Born in the deep palace in the deep palace, after the Southern Tang of the woman's hand, Li Yu has a lofty position in the history of Chinese culture. He has no politics nor the emperor's talent and qualifications. He is the emperor. The wind and rain are still difficult to escape the fate of the country. Song Taizong has a cup of “ the lead medicine is ” the poison has ended his tragic life. .
Over the long history, &ldquo, the secret medicine of &rdquo, was gradually uncovered and changed into a new vitality in the hands of chemists.
Many of the literary works and novels such as films and dramas, novels and other literary works will appear with poison killings. China's most familiar poison is arsenic. In Guan Hanqing's work "Dou E yuan", Zhang donkey poisoned his father with arsenic, and Pan Jinlian murdered Wu Dou in the water margin of the water margin in recent years. The evidence shows that Emperor Guangxu is also likely to die from arsenic poisoning.
In fact, the use of poison was not unique to China. As early as the ancient European period, sage Socrates was sentenced to death without fear of &ldquo after being sentenced to death by the Athens tribunal.
In ancient European courts, poisoning cases often occur, which is no less exciting than today's court fighting. In history, there are two statements about the mystery of the death of Li Yu after the Southern Tang Dynasty, one of which is Li Yu's depression after the death of the country; and the most commonly accepted one is that Li Yu died of poison.

The death of Socrates, Jacques-Louis David (1787)
Li Yuzhi's death
Historical records: “ Yu is born on the eve of the seventh day of the seventh lunar month. Taizong has its ‘ the old country cannot bear to look back on ’ the word is so resentful that the king of Chu and Yuan Zuo and so on take the lead to help him.
In the wine, Yu was killed by the drug. ” after the death of the Southern Tang Dynasty in the Northern Song Dynasty, the emperor Li Yu was taken prisoner to Bian Jing (Kaifeng, Henan), and his prisoner's life began. The former Emperor was reduced to a prisoner, and the great fall made it difficult for him to suppress the thoughts of his homeland.
978 A.D. on the seventh anniversary of Li Yu's 42 birthday, on that day Li Yu ordered the song prostitute to sing his word "Yu beauty", and the rich native state in his word annoyed Song Taizong and Zhao Guangyi. He gave his birthday a name, gave Li Yu a pot of “ the drug ” the wine, Li Yu and did not know how to drink poison in sorrow. Wine, then poisoned and died, extremely painful, Wang Zhi's "silent record" records: “ head and foot, such as the aircraft also &rdquo.

What is “ the drug ”?
“ lead medicine ” in the case of poisoning, the dead body is severely deformed because of its whole body agitation, convulsion spasm, back and back, and the shape is very like the loom of ancient bandage, so it is named.
Modern medical experts from the Li Yu poisoning symptoms and principles of comprehensive analysis, think “ medicine ” probably is Strychni. The main active components are Strychnine, “ strychnine ” and brucine (Brucine). The former is more content, the two substances are similar, and the mechanism of action is the same, but the activity and toxicity of the papyturine is much higher than that of brucine.

Strychnine, Chinese medicine, strychnine and Brucine
The strychnine can antagonize the glycine and acetylcholine needed for the binding of the surface receptor on the motor neuron, thus keeping the motor nerve excited and causing the extreme spasm of the muscles. The typical symptoms of the victims of a soft shelled turtle are extremely contractile muscles, high head, arches on the back, like a bow, usually called “ ”

Toxo is a typical symptom of strychnine poisoning (1809 oil painting).
Poison is also a good cure
The ancient book "materia medica original" records: “ papaya, wood like wood turtle shell big, round and flat, white haired, bitter taste. The poison in a bird is numb and jerk, but the poison in a dog is painful and heartbroken. If it is misunderstood, it is a limb. ” therefore, it is not difficult to find the toxic effect of the papyturine, which is often used in China by emperors to die of ministers and concubines. In ancient Europe, it was no exception. It was also a famous court battle poison.
With the deepening of the research on Strychni, it has been found that strychnine has many medicinal effects.
1. the analgesic effect of brucine may be related to its sedative effect and paralytic sensory nerve ending, and it is not addictive.
2. brucine can be used to treat rheumatoid arthritis, ankylosing spondylitis and other immune diseases.
3. antitumor effect, semen Strychni has good Tongluo analgesic effect, widely used in clinical treatment of a variety of pain, in the treatment of cancer pain in cancer also has a better effect.
4. protect the cardiovascular effect, the internal medicine can antagonize the formation of thrombus. The protective effect of NOx and semen Strychni on myocardial cells is beneficial to the improvement of microcirculation and the increase of blood flow.
Because of the particularity of the semen Strychni, how to use new technology or new dosage forms to avoid the damage caused by its toxicity to the human body, and to play the role of the semen Strychni in the future is a challenging research field.

