DFT/PCM theoretical study of the conversion of methyl 4-O-methyl-α-d-galactopyranoside 6-sulfate and its 2-sulfated derivative into their 3,6-anhydro counterparts

Modeling of the conversion of methyl 4-O-methyl-α-d-galactopyranoside 6-sulfate (2) and 2,6-disulfate (1) into methyl 3,6-anhydro-4-O-methyl-α-d-galactopyranoside (4) and its 2-sulfate (3), respectively (Scheme 1) has been carried out using DFT at the M06-2X/6-311 + G(d,p)//M06-2X/6-31 + G(d,p) leve...

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Autores principales:	Navarro, Diego Alberto, Stortz, Carlos Arturo
Publicado:	2016
Materias:	3,6-Anhydrogalactose Alkaline treatment Carrageenans Conformation Density functional theory Galactose 6-sulfate Activation energy Chemical activation Conformations Continuum mechanics Reaction kinetics Reaction rates Thermodynamics Conformational pathways Polarizable continuum model Substitution step Thermodynamics and kinetics 2,6 disulfate 4-o methyl alpha dextro galactopyranoside 6 sulfate galactose methyl 3,6 anhydro 4 o methyl alpha dextro galactopyranoside oxygen pyranoside sulfate unclassified drug water analysis Article chair inversion chemical reaction kinetics chemical structure conformational transition density functional theory deprotonation investigative procedures kinetics molecular model polarizable continuum model priority journal quantum mechanics sulfation thermodynamics
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00086215_v426_n_p15_Cosenza http://hdl.handle.net/20.500.12110/paper_00086215_v426_n_p15_Cosenza
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_00086215_v426_n_p15_Cosenza
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spelling	paper:paper_00086215_v426_n_p15_Cosenza2023-06-08T14:33:06Z DFT/PCM theoretical study of the conversion of methyl 4-O-methyl-α-d-galactopyranoside 6-sulfate and its 2-sulfated derivative into their 3,6-anhydro counterparts Navarro, Diego Alberto Stortz, Carlos Arturo 3,6-Anhydrogalactose Alkaline treatment Carrageenans Conformation Density functional theory Galactose 6-sulfate Activation energy Chemical activation Conformations Continuum mechanics Reaction kinetics Reaction rates Thermodynamics 3,6-Anhydrogalactose Alkaline treatment Carrageenans Conformational pathways Galactose 6-sulfate Polarizable continuum model Substitution step Thermodynamics and kinetics Density functional theory 2,6 disulfate 4-o methyl alpha dextro galactopyranoside 6 sulfate galactose methyl 3,6 anhydro 4 o methyl alpha dextro galactopyranoside oxygen pyranoside sulfate unclassified drug water analysis Article chair inversion chemical reaction kinetics chemical structure conformational transition density functional theory deprotonation investigative procedures kinetics molecular model polarizable continuum model priority journal quantum mechanics sulfation thermodynamics Modeling of the conversion of methyl 4-O-methyl-α-d-galactopyranoside 6-sulfate (2) and 2,6-disulfate (1) into methyl 3,6-anhydro-4-O-methyl-α-d-galactopyranoside (4) and its 2-sulfate (3), respectively (Scheme 1) has been carried out using DFT at the M06-2X/6-311 + G(d,p)//M06-2X/6-31 + G(d,p) level with the polarizable continuum model (PCM) in water. The three steps necessary for the alkaline transformation of 6-sulfated (and 2,6-disulfated) galactose units into 3,6-anhydro derivatives were evaluated. The final substitution step appears to be the rate limiting, involving an activation energy of ca. 23 kcal/mol. The other two steps (deprotonation and chair inversion) combined involve lower activation energies (9-12 kcal/mol). Comparison of the thermodynamics and kinetics of the reactions suggest that if the deprotonation step precedes the chair inversion, the reaction should be faster for both compounds. No major differences in reaction rate can be theoretically predicted to be caused by the presence of sulfate on O-2, although one experimental result suggested that O-2 sulfation should increase the reaction rate. The conformational pathways are complex, given the large number of rotamers available for each compound, and the way that some of these rotamers combine into some of the pathways. In any case, the conformation OS2 appears as a common intermediate for the chair inversion processes. © 2016 Elsevier Ltd. All rights reserved. Fil:Navarro, D.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Stortz, C.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2016 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00086215_v426_n_p15_Cosenza http://hdl.handle.net/20.500.12110/paper_00086215_v426_n_p15_Cosenza
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	3,6-Anhydrogalactose Alkaline treatment Carrageenans Conformation Density functional theory Galactose 6-sulfate Activation energy Chemical activation Conformations Continuum mechanics Reaction kinetics Reaction rates Thermodynamics 3,6-Anhydrogalactose Alkaline treatment Carrageenans Conformational pathways Galactose 6-sulfate Polarizable continuum model Substitution step Thermodynamics and kinetics Density functional theory 2,6 disulfate 4-o methyl alpha dextro galactopyranoside 6 sulfate galactose methyl 3,6 anhydro 4 o methyl alpha dextro galactopyranoside oxygen pyranoside sulfate unclassified drug water analysis Article chair inversion chemical reaction kinetics chemical structure conformational transition density functional theory deprotonation investigative procedures kinetics molecular model polarizable continuum model priority journal quantum mechanics sulfation thermodynamics
