Gricela Lobo - Academia.edu (original) (raw)
Papers by Gricela Lobo
ChemInform, Sep 8, 2011
The title compound (III) exhibits only marginal antitumor and antibacterial activities.
![Research paper thumbnail of 1H and13C NMR spectral characterization of some antimalarialin vitro 3-amino-9-methyl-1H-pyrazolo[3,4-b]-4-quinolones](https://attachments.academia-assets.com/113814032/thumbnails/1.jpg)
](Magnetic Resonance in Chemistry, 2000
Avances en Química, 2016
Se reporta la síntesis de una serie de derivados de 6-amino-5-(arilmetilideno)-pirimidina-2,4-dio... more Se reporta la síntesis de una serie de derivados de 6-amino-5-(arilmetilideno)-pirimidina-2,4-dionas 2a-l, análogas de uracilo. Esta involucra una reacción de ciclocondensación entre los derivados de (E)-2-ciano-3-fenil acrilato de etilo 1a-l y urea asistida por K 2 CO 3. 1a-l fueron obtenidos por condensación de aldehídos aromáticos con cianoacetato de etilo en presencia de una cantidad catalítica de KOH. Todos los compuestos fueron caracterizados por el análisis de los datos espectroscópicos de IR, RMN 1 H y RMN 13 C. También se reportan los resultados de la actividad antimicrobiana in vitro de todos los compuestos sintetizados contra Staphylococcus aureus, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa y la levadura Candida tropicalis.
Pharmacy and Pharmacology Communications, Feb 1, 1999
A series of thiochromone derivatives were synthesized from 3-cyano-2-methylthio-1thiocromone with... more A series of thiochromone derivatives were synthesized from 3-cyano-2-methylthio-1thiocromone with hydrazine and guanidine derivatives, and tested for antimalarial activity. Pyrimethamine was used as a reference drug. 3-Amino-[1]-benzothiopyran-[2,3-c]-pyrazol-4-one showed signi®cant antimalarial activity against Plasmodium falciparum in-vitro. The remaining compounds had only modest activity.
Bioorganic & Medicinal Chemistry Letters, May 1, 1998
Chalcones and Mannich bases have been reported to present antiinflammatory activities as well as ... more Chalcones and Mannich bases have been reported to present antiinflammatory activities as well as inhibitory activities on several factors implicated in inflammation disorders. A series of chalcones and some related Mannich bases were prepared by Claisen-Schmidt condensation of appropriate acetophenones with appropriate aromatic aldehyde. Mannich bases were derived from chalcones, with formaldehyde and the corresponding amine. The compounds were tested in vitro for their ability to inhibit various enzymes involved in the arachidonic acid cascade, for their antioxidant behaviour and in vivo for anti-inflammatory activity. Some chalcones and Mannich bases present strong anti-inflammatory and antioxidant activities. Almost all the tested compounds present high inhibitory activity on lipid peroxidation. Some compounds showed potent inhibitory effect on superoxide anion formation. Among the tested compounds 5 and 6 showed the highest lipoxygenase (LO) inhibitory activity. All the tested compounds inhibit both the proteolytic and esteratic activities of trypsin and chymotrypsin. The results indicated that the anti-inflammatory effects of the compounds were partially mediated, through their antioxidant activity. Attempts to correlate quantitatively structure with activity revealed that lipophilicity and molar refractivity influence the biological response.
![Research paper thumbnail of 1H and 13C NMR spectral characterization of some antimalarial in vitro 3‐amino‐9‐methyl‐1H‐pyrazolo[3,4‐b]‐4‐quinolones](https://attachments.academia-assets.com/111219354/thumbnails/1.jpg)
](Magnetic Resonance in Chemistry, Dec 1, 2000
We report the 1 H NMR and 13 C NMR chemical shifts and J(H,H), J(H,F) and J(C,F) coupling constan... more We report the 1 H NMR and 13 C NMR chemical shifts and J(H,H), J(H,F) and J(C,F) coupling constants of 13 2,4-diamino-10-methylpyrimido[4,5-b]-5-quinolone derivatives, some of them with moderate activity against Plasmodium falciparum in vitro. They were characterized and assigned on the basis of 1 H, 13 C and 13 C-1 H (short-and long-range) correlated spectra.
ChemInform, Jan 7, 2003
For Abstract see ChemInform Abstract in Full Text.
