Design Synthesis (design + synthesis)

Distribution by Scientific Domains


Selected Abstracts


Design syntheses and mitochondrial complex I inhibitory activity of novel acetogenin mimics

FEBS JOURNAL, Issue 9 2000
Kaoru Kuwabara
Some natural acetogenins are the most potent inhibitors of mitochondrial complex I. These compounds are characterized by two functional units [i.e. hydroxylated tetrahydrofuran (THF) and ,,,-unsaturated ,-lactone ring moieties] separated by a long alkyl spacer. To elucidate which structural factors of acetogenins, including their active conformation, are crucial for the potent inhibitory activity we synthesized a novel bis-acetogenin and its analogues possessing two ,-lactone rings connected to bis-THF rings by flexible alkyl spacers. The inhibitory potency of the bis-acetogenin with bovine heart mitochondrial complex I was identical to that of bullatacin, one of the most potent natural acetogenins. This result indicated that one molecule of the bis-acetogenin does not work as two reactive inhibitors, suggesting that a ,-lactone and the THF ring moieties act in a cooperative manner on the enzyme. In support of this, either of the two ring moieties synthesized individually showed no or very weak inhibitory effects. Moreover, combined use of the two ring moieties at various molar ratios exhibited no synergistic enhancement of the inhibitory potency. These observations indicate that both functional units work efficiently only when they are directly linked by a flexible alkyl spacer. Therefore, some specific conformation of the spacer must be important for optimal positioning of the two units in the enzyme. Furthermore, the ,,,-unsaturated ,-lactone, the 4-OH group in the spacer region, the long alkyl tail attached to the THF unit and the stereochemistry surrounding the hydroxylated bis-THF rings were not crucial for the activity, although these are the most common structural features of natural acetogenins. The present study provided useful guiding principles not only for simplification of complicated acetogenin structure, but also for further wide structural modifications of these molecules. [source]


Genetically engineered multiband high-impedance frequency selective surfaces

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2003
Douglas J. Kern
Abstract A methodology is presented for the design synthesis of metamaterials that act as thin multifrequency artificial magnetic conductors. These structures are realized by placing a frequency-selective surface above a conventional prefect electric conductor, separated by a thin dielectric layer. The frequency-selective surface design is optimized using a micro-genetic algorithm to operate at multiple, narrow frequency bands. Two examples of genetically engineered multiband high-impedance frequency-selective surfaces (that is, artificial magnetic conductors) are presented and discussed. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 400,403, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11073 [source]


Material and digital design synthesis

ARCHITECTURAL DESIGN, Issue 2 2006
Michael Hensel
Abstract The advanced material and morphogenetic digital design techniques and technologies presented in this journal call for a higher level methodological integration, which poses a major challenge for the next generation of multidisciplinary architectural research and projects. This collaborative task encompasses the striving for an integrated set of design methods, generative and analytical tools and enabling technologies that facilitate and instrumentalise evolutionary design, and evaluation of differentiated material systems towards a highly performative and sustainable built environment. Michael Hensel and Achim Menges describe recent progress towards a higher-level design synthesis of material self-organisation, digital morphogenesis, associative parametric modelling and computer-aided manufacturing (cam) on the basis of two works produced within the context of the Emergent Technologies and Design Masters programme at the Architectural Association in London, and a recent competition entry by Scheffler + Partner Architects and Achim Menges. Copyright © 2006 John Wiley & Sons, Ltd. [source]