1,721,103 research outputs found
Necrológicas: Dr. Emilio G. Morini (1930-2017)
No full textEl pasado viernes 21 julio falleció el Dr. Emilio G. Morini, a la edad de 100 años. El Dr. Morini nació el 8 de junio de 1917 y egresó como Doctor en Medicina Veterinaria de la Facultad de Agronomía y Veterinaria de la Universidad de Buenos Aires en 1938, perfeccionándose en su especialidad -Parasitología y Enfermedades Parasitarias- en Estados Unidos y en la Escuela de Alfort (Francia) con el Profesor J. Guilhon.Academia Nacional de Agronomía y Veterinari
Lost and found in sweeteners : forgotten molecules and unsolved problems in the chemistry of sweet compounds
No full textThe chemistry of sweet compounds has been an ideal training ground for researchers in the field of taste for a very long time. Sweeteners have a huge importance in the food and pharmaceutical industries, but they have also attracted much interest in connection with their biological function and the general mechanism of action of sweet compounds. Several factors contributed to a large and varied production of scientific data in this field: among these the existence of several active compounds in the plant kingdom, the diversity of structural, stereochemical and conformational hallmarks, the intriguing aspects related to their modulation, inhibition and synergy. Among all molecules that have been isolated and synthesized, only a few have successfully reached the final goal of commercial development while some have been used to derive models and structure-activity relationships. Nevertheless, there is a number of very interesting compounds of natural or synthetic origin that - after a short period of popularity - were apparently lost or forgotten, without any further development. The article will give an overview on some of these compounds and discuss, in the light of current knowledge, the contribution that chemistry still could give in the sweeteners area
Buon risultato funzionale in mani traumatizzate ai limiti dell'amputazione
No full textBuon risultato funzionale in mani traumatizzate ai limiti dell'amputazion
Isovanillyl sweeteners. From molecules to receptors
No full textSystematic modification of the structure of the sweet natural compound phyllodulcin,
containing the isovanillyl glucophoric group, led to the synthesis of about 120 compounds.
Features of the heterocyclic ring conferring high sweetness potency were identified.
A strong increase in sweetness was obtained by the introduction of sulfur atoms in the ring
and by separation of the enantiomers. Results of the quantitative structure–activity relationship
(QSAR) studies on this series are reported. Application of the pseudoreceptor modeling
approach afforded a three-dimensional binding site model for isovanillyl sweeteners.
Extension of this methodology to a large group of structurally diverse compounds, including
the commonly used sweeteners, gave a general pseudoreceptor for the sweet compounds,
consisting of 16 amino acids. This pseudoreceptor, which has the peculiarity of giving a
semiquantitative evaluation of the sweetness intensity, could be used as a valid tool to model
the ligand–receptor interactions and to suggest some clues about the identification of a possible
binding site once the receptor protein(s) are obtained
Molecular modelling and models in the study of sweet and umami taste receptors : A review
No full textThe mechanism of action of tastants has been under investigation for many years. For the sweet taste several models have been developed to describe the nature and topological arrangement of the glucophores of ideal sweet compounds and/or the recognition sites of the sweet taste receptor. In less than a decade our knowledge about the mechanism of sweet taste chemoreception has grown enormously, following the identification and cloning of T1Rs. The observation that receptor cells co-expressing T1R2 and T1R3 respond to a great variety of sweet compounds has been generally interpreted as an inference that there is a single heterodimeric receptor for sweet taste. The three-dimensional structure of the receptor is not known and alternative methodologies are required to model the binding of sweet compounds. Therefore homology modelling and molecular modelling become indispensable tools to suggest point mutations which further define the binding regions. Only their cooperative effect allowed researchers to determine several molecular mechanisms of the sweet taste receptors, including the modality of action of blockers and positive allosteric modulators. For umami taste, despite the general appreciation of the meaty, mouth filling and rich taste found in many foods (and the great interest of the food industry thereof), the existence of an umami receptor has been accepted only after its cloning. Probably because of this, no umami taste receptor models have been developed, while the molecular mechanism for its synergism has been unravelled before that of the sweet taste receptor
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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