A gyökfogó dokozahexaénsav mint agyvédő = Docosahexaenoic acid (DHA) as a free radical scavenger brain protector

Telítetlen zsírsavak (PUFA) fontos szerepet játszanak mint antioxidánsok az emberi testben, különös tekintettel az agyban. Lipidek szisztematikus számítási vizsgálatait az OTKA támogatás előtt már elkezdtük. A támogatás alatt 4 fő tématerületen értünk el eredményeket: Téma 1: Molekuláris konformció változások termodinamikai alapjai Egyszerű szerves molekulák, mint különböző szénhidrogén származékok, peptidek, folytonos termodinamikai fügvényeit állítottuk elő konformációs mozgások mentén. Téma 2: Zsirsavak konformációs információ Igazoltuk a PUFA-k flexibilátásbeli hasonlóságát a peptidekhez a potenciál felületek hasonlóságával. DHA a legfontosabb képviselője a PUFA családnak. Téma 3: Foszfolipidek konformációs információi Az első két téma eredmnyeinek felhasználásával egyszerű foszfolipid modelleket konstruáltunk. A két zsirsavlánc relativ helyzte, kölcsönhatásai, membránszerű elrendeződés esetén állt vizsgálataink homlokterében. Téma4 Szabadgyökök reakciói PUFA és PUFA modellekkel Szabadgyökök és reakcióik PUFA-val lipidek kettősrétegeiben biológiailag nagyon fontos folyamatok. Az E vitamin az egyik leghatékonyabb gyökfogó membránokban. A PUFA-kban mindig megtalálható allil-C-H kötések és különböző típusú gyökök reakcióinak kiterjedt vizsgálata folyt. | Polyunsaturated fatty acids (PUFA) play an important role as an antioxidant in the whole human body but more specifically in the brain. The overall project had 4 Topics: Topic 1 Fundamental Thermodynamics of Molecular Conformational Changes: Simple organic molecules were investigated in computing continues thermodynamic functions along conformational changes. These included a variety of compounds from hydrocarbons to peptides. Topic 2 Conformational information of fatty acid: Interestingly enough their felxibility was similar to that of peptides as could be judged from the similarity of their conformational potential energy surfaces. Topic 3 Conformational information of phospholipids: The results and experience obtained from the first two topics were used to construct simple phospholipids. The relative orientations of the two fatty acids in a phospholipid had to be studied to see if the nearly parallel arrangement within the lipid bilayer is enforced by nearest neighbour interaction or if such a geometry is an intrinsically stable structure. Topic 4 Free radical reactions with PUFA and PUFA models: Free radicals and their reactions with PUFA within the lipid bilayer are a biologically very important reactions. The generation of free radicals and their transformation as well as their reactions with allylic C-H bonds, which are always present is PUFA, has been studied in details

Molecular surgery concept from bench to bedside: a focus on TRPV1+ pain-sensing neurons

“Molecular neurosurgery” is emerging as a new medical concept, and is the combination of two partners: (i) a molecular neurosurgery agent, and (ii) the cognate receptor whose activation results in the selective elimination of a specific subset of neurons in which this receptor is endogenously expressed. In general, a molecular surgery agent is a selective and potent ligand, and the target is a specific cell type whose elimination is desired through the molecular surgery procedure. These target cells have the highest innate sensitivity to the molecular surgery agent usually due to the highest receptor density being in their plasma membrane. The interaction between the ligand and its receptor evokes an overactivity of the receptor. If the receptor is a ligand-activated non-selective cation channel, the overactivity of receptor leads to excess Ca2+ and Na+ influx into the cell and finally cell death. One of the best known examples of such an interaction is the effect of ultrapotent vanilloids on TRPV1- expressing pain-sensing neurons. One intrathecal resiniferatoxin (RTX) dose allows for the receptor-mediated removal of TRPV1+ neurons from the peripheral nervous system. The TRPV1 receptor-mediated ion influx induces necrotic processes, but only in pain-sensing neurons, and usually within an hour. Besides that, target-specific apoptotic processes are also induced. Thus, as a nano-surgery scalpel, RTX removes the neurons responsible for generating pain and inflammation from the peripheral nervous system providing an option in clinical management for the treatment of morphine-insensitive pain conditions. In the future, the molecular surgery concept can also be exploited in cancer research for selectively targeting the specific tumor cell

Model based groundwater pollution prediction

In this paper the cause of the groundwater pollution is a tank containing a liquid. In the liquid one or several pollutants are dissolved. Due to a hole/crack, which exists in the bottom of the tank the liquid filters in the soil and the pollutants migrate. A mathematical model is presented which describes the migration and reaction of a single or multiple pollutants and their interaction. This model facilitates the understanding and prediction of the groundwater pollution. Based on the model, numerical simulations are presented for groundwater pollution

