Pectinases are used in Enology for some different utilities. Enzymatic preparations from moulds are a mixed of different enzymes with strong and unspe-cific activities. Some Saccharomyces cerevisiae pro-duce pectinase...Pectinases are used in Enology for some different utilities. Enzymatic preparations from moulds are a mixed of different enzymes with strong and unspe-cific activities. Some Saccharomyces cerevisiae pro-duce pectinases which can be used instead of com-mercial preparations. The objectives of this work were to study the enzyme secretion by one Saccharo-myces cerevisiae (CECT 11783) for growing on grape skin (industry oenological by-product) as carbon source. Preliminary experiments showed that the strain produced pectinases for growing on grape skin without any other carbon source. Statistical treat-ment (factorial design 25) was applied to evaluate the influences of related factors (agitation, temperature, presence of peptone and detergent in the medium and time of growth) Variables with the most significant interactions for pectinase production were agitation and nitrogen source concentration. Response surface methodology showed that a first order model was not adequate for results. Nevertheless, the built of a sec-ond order model offered a polynomial equation which surface predicted a maximum of activity (52.68 enzymatic units) for specific values of the studied variables (147.8 rpm of agitation and 15.9 g of pep-tone/ L culture medium).展开更多
Using the molecular mechanics and semi-empirical methods, this study analyzes the main characteristics of the grape skin flavonoids: resveratrol, quercetin, rutin, catechin, epicatechin gallate, and epicatechin. We ha...Using the molecular mechanics and semi-empirical methods, this study analyzes the main characteristics of the grape skin flavonoids: resveratrol, quercetin, rutin, catechin, epicatechin gallate, and epicatechin. We have carried out a comparative analysis of the molecular properties of the flavonoids and confirmed their antioxidant properties.展开更多
The skin is a major protective organ of the body. It is constantly exposed to the environment and is very resilient. But exposure to ultraviolet (UV) rays from the sun results in the production of reactive oxygen spec...The skin is a major protective organ of the body. It is constantly exposed to the environment and is very resilient. But exposure to ultraviolet (UV) rays from the sun results in the production of reactive oxygen species (ROS) and subsequent inflammatory responses that can overwhelm the innate protective mechanisms of the skin. This results in damage and premature aging. Strategies to mitigate this premature photoaging might include avoidance of sunlight. However, some sunlight exposure is beneficial to health. One notable example of this is the production of vitamin D. A more practical approach to preventing adverse effects of UV light in the skin is antioxidant supplementation. Dietary antioxidants may help control ROS propagation following UV light exposure. To further evaluate the utility of antioxidants in protecting the skin, in vitro, in vivo and human studies of three well known dietary antioxidants are reviewed and discussed. The data clearly demonstrate that vitamin C, grape seed extract and citrus bioflavonoids have the potential to reduce the damaging effects of excess sun exposure via antioxidant, anti-inflammatory and immunomodulating mechanisms. As such, regular ingestion of dietary antioxidants appears to be a useful strategy for protecting the skin against photoaging.展开更多
