Assuntos
Cálcio/farmacologia , Taninos Hidrolisáveis , Magnésio/farmacologia , Taninos , Tiamina , Animais , Precipitação Química , Interações Medicamentosas , RatosAssuntos
Beriberi/etiologia , Flavonoides , Alimentos , Tiamina/antagonistas & inibidores , Adolescente , Animais , Areca , Ácido Ascórbico/administração & dosagem , Ácido Ascórbico/uso terapêutico , Beriberi/prevenção & controle , Fenômenos Químicos , Química , Dieta/efeitos adversos , Feminino , Fermentação , Peixes , Temperatura Alta , Humanos , Taninos Hidrolisáveis , Masculino , Fenóis/farmacologia , Plantas Medicinais , Polímeros/farmacologia , Polifenóis , Ratos , Chá/efeitos adversos , Deficiência de Tiamina/sangue , Deficiência de Tiamina/tratamento farmacológico , Tiamina Pirofosfato/farmacologia , Transcetolase/sangueRESUMO
In anemic crab-eating monkeys, Macaca fascicularis, there is an alteration in the bone marrow RNA species resulting from early vitamin E deficiency, when compared with those from normal simian bone marrow or from phenylhydrazine-induced anemic bone marrow of rabbit. Anemia of vitamin E deficiency is specifically associated with a reduction in the ribosomal RNA content.
Assuntos
Anemia/metabolismo , Medula Óssea/metabolismo , RNA/metabolismo , Deficiência de Vitamina E/metabolismo , Anemia/induzido quimicamente , Anemia/etiologia , Animais , Núcleo Celular/metabolismo , DNA/metabolismo , Haplorrinos , Macaca fascicularis , RNA/isolamento & purificação , RNA Ribossômico/metabolismo , Deficiência de Vitamina E/complicaçõesRESUMO
The kinetics of interactions between thiamine and seven polyphenols were followed by two types of thiochrome assays. The assays on the reaction mixture showed the extremely rapid initial phase whereas those on the eluate of the mixture previously treated by the Decalso column did not. The former assay methods also produced higher estimates of thiamine modification than the latter over the period of 3 hours of reaction. Arguments are given to show the probable non-existence of the observed extremely rapid initial phase. Reinterpretation of some past results are also presented.
Assuntos
Fenóis , Tiamina , Ácidos Cafeicos , Catequina , Catecóis , Interações Medicamentosas , Ácido Gálico , Taninos Hidrolisáveis , Oxirredução , PirogalolRESUMO
Consumption of food high in tannins can cause thiamin deficiency. The interactions between tannic acid and thiamin were studied by allowing them to react at pH 7.5, 60 C, and determining free remaining thiamin by the thiochrome method and by recording changes in ultraviolet absorption profiles at intervals. The reaction was biphasic, having a rapid initial phase which was oxygen-independent, followed by a slower phase which was oxygen concentration-dependent. Ascorbic acid completely inhibited the reaction if present at the beginning of the reaction and could partially reverse the reaction if added during the first 30 min.
Assuntos
Ácido Ascórbico , Taninos Hidrolisáveis , Taninos , Tiamina , Antimetabólitos , Fenômenos Químicos , Química , Cinética , Oxigênio , Fatores de TempoRESUMO
Bio Rex 70 column chromatography and high voltage paper electrophoresis were used to fractionate and define the reaction products of thiamin-tannic acid and thiamin-tea mixtures. Fractions separated indicated the presence of (a) thiamin-tannic acid adduct(s) and several modified forms of thiamin among the products. Using radioactive thiamin and determining the intact form by scintillation counting, the extent of thiamin modification under various conditions was compared with previous results as determined by the thiochrome method. The elution profile of the thiamin-tea mixture and the electrophoretogram showed features similar to those of the thiamin-tannic acid mixture. The effectiveness of the tea extract and tannic acid in modifying thiamin was compared. Ascorbic acid was found to protect the modification of thiamin by tannic acid, not only at acidic pH as previously found, but also at neutral pH, thus making vitamin C a strong candidate for the protection of thiamin in the alimentary system.
Assuntos
Ácido Ascórbico , Taninos Hidrolisáveis , Taninos , Chá , Tiamina , Antimetabólitos , Fenômenos Químicos , Química , Concentração de Íons de Hidrogênio , Taninos Hidrolisáveis/isolamento & purificação , Taninos/isolamento & purificação , Tiamina/análogos & derivados , Tiamina/isolamento & purificação , Tiamina/metabolismoRESUMO
Thiamin deficiency could result either from inadequate intake of thiamin or consumption of food containing antithiamin factors. Dietary surveys conducted in northeastern Thailand indicated that both thiamin and caloric intake of subjects under studies were sufficient. In Thailand, correlation exists between the consumption of food containing antithiamin factors and the prevalence of thiamin deficiency. Betel nuts and raw fermented fish possess antithiamin activity. Abstention from both betel nut chewing and raw fermented fish consumption resulted in a significant reduction of thiamin pyrophosphate effect. The thiamin pyrophosphate effect again increased significantly when the subjects resume their chewing habits. Cooking of fermented fish destroyed thiaminase, resulted in a significant decrease of thiamin pyrophosphate effect of the subjects. Thiamin supplementation (10 mg/day) could further reduce their thiamin pyrophosphate effect. This amount of thiamin could counteract the effect of raw fermented fish consumption but was not sufficient to neutralize the effect of betel nut chewing.
