MARIA CARMEN AVENDAÑO LOPEZ - Academia.edu (original) (raw)
Papers by MARIA CARMEN AVENDAÑO LOPEZ
Heterocyclic Communications, 2000
The redox properties of a series of 1-aza-, 1,5-diaza-and 1,8-diazaanthracene-4,9,10-triones are ... more The redox properties of a series of 1-aza-, 1,5-diaza-and 1,8-diazaanthracene-4,9,10-triones are reported. The results obtained show that the presence of electron-withdrawing heterocyclic nitrogen atoms causes an increase of the reduction potentials, and also the expected similar effect of electron-withdrawing substituents. /^-substituted derivatives exhibited a reduction at ca.-1.45 V, which is assigned to the α,β-unsaturated carbonyl system. In contrast with their 2-oxo vinylogues, 1,5-diaza-and 1,8-diazaanthracene-4,9,10-triones show three reduction potentials. On the basis of the results obtained with W-substituted derivatives, the first of these potentials is attributed to the presence of detectable amounts of the 4-hydroxy-tautomers.
Tetrahedron, 2010
Pyrazino[1,2-b]isoquinoline-1,4-diones (3) having a bulky activating group at the N(2)-position w... more Pyrazino[1,2-b]isoquinoline-1,4-diones (3) having a bulky activating group at the N(2)-position were rearranged to tetramic acids with a benzo[f]indolizine skeleton (8) in the presence of KtBuO or LHMDS as bases. This rearrangement was diasteroselective for the 6,11a-trans-isomers of the starting compounds. 1-Hydroxy-pyrazino[1,2-b]isoquinolin-4-one (7) afforded a 1-trichloroacetamido derivative (14) after treatment with trichloroacetonitrile and a catalytic amount of sodium hydride as a base, through two subsequent base-promoted transannular rearrangements. In summary, the combination of functions in the piperazine ring of the starting tricyclic compounds conferred to them new reactivities that imply different base-promoted transannular rearrangements and led to unexpected transformations.
Synlett, 2007
... Vellaisamy Sridharan, Carmen Avendaño, J. Carlos Menéndez*. ... 9b Srinivas KVNS, Das W,Synle... more ... Vellaisamy Sridharan, Carmen Avendaño, J. Carlos Menéndez*. ... 9b Srinivas KVNS, Das W,Synlett 2004, 1715. 9c Yadav JS, Reddy BVS, Reddy JSS, Srinivasa Rao S,Tetrahedron 2003, 59: 1599. 9d Kumar RS, Nagarajan R, Chitra S, Perumal PT,Tetrahedron 2001, 57: 3419. ...
Organic Letters, 2005
Table of contents General experimental procedure for the preparation of α-nitroketones (4) 2 Repr... more Table of contents General experimental procedure for the preparation of α-nitroketones (4) 2 Representative procedure for the preparation of bridged macrolactones (3) 3 Data for compounds 3 3 X-Ray structure analysis 11 Representative spectra 18
![Research paper thumbnail of Efficient synthesis of the pyrido[2,3,4-kl]acridin-4-one system common to several cytotoxic marine alkaloids](https://attachments.academia-assets.com/99800871/thumbnails/1.jpg)
](Tetrahedron Letters, 2003
An efficient, four-step synthesis of the pyrido[2,3,4-kl]acridin-4-one system is described, using... more An efficient, four-step synthesis of the pyrido[2,3,4-kl]acridin-4-one system is described, using a Suzuki coupling of a 4-iodoquinoline and a oxidative demethylation of a dimethoxyquinoline containing an anilino unit with cobalt trifluoride as the key steps.