![Research paper thumbnail of 4,6-Diamino-5-[4-(dimethylamino)benzylidene]pyrimidin-2(5H)-one](https://attachments.academia-assets.com/111219320/thumbnails/1.jpg)
](Molbank, Aug 31, 2009
A new compound, 4,6-diamino-5-[4-(dimethylamino)benzylidene]pyrimidin-2(5H)-one, was synthesized ... more A new compound, 4,6-diamino-5-[4-(dimethylamino)benzylidene]pyrimidin-2(5H)-one, was synthesized and its IR, 1 H NMR and 13 C NMR and MS spectroscopic data are presented.
Journal of Medicinal Chemistry, Aug 1, 1997
Acridinediones have previously been shown to have potent antimalarial activity. A series of sulfu... more Acridinediones have previously been shown to have potent antimalarial activity. A series of sulfur isosteres of acridinediones have been synthesized and evaluated for their inhibition of the Plasmodium falciparum cysteine protease falcipain and for their antimalarial activity. A number of these phenothiazines inhibited falcipain and demonstrated activity against cultured P. falciparum parasites at low micromolar concentrations. We propose that the compounds exerted their antimalarial effects by two mechanisms, one of which involves the inhibition of falcipain and a consequent block in parasite degradation of hemoglobin. These compounds and related phenothiazines are worthy of further study as potential antimalarial agents.
Journal of Chemical Research, 2017
Several trans- and cis-2-acetyl-3-(substituted-phenyl)-3,3a,4,5-tetrahydro-2 H-benzo[ g]indazole ... more Several trans- and cis-2-acetyl-3-(substituted-phenyl)-3,3a,4,5-tetrahydro-2 H-benzo[ g]indazole derivatives have been synthesised via the condensation of the appropriate exocyclic α,β-unsaturated ketones with hydrazine in hot acetic acid, to obtain diastereomeric mixtures of N-acetylated isomers. Structure elucidation was based on their spectral data and the trans–cis stereochemistry using of NOE and NOESY experiments. Biological testing of these derivatives as inhibitors of β-hematin formation was carried out.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
![Research paper thumbnail of ChemInform Abstract: Synthesis and Crystal Structure of (4bRS,9bRS)-5- (2,4-Dimethoxyphenyl) -4b,9b-7,7-dimethyldihydroxy-4b,5,6,7,8,9b-hexahydroindeno [1,2-b]indole-9,10-dione](https://attachments.academia-assets.com/93093559/thumbnails/1.jpg)
](ChemInform, Sep 8, 2011
Synthesis and Crystal Structures of Cs 2 MgD 4 and Cs 3 MgD 5 .-The title compounds are prepared ... more Synthesis and Crystal Structures of Cs 2 MgD 4 and Cs 3 MgD 5 .-The title compounds are prepared by reaction of a stoichiometric mixtures of CsD and α-MgD 2 under a D 2 pressure of 65 bar (625 K, autoclave, 5 d). Cs 2 MgD 4 has a β-K 2 SO 4 type structure (orthorhombic, space group Pnma, Z = 4) and Cs 3 MgD 5 is isotypic with Cs 3 CoCl 5 (tetragonal, space group I4/mcm, Z = 4), as determined by neutron powder diffraction. Mg is tetrahedrally coordinated by deuterium in both compounds.
A new compound, 4,6-diamino-5-(3,4-dichlorobenzylidene)pyrimidin-2(5H)one, was synthesized and it... more A new compound, 4,6-diamino-5-(3,4-dichlorobenzylidene)pyrimidin-2(5H)one, was synthesized and its IR, 1 H NMR, 13 C NMR, MS spectroscopic data and elemental analysis are presented.
Proceedings of 7th International Electronic Conference on Medicinal Chemistry, 2021
Intermediates 3-6 were generated through simple nucleophilic substitution of 1 with 2. Final comp... more Intermediates 3-6 were generated through simple nucleophilic substitution of 1 with 2. Final compounds 7-22 were generated through a Claisen-Schmidt cross aldol condensation between 3-6 and the 1-tetralone respective (scheme 1), the final products were obtained between 41-96% yield. The synthesized compounds 7-22 were characterized using modern spectroscopic techniques of 1 H NMR, 13 C NMR and IR taken in a Perkin Elmer with Fourier transform.
