Phytosterols have received extensive attention owing to their excellent cholesterol-lowering activity and the role in cardiovascular diseases prevention. However, poor solubility in both oil and water limited the appl...Phytosterols have received extensive attention owing to their excellent cholesterol-lowering activity and the role in cardiovascular diseases prevention. However, poor solubility in both oil and water limited the application of free phytosterols in the food industry. Chemical or enzymatic modifications were effective to improve the physicochemical properties as well as the bioavailability and cholesterollowering activity of phytosterols. Higher oil solubility and lower melting point of phytosterols have been achieved by esterification and transesterification with fatty acids and triacylglycerols so as to enhance the bioavailability, reduce formation of precipitates, and improve the sensory quality of products.While the researches on the improvement on its water solubility is a hot topic. Hydrophilic phytosterol derivatives have promising applications in the food industry because most of foods belong to aqueous matrix. Hydrophilic modification is useful and meaningful for phytosterols in both industrial and commercial applications. This review mainly highlights the hydrophilic phytosterol derivatives in the following aspects:(i) hydrophilic modifications of phytosterols by coupling with various polar components;(ii) cholesterol-lowering activity and possible molecular mechanisms of hydrophilic phytosterol derivatives on reducing serum cholesterol level;and(iii) safety evaluation of hydrophilic phytosterol derivatives in cell-culture studies, animal models and clinical trials.展开更多
Reaction of p-t-butylcalix[6]arene with ethylene oxide gives a water soluble host compound with a hydrophobic cavity and it can include organic molecules and ions in aqueous solution.
Combined with an effective copper-catalyzed triazole-forming reaction, a series of novel camptothecin derivatives were synthesized. Incorporating oligo（ethylene glycol） chains into the derivatives enhanced their wat...Combined with an effective copper-catalyzed triazole-forming reaction, a series of novel camptothecin derivatives were synthesized. Incorporating oligo（ethylene glycol） chains into the derivatives enhanced their water-solubility when compared to the parent compound （up to 55-fold）.展开更多
In this study the spectroscopic characteristics of a water-soluble derivative of hypocrellin A (HA), 14-dehydroxy-15-deacetyl-hypocrellin A-13-sulfonate(13-SO3Na-DDHA),and its one- and two-electron reduction products ...In this study the spectroscopic characteristics of a water-soluble derivative of hypocrellin A (HA), 14-dehydroxy-15-deacetyl-hypocrellin A-13-sulfonate(13-SO3Na-DDHA),and its one- and two-electron reduction products have been investigated. From the changes in absorbance with pH it was observed that the two phenolic hydroxy groups at C-3 and C-10 positions of 13-SO3Na-DDHA or HA dissociated stepwise with increase of pH values. The pKa values for 13-SO3Na-DDHA and HA were determined using an effective method established in this study. Attempts were also made to use absorption and ESR spectroscopies to study the photoreduction of 13-SO3Na-DDHA. It was found that 13-SO3Na-DDHA was directly reduced to its two-electron reduction product in buffered aqueous solution (pH 7. 7). However, in DMF-buffer (1 :1/ v : v,pH 7. 7), it proceeded with one-electron reduction to generate its semiquinone radical anions. The semiquinone radical anions decayed according to second-order kinetics. indicating that the展开更多
