How to extract effective components from plants? Is it difficult?

1. Selected plants/herbs. Nothing more than looking for ancient prescriptions, prescriptions and folk herbs. At present, common and uncommon medicinal materials have been studied. At present, most of them increase the amount of medicinal materials to extract and separate low-content components, or look for medicinal plants that have not been studied from Miao medicine, Tibetan medicine, Mongolian medicine, Africa and Latin America.

2. Excerpts. Solvents include petroleum ether, n-hexane, cyclohexane, benzene, chloroform, ethyl acetate, n-butanol, acetone, ethanol, methanol and water (small polarity → large polarity). If the decoction of daily medicine is effective, it should be extracted with polar solvents such as water and ethanol, and if the decoction of artemisinin is ineffective, it should be extracted with polar solvents such as petroleum ether. Water/alcohol/ether are common medicinal materials, and more compounds can be separated and identified once.

3. separation. This is the most important job. The solution extracted in the second step contains dozens of compounds. Column chromatography is generally used, which is what we often say. Heavy workload, boring and low technical content. A master may do this every day for two years. As shown in the figure below, the chromatographic column for separating compounds is as large as 2 meters high and as small as 10 cm. Monomer compounds can only be separated by changing the conditions of mobile phase solvent and the material of chromatographic column, and repeatedly punching holes under different conditions and different separation principles.

4. Structural identification. Thirdly, the monomer compound was separated and its structure was identified by means of infrared, nuclear magnetic resonance and mass spectrometry. This is not difficult, and it is not difficult for experienced people to make a score. The master can graduate after finishing this. Should the doctor discover new compounds or do 5? To graduate.

5. Activity learning. After in vitro and in vivo experiments, cell and animal experiments, the activities of most compounds are basically clear, and the material basis of Chinese herbal medicine is understood. Buy a textbook "Pharmacology of Traditional Chinese Medicine", which is full of works in this field.