![Research paper thumbnail of Synthesis, Characterization, Crystal Structure and Antimalarial Activity of (2E)-2-(1-{4-[(7-chloroquinolin-4-yl)amino]phenyl} ethylidene)hydrazine Carbothioamide](https://attachments.academia-assets.com/93093553/thumbnails/1.jpg)
](Orbital - The Electronic Journal of Chemistry, 2017
A simple synthesis and study by UV-vis, IR, NMR, ESI-CID-MS 2 and X-ray diffraction of ((2E)-2-(1... more A simple synthesis and study by UV-vis, IR, NMR, ESI-CID-MS 2 and X-ray diffraction of ((2E)-2-(1-{4-[(7-chloroquinolin-4-yl)amino]phenyl}ethylidene)hydrazinecarbothioamide is reported. It was tested in vitro against chloroquine-resistant strain (W2) of Plasmodium falciparum, hemozoin (β-hematin) formation and cysteine protease falcipain-2. In general, it was found to possess a proved activity in its inhibitory power on the parasite but less active on the formation of hemozoin (β-hematin) and falcipain-2. Also, the X-ray analysis presented an unexpected electronic density that can be assigned like S(2). This electronic density can be attributed to autocondensation of thiosemicarbazide, generating H2S as a subproduct.
ChemInform, Sep 8, 2011
The title compound (III) exhibits only marginal antitumor and antibacterial activities.
Magnetic Resonance in Chemistry, 2000
Avances en Química, 2016
Se reporta la síntesis de una serie de derivados de 6-amino-5-(arilmetilideno)-pirimidina-2,4-dio... more Se reporta la síntesis de una serie de derivados de 6-amino-5-(arilmetilideno)-pirimidina-2,4-dionas 2a-l, análogas de uracilo. Esta involucra una reacción de ciclocondensación entre los derivados de (E)-2-ciano-3-fenil acrilato de etilo 1a-l y urea asistida por K 2 CO 3. 1a-l fueron obtenidos por condensación de aldehídos aromáticos con cianoacetato de etilo en presencia de una cantidad catalítica de KOH. Todos los compuestos fueron caracterizados por el análisis de los datos espectroscópicos de IR, RMN 1 H y RMN 13 C. También se reportan los resultados de la actividad antimicrobiana in vitro de todos los compuestos sintetizados contra Staphylococcus aureus, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa y la levadura Candida tropicalis.
Pharmacy and Pharmacology Communications, Feb 1, 1999
A series of thiochromone derivatives were synthesized from 3-cyano-2-methylthio-1thiocromone with... more A series of thiochromone derivatives were synthesized from 3-cyano-2-methylthio-1thiocromone with hydrazine and guanidine derivatives, and tested for antimalarial activity. Pyrimethamine was used as a reference drug. 3-Amino-[1]-benzothiopyran-[2,3-c]-pyrazol-4-one showed signi®cant antimalarial activity against Plasmodium falciparum in-vitro. The remaining compounds had only modest activity.
Bioorganic & Medicinal Chemistry Letters, May 1, 1998
Chalcones and Mannich bases have been reported to present antiinflammatory activities as well as ... more Chalcones and Mannich bases have been reported to present antiinflammatory activities as well as inhibitory activities on several factors implicated in inflammation disorders. A series of chalcones and some related Mannich bases were prepared by Claisen-Schmidt condensation of appropriate acetophenones with appropriate aromatic aldehyde. Mannich bases were derived from chalcones, with formaldehyde and the corresponding amine. The compounds were tested in vitro for their ability to inhibit various enzymes involved in the arachidonic acid cascade, for their antioxidant behaviour and in vivo for anti-inflammatory activity. Some chalcones and Mannich bases present strong anti-inflammatory and antioxidant activities. Almost all the tested compounds present high inhibitory activity on lipid peroxidation. Some compounds showed potent inhibitory effect on superoxide anion formation. Among the tested compounds 5 and 6 showed the highest lipoxygenase (LO) inhibitory activity. All the tested compounds inhibit both the proteolytic and esteratic activities of trypsin and chymotrypsin. The results indicated that the anti-inflammatory effects of the compounds were partially mediated, through their antioxidant activity. Attempts to correlate quantitatively structure with activity revealed that lipophilicity and molar refractivity influence the biological response.
Magnetic Resonance in Chemistry, Dec 1, 2000
We report the 1 H NMR and 13 C NMR chemical shifts and J(H,H), J(H,F) and J(C,F) coupling constan... more We report the 1 H NMR and 13 C NMR chemical shifts and J(H,H), J(H,F) and J(C,F) coupling constants of 13 2,4-diamino-10-methylpyrimido[4,5-b]-5-quinolone derivatives, some of them with moderate activity against Plasmodium falciparum in vitro. They were characterized and assigned on the basis of 1 H, 13 C and 13 C-1 H (short-and long-range) correlated spectra.
ChemInform, Jan 7, 2003
For Abstract see ChemInform Abstract in Full Text.
