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1.
Carbohydr Res ; 534: 108974, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37922684

RESUMO

A solvent catalysed and metal catalyst-free Groebke-Blackburn-Bienayame three component reaction (GBB-3CR) has been developed for the synthesis of 2-(ß-D-glycal-1-yl)-3-N-alkylamino-1-azaindolizines and 2-alkyl/aryl/heteroaryl-3-N-alkylamino-1-azaindolizines. The modified GBB reaction protocol is highly efficient, versatile, atom economic and has been performed in hexafluoroisopropanol (HFIP) without any added catalyst. The GBB-3CR showed high tolerance for a large no of substrates in term of aldehydes, differently substituted 2-aminopyridines and isocyanides without being affected by the presence of electron donating and electron withdrawing substituents at either aldehydes or 2-aminopyridines.


Assuntos
Imidazóis , Piridinas , Solventes , Metais , Aminopiridinas , Aldeídos
2.
ACS Omega ; 6(17): 11248-11259, 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-34056280

RESUMO

We have developed an efficient methodology for the synthesis of (2R,3S,4R)-2-hydroxymethyl-3,4-dihydroxy-6-aryl-7-aroylchromanes in which the chirality at the C-2, C-3, and C-4 positions is being drawn from C-glucopyranosyl aldehyde, which in turn can be efficiently synthesized from d-glucose. Thus, the synthesis starts with the transformation of sugar aldehyde into 1-(E-1-arylpropenon-3-yl)-3,4,6-tri-O-benzyl-d-glucals using Claisen-Schmidt type condensation reaction with different acetophenones and then to 1,2-disubstituted glucals via Pd(II)-catalyzed cross dehydrogenative coupling reaction, which in turn has been efficiently converted into (2R,3S,4R)-chromanes via 6π-electrocyclization and in situ dehydrogenative aromatization.

3.
Diabetes Care ; 29(10): 2289-94, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17003308

RESUMO

OBJECTIVE: After the demonstration that one-third of male patients with type 2 diabetes have hypogonadotrophic hypogonadism, we have shown that patients with hypogonadotrophic hypogonadism also have markedly elevated C-reactive protein (CRP) concentrations. We have now hypothesized that type 2 diabetic subjects with hypogonadotrophic hypogonadism may have a lower hematocrit because testosterone stimulates, whereas chronic inflammation suppresses, erythropoiesis. RESEARCH DESIGN AND METHODS: Seventy patients with type 2 diabetes at a tertiary referral center were included in this study. RESULTS: The mean hematocrit in patients with hypogonadotrophic hypogonadism (n = 37), defined as calculated free testosterone (cFT) of <6.5 ng/dl, was 40.6 +/- 1.1%, whereas that in eugonadal patients (n = 33) was 43.3 +/- 0.7% (P = 0.011). The hematocrit was related to cFT concentration (r = 0.46; P < 0.0001); it was inversely related to plasma CRP concentration (r = 0.41; P < 0.0004). Patients with CRP <3 mg/l had a higher hematocrit (42.7 +/- 0.7%) than those with CRP >3 mg/l (39.9 +/- 1.1%; P < 0.05). The prevalence of normocytic normochromic anemia (hemoglobin <13 g/dl) was 23% in the entire group, whereas it was 37.8% in the men with hypogonadotrophic hypogonadism and 3% in the eugonadal men (P < 0.01). Erythropoietin concentration was elevated or high normal in all 11 patients with anemia in whom it was tested. CONCLUSIONS: We conclude that hypogonadotrophic hypogonadism in male type 2 diabetic subjects is associated with a lower hematocrit and a frequent occurrence of mild normocytic normochromic anemia with normal or high erythropoietin concentrations. In these patients, hematocrit is also inversely related to CRP concentration. Thus, low testosterone and chronic inflammatory mechanisms may contribute to mild anemia. Such patients may also have a high risk of atherosclerotic cardiovascular events in view of their markedly elevated CRP concentrations.


Assuntos
Proteína C-Reativa/análise , Diabetes Mellitus Tipo 2/sangue , Hematócrito , Hipogonadismo/sangue , Testosterona/sangue , Adulto , Idoso , Diabetes Mellitus Tipo 2/complicações , Humanos , Hipogonadismo/etiologia , Masculino , Pessoa de Meia-Idade
4.
Artigo em Inglês | MEDLINE | ID: mdl-23591076

RESUMO

The experimental IR and Raman spectra of 2-amino-3,5-dichlorobenzonitrile molecule were recorded, and the results compared with theoretical values. Molecular geometry, vibrational wavenumbers and thermodynamic parameters were calculated using MP2 and DFT quantum chemical methods. With the help of specific scaling procedures for the computed wavenumbers, the experimentally observed FTIR and FT-Raman bands were analyzed and assigned to different normal modes of vibrations of the molecule. Simulations in the dimer form were carried out to improve the assignment of the bands in the solid state experimental spectra. The error obtained was in general very low. Using PED's were determined the contributions of the different modes to each wavenumber. Several general conclusions were also deduced.


Assuntos
Nitrilas/química , Aminação , Modelos Moleculares , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Termodinâmica
6.
Am J Reprod Immunol ; 68(6): 486-90, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22985091

RESUMO

PROBLEM: There is a possibility that mitochondrial respiration defects may contribute to asthenozoospermia. METHOD OF STUDY: Immunocytochemical detection was used to localize succinic dehydrogenase (SDH) in the head and mid-piece of spermatozoa by fluorescent microscope. RESULTS: The study revealed dispersed SDH activity in the semen of asthenozoospermic subjects in comparison with control semen samples. While the stain intensity varied from cell to cell in controls as well as in patients, it was predominantly localized within mid-piece of spermatozoa in healthy individuals. In contrast, in semen of infertile male, the diffused and dispersed SDH immunoreactivity was observed in head as well as in mid-piece region of spermatozoa. CONCLUSION: Dispersed expression of mitochondrial SDH in head and mid-piece of spermatozoa of asthenozoospermia subjects indicates mitochondrial damage because of metabolic or genetic factors, affecting energy production and leading to disturbed sperm motility, which could be pathologically significant. Detailed mitochondrial SDH immunolocalization studies are warranted to establish a role of deranged tricarboxylic acid cycle in causation of male infertility.


Assuntos
Astenozoospermia/enzimologia , Doenças Mitocondriais/metabolismo , Espermatozoides/enzimologia , Succinato Desidrogenase/metabolismo , Acidose Láctica/metabolismo , Encefalopatias Metabólicas Congênitas/metabolismo , Humanos , Masculino , Mitocôndrias/metabolismo , Sêmen/enzimologia , Motilidade dos Espermatozoides
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 78(5): 1437-44, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21330186

RESUMO

The FT-IR and Raman spectra of 3,5-dinitrobenzoic acid (DNBA) have been recorded and analyzed. The equilibrium geometry, various bonding and harmonic vibrational wavenumbers have been calculated with the help of density functional theory (DFT) method. Most of the vibrational modes are observed in the expected range. Mulliken population analysis shows the interactions C-N-O⋯H-C and C-O⋯H-C. The most possible interaction is explained using natural bond orbital (NBO) analysis. The strengthening and polarization of the CO bond increases due to the degree of conjugation. HOMO-LUMO energy and the thermodynamic properties are also evaluated.


Assuntos
Modelos Químicos , Nitrobenzoatos/química , Teoria Quântica , Análise Espectral Raman , Vibração , Modelos Moleculares , Conformação Molecular , Espectroscopia de Infravermelho com Transformada de Fourier
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