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2.
Nutr Res Pract ; 18(2): 239-256, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38584808

RESUMO

BACKGROUND/OBJECTIVES: Over the past 10 yrs, the prevalence of diabetes in Korea has continued to incline, and the importance of lifestyle modification to manage diabetes has been highlighted. For patients with diabetes, carbohydrate intake reduction is effective in improving glycemic control; thus, we aimed to analyze the effect of carbohydrate intake ratio and suggest an appropriate carbohydrate intake ratio. SUBJECTS/METHODS: Using the 8th Korea National Health and Nutrition Examination Survey (2019-2021), we analyzed the data including participants aged 30 yrs or older with diabetes, and they were stratified into good and poor glycemic control groups. To analyze the correlation between the dietary behavior characteristics of participants with diabetes and the carbohydrate intake ratio, sociodemographic characteristics, dietary behavior, and health behavior were adjusted, and multivariate logistic regression analysis was conducted to present the adjusted odds ratio and 95% confidence interval (CI). RESULTS: In the unadjusted crude model, when carbohydrate intake ratio in total energy intake increased by 1%, the likelihood of poor glycemic control increased by 1.007-fold (95% CI, 0.998-1.016; P = 0.121). In model 1, which uses age and sex as adjustment variables, an increase of up to 1.011-fold was possible (95% CI, 1.001-1.021; P = 0.008). In model 2, which added variables such as diabetes duration, frequency of fruit consumption, frequency of lunch and, frequency of dinner, the risk of poor glycemic control increased by 1.010-fold as the carbohydrate intake ratio increased (95% CI, 0.998-1.022; P < 0.001). CONCLUSION: This study confirmed that as the ratio of carbohydrate intake to total energy intake increases the likelihood of poor glycemic control also increases in patients with diabetes. Therefore, to improve glycemic control in patients with diabetes, controlling the carbohydrate intake may be helpful.

3.
Chemistry ; 12(4): 1237-43, 2006 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-16267870

RESUMO

Second-order rate constants (k(N)) have been determined spectrophotometrically for the reactions of 2,4-dinitrophenyl X-substituted benzoates (1 a-f) and Y-substituted phenyl benzoates (2 a-h) with a series of alicyclic secondary amines in MeCN at 25.0 +/- 0.1 degrees C. The k(N) values are only slightly larger in MeCN than in H2O, although the amines studied are approximately 8 pK(a) units more basic in the aprotic solvent than in H2O. The Yukawa-Tsuno plot for the aminolysis of 1 a-f is linear, indicating that the electronic nature of the substituent X in the nonleaving group does not affect the rate-determining step (RDS) or reaction mechanism. The Hammett correlation with sigma- constants also exhibits good linearity with a large slope (rho(Y) = 3.54) for the reactions of 2 a-h with piperidine, implying that the leaving-group departure occurs at the rate-determining step. Aminolysis of 2,4-dinitrophenyl benzoate (1 c) results in a linear Brønsted-type plot with a beta(nuc) value of 0.40, suggesting that bond formation between the attacking amine and the carbonyl carbon atom of 1 c is little advanced in the transition state (TS). A concerted mechanism is proposed for the aminolysis of 1 a-f in MeCN. The medium change from H2O to MeCN appears to force the reaction to proceed concertedly by decreasing the stability of the zwitterionic tetrahedral intermediate (T+/-) in aprotic solvent.


Assuntos
Aminas/química , Benzoatos/química , Acetonitrilas/química , Cinética , Morfolinas/química , Piperidinas/química
4.
J Org Chem ; 70(4): 1438-44, 2005 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-15704981

RESUMO

[reaction: see text] We report on a kinetic study for the nucleophilic substitution reactions of 2,4-dinitrophenyl X-substituted benzensulfonates (X = 4-MeO, 1a, and X = 4-NO(2), 1c) with a series of primary amines in 80 mol % H(2)O/20 mol % DMSO at 25.0 degrees C. The reactions proceed through S-O and C-O bond fission pathways competitively. The fraction of the S-O bond fission increases as the attaching amine becomes more basic and the substituent X changes from 4-MeO to 4-NO(2), indicating that the regioselectivity is governed by the electronic nature of the substituent X as well as the basicity of amines. The S-O bond fission has been suggested to proceed through an addition intermediate with a change in the rate-determining step (RDS) at pK(a) degrees = 8.9 +/- 0.1. The electronic nature of the substituent X influences k(N)(S-O) and k(1) values, but not the k(2)/k(-1) ratios and the pK(a) degrees value significantly. Stabilization of the ground state (GS) through resonance interaction between the electron-donating substituent and the electrophilic center has been suggested to be responsible for the decreased reactivity of 1a compared to 1c. The second-order rate constants for the C-O bond fission exhibit no correlation with the electronic nature of the substituent X. The distance effect and the nature of the reaction mechanism have been suggested to be responsible for the absence of the correlation.

5.
J Org Chem ; 70(19): 7530-6, 2005 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-16149780

RESUMO

[reaction: see text] Second-order rate constants (kN) have been measured for the Michael-type reaction of 1-(X-substituted phenyl)-2-propyn-1-ones (2a-f) with a series of primary amines in H2O at 25.0 +/- 0.1 degree C. A linear Brønsted-type plot with a small beta(nuc) value (beta(nuc) = 0.30) has been obtained for the reactions of 1-phenyl-2-propyn-1-one (2c) with non-alpha-nucleophile amines. Hydrazine is more reactive than other primary amines of similar basicity (e.g., glycylglycine and glycine ethyl ester) and results in a positive deviation from the linear Brønsted-type plot. The reactions of 2a-f with hydrazine exhibit a linear Hammett plot, while those with non-alpha-nucleophile amines give linear Yukawa-Tsuno plots, indicating that the electronic nature of the substituent X does not affect the reaction mechanism. The alpha-effect increases as the substituent X in the phenyl ring of 2a-f becomes a stronger electron-donating group. However, the magnitude of the alpha-effect for the reactions of 2a-f is small (e.g., kN(hydrazine)/kN(glycylglycine) = 4.6-13) regardless of the electronic nature of the substituent X. The small beta(nuc) has been suggested to be responsible for the small alpha-effect. A solvent kinetic isotope effect (e.g., kN(H2O)/kN(D2O) = 1.86) was observed for the reaction with hydrazine but absent for the reactions with non-alpha-nucleophile amines. The reactions with hydrazine and other primary amines have been suggested to proceed through a five-membered intramolecular H-bonding structure VI and a six-membered intermolecular H-bonding structure VII, respectively. The transition state modeled on VI can account for the substituent dependent alpha-effect and the difference in the solvent kinetic isotope effect exhibited by the reactions with hydrazine and other primary amines. It has been proposed that the beta(nuc) value is more important than the hybridization type of the reaction site to determine the magnitude of the alpha-effect.

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