问题
单项选择题
结构属于异环双键类的皂苷为( )
A．柴胡皂苷a
B．柴胡皂苷b2
C．柴胡皂苷b3
D．柴胡皂苷g
E．柴胡皂苷d
答案
参考答案：B
解析：
柴胡的主要有效成分为柴胡皂苷，具有镇静、止痛、解热、镇咳和抗炎的作用。其结构均为齐墩果烷型，C-3位连接一个糖链，苷元结构中均含有双键，但只有柴胡皂苷b1、柴胡皂苷b2含有异环双烯，其余仅含一个双键。
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结构属于异环双键类的皂苷为( )
A．柴胡皂苷a
B．柴胡皂苷b2
C．柴胡皂苷b3
D．柴胡皂苷g
E．柴胡皂苷d
参考答案：B
解析：
柴胡的主要有效成分为柴胡皂苷，具有镇静、止痛、解热、镇咳和抗炎的作用。其结构均为齐墩果烷型，C-3位连接一个糖链，苷元结构中均含有双键，但只有柴胡皂苷b1、柴胡皂苷b2含有异环双烯，其余仅含一个双键。
| 阅读理解。读一读，选择正确答案。 |
| L: Hi, Steven! How are you? S: I'm fine. Thanks. And you? L: I'm fine, too. Today is my birthday. Please come to my birthday party tonight. S: Happy birthday to you, Li Ming! What's the date today? L: Today is August twelfth. S: How old are you? L: I'm eleven years old. S: What is your address? L: My address is 268 Ninth Avenue. S: Look! This is for you. L: Birthday present! A black and white football! I like it very much. Thank you. |
| 1. When is Li Ming's birthday? |
[ ] |
| A. On August ninth. B. On August twelfth. |
| 2. How old is Li Ming? |
[ ] |
| A. Nine years old. B. Eleven years old. |
| 3. What is Li Ming's address? |
[ ] |
| A. 268 Ninth Avenue. B. 286 Ninth Avenue |
| 4. What is Li Ming's birthday present? |
[ ] |
| A. Football. B. Basketball. |
| 5. What colour is the football? |
[ ] |
| A. Black. B. Black and white. |