Biman Pal - Academia.edu (original) (raw)
Papers by Biman Pal
Life Sciences, 1993
Neuropeptide FF (NPFF) has been shown to exert various antiopiate actions, including precipitatio... more Neuropeptide FF (NPFF) has been shown to exert various antiopiate actions, including precipitation of opiate abstinence syndrome by third ventricle injection in morphine dependent rats. In the present study, dansyl-Pro-Gln-Arg-Phe-amide, a lipophilic analog of NPFF, was injected into morphine dependent rats and appropriate sham controls at a dose of 9 mg/kg s.c. Comparison groups were injected with ethanol/water vehicle alone. The NPFF analog precipitated a vigorous opiate abstinence syndrome in morphine dependent rats, but not in sham controls.
ChemInform, 2010
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Life Sciences, 1993
Neuropeptide FF (NPFF) has been shown to exert various antiopiate actions, including precipitatio... more Neuropeptide FF (NPFF) has been shown to exert various antiopiate actions, including precipitation of opiate abstinence syndrome by third ventricle injection in morphine dependent rats. In the present study, dansyl-Pro-Gln-Arg-Phe-amide, a lipophilic analog of NPFF, was injected into morphine dependent rats and appropriate sham controls at a dose of 9 mg/kg s.c. Comparison groups were injected with ethanol/water vehicle alone. The NPFF analog precipitated a vigorous opiate abstinence syndrome in morphine dependent rats, but not in sham controls.
The Journal of Organic Chemistry, 1993
@-Amino acids 1 are potentially valuable for preparations of peptidomimetics,' functionalized 8-l... more @-Amino acids 1 are potentially valuable for preparations of peptidomimetics,' functionalized 8-lactams, and some naturally occurring materials." These disubstituted amino acids are not easily prepared in stereochemically pure form, however. The most accessible members of this series of compounds are aspartic acid (R' = C02H, R2 = H) derivatives obtained via enolate formation and alkylation at the 8-carbon, reactions which can be made to be highly diastereoselective by judicious choice of N-protecting functi0nalities.M Compounds 1 not derived from aspartic acid are more difficult to make. For instance, one recently published procedure involves incorporating an optically active a-unsubstituted &amino acid in a heterocyclic system (specifically, a perhydropyrimidinone), enolate formation, alkylation, and then vigorous hydrolysis? This method has several limitations, not least of which being the availability of the starting material. Described here are syntheses of disubstituted systems 1 with high absolute and relative stereochemical purity, from naturally occurring a-amino acids. Some limitations of the methodology are also described.
Bioorganic & Medicinal Chemistry, 1996
The synthesis of cyclopentyl and cyclopentenyl analogues of the a-anomer of D-ribose-5-phosphate ... more The synthesis of cyclopentyl and cyclopentenyl analogues of the a-anomer of D-ribose-5-phosphate from D-ribonolactone and D-ribose is described. These analogues, which have the same absolute configuration as D-ribose-5-phosphate, were incubated with PRPP synthetases in an attempt to prepare the corresponding carbocyclic PRPP analogues. The carbocyclic ribose-5-phosphate analogues were found to be inhibitors, rather than substrates, for 5-phosphoribosyl a-l-pyrophosphate synthetases of both bacterial and human origin. The inhibitory behavior of the analogues is described.
Bioorganic & Medicinal Chemistry, 1994
Peptide mimics of substrates for HIV-proteases were prepared. These "norpeptides&quo... more Peptide mimics of substrates for HIV-proteases were prepared. These "norpeptides" are identical to a fragment of the HIV-polyprotein except that a crucial scissile bond was deleted, and an alpha,beta-disubstituted amino acid spans the P1 and P1 site. Thus all four stereoisomers of Leu psi[]Ala (i.e. H2NCH(CH2iPr)CH(Me)CO2H, 1) were incorporated into Ac-Ala-Arg-Val-Leu psi[]Ala-Glu-Ala-NH2 (all other residues being L-amino acids), and tested with respect to inhibition of HIV-1 and HIV-2 proteases.
