湖北小连翘(Hypericum hubeiense L.H.Wu et D.P.Yang)是2004年在我国发现的一个金丝桃属(Hyperi-cum)植物(藤黄科)新种。利用高效液相色谱与质谱联用技术对该植物中主要化学成分进行了分离分析,初步鉴定出金丝桃素类、黄酮类等12种化...湖北小连翘(Hypericum hubeiense L.H.Wu et D.P.Yang)是2004年在我国发现的一个金丝桃属(Hyperi-cum)植物(藤黄科)新种。利用高效液相色谱与质谱联用技术对该植物中主要化学成分进行了分离分析,初步鉴定出金丝桃素类、黄酮类等12种化学成分。同时,以金丝桃素为外标,采用HPLC法在590nm波长下测定了金丝桃素类成分的含量。展开更多
Two kinds of saponins have been investigated by negative electrospray ionization(NESI) mass spectrometry. Under ESI conditions, the - ions of saponins were observed which provide the molecular weights of saponins. The...Two kinds of saponins have been investigated by negative electrospray ionization(NESI) mass spectrometry. Under ESI conditions, the - ions of saponins were observed which provide the molecular weights of saponins. The fragment pathways of - ions of these two saponins depend on their structures. For steroidic saponins, - ion only produces the fragment ions by the losses of sugar units. For oleanolic saponins, - ion yields the cross ring ions as well as the fragment ions by the losses of sugar units. Moreover, the abundance of the former is higher than that of the latter. The characteristic fragments are used to provide the sequence and some linkage information of sugar moieties of saponins. Especially, their fragment difference strongly depends on the linkage between the aglycone and the sugar moieties.展开更多
In this paper,the noncovalent interactions between α1-acid glycoprotein（AAG） and the drugs,such as ketoprofen（KP） and anisodine hydrobromide（AN） were studied by using electrospray ion trap mass spectrometry met...In this paper,the noncovalent interactions between α1-acid glycoprotein（AAG） and the drugs,such as ketoprofen（KP） and anisodine hydrobromide（AN） were studied by using electrospray ion trap mass spectrometry method.The results show that both of the drugs had a strong coalescent interaction with AAG,the（dissociation） constants（Kd） and the apparent stoichiometric ratio of noncovalent complexes AN-AAG were（1.75×10-3 mol/L） and 1∶7,and those for KP-AAG complex were 4.95×10-4 mol/L and 1∶4,respectively.According to the thermodynamic parameters of the noncoralent complexes,the main sorts of binding force were static-electricity gravitation for KP-AAG and Van der Waals force for AN-AAG,respectively. The experiment proves that ESI-MS technology as a new method for studying the drug-protein noncoralent binding can offer some advantages in sensitivity,speed,accuracy and directness particularly in the determination of the stoichiormetry of the complex compared to other well-established methods such as circular dichroism and fluorescence spectroscopy,etc.展开更多
文摘湖北小连翘(Hypericum hubeiense L.H.Wu et D.P.Yang)是2004年在我国发现的一个金丝桃属(Hyperi-cum)植物(藤黄科)新种。利用高效液相色谱与质谱联用技术对该植物中主要化学成分进行了分离分析,初步鉴定出金丝桃素类、黄酮类等12种化学成分。同时,以金丝桃素为外标,采用HPLC法在590nm波长下测定了金丝桃素类成分的含量。
文摘Two kinds of saponins have been investigated by negative electrospray ionization(NESI) mass spectrometry. Under ESI conditions, the - ions of saponins were observed which provide the molecular weights of saponins. The fragment pathways of - ions of these two saponins depend on their structures. For steroidic saponins, - ion only produces the fragment ions by the losses of sugar units. For oleanolic saponins, - ion yields the cross ring ions as well as the fragment ions by the losses of sugar units. Moreover, the abundance of the former is higher than that of the latter. The characteristic fragments are used to provide the sequence and some linkage information of sugar moieties of saponins. Especially, their fragment difference strongly depends on the linkage between the aglycone and the sugar moieties.
文摘In this paper,the noncovalent interactions between α1-acid glycoprotein（AAG） and the drugs,such as ketoprofen（KP） and anisodine hydrobromide（AN） were studied by using electrospray ion trap mass spectrometry method.The results show that both of the drugs had a strong coalescent interaction with AAG,the（dissociation） constants（Kd） and the apparent stoichiometric ratio of noncovalent complexes AN-AAG were（1.75×10-3 mol/L） and 1∶7,and those for KP-AAG complex were 4.95×10-4 mol/L and 1∶4,respectively.According to the thermodynamic parameters of the noncoralent complexes,the main sorts of binding force were static-electricity gravitation for KP-AAG and Van der Waals force for AN-AAG,respectively. The experiment proves that ESI-MS technology as a new method for studying the drug-protein noncoralent binding can offer some advantages in sensitivity,speed,accuracy and directness particularly in the determination of the stoichiormetry of the complex compared to other well-established methods such as circular dichroism and fluorescence spectroscopy,etc.
