Manifestation of a Chiral Smectic C Phase in Diphenylbutadiene- Cored Bolaamphiphilic Sugars

A series of symmetrical bolaamphiphiles possessing a diphenylbutadiene core and glucopyranoside head groups linked together by oligomethylene spacers, were synthesized and their thermotropic liquid crystalline properties investigated by polarized light optical microscopy, differential scanning calorimetry, X-ray diffraction and electro-optic switching. In spite of the presence of chiral centers, amphiphilic sugars in general do not exhibit macroscopic chirality and this phenomenon is attributed to strong hydrogen bonding between sugar head groups resulting in microphase-segregated layer like arrangements. In the present study all the molecules investigated exhibited the smectic $C^*$ phase, i.e., tilted lamellar phase with acroscopic chiral ordering of the molecules. The stability of this phase increased with increase in the length of the oligomethylene spacers. Whereas for derivatives with spacers containing \leq 4 methylene groups, the smectic $C^*$ phase was observed only in the cooling phase, for those containing spacers with \geq 5 methylene groups this phase was observed both in the heating and cooling cycles. The absorption and fluorescence spectra of these materials suggest that the unusual observation of macroscopic chirality in these bolaamphiphiles containing free hydroxyl groups could be attributed to self-aggregating behavior of the diphenylbutadiene core

Path-breaking or history-repeating? Analysing the Paris Agreement's research and development paradigm for climate-smart agriculture

This chapter provides an initial exploration and analysis of agricultural research and development paradigms under the Paris Agreement for climate-smart agriculture. Drawing on diverse bodies of literature, this chapter provides an examination of agricultural socio-technical regimes with a focus on how problems, means and solutions are constructed by three broad archetypes: the intensive agricultural paradigm, the Life-Sciences Integrated paradigm, and the Ecological-Integrated paradigm. Re-conceptualisation of climate-smart agriculture in line with the Ecological-Integrated Paradigm is positioned as a critical step towards climate justice. Through an examination of the Paris Agreement and related documents, this chapter argues that the Paris Agreement creates an enabling environment for the development of an agricultural socio-technical regime more consistent with the existing intensive agricultural model than with genuine climate-smart agriculture

Recent progress in research on the pharmacological potential of mushrooms and prospects for their clinical application

International audienceFungi are considered one of the most diverse, ecologically significant, and economically important organisms on Earth. The edible and medicinal mushrooms have long been known by humans and were used by ancient civilizations not only as valuable food but also as medicines. Mushrooms are producers of high- and low-molecular-weight bioactive compounds (alkaloids, lectins, lipids, peptidoglycans, phenolics, polyketides, polysaccharides, proteins, polysaccharide-protein/peptides, ribosomal and non-ribosomal peptides, steroids, terpenoids, etc.) possessing more than 130 different therapeutic effects (analgesic, antibacterial, antifungal, anti-inflammatory, antioxidant, antiplatelet, antiviral, cytotoxic, hepatoprotective, hypocholesterolemic, hypoglycemic, hypotensive, immunomodulatory, immunosuppressive, mitogenic/regenerative, etc.). The early record of Materia Medica shows evidence of using mushrooms for treatment of different diseases. Mushrooms were widely used in the traditional medicine of many countries around the world and became great resources for modern clinical and pharmacological research. However, the medicinal and biotechnological potential of mushrooms has not been fully investigated. This review discusses recent advances in research on the pharmacological potential of mushrooms and perspectives for their clinical application