spellingShingle	3,6-Anhydrogalactose Alkaline treatment Carrageenans Conformation Density functional theory Galactose 6-sulfate Activation energy Chemical activation Conformations Continuum mechanics Reaction kinetics Reaction rates Thermodynamics 3,6-Anhydrogalactose Alkaline treatment Carrageenans Conformational pathways Galactose 6-sulfate Polarizable continuum model Substitution step Thermodynamics and kinetics Density functional theory 2,6 disulfate 4-o methyl alpha dextro galactopyranoside 6 sulfate galactose methyl 3,6 anhydro 4 o methyl alpha dextro galactopyranoside oxygen pyranoside sulfate unclassified drug water analysis Article chair inversion chemical reaction kinetics chemical structure conformational transition density functional theory deprotonation investigative procedures kinetics molecular model polarizable continuum model priority journal quantum mechanics sulfation thermodynamics Navarro, Diego Alberto Stortz, Carlos Arturo DFT/PCM theoretical study of the conversion of methyl 4-O-methyl-α-d-galactopyranoside 6-sulfate and its 2-sulfated derivative into their 3,6-anhydro counterparts
topic_facet	3,6-Anhydrogalactose Alkaline treatment Carrageenans Conformation Density functional theory Galactose 6-sulfate Activation energy Chemical activation Conformations Continuum mechanics Reaction kinetics Reaction rates Thermodynamics 3,6-Anhydrogalactose Alkaline treatment Carrageenans Conformational pathways Galactose 6-sulfate Polarizable continuum model Substitution step Thermodynamics and kinetics Density functional theory 2,6 disulfate 4-o methyl alpha dextro galactopyranoside 6 sulfate galactose methyl 3,6 anhydro 4 o methyl alpha dextro galactopyranoside oxygen pyranoside sulfate unclassified drug water analysis Article chair inversion chemical reaction kinetics chemical structure conformational transition density functional theory deprotonation investigative procedures kinetics molecular model polarizable continuum model priority journal quantum mechanics sulfation thermodynamics
description	Modeling of the conversion of methyl 4-O-methyl-α-d-galactopyranoside 6-sulfate (2) and 2,6-disulfate (1) into methyl 3,6-anhydro-4-O-methyl-α-d-galactopyranoside (4) and its 2-sulfate (3), respectively (Scheme 1) has been carried out using DFT at the M06-2X/6-311 + G(d,p)//M06-2X/6-31 + G(d,p) level with the polarizable continuum model (PCM) in water. The three steps necessary for the alkaline transformation of 6-sulfated (and 2,6-disulfated) galactose units into 3,6-anhydro derivatives were evaluated. The final substitution step appears to be the rate limiting, involving an activation energy of ca. 23 kcal/mol. The other two steps (deprotonation and chair inversion) combined involve lower activation energies (9-12 kcal/mol). Comparison of the thermodynamics and kinetics of the reactions suggest that if the deprotonation step precedes the chair inversion, the reaction should be faster for both compounds. No major differences in reaction rate can be theoretically predicted to be caused by the presence of sulfate on O-2, although one experimental result suggested that O-2 sulfation should increase the reaction rate. The conformational pathways are complex, given the large number of rotamers available for each compound, and the way that some of these rotamers combine into some of the pathways. In any case, the conformation OS2 appears as a common intermediate for the chair inversion processes. © 2016 Elsevier Ltd. All rights reserved.
author	Navarro, Diego Alberto Stortz, Carlos Arturo
author_facet	Navarro, Diego Alberto Stortz, Carlos Arturo
author_sort	Navarro, Diego Alberto
title	DFT/PCM theoretical study of the conversion of methyl 4-O-methyl-α-d-galactopyranoside 6-sulfate and its 2-sulfated derivative into their 3,6-anhydro counterparts
title_short	DFT/PCM theoretical study of the conversion of methyl 4-O-methyl-α-d-galactopyranoside 6-sulfate and its 2-sulfated derivative into their 3,6-anhydro counterparts
title_full	DFT/PCM theoretical study of the conversion of methyl 4-O-methyl-α-d-galactopyranoside 6-sulfate and its 2-sulfated derivative into their 3,6-anhydro counterparts
title_fullStr	DFT/PCM theoretical study of the conversion of methyl 4-O-methyl-α-d-galactopyranoside 6-sulfate and its 2-sulfated derivative into their 3,6-anhydro counterparts
title_full_unstemmed	DFT/PCM theoretical study of the conversion of methyl 4-O-methyl-α-d-galactopyranoside 6-sulfate and its 2-sulfated derivative into their 3,6-anhydro counterparts
title_sort	dft/pcm theoretical study of the conversion of methyl 4-o-methyl-α-d-galactopyranoside 6-sulfate and its 2-sulfated derivative into their 3,6-anhydro counterparts
publishDate	2016
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00086215_v426_n_p15_Cosenza http://hdl.handle.net/20.500.12110/paper_00086215_v426_n_p15_Cosenza
work_keys_str_mv	AT navarrodiegoalberto dftpcmtheoreticalstudyoftheconversionofmethyl4omethyladgalactopyranoside6sulfateandits2sulfatedderivativeintotheir36anhydrocounterparts AT stortzcarlosarturo dftpcmtheoreticalstudyoftheconversionofmethyl4omethyladgalactopyranoside6sulfateandits2sulfatedderivativeintotheir36anhydrocounterparts
_version_	1768544849576853504

DFT/PCM theoretical study of the conversion of methyl 4-O-methyl-α-d-galactopyranoside 6-sulfate and its 2-sulfated derivative into their 3,6-anhydro counterparts

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