Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Yakugaku Zasshi ; 142(8): 893-900, 2022.
Artigo em Japonês | MEDLINE | ID: mdl-35908950

RESUMO

"Leukerin® powder 10%" containing mercaptopurine (6-MP) is an oral anticancer drug that requires careful handling. As a powder formulation, there are risks of exposure due to scattering during dispensing and possible 6-MP contamination to other drugs due to adhesion to the packaging machine. We previously reported that wiping with an alcohol-containing towel is useful for removing scattered powder after dispensing. However, it is recommended to wipe disk-type powder-packaging machines with water instead of cleaning with the alcohol-containing towel. Hence, we scattered 6-MP powder 100 mg (total amount of 6-MP: 10 mg), and then wiped with water three times using different types of cloth each time. We confirmed that third time wiping cloth did not have any 6-MP. Furthermore, we confirmed that the adhering 6-MP could be removed by wipe-cleaning (water-wiping twice and dry-wiping once) after dispensing 6-MP powder at two pharmacies that routinely dispensed 6-MP powder using a disk-type powder-packaging machine. In addition, we confirmed the adhesion of 6-MP in parts of the machine not cleaned by wipe-cleaning and also in parts that were washed only with water, in both the pharmacies. Based on the above observations, we recommend the following steps for cleaning disk-type powder-packaging machines after dispensing 6-MP powder: (1) wipe-cleaning that includes water-wiping twice and then dry-wiping once, (2) cleaning all areas of the packaging machine, and (3) wipe-cleaning with water before washing with water.


Assuntos
Farmácias , Embalagem de Medicamentos , Humanos , Mercaptopurina , Pós , Água
2.
Yakugaku Zasshi ; 141(1): 125-133, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-33390439

RESUMO

The immunosuppressant azathioprine (AZA) is classified as a hazardous drug. AZA contamination during tablet-splitting increases exposure risk. However, there is no study on contamination and exposure during AZA tablet splitting and dispensing. AZA tablet splitting and dispensing methods were classified based on whether tweezers are used during splitting and packaging. In Dispensing Method (1), no tweezers were used in either step. In Dispensing Method (2), no tweezers were used during tablet splitting, but were used during packaging. In Dispensing Method (3), tweezers were used in both steps. After AZA half-tablet split-dispensing, we quantified the adherent AZA removed from the tools, packaging machines, and dispensing counters by three consecutive wipings with water-dampened polypropylene cloths. A large amount of AZA adhered to the gloves used in Dispensing Methods (1) and (2), wherein tablets were placed with gloved hands, compared with Dispensing Method (3), wherein tablets were held with tweezers. Thus, the gloves must be replaced before touching the packaging paper during the final step. After three consecutive wipings, AZA was not detected at most of the sites in the third round. Thus, we recommend that (1) AZA tablet splitting should be performed while wearing gloves, (2) the gloves should be changed before packaging the half tablets, and (3) the tools, packaging machines, and dispensing counters should be wiped twice or thrice with a water-dampened cloth after dispensing.


Assuntos
Azatioprina , Composição de Medicamentos/métodos , Contaminação de Medicamentos/prevenção & controle , Embalagem de Medicamentos/métodos , Imunossupressores , Exposição Ocupacional/prevenção & controle , Azatioprina/efeitos adversos , Imunossupressores/efeitos adversos , Comprimidos
3.
Clin Epigenetics ; 11(1): 111, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31370878