Canadian Journal of Chemistry, 1988
Tautomerism of dibenzothiazolylmethane (1) and its C-methyl derivative (2) has been studied by 1H... more Tautomerism of dibenzothiazolylmethane (1) and its C-methyl derivative (2) has been studied by 1H nuclear magnetic resonance, ultraviolet, and infrared spectroscopy using C,C-dimethyl (3) and N-methyl (4) derivatives as model compounds of the "CH" and "NH" forms, respectively. X-ray diffraction analysis of the "fixed" N-methyl derivative 4 shows that it corresponds to the Z-sE isomer 4b2. The CH tautomers are unstable in solution and they slowly isomerize into a mixture of NH tautomers that depends on the solvent and on the C-substituent (H or CH3).
Medicinal Chemistry of Anticancer Drugs, 2008
Cell membranes are one of the biological structures more sensitive to damage by radicals because ... more Cell membranes are one of the biological structures more sensitive to damage by radicals because of the presence of polyunsaturated fatty acids in them, containing methylene groups that are simultaneously adjacent to two double bonds. Oxidative stress by hydroxyl radical also causes direct DNA damage, mainly by strand cleavage and oxidation of pyrimidine and purine bases. Attack of hydroxyl radicals to purine or pyrimidine bases produces other DNA damages. Another consequence of the formation of hydroxyl radicals can be the generation of formaldehyde by reaction with certain cell components like spermine and lipids. Anthracyclines are a group of antibiotics characterized by the presence of a planar chromophore containing an anthraquinone fragment, attached to an amino sugar. Mitoxantrone, an anthraquin one derivative bearing poly amine side chains, can be considered as a partial analog of the anthracyclines including the hydroxyquin one function. The bleomycins (BLMs) are a family of natural glycopeptidic antibiotics produced by Streptomyces verticillus with clinical efficacy against several types of tumors, specially squamous cell carcinoma, testicular carcinoma, and malignant lymphomas.
Medicinal Chemistry of Anticancer Drugs, 2015
Chapter 3 discusses cancer chemotherapy related to the hormonal regulation of tumors, starting wi... more Chapter 3 discusses cancer chemotherapy related to the hormonal regulation of tumors, starting with the regulation of gene transcription by estrogens and the proposed mechanisms to explain the development of estrogen-dependent tumors. Nonsteroidal antiestrogens, also known as “selective estrogen receptor modulators” (SERMs), are explained at the molecular and atomic levels, and their action is rationalized by using the structures of their complexes with the receptor. The mechanisms of resistance to hormonal therapy are discussed, as well as alternative endocrine treatments. After explaining different mechanisms to rationalize aromatase action, steroidal (type I) and nonsteroidal (type II) aromatase inhibitors are studied, first discussing the advantages of the mechanism-based inhibitors known as aromatase inactivators and then the structure–activity relationships in steroidal aromatase inhibitors, especially how the coordination of azole derivatives to the iron atom of the heme group of the enzyme explains their affinity but also their problematic selectivity. We comment on the role of steroid sulfatase in steroid biosynthesis, the mechanism of action of its inhibitors, and the advantages of dual aromatase–sulfatase inhibitors. The chapter discusses the importance in prostatic cancer of steroidal and nonsteroidal antiandrogens and the resistance associated with the presence of a variant of the androgen receptors, as well as inhibitors of the different enzymes involved in androgen biosynthesis. The mechanisms associated with the anticancer activity of agonists of the gestagen receptor, glucocorticoids, retinoids, and agonists of vitamin D receptors and peroxysome proliferator activating receptors (PPARγ) are also commented.
Synthetic Communications, 2002
![Research paper thumbnail of Fused Imidazophenothiazines: Synthesis of 2-Methyl-3-phenyl-6H-imidzo[4,5-c]phenothiazine](https://attachments.academia-assets.com/93251161/thumbnails/1.jpg)
](HETEROCYCLES, 1990
_Abstract-A new and r e l i a b l e procedure f o r the multigram-scale preparation o f 2-methyl-... more _Abstract-A new and r e l i a b l e procedure f o r the multigram-scale preparation o f 2-methyl-1-phenyl-5-phenylaminobenzirnidazole (6) i s reported. Bernthsen t h i o n a t i o n of 5 leads t o 2-methyl-3-phenyl-6~-imidazo[4,5-c]phenothiazine (x), whose s t r u c t u r e was established through a d e t a i l e d mono-and bidimensional 'H-nmr and 13c-nmr spectroscopic study o f model compounds.
