Studien zur Totalsynthese der Naturstoffe (-)-Englerin A und Crotogoudin

In the first part of the thesis four different approaches to the core structure of the novel guaiane sesquiterpene englerin A are described. The first approach features a Rh(II)-catalyzed generation of a cyclic carbonyl ylide from a diazoketone precursor which was trapped with allyl propiolate. The 1,3-dipolar cycloaddition led to the stereoselective formation of an oxygen-bridged polycyclic structure, however with opposite stereochemistry of the ether bridge compared to natural englerin. In further studies the core structure of the sesquiterpene was prepared by an oxy-Cope rearrangement/transannular epoxide opening sequence. Utilizing this strategy an analogue of the natural product without a glycolate at C-9 (9-deoxy-englerin) was synthesized. Studies on the cytotoxic activity of this analog proved the importance of the hydroxyl group and glycolic acid at C-9. The second part describes studies on the total synthesis of another terpene – crotogoudin. The key bicyclo[2.2.2]octane subunit was constructed by an early stage domino Michael reaction. Subsequent Stork reductive alkylation resulted in an opposite stereochemistry at C-10 in respect to the one in natural crotogoudin. Attempts to perform a late stage double Michael reaction were not successful, however the total synthesis of another diterpene – moluccanic acid, was achieved from the common intermediate.Im ersten Teil der Dissertation wurden vier verschiedene Zugänge zur Kernstruktur des neuen Guajan-Sesquiterpens Englerin A entwickelt. Die erste Methode beinhaltet eine Rh(II)- katalysierte Bildung eines cyclischen Carbonylylides aus einer Diazoketon-Vorstufe, welche mittels Allylpropiolat abgefangen wurde. Die 1,3-dipolare Cycloaddition führte zur stereoselektiven Bildung einer sauerstoffverbrückten polycyclischen Struktur, jedoch wies die Etherbrücke im Vergleich zu Englerin A die entgegengesetzte Stereochemie auf. In weiteren Studien konnte die Kernstruktur des Sesquiterpens über eine Oxy-Cope Umlagerung und anschließende transannulare Epoxidöffnung erhalten werden. Mittels dieser Synthesestrategie konnte ein Analogon des Naturstoffes, ohne Glykolat an C-9 synthetisiert werden. Studien zur cytotoxischen Aktivität des Analogons bewiesen die bedeutende Rolle der Hydroxygruppe und der Glykolsäure an C-9. Der zweite Teil der Dissertation befasst sich mit Studien zur Totalsynthese eines weiteren Terpens- Crotogoudin. Die Schlüsselverbindung ein Bicyclo[2.2.2]octan wurde über eine Domino Michael Reaktion in einem frühen Stadium der Synthese aufgebaut. Die anschließende Stork Alkylierung führte zur entgegengesetzten Stereochemie an C-10, verglichen mit dem Naturstoff Crotogoudin. Der Versuch einer doppelten Michaeladdition in einem späten Stadium der Synthese scheiterte, jedoch war die Totalsynthese eines anderen Diterpens erfolgreich - Moluccansäure, diese konnte aus dem gemeinsamen Intermediat synthetisiert werden

The role of environmental education in formation of environmental literacy of society

The article explores the role of ecological education in the formation of ecological literacy of society at the current stage of development of pedagogical thought. The main approaches to studying various aspects of environmental education are discussed. An overview of the main directions in this scientific field is given and the peculiarities of their interpretation by researchers are analyzed. This research investigates the concepts and meanings associated with environmental education. The study finds that environmental education and learning are practical and interdisciplinary, seeking to facilitate harmonious interaction between humans and the natural world. The paper also emphasizes the significance of the mentioned above concepts within the national education system

The Northern Sea Route as a reefer container transport corridor

The use of the Northern Sea Route as a transport corridor between the European and Asian continents is currently attracting increased interest in the trade, economic and logistic communities. The possibility to deliver cargo from Europe to Asia and back much faster is extremely attractive for cargo owners in the conditions of instability of the development of modern regional economic trends, turbulence of the global economy as a whole. In the conditions of rapidly changing market demand and supply in the markets of food products in Europe and Asia, the use of the Northern Sea Route as the shortest route between two continents is becoming especially popular for operators in the field of perishable goods logistics. Nevertheless, the possibility of using the Northern Sea Route is significantly limited by the complexity of transporting cargo in the autumn-winter period due to the need for ice pilotage. Assessment of the competitiveness of the Northern Sea Route compared to traditional routes seems to be an important aspect of the formation of consumer preferences among the owners of perishable goods and operators of transportation in reefer containers. The paper proposes a method for assessing the competitiveness of the Northern Sea Route with respect to alternative routes, taking into account the specifics of transportation of perishable goods in reefer containers. Criteria and indicators of competitiveness of the compared routes are presented, covering the full range of economic and technological components that determine the handling and transportation of perishable goods in reefer containers

Quantitative Estimate of the Macropsychological State of Modern Russian Society

The authors give the quantitative estimation of the macropsychological state of modern Russian society based on its political, social and economic characteristics. For these purposes the composite index of the macropsychological state of society is developed. It combines two secondary indexes such as a societal psychological stability index and a societal socio-psychological well-being index

The role of ecolinguistics in traditional media and on the internet in terms of the coronavirus pandemic

The article touches upon the most up-to-date problem of language and ecology interaction in terms of frequently spoken event which has been mentioned everywhere for the last two years – coronavirus pandemic. This disease influenced almost all spheres of the life over the world. The spread of coronavirus infection also had an impact on the information environment and ecological model of communication as a whole. At present we can see how terms, ordinary words and our speech as a whole get another meaning or they are understood in a different way. In this study we analyzed the dissemination of information about coronavirus infection in traditional media, in social media and on YouTube video hosting (on the material of the popular Russian science blogs). Also we tried to assess the role of popular science content, advertising campaign in traditional media and rules for posting information on the spread and prevention of coronavirus infection in social networks in stabilizing the mood of society during the pandemic period

Conjugacy Separation Problem in Braids: an Attack on the Original Colored Burau Key Agreement Protocol

In this paper, we consider the conjugacy separation search problem in braid groups. We deeply redesign the algorithm presented in (Myasnikov & Ushakov, 2009) and provide an experimental evidence that the problem can be solved for $100\%$ of very long randomly generated instances. The lengths of tested randomly generated instances is increased by the factor of two compared to the lengths suggested in the original proposal for $120$ bits of security. An implementation of our attack is freely available in CRAG. In particular, the implementation contains all challenging instances we had to deal with on a way to $100\%$ success. We hope it will be useful to braid-group cryptography community

Vive la radiorésistance!: converging research in radiobiology and biogerontology to enhance human radioresistance for deep space exploration and colonization.

While many efforts have been made to pave the way toward human space colonization, little consideration has been given to the methods of protecting spacefarers against harsh cosmic and local radioactive environments and the high costs associated with protection from the deleterious physiological effects of exposure to high-Linear energy transfer (high-LET) radiation. Herein, we lay the foundations of a roadmap toward enhancing human radioresistance for the purposes of deep space colonization and exploration. We outline future research directions toward the goal of enhancing human radioresistance, including upregulation of endogenous repair and radioprotective mechanisms, possible leeways into gene therapy in order to enhance radioresistance via the translation of exogenous and engineered DNA repair and radioprotective mechanisms, the substitution of organic molecules with fortified isoforms, and methods of slowing metabolic activity while preserving cognitive function. We conclude by presenting the known associations between radioresistance and longevity, and articulating the position that enhancing human radioresistance is likely to extend the healthspan of human spacefarers as well