Journal of the American Chemical Society, 1995
The goal of this paper is to lay foundations for an understanding of the local conformational eff... more The goal of this paper is to lay foundations for an understanding of the local conformational effects of 2,3-methanoamino acids on secondary structures. These studies are a necessary preliminary to the anticipated applications of 2,3-methanoamino acids in rational manipulation of peptidomimetic and protein-mimic conformations. Details of the research described are as follows. Quenched molecular dynamics (QMD) studies have been performed to compare the conformational effects of (2S,3S)-2,3-methanomethionine (2S,3S-cyclo-M), (2R,3R)-2,3-methanomethionine (2R,3R-cyclo-M), and (2R,3R)-2,3-methanophenylalanine (2R,3R-cyclo-F) incorporated into small peptide systems. Data generated for F{2R,3R-cyclo-M}RF-NH2 and F{2S,3S-cyclo-M}R{2R,3R-cyclo-F}-NH~ were compared with that previously obtained for F{ZS,3S-cyclo-M)RF-NH2 (J. Am. Chem. SOC. 1995, 117, 54). This approach facilitated comparisons between enantiomeric methanoamino acids (2S,3S-cyclo-M and 2R,3R-cyclo-M which have the amine and side chain functions trans-oriented across a cyclopropane) and between cis-and trans-2,3-methanoamino acids (i.e. 2R,3R-cyclo-M and 2R,3R-cyclo-F). To effect this comparison, the local influences of the 2,3-methanoamino acids were visualized and rationalized using Q,,V dot plots and Newman projections, respectively. For 2S,3S-cyclo-M, the v constraints caused by the 3-substituent were greater than the corresponding Q, restrictions. The fundamental difference between the enantiomers of (E)-2,3-methanomethionine was that values for 2S,3S-cyclo-M in the peptidomimetics tended to be more positive than the corresponding torsions for 2R,3Rcyclo-M. For the cis methanolog, 2R,3R-cyclo-F, 4 values were more severely affected than torsions, unlike the situation outlined for the E-cyclo-M enantiomers. NMR experiments also were performed to determine any conformational biases of F{2R,3R-cyclo-M}RF-NH2 and F{2S,3S-cyclo-M}R{2R,3R-cyclo-F}-NH~ in dimethyl sulfoxide (DMSO) solution. These data were then compared with results from the calculations. Both the NMR and QMD studies indicated that F(2S,3S-cyclo-M}R{2R,3R-cyclo-F}-NH~ had a bias toward a structure with all the side chains oriented on one face of the molecule and all the carbonyl vectors pointing in the opposite direction. Inconsistencies between the NMR and QMD data arose for F{2R,3R-cyclo-M}RF-NH2, i.e. conformers fitting the NMR data could be located in the families of structures generated by the QMD experiments, but they did not appear to be the most favorable ones in the theoretical approach. It is suggested that these ambiguities could be due to contributions from different conformers with energies relatively close to the global minimum.
La presente invention concerne des formes cristallines d'acide (1aS,5aS)-2-(4-oxy-pyrazin-2-y... more La presente invention concerne des formes cristallines d'acide (1aS,5aS)-2-(4-oxy-pyrazin-2-yl)-1a,2,5,5,5a-tetrahydro-1H-2,3-diaza-cyclopropa[a]pentalene-4-carboxylique((S)-1-hydroxymethyl-2,2-dimethyl-propyl)-amide (Compose 1) et des compositions pharmaceutiques de celui-ci qui modulent l'activite du recepteur CB 2 des cannabinoides et sont par consequent utiles dans le traitement de troubles a mediation par le recepteur CB 2 , par exemple l'arthrose ; la douleur ; l'hyperalgesie ; l'allodynie ; l'hyperalgesie inflammatoire ; l'hyperalgesie neuropathique ; la nociception aigue ; l'osteoporose ; l'hypertonie spastique associee a la sclerose en plaques ; les troubles auto-immuns ; les reactions allergiques ; l'inflammation du systeme nerveux central par exemple ; l'atherosclerose ; l'activite indesirable de cellules immunitaires et l'inflammation associee a un trouble choisi parmi : l'arthrose, l'anaphylaxie, la maladie de ...