Tetrahedron, 2003
Fused pyridine derivatives Fused pyridine derivatives R 0450 Regioselective Diels-Alder Reactions... more Fused pyridine derivatives Fused pyridine derivatives R 0450 Regioselective Diels-Alder Reactions of 3-Indolylquinones.-(3-Indolyl)quinolinequinones, except the derivative (Ib), undergo Diels-Alder reaction with a variety of dienophiles. Even double Diels-Alder reactions take place. In the presence of unsymmetrical dienophiles excellent regioselectivity is observed. Additionally, it is shown that one-pot cascade reaction of indoles to heptacyclic compounds like (XV) is possible.-(ALONSO, M. A.
ChemInform, 2010
Total Synthesis of Diazaquinomycin A.-Two concise routes for the total synthesis of the title ant... more Total Synthesis of Diazaquinomycin A.-Two concise routes for the total synthesis of the title antibiotic (VI) are reported. The first procedure starts with a double hetero-Diels-Alder reaction between the hexenal hydrazone (I) and 2,6-dibromobenzoquinone (II). The resulting (III) is oxidized stepwise to the aromatized N-oxide (V) and then rearranged to the target (VI). The second route is based on the hetero-Diels-Alder reaction of the hydrazone (I) and quinoline-2,5,8-trione (VII).-(PEREZ,
Canadian Journal of Chemistry, 1980
The two isomers of 3-aminotropane-3-carboxylic acid have been prepared by hydrolysis of the two α... more The two isomers of 3-aminotropane-3-carboxylic acid have been prepared by hydrolysis of the two α- and β-tropane-3-spiro-5′-hydantoins whose configurations were determined by X-ray crystallography and 13C nmr. The [Formula: see text] values of these amino acids and the hydrolysis rates of their N-formyl derivatives have been determined to study the influence of the amino group in an axial or equatorial position. The biological transport – inhibitory action of the two tropane amino acids has also been compared.
Heterocyclic Communications, 2000
The redox properties of a series of 1-aza-, 1,5-diaza-and 1,8-diazaanthracene-4,9,10-triones are ... more The redox properties of a series of 1-aza-, 1,5-diaza-and 1,8-diazaanthracene-4,9,10-triones are reported. The results obtained show that the presence of electron-withdrawing heterocyclic nitrogen atoms causes an increase of the reduction potentials, and also the expected similar effect of electron-withdrawing substituents. /^-substituted derivatives exhibited a reduction at ca.-1.45 V, which is assigned to the α,β-unsaturated carbonyl system. In contrast with their 2-oxo vinylogues, 1,5-diaza-and 1,8-diazaanthracene-4,9,10-triones show three reduction potentials. On the basis of the results obtained with W-substituted derivatives, the first of these potentials is attributed to the presence of detectable amounts of the 4-hydroxy-tautomers.
Tetrahedron, 2010
Pyrazino[1,2-b]isoquinoline-1,4-diones (3) having a bulky activating group at the N(2)-position w... more Pyrazino[1,2-b]isoquinoline-1,4-diones (3) having a bulky activating group at the N(2)-position were rearranged to tetramic acids with a benzo[f]indolizine skeleton (8) in the presence of KtBuO or LHMDS as bases. This rearrangement was diasteroselective for the 6,11a-trans-isomers of the starting compounds. 1-Hydroxy-pyrazino[1,2-b]isoquinolin-4-one (7) afforded a 1-trichloroacetamido derivative (14) after treatment with trichloroacetonitrile and a catalytic amount of sodium hydride as a base, through two subsequent base-promoted transannular rearrangements. In summary, the combination of functions in the piperazine ring of the starting tricyclic compounds conferred to them new reactivities that imply different base-promoted transannular rearrangements and led to unexpected transformations.