RESUMO

BACKGROUND: DNA demethylation therapy is now used in practice for hematological tumors and is being developed for solid tumors. Nevertheless, it is difficult to achieve stable pharmacokinetics with the current DNA-demethylating agents, azacitidine (AZA) and decitabine (DAC), because of their rapid deamination by cytidine deaminase in vivo and spontaneous hydrolytic cleavage. Here, we aimed to develop metabolically stable prodrugs of AZA and DAC as novel DNA-demethylating agents. RESULTS: Thirty-five 5'-O-trialkylsilylated AZAs/DACs were synthesized with potential resistance to deamination. Out of these, 11 compounds exhibited demethylating activity similar to that of DAC and guadecitabine, and a suitable aqueous solubility. Pharmacokinetic analysis in mice showed that OR-2003 displayed the highest serum concentration and the area under the curve in an intraperitoneal experiment, whereas OR-2100 exhibited high stability to cytidine deaminase. Treatment of cells with OR-2003 and OR-2100 depleted DNA methyltransferase 1 completely and induced both gene-specific and genome-wide demethylation. The treatment suppressed the growth of multiple types of cancer cells and induced re-expression of tumor suppressor genes. The anti-tumor effect and DNA demethylation effect of OR-2003 and OR-2100 were comparable to that of DAC with fewer adverse effects in vivo. CONCLUSIONS: We developed two novel prodrugs of DAC that exhibited greater stability, comparable DNA demethylation activity, and less toxicity. These compounds are expected to overcome the difficulty in achieving stable pharmacokinetics in patients, leading to maximum DNA demethylation activity with minimum adverse effects.


Assuntos
Metilação de DNA/efeitos dos fármacos , Decitabina/química , Neoplasias/tratamento farmacológico , Pró-Fármacos/síntese química , Pró-Fármacos/farmacocinética , Animais , Área Sob a Curva , Azacitidina/química , Análise Química do Sangue , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Estabilidade de Medicamentos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Injeções Intraperitoneais , Camundongos , Neoplasias/genética , Pró-Fármacos/administração & dosagem , Pró-Fármacos/química , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Artigo em Inglês | MEDLINE | ID: mdl-29881633

RESUMO

BACKGROUND: In recent years, the popularity of LED lighting has rapidly increased, owing to its many advantages, including economic benefits. We examined the change in the quality of drugs during storage under LED and fluorescent lighting and found that some medicines exhibited a different degree of color change depending on the light source. The purpose of this study was to investigate the effects of different plastic storage bags on the color change over time when various medicines were stored under LED and fluorescent lighting conditions. METHODS: Photostability tests were conducted on several types of target drugs. Subsequently, subjective evaluation by ten evaluators and objective evaluation by image analysis software were carried out regarding color change. RESULTS: A similar change in color tone was observed after all types of illumination. Subjective evaluation by 10 evaluators revealed that "change in color tone" occurred in the order of bulb-color LED lighting < daylight-color LED lighting < fluorescent lighting, regardless of the type of plastic bags. A similar tendency was observed also in objective evaluation. In this study, it was considered that a brown light-shielding plastic bag was more effective than a normal plastic bag for the prevention of the color change of medicines stored under LED lighting. CONCLUSIONS: The above results suggested that the most appropriate combination of plastic bag and light source for medicine storage was a brown light-shielding plastic bag and bulb-color LED lighting.

5.
Nat Prod Res ; 23(12): 1089-94, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19662573

RESUMO

Three new isoflavanones, 5,7,3'-trihydroxy-4'-methoxy-6,5'-di(gamma, gamma-dimethylallyl)-isoflavanone (1), 5,3'-dihydroxy-4'-methoxy-5'-gamma,gamma-dimethylallyl-2'',2''-dimethylpyrano[5,6 : 6,7]isoflavanone (2) and 5,3'-dihydroxy-2'',2''-dimethylpyrano[5,6 : 6,7]-2''',2'''-dimethylpyrano[5,6 : 5,4]isoflavanone (3), along with two known isoflavonoids, cristacarpin and euchrenone b(10), were isolated from the stems of Erythrina costaricensis. Their structures were established on the basis of spectroscopic evidence. Compound 3 is a rare isoflavanone possessing two 2,2-dimethylpyran moieties. Among the new isoflavanones, compound 1 showed potent antibacterial activity against methicillin-resistant Staphylococcus aureus.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Erythrina/química , Isoflavonas/química , Isoflavonas/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Antibacterianos/isolamento & purificação , Isoflavonas/isolamento & purificação , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Estrutura Molecular
6.
J Asian Nat Prod Res ; 10(9-10): 983-7, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19003619