Commercialized medicine of strychnine (pictures from the Internet)
Chemical synthesis of strychnine
Two chemists in France had isolated the strychnine in 1818, but its structure was uncertain at that time.
Before the advent of modern spectroscopy, two outstanding chemists, RobertRobinson and HerMannLeuchs has done a lot of research on the structure of strychnine and published the research results in 1946.
In 1950s, X- ray diffraction was used as another powerful structural characterization method, and the stereostructure of brucine was successfully determined.

From left to right, the club model and Leuchs of Robinson, strychnine.
Not long after the structure of the strychnine was established, R. B. Woodward, the master of organic synthesis, opened its total synthesis and achieved its first chemical synthesis in 1954.
Woodward, with its unique insight, found the indole core structure in the complex molecules of the soft shelled turtle base. With the hydrazine and carbonyl compounds as raw materials, the indole structure 3 was successfully constructed with the indole synthesis method found in 1883 by EmilFischer.
Subsequently, he successfully synthesized the intermediate 4 through multistep reactions such as N- methylation, reduction, condensation, ozonation, protection and protection. In the process of building multiple complex ring structures in the molecule 4 of the wood turtle base molecule using intermediate 4, he exerts its ingenuity to overcome the difficult calendar through nearly 30 steps to get the key intermediate. 5, the final consideration is how to complete the construction of the last seven membered ring of oxygen. It was known that Isostrychnine could get the basine by one step reaction under the basic condition. Therefore, Woodward first obtained the product of the alkaloid of the hetero soft shelled turtle.

The route of Woodward total synthesis of soft shelled turtle
From a modern chemical point of view, Woodward is too complex and lengthy to construct the ring structure and the stereoscopic center of the soft shelled turtle, but limited to the organic chemistry and experimental technology at that time, the work of Woodward is still a fine “ art ”
The chemists after Woodward are still very interested in the synthesis of biorine, the most representative of which is the synthetic method reported by the University of California at Irvine's LarryE. Overman in 1993. This is the first asymmetric synthesis of the soft shelled turtle, which is more than ten thousand times higher than the Woodward method.
Overman uses a completely different &ldquo from Woodward; cyclized ” strategy, he cleverly uses the aza-Cope rearrangement and the intramolecular Mannich reaction to build the Wieland-Gumlichaldehyde intermediates. This new and ingenious synthetic strategy has a profound influence on the later chemists.
In the last few years, many synthetic chemists, including Kuehne, Stork and Rawal, have made use of different strategies to complete the synthesis of soft shelled turtle. Their work has greatly promoted the development of synthetic chemistry and made the biosynthesis a classic.

The route of Overman asymmetric total synthesis of soft shelled turtle
Last
Li Yu is a very successful poet, “ a talented man and a poor man of ” his life is full of tragedies, kills his &ldquo, the lead medicine ” and with the development of science and technology, it blooms in the hands of chemists. In the past, the innumerable evil people have been stripped of the mysterious veil in the efforts of chemists. The future can become a good medicine for treatment, and can not help exclamation the unique charm of chemistry.
Reference material
[1] Li Yongji, Zhang Xinyuan, Guan Qingxia, et al. On the research progress of Strychni. [J]. Journal of Chinese medicine, 2011.
[2] R.B. Woodward., et al. " The total synthesis of strychnine." of, 1954, 76 (18):
[3] Knight, Steven D., Larry E. Overman, and Garry Pairaudeau. ".
[4] Bonjoch, Josep, and Daniel Solé. " Synthesis of strychnine." Chem. Rev., 2000, 100 (9): *; 3482.
[5] Wikipedia: https://zh.wikipedia.org/wiki/李煜