareup of motor activity with a definite coordinated structure of the motor acts in response to a change in the animal's posture. Repeated reproduction of this response leads to a rapid summation of the electromyographic activity and a rise in the temperature. In experiments on heterothermic animals these responses are even more pronounced and are accompanied by a restoration of the original body posture and substantial temperature rise. Such an effective process of heat formation in the bodies of heterothermic animals during the "arousal response" may be associated with the mechanism of "special" awakening under conditions of reduced activity.