RESUMO

Two new isoflavanones, 5,3'-dihydroxy-4'-methoxy-5'-(3-methyl-1,3-butadienyl)-2'',2''-dimethylpyrano[5,6:6,7]isoflavanone (1) and 5,3'-dihydroxy-5'-(3-hydroxy-3-methyl-1-butenyl)-4'-methoxy-2'',2''-dimethylpyrano[5,6:6,7]isoflavanone (2), together with two known isoflavonoids, cristacarpin, and euchrenone b10, were isolated from the stems of Erythrina costaricensis. Their structures were established on the basis of spectroscopic evidence. These new compounds are rare isoflavanones, possessing both a 2,2-dimethylpyran substituent and a prenyl analog. The antibacterial activities of 1 and 2 against the methicillin-resistant Staphylococcus aureus were examined.


Assuntos
Erythrina/química , Isoflavonas/química , Estrutura Molecular , Caules de Planta/química
7.
Biosci Biotechnol Biochem ; 70(4): 897-906, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16636457

RESUMO

An extract of royal jelly (RJ) induced processes from cultured rat pheochromocytoma PC12 cells. Active components were isolated, and identified as adenosine monophosphate (AMP) and AMP N1-oxide. AMP N1-oxide was more than 20 times as active as AMP, judging from the minimal concentration to elicit activity. AMP N1-oxide was thought to be responsible for about half of the process-forming activity of whole RJ. Chemically-synthesized AMP N1-oxide was active similarly to the molecule purified from RJ, confirming AMP N1-oxide as the active entity. AMP N1-oxide also suppressed proliferation of PC12 cells and stimulated expression of neurofilament M, a specific protein of mature neurons, demonstrating the stimulatory activity of AMP N1-oxide to induce neuronal differentiation of PC12 cells. Pharmacological experiments suggested that AMP N1-oxide actions are mediated by adenyl cyclase-coupled adenosine receptors, including A2A. Thus AMP N1-oxide is a key molecule that characterizes RJ, and is not found in natural products other than RJ.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Movimento Celular/efeitos dos fármacos , Ácidos Graxos/química , Neurônios/citologia , Neurônios/efeitos dos fármacos , Óxidos/química , Óxidos/farmacologia , Monofosfato de Adenosina/química , Monofosfato de Adenosina/isolamento & purificação , Monofosfato de Adenosina/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Forma Celular , Cromatografia por Troca Iônica , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Óxidos/isolamento & purificação , Células PC12 , Agonistas do Receptor Purinérgico P1 , Ratos , Receptores Purinérgicos P1/metabolismo , Espectrometria de Massas por Ionização por Electrospray
8.
J Org Chem ; 69(23): 8148-50, 2004 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-15527310

RESUMO

The treatment of (15)N(4)-labeled cytidine N(3)-oxide and (15)N(4)-labeled 2'-deoxycytidine N(3)-oxide, prepared from the appropriate unprotected uridines in three reaction steps, with benzyl bromide in the presence of excess lithium methoxide allowed the smooth occurrence of their Dimroth rearrangement even under mild conditions leading to the corresponding (15)N(3)-labeled uridine 4-O-benzyloximes which can easily undergo the reductive N-O bond cleavage to give the desirable (15)N(3)-labeled cytosine nucleosides in high total yields.