Ortho-Methoxy Group as a Mild Inhibitor of the Reactions Between Carboxylic Acid and Phenols

According to the current database of natural products, over 25,000 compounds contain a vanillyl ring in their structure. The reasoning behind the high occurrence of the vanillyl ring structure seemed to be poorly understood, specifically the preference for a methoxy-substituted phenol structure as opposed to its dihydroxy analogue. To better understand this, we investigated the reaction mechanisms of two methoxyphenol structures, in syn and anti conformations, two hydroxyphenol structures, also in syn and anti conformations, and phenol as a reference structure, with acetic acid. Of the starting structures, the syn hydroxyphenol was found to be kinetically the most reactive, and formed the most stable product, while both hydroxyl-substituted phenols reacted more favorably with acetic acid than the methoxyphenols. A preference for the methoxyphenol molecule may exist as a way to hinder the formation of stable covalent bonds between natural products and cellular components. This work is licensed under a Creative Commons Attribution 4.0 International License

Glutathione as a Prebiotic Answer to alpha-Peptide Based Life.

The energetics of peptide bond formation is an important factor not only in the design of chemical peptide synthesis, but it also has a role in protein biosynthesis. In this work, quantum chemical calculations at 10 different levels of theory including G3MP2B3 were performed on the energetics of glutathione formation. The strength of the peptide bond is found to be closely related to the acid strength of the to-be N-terminal and the basicity of the to-be C-terminal amino acid. It is shown that the formation of the first peptide activates the amino acid for the next condensation step, manifested in bacterial protein synthesis where the first step is the formation of an N-formylmethionine dipeptide. The possible role of glutathione in prebiotic molecular evolution is also analyzed. The implications of the thermodynamics of peptide bond formation in prebiotic peptide formation as well as in the preference of alpha- instead of beta- or gamma-amino acids are discussed. An empirical correction is proposed for the compensation of the error due to the incapability of continuum solvation models in describing the change of the first solvation shell when a peptide bond is formed from two zwitterions accompanied by the disappearance of one ion pair

Molecular Design of Sugar-Based Polyurethanes

Polyurethane (PUs) are present in many aspects of everyday lives such as the rigid foam insulation panel in construction, seat cushion in automotive and elastomeric materials in medical industries. Conventional PUs are made from petrochemical based starting materials which raised severe health and environmental concerns. The substitution of petro-based polyols with carbohydrate polyols have shown to improve biodegradability and mechanical properties of PUs. Reaction pathways were examined with density functional theory to design novel environmental friendly polyurethanes. Based on the calculated thermodynamic properties, the reactivity of sugars towards isocyanates was compared. Fructose was found to be the most reactive as the corresponding fructose-isocyanate reaction has the lowest energy barrier of 135.6 kJ/mol. Therefore, the results obtained have encouraged the synthesis of fructose-based polyurethane foam. The synthesis was successful, and the produced fully fructose-based foam was stable with minimal sign of shrinkage. This work is licensed under a Creative Commons Attribution 4.0 International License

Molecular Surgery Concept from Bench to Bedside: A Focus on TRPV1+ Pain-Sensing Neurons

“Molecular neurosurgery” is emerging as a new medical concept, and is the combination of two partners: (i) a molecular neurosurgery agent, and (ii) the cognate receptor whose activation results in the selective elimination of a specific subset of neurons in which this receptor is endogenously expressed. In general, a molecular surgery agent is a selective and potent ligand, and the target is a specific cell type whose elimination is desired through the molecular surgery procedure. These target cells have the highest innate sensitivity to the molecular surgery agent usually due to the highest receptor density being in their plasma membrane. The interaction between the ligand and its receptor evokes an overactivity of the receptor. If the receptor is a ligand-activated non-selective cation channel, the overactivity of receptor leads to excess Ca2+ and Na+ influx into the cell and finally cell death. One of the best known examples of such an interaction is the effect of ultrapotent vanilloids on TRPV1-expressing pain-sensing neurons. One intrathecal resiniferatoxin (RTX) dose allows for the receptor-mediated removal of TRPV1+ neurons from the peripheral nervous system. The TRPV1 receptor-mediated ion influx induces necrotic processes, but only in pain-sensing neurons, and usually within an hour. Besides that, target-specific apoptotic processes are also induced. Thus, as a nano-surgery scalpel, RTX removes the neurons responsible for generating pain and inflammation from the peripheral nervous system providing an option in clinical management for the treatment of morphine-insensitive pain conditions. In the future, the molecular surgery concept can also be exploited in cancer research for selectively targeting the specific tumor cell