Search results for "Molecular chemistry"
showing 10 items of 1103 documents
Biodegradability Prediction of Fragrant Molecules by Molecular Topology
2016
Biodegradability is a key property in the development of safer fragrances. In this work we present a green methodology for its preliminary assessment. The structure of various fragrant molecules is characterized by computing a large set of topological indices. Those relevant to biodegradability are selected by means of a hybrid stepwise selection method to build a linear classifier. This model is compared with a more complex artificial neural network trained with the indices previously found. After validation, the models show promise for time and cost reduction in the development of new, safer fragrances. The methodology presented could easily be adapted to many quasi-big data problems in R…
Todavía unas palabras sobre las venas cefálica y basílica
1993
Ever since 1879, when Josef Hyrtl first formulated his thesis that the names of the cephalic and basilic veins, as applied to the arm veins, were of Arab origin, a discussion began between philologists and historians of medicine as the former defended the Greek source of such denominations whilst the latter shared the view of the Viennese anatomist. The author, after making a critical review of the -relevant works published hitherto, unearthes a text drawn from a Persian manuscript dating back to the 15th century that, in his view, confirms the rigthness of the Viennese anatomist's thesis.
Discovery of benzimidazole-based Leishmania mexicana cysteine protease CPB2.8ΔCTE inhibitors as potential therapeutics for leishmaniasis
2018
Abstract: Chemotherapy is currently the only effective approach to treat all forms of leishmaniasis. However, its effectiveness is severely limited due to high toxicity, long treatment length, drug resistance, or inadequate mode of administration. As a consequence, there is a need to identify new molecular scaffolds and targets as potential therapeutics for the treatment of this disease. We report a small series of 1,2‐substituted‐1H‐benzo[d]imidazole derivatives (9ad) showing affinity in the submicromolar range (Ki = 0.150.69 μM) toward Leishmania mexicanaCPB2.8ΔCTE, one of the more promising targets for antileishmanial drug design. The compounds confirmed activity in vitro against intrace…
Supramolecular Adducts of Ferrocene and Five Bile Acid Derived Triolides
1997
Formation of supramolecular adducts of ferrocene (guest) and cyclic head-to-tail trimers (hosts) derived from bile acid: 3α-hydroxy-5β-cholan-24-oic acid triolide (1), 3α-hydroxy-7-oxo-5β-cholan-24-oic acid triolide (2), 3α-hydroxy-12-oxo-5β-cholan-24-oic acid triolide (3), 3α-hydroxy-7α-trifluoroacetoxy-6β-cholan-24-oic acid triolide (4) and 3α-hydroxy-12α-TFA-5β-cholan-24-oic acid triolide (5) (TFA = trifluoroacetoxy) have been studied by 1H NMR. The best computer-assisted data fitting on the 1H-NMR chemical shift data was given by a 1:2 (guest/host) association model. The association constants vary in the range 170–990 M−1, 7-oxo-substituted triolide 2 and 12α-TFA triolide 5 showing the …
Zinc Binding Sites Conserved in Short Neuropeptides Containing a Diphenylalanine Motif
2019
A diphenylalanine motif in peptides plays a crucial role in supramolecular systems. The current work represents a novel strategy in which a diphenylalanine motif in the central domain of neuropeptides conserves the specific Zn2+ binding site and prevents "hopping" of the Zn2+ ion between alternative metal binding sites. Alternative metal binding sites may also include carboxylic atoms in the terminal domains of a peptide. Therefore, one needs to design a peptide in which the metal will not bind the carboxylic groups in the terminal domains. Herein, we propose that engineering and designing peptides with a diphenylalanine motif in the central domain may yield excellent metal chelators.
Pyrene derived functionalized low molecular weight organic gelators and gels
2008
Pyrene derived binary functionalized low molecular weight organic gelators (FLMOGs) and gels thereof in selected organic solvents were synthesized and characterized. The functionality refers to a functional group that does not take part in formation of the supramolecular gel network, but remains free and available for other purposes, such as to bind nanoparticles or other molecules into the gel structure. Functional groups were observed to disturb gel formation strongly, if they interact with each other within the same supramolecule due to the formation of competitive structures. Preventing such interactions restored the original gel properties. A gel with weaker supramolecular bonding than…
Multiscale modeling on biological systems
2018
Development of Polyamine‐Substituted Triphenylamine Ligands with High Affinity and Selectivity for G‐Quadruplex DNA
2019
Currently, significant efforts are devoted to designing small molecules able to bind selectively to guanine quadruplexes (G4s). These noncanonical DNA structures are implicated in various important biological processes and have been identified as potential targets for drug development. Previously, a series of triphenylamine (TPA)-based compounds, including macrocyclic polyamines, that displayed high affinity towards G4 DNA were reported. Following this initial work, herein a series of second-generation compounds, in which the central TPA has been functionalised with flexible and adaptive linear polyamines, are presented with the aim of maximising the selectivity towards G4 DNA. The acid-bas…
The Application of the Essential Oils of Thymus vulgaris L. and Crithmum maritimum L. as Biocidal on Two Tholu Bommalu Indian Leather Puppets
2021
The chemical profile of the Thymus vulgaris (Lamiaceae) essential oil (EO) was investigated in order to evaluate its biological properties against microorganisms affecting two Tholu Bommalu, typical Indian leather puppets stored at the International Puppets Museum “Antonio Pasqualino” of Palermo, Italy. A GC–MS analysis, using both polar and apolar columns, was used to determine the chemical composition of the essential oil. The aim of this study was to evaluate the antimicrobial effectiveness of the Thymus vulgaris and Crithmum maritimum essential oils in vapor phase to disinfect heritage leather puppets. Pieces of leather artifacts that were affected by different bacterial colonies were e…
1,5-Disubstituted 1,2,3-Triazoles as Amide Bond Isosteres Yield Novel Tumor-Targeting Minigastrin Analogs.
2021
[Image: see text] 1,5-Disubstituted 1,2,3-triazoles (1,5-Tz) are considered bioisosteres of cis-amide bonds. However, their use for enhancing the pharmacological properties of peptides or proteins is not yet well established. Aiming to illustrate their utility, we chose the peptide conjugate [Nle(15)]MG11 (DOTA-dGlu-Ala-Tyr-Gly-Trp-Nle-Asp-Phe-NH(2)) as a model compound since it is known that the cholecystokinin-2 receptor (CCK2R) is able to accommodate turn conformations. Analogs of [Nle(15)]MG11 incorporating 1,5-Tz in the backbone were synthesized and radiolabeled with lutetium-177, and their pharmacological properties (cell internalization, receptor binding affinity and specificity, pla…