Assuntos
Citidina/química , Nucleosídeos de Pirimidina/síntese química , Catálise , Estrutura Molecular , Isótopos de Nitrogênio , Ressonância Magnética Nuclear Biomolecular , Uridina
9.
J Org Chem ; 69(7): 2598-600, 2004 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-15049668

RESUMO

Treatment of 5-[2-(4-hydroxyphenyl)vinyl]benzene-1,3-diol (resveratrol) with an equimolar amount of silver(I) acetate in dry MeOH at 50 degrees C for 1 h followed by chromatographic purification with a short silica gel column allowed the isolation of its (E)-dehydrodimer, 5-[5-[2-(3,5-dihydroxyphenyl)vinyl]-2-(4-hydroxyphenyl)-2,3-dihydrobenzofuran-3-yl]benzene-1,3-diol, as a racemic mixture in high yield. The present method was applicable to the oxidative dimerization of 4-hydroxystilbenes such as trans-styrylphenol and 5-[6-hydroxy-2-(4-hydroxyphenyl)-4-[2-(4-hydroxyphenyl)vinyl]-2,3-dihydrobenzofuran-3-yl]benzene-1,3-diol (epsilon-viniferin) leading to the corresponding 2-(4-hydroxyphenyl)-2,3-dihydrobenzofurans possessing various types of biological activities.


Assuntos
Benzofuranos/química , Benzofuranos/síntese química , Técnicas de Química Combinatória , Estilbenos/química , Estilbenos/síntese química , Catálise , Indicadores e Reagentes , Estrutura Molecular , Oxirredução , Resveratrol , Estereoisomerismo
10.
Biol Pharm Bull ; 27(3): 273-6, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14993787

RESUMO

The formation of cyclic 1,N2-propano guanine (CPr-Gua) adduct is significantly accelerated by the addition of arginine or histone in the reaction of calf thymus DNA with acetaldehyde (AA) or crotonaldehyde (CA). Histone proteins, containing a large amount of basic amino acids such as arginine, are essential as nucleosome cores to package DNA. In the presence of 0.60% (w/v) histone in the reaction mixture, 8-times and 25-times larger amounts of the CPr-Gua adduct were formed in the reaction of the DNA with AA and CA, respectively, compared with those in the absence of histone. Furthermore, for the DNA incubated at 95 degrees C for 10 min and cooled on ice to make the single-stranded moieties, 72-times and 178-times larger amounts of the CPr-Gua adduct were formed by AA and CA, respectively, in the presence of 0.60% (w/v) histone. These results strongly suggest that DNA in vivo should be exposed to a much more dangerous situation, compared with DNA alone, from the viewpoint of reactivity with the aldehydes. During DNA replication and transcriptional events of cells, the danger will be further increased markedly because of opening of double-strands. Semi-micro HPLC-ESI-MS measurements following deprination of DNA samples were performed for quantification of the adduct as the corresponding base form, CPr-Gua, in evaluation of the reactivity of DNA with AA and CA.


Assuntos
Acetaldeído/química , Adutos de DNA/química , Guanina/análogos & derivados , Guanina/síntese química , Histonas/química , Aldeídos/química , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , DNA/química , Espectrometria de Massas , Timo/química
11.
Chem Biodivers ; 1(7): 1101-8, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17191901

RESUMO

Three new isoflavonoids, eryvarins M-O (1-3), two new 2-arylbenzofurans, eryvarins P and Q (4 and 5), and a new 3-aryl-2,3-dihydrobenzofuran, eryvarin R (6), together with three known compounds, were isolated from the roots of Erythrina variegata. The structures of these compounds were established by spectroscopic analysis. Eryvarin R (6) is an unusual 3-aryl-2,3-dihydrobenzofuran derivative with a formyl (CHO) group. Eryvarin Q (5) showed potent antibacterial activity against methicillin-resistant Staphylococcus aureus.


