[Objective] The kinetic characteristics of alliinase was studied to select the optimum reaction performance. [Method] Alliinase activity was measured to analysis the influence of temperature, pH, substrate concentrati...[Objective] The kinetic characteristics of alliinase was studied to select the optimum reaction performance. [Method] Alliinase activity was measured to analysis the influence of temperature, pH, substrate concentration and metal iron. [Result] Alliinase was an enzyme with thermal instability. Its optimum reaction temperature was 29℃ and pH value was 6.1. The Vmax was 0. 439 IU/mg and Km was 0.483 mmol/L by using natural extract as substrate. Alliinase activity was activated when the K^＋ , Mg^2＋ , Na^＋ and Cd^2＋ existed and alliinase activity was inhibited when Cu^2＋ existed. [Condusion] Results showed that the kinetic characteristics of alliinase supply the academic foundation for development and application of garlic medical products.展开更多
A simple, precise and accurate method was developed and validated for the determination of allicin release from alliin/alliinase double-layer tablets. According to Appendix XC Ⅱ of Chinese Pharmacopoeia 2010 edition ...A simple, precise and accurate method was developed and validated for the determination of allicin release from alliin/alliinase double-layer tablets. According to Appendix XC Ⅱ of Chinese Pharmacopoeia 2010 edition Volume II, a small glass-method was adopted at the rotational speed of 100 r/min using 100 mL phosphate buffer （pH 6.8） as release medium. The release amount was determined by HPLC with a C18 column （250 mm × 4.6 mm, 5 μm） using the mobile phase consisting of methanol -0.4% carboxylic acid （65：35） at a flow rate of 1 mL/min and UV detection at 242 nm. The current method demonstrates good linearity over the range 4.052- 405.2 μg/mL （r2=0.9999） with an average recovery of 105.5%（RSD= 1.25%）. The accumulative release of alliin/alliinase double-layer tablets had good homogeneity for withinand betweenbatches. The method established is simple, accurate and repeatable for the determination of allicin release from alliin/alliinase double-layer tablets.展开更多
Objectives： Alliinase is a pyridoxal-5＇-phosphate （PLP）-dependent enzyme responsible for the production of diallyl thiosulfinate （allicin）, the biologically active component of garlic, from alliin. The use of al...Objectives： Alliinase is a pyridoxal-5＇-phosphate （PLP）-dependent enzyme responsible for the production of diallyl thiosulfinate （allicin）, the biologically active component of garlic, from alliin. The use of allicin for treatment of various diseases has been proposed but it is very unstable in the blood stream. This difficulty can be overcome by administration of alliin, together with a conjugate of alliinase directed towards the target cells. This, in turn requires a stable and active form of the enzyme. In this study we evaluate the stability of alliinase itself, in the presence mad absence of osmolytes, as well as that of its catalytically active complex with a mannose-specific lectin, ASAI （Allium sativum agglutinin I）, also presents in garlic. Methods： Alliinase, mad ASAI were both purified from garlic cloves. Thermal stability of alliinase itself, mad of its complexes with PLP and ASAI, in the presence mad absence of osmolytes, was analyzed by monitoring enzymic activity, and using DSC （differential scanning calorimetry）. Key findings： PLP exerts only a minor influence on alliinase structure and stablity. But both osmolytes and ASAI stabilize the enzyme considerably. Conclusions： The principle finding is that ASAI greatly stabilizes alliinase. Thus, the lectin-enzyme complex, which can be lyophilized and stored until used, provides an effective formulation of alliinase for generation of allicin from alliin in vivo.展开更多
基金Supported by the Natural Science Foundation Program of Tianjin Science Committee(043611111)the Science and Technology Develop-ment Foundation Programof Tianjin Colleges and Universities(20050901)~~
文摘[Objective] The kinetic characteristics of alliinase was studied to select the optimum reaction performance. [Method] Alliinase activity was measured to analysis the influence of temperature, pH, substrate concentration and metal iron. [Result] Alliinase was an enzyme with thermal instability. Its optimum reaction temperature was 29℃ and pH value was 6.1. The Vmax was 0. 439 IU/mg and Km was 0.483 mmol/L by using natural extract as substrate. Alliinase activity was activated when the K^＋ , Mg^2＋ , Na^＋ and Cd^2＋ existed and alliinase activity was inhibited when Cu^2＋ existed. [Condusion] Results showed that the kinetic characteristics of alliinase supply the academic foundation for development and application of garlic medical products.
文摘A simple, precise and accurate method was developed and validated for the determination of allicin release from alliin/alliinase double-layer tablets. According to Appendix XC Ⅱ of Chinese Pharmacopoeia 2010 edition Volume II, a small glass-method was adopted at the rotational speed of 100 r/min using 100 mL phosphate buffer （pH 6.8） as release medium. The release amount was determined by HPLC with a C18 column （250 mm × 4.6 mm, 5 μm） using the mobile phase consisting of methanol -0.4% carboxylic acid （65：35） at a flow rate of 1 mL/min and UV detection at 242 nm. The current method demonstrates good linearity over the range 4.052- 405.2 μg/mL （r2=0.9999） with an average recovery of 105.5%（RSD= 1.25%）. The accumulative release of alliin/alliinase double-layer tablets had good homogeneity for withinand betweenbatches. The method established is simple, accurate and repeatable for the determination of allicin release from alliin/alliinase double-layer tablets.
文摘Objectives： Alliinase is a pyridoxal-5＇-phosphate （PLP）-dependent enzyme responsible for the production of diallyl thiosulfinate （allicin）, the biologically active component of garlic, from alliin. The use of allicin for treatment of various diseases has been proposed but it is very unstable in the blood stream. This difficulty can be overcome by administration of alliin, together with a conjugate of alliinase directed towards the target cells. This, in turn requires a stable and active form of the enzyme. In this study we evaluate the stability of alliinase itself, in the presence mad absence of osmolytes, as well as that of its catalytically active complex with a mannose-specific lectin, ASAI （Allium sativum agglutinin I）, also presents in garlic. Methods： Alliinase, mad ASAI were both purified from garlic cloves. Thermal stability of alliinase itself, mad of its complexes with PLP and ASAI, in the presence mad absence of osmolytes, was analyzed by monitoring enzymic activity, and using DSC （differential scanning calorimetry）. Key findings： PLP exerts only a minor influence on alliinase structure and stablity. But both osmolytes and ASAI stabilize the enzyme considerably. Conclusions： The principle finding is that ASAI greatly stabilizes alliinase. Thus, the lectin-enzyme complex, which can be lyophilized and stored until used, provides an effective formulation of alliinase for generation of allicin from alliin in vivo.