L'invention concerne certains procedes utilises dans le traitement du cancer qui consistent a... more L'invention concerne certains procedes utilises dans le traitement du cancer qui consistent a administrer un compose de formule (Ia) et des compositions pharmaceutiques de celui-ci qui modulent l'activite du recepteur cannabinoide CB2.
La presente invention se rapporte a un procede de fabrication d'un produit chimique intermedi... more La presente invention se rapporte a un procede de fabrication d'un produit chimique intermediaire 1,3-diamino-2-propanol substitue en position 3 a partir duquel on peut realiser la synthese de divers produits chimiques, tels que des inhibiteurs selectionnes de la protease et autres medicaments, ainsi que de polymeres. Le procede consiste a mettre en contact un compose d'amino-acide nitromethyle avec au moins un agent de reduction afin d'obtenir le produit chimique intermediaire 1,3-diamino-2-propanol substitue en position 3.
Journal of medicinal chemistry, Feb 19, 2017
The design and synthesis of a new series of potent non-prostanoid IP receptor agonists that showe... more The design and synthesis of a new series of potent non-prostanoid IP receptor agonists that showed oral efficacy in the rat monocrotaline model of pulmonary arterial hypertension (PAH) are described. Detailed profiling of a number of analogues resulted in the identification of 5c (ralinepag) that has good selectivity in both binding and functional assays with respect to most members of the prostanoid receptor family and a more modest 30- to 50-fold selectivity over the EP3 receptor. In our hands, its potency and efficacy are comparable or superior to MRE269 (the active metabolite of the clinical compound NS-304) with respect to in vitro IP receptor dependent cAMP accumulation assays. 5c had an excellent PK profile across species. Enterohepatic recirculation most probably contributes to a concentration-time profile after oral administration in the cynomolgus monkey that showed a very low peak-to-trough ratio. Following the identification of an acceptable solid form, 5c was selected f...
Life Sciences, 1993
Neuropeptide FF (NPFF) has been shown to exert various antiopiate actions, including precipitatio... more Neuropeptide FF (NPFF) has been shown to exert various antiopiate actions, including precipitation of opiate abstinence syndrome by third ventricle injection in morphine dependent rats. In the present study, dansyl-Pro-Gln-Arg-Phe-amide, a lipophilic analog of NPFF, was injected into morphine dependent rats and appropriate sham controls at a dose of 9 mg/kg s.c. Comparison groups were injected with ethanol/water vehicle alone. The NPFF analog precipitated a vigorous opiate abstinence syndrome in morphine dependent rats, but not in sham controls.
ChemInform, 2010
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Life Sciences, 1993
Neuropeptide FF (NPFF) has been shown to exert various antiopiate actions, including precipitatio... more Neuropeptide FF (NPFF) has been shown to exert various antiopiate actions, including precipitation of opiate abstinence syndrome by third ventricle injection in morphine dependent rats. In the present study, dansyl-Pro-Gln-Arg-Phe-amide, a lipophilic analog of NPFF, was injected into morphine dependent rats and appropriate sham controls at a dose of 9 mg/kg s.c. Comparison groups were injected with ethanol/water vehicle alone. The NPFF analog precipitated a vigorous opiate abstinence syndrome in morphine dependent rats, but not in sham controls.
The Journal of Organic Chemistry, 1993
@-Amino acids 1 are potentially valuable for preparations of peptidomimetics,' functionalized 8-l... more @-Amino acids 1 are potentially valuable for preparations of peptidomimetics,' functionalized 8-lactams, and some naturally occurring materials." These disubstituted amino acids are not easily prepared in stereochemically pure form, however. The most accessible members of this series of compounds are aspartic acid (R' = C02H, R2 = H) derivatives obtained via enolate formation and alkylation at the 8-carbon, reactions which can be made to be highly diastereoselective by judicious choice of N-protecting functi0nalities.M Compounds 1 not derived from aspartic acid are more difficult to make. For instance, one recently published procedure involves incorporating an optically active a-unsubstituted &amino acid in a heterocyclic system (specifically, a perhydropyrimidinone), enolate formation, alkylation, and then vigorous hydrolysis? This method has several limitations, not least of which being the availability of the starting material. Described here are syntheses of disubstituted systems 1 with high absolute and relative stereochemical purity, from naturally occurring a-amino acids. Some limitations of the methodology are also described.