Synlett, 2007
... Vellaisamy Sridharan, Carmen Avendaño, J. Carlos Menéndez*. ... 9b Srinivas KVNS, Das W,Synle... more ... Vellaisamy Sridharan, Carmen Avendaño, J. Carlos Menéndez*. ... 9b Srinivas KVNS, Das W,Synlett 2004, 1715. 9c Yadav JS, Reddy BVS, Reddy JSS, Srinivasa Rao S,Tetrahedron 2003, 59: 1599. 9d Kumar RS, Nagarajan R, Chitra S, Perumal PT,Tetrahedron 2001, 57: 3419. ...
Organic Letters, 2005
Table of contents General experimental procedure for the preparation of α-nitroketones (4) 2 Repr... more Table of contents General experimental procedure for the preparation of α-nitroketones (4) 2 Representative procedure for the preparation of bridged macrolactones (3) 3 Data for compounds 3 3 X-Ray structure analysis 11 Representative spectra 18
Tetrahedron Letters, 2003
An efficient, four-step synthesis of the pyrido[2,3,4-kl]acridin-4-one system is described, using... more An efficient, four-step synthesis of the pyrido[2,3,4-kl]acridin-4-one system is described, using a Suzuki coupling of a 4-iodoquinoline and a oxidative demethylation of a dimethoxyquinoline containing an anilino unit with cobalt trifluoride as the key steps.
Canadian Journal of Chemistry, 1988
Tautomerism of dibenzothiazolylmethane (1) and its C-methyl derivative (2) has been studied by 1H... more Tautomerism of dibenzothiazolylmethane (1) and its C-methyl derivative (2) has been studied by 1H nuclear magnetic resonance, ultraviolet, and infrared spectroscopy using C,C-dimethyl (3) and N-methyl (4) derivatives as model compounds of the "CH" and "NH" forms, respectively. X-ray diffraction analysis of the "fixed" N-methyl derivative 4 shows that it corresponds to the Z-sE isomer 4b2. The CH tautomers are unstable in solution and they slowly isomerize into a mixture of NH tautomers that depends on the solvent and on the C-substituent (H or CH3).
Medicinal Chemistry of Anticancer Drugs, 2008
Cell membranes are one of the biological structures more sensitive to damage by radicals because ... more Cell membranes are one of the biological structures more sensitive to damage by radicals because of the presence of polyunsaturated fatty acids in them, containing methylene groups that are simultaneously adjacent to two double bonds. Oxidative stress by hydroxyl radical also causes direct DNA damage, mainly by strand cleavage and oxidation of pyrimidine and purine bases. Attack of hydroxyl radicals to purine or pyrimidine bases produces other DNA damages. Another consequence of the formation of hydroxyl radicals can be the generation of formaldehyde by reaction with certain cell components like spermine and lipids. Anthracyclines are a group of antibiotics characterized by the presence of a planar chromophore containing an anthraquinone fragment, attached to an amino sugar. Mitoxantrone, an anthraquin one derivative bearing poly amine side chains, can be considered as a partial analog of the anthracyclines including the hydroxyquin one function. The bleomycins (BLMs) are a family of natural glycopeptidic antibiotics produced by Streptomyces verticillus with clinical efficacy against several types of tumors, specially squamous cell carcinoma, testicular carcinoma, and malignant lymphomas.