Assuntos
Erythrina , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Raízes de Plantas
12.
Phytochemistry ; 64(3): 753-8, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-13679098

RESUMO

Five isoflavonoids, (+/-)-7,2',4'-trihydroxy-8,3'-di(gamma,gamma-dimethylallyl)isoflavanone, (3R)-7,4'-dihydroxy-2'-methoxy-6,8-di(gamma,gamma-dimethylallyl)isoflavanone, (3R)-7,2',4'-trihydroxy-6,8-di(gamma,gamma-dimethylallyl)isoflavan, 2',4'-dihydroxy-8-gamma,gamma-dimethylallyl-2",2"-dimethylpyrano-[5,6:6,7]isoflavan and (6aS, 11aS)-3,6a-dihydroxy-9-methoxy-4,10-di(gamma,gamma-dimethylallyl)pterocarpan, along with five known compounds, were isolated from the roots of Erythrina zeyheri. Their structures were established on the basis of spectroscopic evidence, and their antibacterial activities against methicillin-resistant Staphylococcus aureus (MRSA) were estimated by determining minimum inhibitory concentrations.


Assuntos
Erythrina/química , Isoflavonas/isolamento & purificação , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Isoflavonas/química , Isoflavonas/farmacologia , Espectroscopia de Ressonância Magnética , Resistência a Meticilina , Testes de Sensibilidade Microbiana , Raízes de Plantas/química , Staphylococcus aureus/efeitos dos fármacos , Estereoisomerismo
13.
Bioorg Med Chem Lett ; 13(20): 3497-8, 2003 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-14505656

RESUMO

Chemical modification of 2'-deoxyguanosine and DNA by excessive acetaldehyde and crotonaldehyde were significantly accelerated by the presence of histones, which are nuclear proteins very rich in the basic amino acids such as L-arginine and L-lysine, resulting in the smooth and selective formation of the corresponding cyclic 1,N(2)-propanoguanine adducts under physiological conditions. Thus, histones have a very close connection with the genotoxic and carcinogenic effects of these aldehydes.


Assuntos
Álcoois/toxicidade , Aldeídos/toxicidade , Carcinógenos/toxicidade , Adutos de DNA/metabolismo , DNA/efeitos dos fármacos , Histonas/metabolismo , Adutos de DNA/biossíntese
14.
Phytochemistry ; 63(5): 597-602, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12809721

RESUMO

An arylbenzofuran, erypoegin F and four isoflavonoids, erypoegins G-J, together with six known compounds were isolated from the roots of Erythrina poeppigiana, and their structures were elucidated on the basis of spectroscopic evidence. Erypoegin F is a rare 2-arylbenzofuran possessing a formyl group from a natural source, and erypoegin I is the first naturally occurring isoflavonoid with a 2-oxo-3-methylbutyl group.


Assuntos
Benzofuranos/química , Benzofuranos/isolamento & purificação , Erythrina/química , Isoflavonas/química , Isoflavonas/isolamento & purificação , Raízes de Plantas/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular
15.
Phytochemistry ; 62(8): 1243-6, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12648545

RESUMO

Two 3-phenoxychromones, eryvarins F and G, were isolated from the roots of Erythrina variegata. Their structures were established to be 3-(2,4-dihydroxyphenoxy)-7-hydroxy-6,8-di(3,3-dimethylallyl)chromen-4-one and 3-(2,4-dihydroxyphenoxy)-8-(3,3-dimethylallyl)-2,2-dimethylpyrano[5,6:6,7]chromen-4-one on the basis of spectroscopic and chemical evidence. Eryvarins F and G are unusual 3-phenoxychromone derivatives with two isoprenoid groups.


Assuntos
Cromonas/química , Erythrina/química , Cromatografia em Gel/métodos , Cromonas/isolamento & purificação , Ressonância Magnética Nuclear Biomolecular , Raízes de Plantas/química , Terpenos/química
16.
J Chromatogr A ; 987(1-2): 341-7, 2003 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-12613828