Bioorganic & Medicinal Chemistry, 1996
The synthesis of cyclopentyl and cyclopentenyl analogues of the a-anomer of D-ribose-5-phosphate ... more The synthesis of cyclopentyl and cyclopentenyl analogues of the a-anomer of D-ribose-5-phosphate from D-ribonolactone and D-ribose is described. These analogues, which have the same absolute configuration as D-ribose-5-phosphate, were incubated with PRPP synthetases in an attempt to prepare the corresponding carbocyclic PRPP analogues. The carbocyclic ribose-5-phosphate analogues were found to be inhibitors, rather than substrates, for 5-phosphoribosyl a-l-pyrophosphate synthetases of both bacterial and human origin. The inhibitory behavior of the analogues is described.
Bioorganic & Medicinal Chemistry, 1994
Peptide mimics of substrates for HIV-proteases were prepared. These "norpeptides&quo... more Peptide mimics of substrates for HIV-proteases were prepared. These "norpeptides" are identical to a fragment of the HIV-polyprotein except that a crucial scissile bond was deleted, and an alpha,beta-disubstituted amino acid spans the P1 and P1 site. Thus all four stereoisomers of Leu psi[]Ala (i.e. H2NCH(CH2iPr)CH(Me)CO2H, 1) were incorporated into Ac-Ala-Arg-Val-Leu psi[]Ala-Glu-Ala-NH2 (all other residues being L-amino acids), and tested with respect to inhibition of HIV-1 and HIV-2 proteases.
Journal of the American Chemical Society, 1995
The goal of this paper is to lay foundations for an understanding of the local conformational eff... more The goal of this paper is to lay foundations for an understanding of the local conformational effects of 2,3-methanoamino acids on secondary structures. These studies are a necessary preliminary to the anticipated applications of 2,3-methanoamino acids in rational manipulation of peptidomimetic and protein-mimic conformations. Details of the research described are as follows. Quenched molecular dynamics (QMD) studies have been performed to compare the conformational effects of (2S,3S)-2,3-methanomethionine (2S,3S-cyclo-M), (2R,3R)-2,3-methanomethionine (2R,3R-cyclo-M), and (2R,3R)-2,3-methanophenylalanine (2R,3R-cyclo-F) incorporated into small peptide systems. Data generated for F{2R,3R-cyclo-M}RF-NH2 and F{2S,3S-cyclo-M}R{2R,3R-cyclo-F}-NH~ were compared with that previously obtained for F{ZS,3S-cyclo-M)RF-NH2 (J. Am. Chem. SOC. 1995, 117, 54). This approach facilitated comparisons between enantiomeric methanoamino acids (2S,3S-cyclo-M and 2R,3R-cyclo-M which have the amine and side chain functions trans-oriented across a cyclopropane) and between cis-and trans-2,3-methanoamino acids (i.e. 2R,3R-cyclo-M and 2R,3R-cyclo-F). To effect this comparison, the local influences of the 2,3-methanoamino acids were visualized and rationalized using Q,,V dot plots and Newman projections, respectively. For 2S,3S-cyclo-M, the v constraints caused by the 3-substituent were greater than the corresponding Q, restrictions. The fundamental difference between the enantiomers of (E)-2,3-methanomethionine was that values for 2S,3S-cyclo-M in the peptidomimetics tended to be more positive than the corresponding torsions for 2R,3Rcyclo-M. For the cis methanolog, 2R,3R-cyclo-F, 4 values were more severely affected than torsions, unlike the situation outlined for the E-cyclo-M enantiomers. NMR experiments also were performed to determine any conformational biases of F{2R,3R-cyclo-M}RF-NH2 and F{2S,3S-cyclo-M}R{2R,3R-cyclo-F}-NH~ in dimethyl sulfoxide (DMSO) solution. These data were then compared with results from the calculations. Both the NMR and QMD studies indicated that F(2S,3S-cyclo-M}R{2R,3R-cyclo-F}-NH~ had a bias toward a structure with all the side chains oriented on one face of the molecule and all the carbonyl vectors pointing in the opposite direction. Inconsistencies between the NMR and QMD data arose for F{2R,3R-cyclo-M}RF-NH2, i.e. conformers fitting the NMR data could be located in the families of structures generated by the QMD experiments, but they did not appear to be the most favorable ones in the theoretical approach. It is suggested that these ambiguities could be due to contributions from different conformers with energies relatively close to the global minimum.