建立高速逆流色谱(HSCCC)法分离制备红葡萄皮中花色苷单体的方法。以乙腈-正丁醇-甲基叔丁基醚-水-三氟乙酸(1∶40∶1∶50∶0.01,V/V)为溶剂体系,上相(有机相)为固定相,下相(水相)为流动相,流速为2.0 m L/min,转速为950 r/min,进样量为2...建立高速逆流色谱(HSCCC)法分离制备红葡萄皮中花色苷单体的方法。以乙腈-正丁醇-甲基叔丁基醚-水-三氟乙酸(1∶40∶1∶50∶0.01,V/V)为溶剂体系,上相(有机相)为固定相,下相(水相)为流动相,流速为2.0 m L/min,转速为950 r/min,进样量为200 mg,分离得到的组分利用紫外-可见(UV)光谱和液质联用(HPLC-MS)技术进行定性分析。结果表明,经过一次高速逆流分离即可得到3种花色苷单体,分别为飞燕草色素-3-O-葡萄糖苷、锦葵色素-3-O-葡萄糖苷和芍药色素-3-O-葡萄糖苷,高效液相色谱(HPLC)峰面积归一法计算其纯度分别为93.7%、95.2%、91.6%。采用高速逆流色谱法成功从红葡萄皮中一次性分离得到3种高纯度的花色苷单体,其中芍药色素-3-O-葡萄糖苷为首次分离得到。展开更多
文摘Pectinases are used in Enology for some different utilities. Enzymatic preparations from moulds are a mixed of different enzymes with strong and unspe-cific activities. Some Saccharomyces cerevisiae pro-duce pectinases which can be used instead of com-mercial preparations. The objectives of this work were to study the enzyme secretion by one Saccharo-myces cerevisiae (CECT 11783) for growing on grape skin (industry oenological by-product) as carbon source. Preliminary experiments showed that the strain produced pectinases for growing on grape skin without any other carbon source. Statistical treat-ment (factorial design 25) was applied to evaluate the influences of related factors (agitation, temperature, presence of peptone and detergent in the medium and time of growth) Variables with the most significant interactions for pectinase production were agitation and nitrogen source concentration. Response surface methodology showed that a first order model was not adequate for results. Nevertheless, the built of a sec-ond order model offered a polynomial equation which surface predicted a maximum of activity (52.68 enzymatic units) for specific values of the studied variables (147.8 rpm of agitation and 15.9 g of pep-tone/ L culture medium).
文摘Using the molecular mechanics and semi-empirical methods, this study analyzes the main characteristics of the grape skin flavonoids: resveratrol, quercetin, rutin, catechin, epicatechin gallate, and epicatechin. We have carried out a comparative analysis of the molecular properties of the flavonoids and confirmed their antioxidant properties.
文摘The skin is a major protective organ of the body. It is constantly exposed to the environment and is very resilient. But exposure to ultraviolet (UV) rays from the sun results in the production of reactive oxygen species (ROS) and subsequent inflammatory responses that can overwhelm the innate protective mechanisms of the skin. This results in damage and premature aging. Strategies to mitigate this premature photoaging might include avoidance of sunlight. However, some sunlight exposure is beneficial to health. One notable example of this is the production of vitamin D. A more practical approach to preventing adverse effects of UV light in the skin is antioxidant supplementation. Dietary antioxidants may help control ROS propagation following UV light exposure. To further evaluate the utility of antioxidants in protecting the skin, in vitro, in vivo and human studies of three well known dietary antioxidants are reviewed and discussed. The data clearly demonstrate that vitamin C, grape seed extract and citrus bioflavonoids have the potential to reduce the damaging effects of excess sun exposure via antioxidant, anti-inflammatory and immunomodulating mechanisms. As such, regular ingestion of dietary antioxidants appears to be a useful strategy for protecting the skin against photoaging.
文摘建立高速逆流色谱(HSCCC)法分离制备红葡萄皮中花色苷单体的方法。以乙腈-正丁醇-甲基叔丁基醚-水-三氟乙酸(1∶40∶1∶50∶0.01,V/V)为溶剂体系,上相(有机相)为固定相,下相(水相)为流动相,流速为2.0 m L/min,转速为950 r/min,进样量为200 mg,分离得到的组分利用紫外-可见(UV)光谱和液质联用(HPLC-MS)技术进行定性分析。结果表明,经过一次高速逆流分离即可得到3种花色苷单体,分别为飞燕草色素-3-O-葡萄糖苷、锦葵色素-3-O-葡萄糖苷和芍药色素-3-O-葡萄糖苷,高效液相色谱(HPLC)峰面积归一法计算其纯度分别为93.7%、95.2%、91.6%。采用高速逆流色谱法成功从红葡萄皮中一次性分离得到3种高纯度的花色苷单体,其中芍药色素-3-O-葡萄糖苷为首次分离得到。
