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- Clarithromycin was prepared from erythromycin A through oximation,protection, methylation and deprotection. The overall yield of clarithromycin was 40%. 红霉素碱经肟化、保护再经甲基化、脱保护得到克拉霉素,总收率达40%25以上。
- Erythromycin A has been routinely used in clinical treatment.However,Erythromycin is hindered by its narrow antimicrobial spectrum and poor stability in acid solution. 红霉素A是目前临床常用的大环内酯类抗生素,但由于抗菌谱窄、酸稳定性差,其应用受到限制。
- The main impurity involved in the synthesis of erythromycin oxime was separated and purified, which was identified as the very compound formed in the acidic hydrolysis of erythromycin A, i.e erythromycin A 8,9 dehydro 6,9 hemiketal. 分离和鉴定了在合成红霉素肟的过程中产生的一种主要杂质 ;通过 IR;UV;MS;1 H NMR和 1 3C NMR确证它和红霉素在酸性水解时生成的红霉素 A 8;9-脱水 - 6;9-半缩酮为同一化合物 .
- There is a vein of melancholy in his character. 他的性格中有少许忧郁的气质。
- There was a long lag in forwarding mail to us. 转寄给我们的邮件晚了很久才拿到。
- A bowl of hot chicken soup is good for you. 喝一碗热鸡汤对你有好处。
- A cloud is a mass of vapor in the sky. 云是天空中的水汽团。
- A country must have the will to repel any invader. 一个国家得有决心击退任何入侵者。
- A fire was burning in the grate. 火在壁炉中燃烧着。
- They cleaved a path through the wilderness. 他们在荒原中开辟出一条路。
- They denounced him to the police as a criminal. 他们向警方告发他是罪犯。
- This place doesn't have a very savory reputation. 这个地方的名声可不太好。
- This strain of wheat can grow during a cold spring. 这种小麦可以在寒冷的春天生长。
- Have a glass of beer to rinse your dinner down. 喝杯啤酒把你吃的晚饭冲下去。
- I am a hundred percent in agreement with you. 我百分之百同意你的看法。
- A simple test will show if this is real gold. 简单的试验就能证明这是否是真金。
- I am well aware that this is a tough job. 我深知这是一件棘手的工作。
- I bought a pair of tan leather shoes the other day. 前几天我买了双棕褐色的皮鞋。
- A stunt man needs to have a good guardian angel. 当特技替身演员的得有个守护天使来保佑。
- He bit off a large piece of the apple. 他咬下一大块苹果。