La presente invention concerne des formes cristallines d'acide (1aS,5aS)-2-(4-oxy-pyrazin-2-y... more La presente invention concerne des formes cristallines d'acide (1aS,5aS)-2-(4-oxy-pyrazin-2-yl)-1a,2,5,5,5a-tetrahydro-1H-2,3-diaza-cyclopropa[a]pentalene-4-carboxylique((S)-1-hydroxymethyl-2,2-dimethyl-propyl)-amide (Compose 1) et des compositions pharmaceutiques de celui-ci qui modulent l'activite du recepteur CB 2 des cannabinoides et sont par consequent utiles dans le traitement de troubles a mediation par le recepteur CB 2 , par exemple l'arthrose ; la douleur ; l'hyperalgesie ; l'allodynie ; l'hyperalgesie inflammatoire ; l'hyperalgesie neuropathique ; la nociception aigue ; l'osteoporose ; l'hypertonie spastique associee a la sclerose en plaques ; les troubles auto-immuns ; les reactions allergiques ; l'inflammation du systeme nerveux central par exemple ; l'atherosclerose ; l'activite indesirable de cellules immunitaires et l'inflammation associee a un trouble choisi parmi : l'arthrose, l'anaphylaxie, la maladie de ...
L'invention concerne certains procedes utilises dans le traitement du cancer qui consistent a... more L'invention concerne certains procedes utilises dans le traitement du cancer qui consistent a administrer un compose de formule (Ia) et des compositions pharmaceutiques de celui-ci qui modulent l'activite du recepteur cannabinoide CB2.
La presente invention se rapporte a un procede de fabrication d'un produit chimique intermedi... more La presente invention se rapporte a un procede de fabrication d'un produit chimique intermediaire 1,3-diamino-2-propanol substitue en position 3 a partir duquel on peut realiser la synthese de divers produits chimiques, tels que des inhibiteurs selectionnes de la protease et autres medicaments, ainsi que de polymeres. Le procede consiste a mettre en contact un compose d'amino-acide nitromethyle avec au moins un agent de reduction afin d'obtenir le produit chimique intermediaire 1,3-diamino-2-propanol substitue en position 3.
Journal of medicinal chemistry, Feb 19, 2017
The design and synthesis of a new series of potent non-prostanoid IP receptor agonists that showe... more The design and synthesis of a new series of potent non-prostanoid IP receptor agonists that showed oral efficacy in the rat monocrotaline model of pulmonary arterial hypertension (PAH) are described. Detailed profiling of a number of analogues resulted in the identification of 5c (ralinepag) that has good selectivity in both binding and functional assays with respect to most members of the prostanoid receptor family and a more modest 30- to 50-fold selectivity over the EP3 receptor. In our hands, its potency and efficacy are comparable or superior to MRE269 (the active metabolite of the clinical compound NS-304) with respect to in vitro IP receptor dependent cAMP accumulation assays. 5c had an excellent PK profile across species. Enterohepatic recirculation most probably contributes to a concentration-time profile after oral administration in the cynomolgus monkey that showed a very low peak-to-trough ratio. Following the identification of an acceptable solid form, 5c was selected f...