给小鼠喂食壳聚糖(chitosan,CS)、羧甲基壳聚糖(carboxymethyl chitosan,CMCS)、壳聚糖季铵盐(quaternary ammonium salt of chitosan,HACC)和羟丙基壳聚糖(hydroxypropyl chitosan,HPCS)30 d后,测定其免疫器官指数、碳粒廓清速率、迟...给小鼠喂食壳聚糖(chitosan,CS)、羧甲基壳聚糖(carboxymethyl chitosan,CMCS)、壳聚糖季铵盐(quaternary ammonium salt of chitosan,HACC)和羟丙基壳聚糖(hydroxypropyl chitosan,HPCS)30 d后,测定其免疫器官指数、碳粒廓清速率、迟发型变态反应、血清溶血素含量(半数溶血值HC_(50))。结果表明:摄食CS及其水溶性衍生物的小鼠以上指标均高于对照组;除胸腺指数和双耳质量差值外,HACC组小鼠其他各项免疫指标与对照组相比均呈显著或极显著差异(P<0.05或P<0.01);同样,除胸腺指数外,HPCS组小鼠其他各项免疫指标均显著或极显著高于对照组(P<0.05或P<0.01);CMCS组小鼠的吞噬指数(K)和半数溶血值(HC_(50))与对照组相比均呈显著差异(P<0.05);壳聚糖及其3种水溶性衍生物都能够增强小鼠免疫功能,增强效果排序为HPCS>HACC>CMCS>CS,这可能与引入的化学基团不同有关。展开更多
基金supported by the National Natural Science Foundation of China(No.31972110)。
文摘Phytosterols have received extensive attention owing to their excellent cholesterol-lowering activity and the role in cardiovascular diseases prevention. However, poor solubility in both oil and water limited the application of free phytosterols in the food industry. Chemical or enzymatic modifications were effective to improve the physicochemical properties as well as the bioavailability and cholesterollowering activity of phytosterols. Higher oil solubility and lower melting point of phytosterols have been achieved by esterification and transesterification with fatty acids and triacylglycerols so as to enhance the bioavailability, reduce formation of precipitates, and improve the sensory quality of products.While the researches on the improvement on its water solubility is a hot topic. Hydrophilic phytosterol derivatives have promising applications in the food industry because most of foods belong to aqueous matrix. Hydrophilic modification is useful and meaningful for phytosterols in both industrial and commercial applications. This review mainly highlights the hydrophilic phytosterol derivatives in the following aspects:(i) hydrophilic modifications of phytosterols by coupling with various polar components;(ii) cholesterol-lowering activity and possible molecular mechanisms of hydrophilic phytosterol derivatives on reducing serum cholesterol level;and(iii) safety evaluation of hydrophilic phytosterol derivatives in cell-culture studies, animal models and clinical trials.
文摘Reaction of p-t-butylcalix[6]arene with ethylene oxide gives a water soluble host compound with a hydrophobic cavity and it can include organic molecules and ions in aqueous solution.
文摘Combined with an effective copper-catalyzed triazole-forming reaction, a series of novel camptothecin derivatives were synthesized. Incorporating oligo（ethylene glycol） chains into the derivatives enhanced their water-solubility when compared to the parent compound （up to 55-fold）.
基金Project supported by the National Natural Science Foundation of China.
文摘In this study the spectroscopic characteristics of a water-soluble derivative of hypocrellin A (HA), 14-dehydroxy-15-deacetyl-hypocrellin A-13-sulfonate(13-SO3Na-DDHA),and its one- and two-electron reduction products have been investigated. From the changes in absorbance with pH it was observed that the two phenolic hydroxy groups at C-3 and C-10 positions of 13-SO3Na-DDHA or HA dissociated stepwise with increase of pH values. The pKa values for 13-SO3Na-DDHA and HA were determined using an effective method established in this study. Attempts were also made to use absorption and ESR spectroscopies to study the photoreduction of 13-SO3Na-DDHA. It was found that 13-SO3Na-DDHA was directly reduced to its two-electron reduction product in buffered aqueous solution (pH 7. 7). However, in DMF-buffer (1 :1/ v : v,pH 7. 7), it proceeded with one-electron reduction to generate its semiquinone radical anions. The semiquinone radical anions decayed according to second-order kinetics. indicating that the
文摘给小鼠喂食壳聚糖(chitosan,CS)、羧甲基壳聚糖(carboxymethyl chitosan,CMCS)、壳聚糖季铵盐(quaternary ammonium salt of chitosan,HACC)和羟丙基壳聚糖(hydroxypropyl chitosan,HPCS)30 d后,测定其免疫器官指数、碳粒廓清速率、迟发型变态反应、血清溶血素含量(半数溶血值HC_(50))。结果表明:摄食CS及其水溶性衍生物的小鼠以上指标均高于对照组;除胸腺指数和双耳质量差值外,HACC组小鼠其他各项免疫指标与对照组相比均呈显著或极显著差异(P<0.05或P<0.01);同样,除胸腺指数外,HPCS组小鼠其他各项免疫指标均显著或极显著高于对照组(P<0.05或P<0.01);CMCS组小鼠的吞噬指数(K)和半数溶血值(HC_(50))与对照组相比均呈显著差异(P<0.05);壳聚糖及其3种水溶性衍生物都能够增强小鼠免疫功能,增强效果排序为HPCS>HACC>CMCS>CS,这可能与引入的化学基团不同有关。