Medicinal Chemistry of Anticancer Drugs, 2015
Chapter 3 discusses cancer chemotherapy related to the hormonal regulation of tumors, starting wi... more Chapter 3 discusses cancer chemotherapy related to the hormonal regulation of tumors, starting with the regulation of gene transcription by estrogens and the proposed mechanisms to explain the development of estrogen-dependent tumors. Nonsteroidal antiestrogens, also known as “selective estrogen receptor modulators” (SERMs), are explained at the molecular and atomic levels, and their action is rationalized by using the structures of their complexes with the receptor. The mechanisms of resistance to hormonal therapy are discussed, as well as alternative endocrine treatments. After explaining different mechanisms to rationalize aromatase action, steroidal (type I) and nonsteroidal (type II) aromatase inhibitors are studied, first discussing the advantages of the mechanism-based inhibitors known as aromatase inactivators and then the structure–activity relationships in steroidal aromatase inhibitors, especially how the coordination of azole derivatives to the iron atom of the heme group of the enzyme explains their affinity but also their problematic selectivity. We comment on the role of steroid sulfatase in steroid biosynthesis, the mechanism of action of its inhibitors, and the advantages of dual aromatase–sulfatase inhibitors. The chapter discusses the importance in prostatic cancer of steroidal and nonsteroidal antiandrogens and the resistance associated with the presence of a variant of the androgen receptors, as well as inhibitors of the different enzymes involved in androgen biosynthesis. The mechanisms associated with the anticancer activity of agonists of the gestagen receptor, glucocorticoids, retinoids, and agonists of vitamin D receptors and peroxysome proliferator activating receptors (PPARγ) are also commented.
Synthetic Communications, 2002
HETEROCYCLES, 1990
_Abstract-A new and r e l i a b l e procedure f o r the multigram-scale preparation o f 2-methyl-... more _Abstract-A new and r e l i a b l e procedure f o r the multigram-scale preparation o f 2-methyl-1-phenyl-5-phenylaminobenzirnidazole (6) i s reported. Bernthsen t h i o n a t i o n of 5 leads t o 2-methyl-3-phenyl-6~-imidazo[4,5-c]phenothiazine (x), whose s t r u c t u r e was established through a d e t a i l e d mono-and bidimensional 'H-nmr and 13c-nmr spectroscopic study o f model compounds.
Tetrahedron, 2003
Fused pyridine derivatives Fused pyridine derivatives R 0450 Regioselective Diels-Alder Reactions... more Fused pyridine derivatives Fused pyridine derivatives R 0450 Regioselective Diels-Alder Reactions of 3-Indolylquinones.-(3-Indolyl)quinolinequinones, except the derivative (Ib), undergo Diels-Alder reaction with a variety of dienophiles. Even double Diels-Alder reactions take place. In the presence of unsymmetrical dienophiles excellent regioselectivity is observed. Additionally, it is shown that one-pot cascade reaction of indoles to heptacyclic compounds like (XV) is possible.-(ALONSO, M. A.
ChemInform, 2010
Total Synthesis of Diazaquinomycin A.-Two concise routes for the total synthesis of the title ant... more Total Synthesis of Diazaquinomycin A.-Two concise routes for the total synthesis of the title antibiotic (VI) are reported. The first procedure starts with a double hetero-Diels-Alder reaction between the hexenal hydrazone (I) and 2,6-dibromobenzoquinone (II). The resulting (III) is oxidized stepwise to the aromatized N-oxide (V) and then rearranged to the target (VI). The second route is based on the hetero-Diels-Alder reaction of the hydrazone (I) and quinoline-2,5,8-trione (VII).-(PEREZ,
Canadian Journal of Chemistry, 1980
The two isomers of 3-aminotropane-3-carboxylic acid have been prepared by hydrolysis of the two α... more The two isomers of 3-aminotropane-3-carboxylic acid have been prepared by hydrolysis of the two α- and β-tropane-3-spiro-5′-hydantoins whose configurations were determined by X-ray crystallography and 13C nmr. The [Formula: see text] values of these amino acids and the hydrolysis rates of their N-formyl derivatives have been determined to study the influence of the amino group in an axial or equatorial position. The biological transport – inhibitory action of the two tropane amino acids has also been compared.