RESUMO

A highly sensitive method using liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) was developed for the analysis of DNA adducts of acetaldehyde (AA). AA, which is the primary oxidative metabolite of ethanol, is considered to possess carcinogenic activity. AA reacts with the exocyclic amino group of guanine in DNA to form N2-ethylguanine (Et-Gua) and 1,N2-propanoguanine (Pr-Gua) adducts. With the present method, such adducts were detected as the base forms from DNA chains using depurination in the pretreatment process. In our measurement with LC-ESI-MS, the limits of detection (LODs) of the Et-Gua and Pr-Gua adducts of the base forms were 3.0 x 10(-10) and 1.0 x 10(-9) M, respectively, and the LODs are about two orders of magnitude lower than those of the nucleoside forms. Calf thymus DNA samples treated with AA and NaBH3CN were analyzed by this method. Et-Gua was clearly detected and, in the absence of NaBH3CN, Pr-Gua was detected predominantly. Furthermore, the method was also applied to study whether or not these two adducts are formed in DNA of cultured HL-60 cells during exposure to AA for 24 h. Pr-Gua was clearly detected and traces of Et-Gua were also detected in the DNA of the cells. Although the sensitivity of this method is lower by at least oneorder of magnitude than the 32P-postlabeling assay, currently the most sensitive method, our method does not involve complex enzymatic reactions for the postlabeling and the use of troublesome radioactive materials. Furthermore, it enables structural identification of guanine adducts. The present method would be a useful tool for studies of Et-Gua and Pr-Gua adducts in connection with carcinogenesis.


Assuntos
Acetaldeído/química , Cromatografia Líquida de Alta Pressão/métodos , Adutos de DNA/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Células HL-60 , Humanos
17.
J Org Chem ; 67(3): 668-73, 2002 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-11856005

RESUMO

The UV irradiation of pyrrolnitrin (1a), which is an antibiotic clinically useful against dermatophytosis and possesses a unique 2-(pyrrol-3-yl)nitrobenzene moiety in the molecule, in an anhydrous aprotic solvent resulted in the exclusive formation of transient 7,4'-dichlorospiro[1,3-dihydrobenzo(c)isoxazole-3,3'-pyrrolin-2'-one] (2a) via the intramolecular oxidation of the juxtaposed pyrrole ring by the triplet-excited nitro group. The irradiation in an aqueous aprotic solvent, however, allowed the concurrent occurrence of intramolecular cyclization by the singlet-excited nitro group in 1a and the hydroxylation at the 2-position of the pyrrole ring by water to afford 3,7-dichloro-8-hydroxy-8,8a-dihydropyrrolo[2,3-b]indol-2-one (3a), accompanied by the formation of 2a. Elongation of the irradiation time in these photoreactions caused a rapid consumption of the products, 2a and 3a, to give undetermined polar polymeric products. The present results indicate that the photodegradation of 1a is significantly influenced by the presence of water in the reaction media and by the nature of its excited state. Thus, the loss of the antifungal activities by the photosensitive antibiotic 1a was chemically proved.


Assuntos
Antifúngicos/química , Pirrolnitrina/química , Estrutura Molecular , Fotoquímica , Solventes , Análise Espectral , Água
18.
Nucleic Acids Res Suppl ; (2): 21-2, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12903085

RESUMO

The reactions of guanine nucleosides and nucleotides with acetaldehyde or crotonaldehyde were significantly accelerated even under mild conditions by the presence of a basic amino acid such as arginine and lysine to form smoothly and selectively the corresponding cyclic 1,N2-propano adducts.


Assuntos
Acetaldeído/química , Aldeídos/química , Ácidos Nucleicos/química
20.
J Org Chem ; 63(20): 6947-6951, 1998 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-11672316

RESUMO

4H-[1,2,5]Oxadiazolo[3,4-d]pyrimidine-5,7-dione 1-oxides (2) are conveniently prepared in high yields by the oxidative intramolecular cyclization of 6-amino-5-nitro-1H-pyrimidine-2,4-diones (1) employing iodosylbenzene diacetate as an oxidant in the presence of lithium hydride. The generation of nitric oxide (NO) and NO-related species from 2 occurs in the presence of thiols such as N-acetylcysteamine, cysteine, and glutathione under physiological conditions. The evidence for the NO generation derives from mechanistic interpretations for the reaction of 2 with thiols and other chemical observations.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA