Clara Uriel - Academia.edu (original) (raw)

Papers by Clara Uriel

Organic Letters, Jun 20, 2007

Bis(pyridinium) iodonium(I) tetrafluoroborate (IPy2BF4), a solid and stable reagent, can be used ... more Bis(pyridinium) iodonium(I) tetrafluoroborate (IPy2BF4), a solid and stable reagent, can be used to transform n-pentenyl orthoesters (NPOEs) and n-pentenyl glycosides (NPGs) into glycosyl fluorides. The latter pair constitutes a new set of semiorthogonal glycosyl donors that can be used in glycosylation strategies, alone or in combination with NPOEs.

Biomedical and biopharmaceutical research, 2023

Lysyl oxidase (LOX) and LOX-like 1-4 (LOXL 1-4) enzymes catalyze the cross-linking of elastin and... more Lysyl oxidase (LOX) and LOX-like 1-4 (LOXL 1-4) enzymes catalyze the cross-linking of elastin and collagen in the extracellular matrix, facilitating cell migration and invasion. The inhibition of these enzymes, particularly LOXL2, has been suggested as a therapeutic strategy to prevent breast cancer metastasis. In this work, new natural LOXL2 inhibitors were searched from Aeollanthus rydingianus, a medicinal plant rich in bioactive products. Five pimarane diterpenoids, two isolated from the plant and three derivatives, were tested. These compounds have been described for their bioactive properties such as anti-tumor, anti-inflammatory, analgesic, and antibacterial activities. In this regard, we intended to explore the mechanisms of these compounds by studying their effects on LOXL2 activity. Two pimarane diterpenoids showed a mild LOXL2 inhibitory activity as evaluated by an Amplex Ultra Red-based technique. The cytotoxicity of the most active compound was analyzed by the MTT assay in the MDA-MB-231 cell line, representative of triplenegative breast cancer. This compound decreased cell viability as single agent and increased the cytotoxic effect of doxorubicin. Its glycoconjugate was considerably more toxic, likely due to a higher uptake by cancer cells.

Chemistry: A European Journal, Oct 25, 2019

The development of efficient and stable red and near-IR emitting materials under hard radiation d... more The development of efficient and stable red and near-IR emitting materials under hard radiation doses and/or prolonged times is a sought-after task due to their widespread applications in optoelectronic and bio-photonic. To this aim, novel symmetric all-BODIPY-triads,-pentads, and-hexads have been designed and synthesized as light-harvesting arrays. These photonic materials are spectrally active in the 655-730 nm region and display high molar absorption across UV-visible region. Furthermore, they provide, to the best of our knowledge, the highest lasing efficiency (up to 68%) and the highest photostability (tolerance >1300 GJ.mol-1) in the near-IR spectral region ever recorded under drastic pumping conditions. Additionally, the modular synthetic strategy to access the cassettes allows the systematic study of their photonic behavior related to structural factors. Collectively, the outstanding behavior of these multichromophoric photonic materials provides keystones for engineering multifunctional systems to expedite the next generation of effective red optical materials.

Journal of Carbohydrate Chemistry, Aug 1, 2005

Carbohydrates U 0500 Some Aspects of Selectivity in the Reaction of Glycosyl Donors.-Armed and di... more Carbohydrates U 0500 Some Aspects of Selectivity in the Reaction of Glycosyl Donors.-Armed and disarmed protocols for glycosylation are studied in detail and the results are discussed. The reaction of (VI) in the presence of (IX) gives only product (VIII).-(URIEL, C.;

Tetrahedron Letters, Jul 1, 2002

ABSTRACT

Antimicrobial Agents and Chemotherapy, Apr 1, 1998

We compared the biological activity of a new group of keto-C-glycosides to that of a narrow spect... more We compared the biological activity of a new group of keto-C-glycosides to that of a narrow spectrum of unsaturated ketonucleosides in a panel of non-small-cell lung cancer (NSCLC) cells with various levels of intrinsic resistance to standard chemotherapy drugs. Unlike cisplatin, etoposide, adriamycin, or taxol, for which a significant difference in the cytotoxic effect was observed between sensitive cell lines (H460, H125, and MGH4) and drug-resistant cell lines (H661, MGH7, and FADU), nucleoside analogs were equally cytotoxic in NSCLC cell lines, with compound 92 being 10-fold more active than compound 43, 44, 81, or 161, while compound 3 was the least active. Apoptotic measurements with flow cytometric analysis of terminal uridine deoxynucleotide nick end-labeled cells revealed that the cytotoxic activity of these nucleosides correlated with their potency to induce apoptosis. Compound 92 triggered death in cells with wild-type p53, mutated p53, or p53 gene deletion. Our findings suggest that keto-C-glycosides may be promising alternative anticancer agents which merit further studies in in vivo cancer models refractory to standard chemotherapy drugs.

Australian Journal of Chemistry, 2002

A 1965 publication from Angyal's laboratory reported that the cis-vicinal diol group of tetra... more A 1965 publication from Angyal's laboratory reported that the cis-vicinal diol group of tetra-O-benzyl myo-inositol reacted regioselectively, sometimes exclusively, with acylating agents at the equatorial OH, but with alkylating agents at the axial OH. Recent reports by Fraser-Reid and coworkers showed that such selectivities were also found for the trans-1,3-diol of tetra-O-benzyl myo-inositol, as well as the C2-C4 hydroxyls of a di-O-allyl mannopyranoside. In addition, the latter workers reported that regioselectivities could be extended to glycosidation reactions. Thus, n-pentenyl ortho ester (NPOE) and 2-O-acyl n-pentenyl glycoside (NPGAC) donors reacted preferentially, if not exclusively, at the equatorial OH, whereas 2-O-alkyl counterparts (NPGALK) gave mixtures, usually with major glycosidation occuring at the axial OH. The present manuscript examines several vicinal diols, and reports that the NPOE and (NPGAC) donors frequently react at only one of the two hydroxy groups in good yield, whereas the corresponding benzylated donor (NPGALK) is less discriminating, and frequently gives lower yields. In a key experiment to examine the basis of the selectivity, it was found that the highly hindered C3 OH of 4,6-O-benzylidene methyl a-D-altropyranoside was selectively glycosylated with NPOE in 92% yield, thereby establishing that the glycosidation preference is not due to steric hindrance.

Synthesis Stuttgart, 2001

ChemInform, Jun 17, 2010

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT 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.

ChemInform, Jun 14, 2010

Short and Efficient Synthesis of the Antitumor Heptenes Melodienone and Isomelodienone.-Oxidative... more Short and Efficient Synthesis of the Antitumor Heptenes Melodienone and Isomelodienone.-Oxidative opening of the furan (I) (prepared in 4 steps from commercially available 2-methoxyfuran) using Kobayashi's modification of the Clauson-Kaas reaction provides selectively the single isomer melodienone (II). Exposure to dimethyldioxirane leads uniquely to isomelodienone (III).-(BOUKOUVALAS,

Synthesis, Sep 30, 2004

Dicarbonyl(D-cyclopentadienyl)iron tetrafluoroborates containing aromatic nitriles as ligands wer... more Dicarbonyl(D-cyclopentadienyl)iron tetrafluoroborates containing aromatic nitriles as ligands were synthesized. These and other (D-cyclopentadienyl)iron derivatives were used to obtain intercalation compounds with >-cyclodextrin.

Carbohydrate Research

Convergent synthetic routes to PI-88 tetra- and pentasaccharide-component analogues, have been de... more Convergent synthetic routes to PI-88 tetra- and pentasaccharide-component analogues, have been developed featuring regioselective glycosylations of mannose-polyol n-pentenyl glycosides (NPG) acceptors with 1,2-methyl orthoesters (MeOE) glycosyl donors.

Chemistry – A European Journal, 2020

Chemistry – A European Journal, 2020

A series of fluorescent boron‐dipyrromethene (BODIPY, 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene)... more A series of fluorescent boron‐dipyrromethene (BODIPY, 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene) dyes have been designed to participate, as aglycons, in synthetic oligosaccharide protocols. As such, they served a dual purpose: first, by being incorporated at the beginning of the process (at the reducing‐end of the growing saccharide moiety), they can function as fluorescent glycosyl tags, facilitating the detection and purification of the desired glycosidic intermediates, and secondly, the presence of these chromophores on the ensuing compounds grants access to fluorescently labeled saccharides. In this context, a sought‐after feature of the fluorescent dyes has been their chemical robustness. Accordingly, some BODIPY derivatives described in this work can withstand the reaction conditions commonly employed in the chemical synthesis of saccharides; namely, glycosylation and protecting‐group manipulations. Regarding their photophysical properties, the BODIPY‐labeled saccharides obta...

Chemistry – A European Journal, 2019

The development of efficient and stable red and near‐IR emitting materials under hard radiation d... more The development of efficient and stable red and near‐IR emitting materials under hard radiation doses and/or prolonged times is a sought‐after task due to their widespread applications in optoelectronics and biophotonics. To this aim, novel symmetric all‐BODIPY‐triads, ‐pentads, and ‐hexads have been designed and synthesized as light‐harvesting arrays. These photonic materials are spectrally active in the 655–730 nm region and display high molar absorption across UV–visible region. Furthermore, they provide, to the best of our knowledge, the highest lasing efficiency (up to 68 %) and the highest photostability (tolerance >1300 GJ mol−1) in the near‐IR spectral region ever recorded under drastic pumping conditions. Additionally, the modular synthetic strategy to access the cassettes allows the systematic study of their photonic behavior related to structural factors. Collectively, the outstanding behavior of these multichromophoric photonic materials provides the keystone for engi...

Australian Journal of Chemistry, 2002

A 1965 publication from Angyal's laboratory reported that the cis-vicinal diol group of tetra... more A 1965 publication from Angyal's laboratory reported that the cis-vicinal diol group of tetra-O-benzyl myo-inositol reacted regioselectively, sometimes exclusively, with acylating agents at the equatorial OH, but with alkylating agents at the axial OH. Recent reports by Fraser-Reid and coworkers showed that such selectivities were also found for the trans-1,3-diol of tetra-O-benzyl myo-inositol, as well as the C2-C4 hydroxyls of a di-O-allyl mannopyranoside. In addition, the latter workers reported that regioselectivities could be extended to glycosidation reactions. Thus, n-pentenyl ortho ester (NPOE) and 2-O-acyl n-pentenyl glycoside (NPGAC) donors reacted preferentially, if not exclusively, at the equatorial OH, whereas 2-O-alkyl counterparts (NPGALK) gave mixtures, usually with major glycosidation occuring at the axial OH. The present manuscript examines several vicinal diols, and reports that the NPOE and (NPGAC) donors frequently react at only one of the two hydroxy groups...

Organic Letters, Jun 20, 2007

Bis(pyridinium) iodonium(I) tetrafluoroborate (IPy2BF4), a solid and stable reagent, can be used ... more Bis(pyridinium) iodonium(I) tetrafluoroborate (IPy2BF4), a solid and stable reagent, can be used to transform n-pentenyl orthoesters (NPOEs) and n-pentenyl glycosides (NPGs) into glycosyl fluorides. The latter pair constitutes a new set of semiorthogonal glycosyl donors that can be used in glycosylation strategies, alone or in combination with NPOEs.

Biomedical and biopharmaceutical research, 2023

Lysyl oxidase (LOX) and LOX-like 1-4 (LOXL 1-4) enzymes catalyze the cross-linking of elastin and... more Lysyl oxidase (LOX) and LOX-like 1-4 (LOXL 1-4) enzymes catalyze the cross-linking of elastin and collagen in the extracellular matrix, facilitating cell migration and invasion. The inhibition of these enzymes, particularly LOXL2, has been suggested as a therapeutic strategy to prevent breast cancer metastasis. In this work, new natural LOXL2 inhibitors were searched from Aeollanthus rydingianus, a medicinal plant rich in bioactive products. Five pimarane diterpenoids, two isolated from the plant and three derivatives, were tested. These compounds have been described for their bioactive properties such as anti-tumor, anti-inflammatory, analgesic, and antibacterial activities. In this regard, we intended to explore the mechanisms of these compounds by studying their effects on LOXL2 activity. Two pimarane diterpenoids showed a mild LOXL2 inhibitory activity as evaluated by an Amplex Ultra Red-based technique. The cytotoxicity of the most active compound was analyzed by the MTT assay in the MDA-MB-231 cell line, representative of triplenegative breast cancer. This compound decreased cell viability as single agent and increased the cytotoxic effect of doxorubicin. Its glycoconjugate was considerably more toxic, likely due to a higher uptake by cancer cells.

Chemistry: A European Journal, Oct 25, 2019

The development of efficient and stable red and near-IR emitting materials under hard radiation d... more The development of efficient and stable red and near-IR emitting materials under hard radiation doses and/or prolonged times is a sought-after task due to their widespread applications in optoelectronic and bio-photonic. To this aim, novel symmetric all-BODIPY-triads,-pentads, and-hexads have been designed and synthesized as light-harvesting arrays. These photonic materials are spectrally active in the 655-730 nm region and display high molar absorption across UV-visible region. Furthermore, they provide, to the best of our knowledge, the highest lasing efficiency (up to 68%) and the highest photostability (tolerance >1300 GJ.mol-1) in the near-IR spectral region ever recorded under drastic pumping conditions. Additionally, the modular synthetic strategy to access the cassettes allows the systematic study of their photonic behavior related to structural factors. Collectively, the outstanding behavior of these multichromophoric photonic materials provides keystones for engineering multifunctional systems to expedite the next generation of effective red optical materials.

Journal of Carbohydrate Chemistry, Aug 1, 2005

Carbohydrates U 0500 Some Aspects of Selectivity in the Reaction of Glycosyl Donors.-Armed and di... more Carbohydrates U 0500 Some Aspects of Selectivity in the Reaction of Glycosyl Donors.-Armed and disarmed protocols for glycosylation are studied in detail and the results are discussed. The reaction of (VI) in the presence of (IX) gives only product (VIII).-(URIEL, C.;

Tetrahedron Letters, Jul 1, 2002

ABSTRACT

Antimicrobial Agents and Chemotherapy, Apr 1, 1998

We compared the biological activity of a new group of keto-C-glycosides to that of a narrow spect... more We compared the biological activity of a new group of keto-C-glycosides to that of a narrow spectrum of unsaturated ketonucleosides in a panel of non-small-cell lung cancer (NSCLC) cells with various levels of intrinsic resistance to standard chemotherapy drugs. Unlike cisplatin, etoposide, adriamycin, or taxol, for which a significant difference in the cytotoxic effect was observed between sensitive cell lines (H460, H125, and MGH4) and drug-resistant cell lines (H661, MGH7, and FADU), nucleoside analogs were equally cytotoxic in NSCLC cell lines, with compound 92 being 10-fold more active than compound 43, 44, 81, or 161, while compound 3 was the least active. Apoptotic measurements with flow cytometric analysis of terminal uridine deoxynucleotide nick end-labeled cells revealed that the cytotoxic activity of these nucleosides correlated with their potency to induce apoptosis. Compound 92 triggered death in cells with wild-type p53, mutated p53, or p53 gene deletion. Our findings suggest that keto-C-glycosides may be promising alternative anticancer agents which merit further studies in in vivo cancer models refractory to standard chemotherapy drugs.

Australian Journal of Chemistry, 2002

A 1965 publication from Angyal's laboratory reported that the cis-vicinal diol group of tetra... more A 1965 publication from Angyal's laboratory reported that the cis-vicinal diol group of tetra-O-benzyl myo-inositol reacted regioselectively, sometimes exclusively, with acylating agents at the equatorial OH, but with alkylating agents at the axial OH. Recent reports by Fraser-Reid and coworkers showed that such selectivities were also found for the trans-1,3-diol of tetra-O-benzyl myo-inositol, as well as the C2-C4 hydroxyls of a di-O-allyl mannopyranoside. In addition, the latter workers reported that regioselectivities could be extended to glycosidation reactions. Thus, n-pentenyl ortho ester (NPOE) and 2-O-acyl n-pentenyl glycoside (NPGAC) donors reacted preferentially, if not exclusively, at the equatorial OH, whereas 2-O-alkyl counterparts (NPGALK) gave mixtures, usually with major glycosidation occuring at the axial OH. The present manuscript examines several vicinal diols, and reports that the NPOE and (NPGAC) donors frequently react at only one of the two hydroxy groups in good yield, whereas the corresponding benzylated donor (NPGALK) is less discriminating, and frequently gives lower yields. In a key experiment to examine the basis of the selectivity, it was found that the highly hindered C3 OH of 4,6-O-benzylidene methyl a-D-altropyranoside was selectively glycosylated with NPOE in 92% yield, thereby establishing that the glycosidation preference is not due to steric hindrance.

Synthesis Stuttgart, 2001

ChemInform, Jun 17, 2010

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT 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.

ChemInform, Jun 14, 2010

Short and Efficient Synthesis of the Antitumor Heptenes Melodienone and Isomelodienone.-Oxidative... more Short and Efficient Synthesis of the Antitumor Heptenes Melodienone and Isomelodienone.-Oxidative opening of the furan (I) (prepared in 4 steps from commercially available 2-methoxyfuran) using Kobayashi's modification of the Clauson-Kaas reaction provides selectively the single isomer melodienone (II). Exposure to dimethyldioxirane leads uniquely to isomelodienone (III).-(BOUKOUVALAS,

Synthesis, Sep 30, 2004

Dicarbonyl(D-cyclopentadienyl)iron tetrafluoroborates containing aromatic nitriles as ligands wer... more Dicarbonyl(D-cyclopentadienyl)iron tetrafluoroborates containing aromatic nitriles as ligands were synthesized. These and other (D-cyclopentadienyl)iron derivatives were used to obtain intercalation compounds with >-cyclodextrin.

Carbohydrate Research

Convergent synthetic routes to PI-88 tetra- and pentasaccharide-component analogues, have been de... more Convergent synthetic routes to PI-88 tetra- and pentasaccharide-component analogues, have been developed featuring regioselective glycosylations of mannose-polyol n-pentenyl glycosides (NPG) acceptors with 1,2-methyl orthoesters (MeOE) glycosyl donors.

Chemistry – A European Journal, 2020

Chemistry – A European Journal, 2020

A series of fluorescent boron‐dipyrromethene (BODIPY, 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene)... more A series of fluorescent boron‐dipyrromethene (BODIPY, 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene) dyes have been designed to participate, as aglycons, in synthetic oligosaccharide protocols. As such, they served a dual purpose: first, by being incorporated at the beginning of the process (at the reducing‐end of the growing saccharide moiety), they can function as fluorescent glycosyl tags, facilitating the detection and purification of the desired glycosidic intermediates, and secondly, the presence of these chromophores on the ensuing compounds grants access to fluorescently labeled saccharides. In this context, a sought‐after feature of the fluorescent dyes has been their chemical robustness. Accordingly, some BODIPY derivatives described in this work can withstand the reaction conditions commonly employed in the chemical synthesis of saccharides; namely, glycosylation and protecting‐group manipulations. Regarding their photophysical properties, the BODIPY‐labeled saccharides obta...

Chemistry – A European Journal, 2019

The development of efficient and stable red and near‐IR emitting materials under hard radiation d... more The development of efficient and stable red and near‐IR emitting materials under hard radiation doses and/or prolonged times is a sought‐after task due to their widespread applications in optoelectronics and biophotonics. To this aim, novel symmetric all‐BODIPY‐triads, ‐pentads, and ‐hexads have been designed and synthesized as light‐harvesting arrays. These photonic materials are spectrally active in the 655–730 nm region and display high molar absorption across UV–visible region. Furthermore, they provide, to the best of our knowledge, the highest lasing efficiency (up to 68 %) and the highest photostability (tolerance >1300 GJ mol−1) in the near‐IR spectral region ever recorded under drastic pumping conditions. Additionally, the modular synthetic strategy to access the cassettes allows the systematic study of their photonic behavior related to structural factors. Collectively, the outstanding behavior of these multichromophoric photonic materials provides the keystone for engi...

Australian Journal of Chemistry, 2002

A 1965 publication from Angyal's laboratory reported that the cis-vicinal diol group of tetra... more A 1965 publication from Angyal's laboratory reported that the cis-vicinal diol group of tetra-O-benzyl myo-inositol reacted regioselectively, sometimes exclusively, with acylating agents at the equatorial OH, but with alkylating agents at the axial OH. Recent reports by Fraser-Reid and coworkers showed that such selectivities were also found for the trans-1,3-diol of tetra-O-benzyl myo-inositol, as well as the C2-C4 hydroxyls of a di-O-allyl mannopyranoside. In addition, the latter workers reported that regioselectivities could be extended to glycosidation reactions. Thus, n-pentenyl ortho ester (NPOE) and 2-O-acyl n-pentenyl glycoside (NPGAC) donors reacted preferentially, if not exclusively, at the equatorial OH, whereas 2-O-alkyl counterparts (NPGALK) gave mixtures, usually with major glycosidation occuring at the axial OH. The present manuscript examines several vicinal diols, and reports that the NPOE and (NPGAC) donors frequently react at only one of the two hydroxy groups...