Enantiomers
Mostrando 1-12 de 214 artigos, teses e dissertações.
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1. Different Degradation Patterns of Chiral Contaminant Enantiomers: Paclobutrazol as a Case Study
Studies often neglect the different trends between enantiomers in soil chiral contaminants. In the present study, paclobutrazol was chosen as the target analyte and the selective degradation patterns of this chiral pesticide were investigated in soils. After 14 days of culture, the degradation kinetics results demonstrated the degradation process of the two
J. Braz. Chem. Soc.. Publicado em: 2021-06
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2. AVALIAÇÃO DA BIOMASSA DE FUNGOS AMAZÔNICOS COMO FONTE DE LIPASES PARA BIOCATÁLISE
We evaluated the biomass of twenty Amazonian fungal isolates as a potential source of mycelium-bound lipases with hydrolytic, synthetic or enantioselective activity for biocatalysis application. We compared the hydrolytic activity of three biomass treatments (delipidated, non-delipidated and cultivated in medium without inducer). Delipidated biomass showed b
Quím. Nova. Publicado em: 2020-02
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3. Synthesis, Characterization and Conformational Analysis of Two Novel 4(1H)‑Quinolinones
Quinolinones are a class of organic compounds known as alkaloids found in several plants and also can be synthesized. Their large use in therapies regards their wide biological potential like antitumor, psychiatric and neurological agents. Two substances were structurally characterized: (E)-3-(2-nitrobenzylidene)-2-(4-methoxyphenyl)-1-(phenylsulfonyl)-2,3-di
J. Braz. Chem. Soc.. Publicado em: 2020-01
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4. Deracemization of sec-Alcohols through Sequential Application of C. albicans and Ketoreductases
A biocatalytic cascade process was developed using immobilized cells of the wild type yeast Candida albicans CCT 0776 in calcium alginate beads and a commercially available ketoreductase. The aim was to promote deracemization by stereoinversion of (±)-1-arylethanols in high substrate concentration (above 100 mmol L-1) to prepare the (R)-enantiomers of the a
J. Braz. Chem. Soc.. Publicado em: 2019-04
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5. Asymmetric bioreduction of β-ketoesters derivatives by Kluyveromyces marxianus: influence of molecular structure on the conversion and enantiomeric excess
ABSTRACT This study presents the bioreduction of six β-ketoesters by whole cells of Kluyveromyces marxianus and molecular investigation of a series of 13 β-ketoesters by hologram quantitative structure-activity relationship (HQSAR) in order to relate with conversion and enantiomeric excess of β-stereogenic-hydroxyesters obtained by the same methodology. F
An. Acad. Bras. Ciênc.. Publicado em: 07/08/2017
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6. Synthesis of N,O-Type Inherently Chiral Calix[4]arenes Substituted on the Lower Rim and their Organocatalysis Properties
This work presented the first study of organocatalytic behaviors of inherently chiral calix[4]arenes substituted at the lower rim. A pair of N, O-type enantiomers based on inherently chiral calix[4]arenes substituted at the lower rim were readily synthesized and applied to catalyze Henry reaction between aromatic aldehydes and nitromethane. Their organocatal
J. Braz. Chem. Soc.. Publicado em: 2017-08
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7. FÁRMACOS QUIRAIS EM DIFERENTES MATRIZES AMBIENTAIS: OCORRÊNCIA, REMOÇÃO E TOXICIDADE
In recent decades, the occurrence of pharmaceuticals in the environment has been widely reported due to their high frequency and recalcitrance in many cases. Concerning the chiral pharmaceuticals (CPs) in environmental matrices, the stereochemistry is often neglected and enantiomers are determined together as unique molecules. However, it is well known that
Quím. Nova. Publicado em: 2016-06
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8. Enantiomeric Separation of Sibutramine by Capillary Zone Electrophoresis
The chiral separation of sibutramine enantiomers was resolved succesfully by capillary zone electrophoresis using cyclodextrins (CDs) as chiral selectors. A complex screening of several different native and derivatized, neutral and ionized cyclodextrine derivatives was performed. The effects of buffer type, concentration and pH, cyclodextrin type and concent
J. Braz. Chem. Soc.. Publicado em: 2016-06
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9. CHROMATOGRAPHIC SEPARATION OF VERAPAMIL RACEMATE USING A VARICOL CONTINUOUS MULTICOLUMN PROCESS
Abstract Verapamil is a chiral drug that is marketed in its racemic form, but because of the pharmacological effects due to molecule’s chirality, one of the enantiomers is more potent, and the other exhibits different activities of therapeutic interest. The preparative separation of the verapamil enantiomers was performed using a continuous Varicol unit op
Braz. J. Chem. Eng.. Publicado em: 2015-12
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10. Coupling DLLME-CE for the Stereoselective Analysis of Venlafaxine and Its Main Metabolites after Biotransformation by Fungi
Fungal biotransformations have become very important in the study of chiral drugs because the reactions performed by these microorganisms may be enantioselective. However, analyses of analytes present in liquid culture medium have proved to be very difficult due to the complexity of this matrix. The aim of this work was to couple dispersive liquid-liquid mic
J. Braz. Chem. Soc.. Publicado em: 2015-09
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11. ASYMMETRIC SULFOXIDATION OF ALBENDAZOLE TO RICOBENDAZOLE BY FUNGI: EFFECT OF pH
Albendazole (ABZ) is an anthelmintic drug used for the treatment of infectious diseases in veterinary and human medicine. This drug is a prochiral drug that after administration, is rapidly oxidized in the pharmacologically active sulfoxide metabolite, which is also known as ricobendazole (ABZSOX). ABZSOX has a stereogenic center and possibly two enantiomers
Quím. Nova. Publicado em: 2015-08
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12. Evaluation of microbiological and biomimetic models in stereoselective metabolism of risperidone by high-performance liquid chromatography / Avaliação de modelos microbiológicos e modelos biomiméticos no metabolismo estereosseletivo da risperidona por cromatografia líquida de alta eficiência
Risperidone is an atypical antipsychotic drug. Its metabolism yields in two hydroxylated chiral metabolites, 7-hydroxyrisperidone (7-RispOH) and 9-hydroxyrisperidone (9-RispOH). The 9-RispOH metabolite presents the same pharmacologic activity of the parent drug risperidone. This led this drug to be marketed as drug under the generic name paliperidone. Studie
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/08/2012