Molbank, Aug 31, 2009
A new compound, 4,6-diamino-5-[4-(dimethylamino)benzylidene]pyrimidin-2(5H)-one, was synthesized ... more A new compound, 4,6-diamino-5-[4-(dimethylamino)benzylidene]pyrimidin-2(5H)-one, was synthesized and its IR, 1 H NMR and 13 C NMR and MS spectroscopic data are presented.
Journal of Medicinal Chemistry, Aug 1, 1997
Acridinediones have previously been shown to have potent antimalarial activity. A series of sulfu... more Acridinediones have previously been shown to have potent antimalarial activity. A series of sulfur isosteres of acridinediones have been synthesized and evaluated for their inhibition of the Plasmodium falciparum cysteine protease falcipain and for their antimalarial activity. A number of these phenothiazines inhibited falcipain and demonstrated activity against cultured P. falciparum parasites at low micromolar concentrations. We propose that the compounds exerted their antimalarial effects by two mechanisms, one of which involves the inhibition of falcipain and a consequent block in parasite degradation of hemoglobin. These compounds and related phenothiazines are worthy of further study as potential antimalarial agents.
Journal of Chemical Research, 2017
Several trans- and cis-2-acetyl-3-(substituted-phenyl)-3,3a,4,5-tetrahydro-2 H-benzo[ g]indazole ... more Several trans- and cis-2-acetyl-3-(substituted-phenyl)-3,3a,4,5-tetrahydro-2 H-benzo[ g]indazole derivatives have been synthesised via the condensation of the appropriate exocyclic α,β-unsaturated ketones with hydrazine in hot acetic acid, to obtain diastereomeric mixtures of N-acetylated isomers. Structure elucidation was based on their spectral data and the trans–cis stereochemistry using of NOE and NOESY experiments. Biological testing of these derivatives as inhibitors of β-hematin formation was carried out.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
ChemInform, Sep 8, 2011
Synthesis and Crystal Structures of Cs 2 MgD 4 and Cs 3 MgD 5 .-The title compounds are prepared ... more Synthesis and Crystal Structures of Cs 2 MgD 4 and Cs 3 MgD 5 .-The title compounds are prepared by reaction of a stoichiometric mixtures of CsD and α-MgD 2 under a D 2 pressure of 65 bar (625 K, autoclave, 5 d). Cs 2 MgD 4 has a β-K 2 SO 4 type structure (orthorhombic, space group Pnma, Z = 4) and Cs 3 MgD 5 is isotypic with Cs 3 CoCl 5 (tetragonal, space group I4/mcm, Z = 4), as determined by neutron powder diffraction. Mg is tetrahedrally coordinated by deuterium in both compounds.
A new compound, 4,6-diamino-5-(3,4-dichlorobenzylidene)pyrimidin-2(5H)one, was synthesized and it... more A new compound, 4,6-diamino-5-(3,4-dichlorobenzylidene)pyrimidin-2(5H)one, was synthesized and its IR, 1 H NMR, 13 C NMR, MS spectroscopic data and elemental analysis are presented.
Proceedings of 7th International Electronic Conference on Medicinal Chemistry, 2021
Intermediates 3-6 were generated through simple nucleophilic substitution of 1 with 2. Final comp... more Intermediates 3-6 were generated through simple nucleophilic substitution of 1 with 2. Final compounds 7-22 were generated through a Claisen-Schmidt cross aldol condensation between 3-6 and the 1-tetralone respective (scheme 1), the final products were obtained between 41-96% yield. The synthesized compounds 7-22 were characterized using modern spectroscopic techniques of 1 H NMR, 13 C NMR and IR taken in a Perkin Elmer with Fourier transform.
Orbital - The Electronic Journal of Chemistry, 2017
A simple synthesis and study by UV-vis, IR, NMR, ESI-CID-MS 2 and X-ray diffraction of ((2E)-2-(1... more A simple synthesis and study by UV-vis, IR, NMR, ESI-CID-MS 2 and X-ray diffraction of ((2E)-2-(1-{4-[(7-chloroquinolin-4-yl)amino]phenyl}ethylidene)hydrazinecarbothioamide is reported. It was tested in vitro against chloroquine-resistant strain (W2) of Plasmodium falciparum, hemozoin (β-hematin) formation and cysteine protease falcipain-2. In general, it was found to possess a proved activity in its inhibitory power on the parasite but less active on the formation of hemozoin (β-hematin) and falcipain-2. Also, the X-ray analysis presented an unexpected electronic density that can be assigned like S(2). This electronic density can be attributed to autocondensation of thiosemicarbazide, generating H2S as a subproduct.