Under the guidance of the theory of traditional Chinese medicine, clinical treatment is dominated by the effective chemical components of drugs, give full play to the characteristics of its effectiveness and multi-function or multi-effect combination, according to clinical needs, balance the benefits and losses, so that some of its chemical components prominent, some weakening, and strive to meet the needs of disease treatment. The chemical components commonly used in clinic are described as follows.

1 Glycosides

It is a class of compounds formed by connecting a sugar or a sugar derivative with another non-sugar substance through the end group carbon atom of the sugar. In nature, because various types of natural ingredients can be combined with sugar to form glycosides, glycosides are widely distributed, many compounds are common natural products, especially in higher plants. If flavonoid glycosides are distributed in 200 families of plants; Cardiac glycosides were found in more than 10 families, such as Scrophulariaceae and Apocynaceae. Glycosides can be distributed in all parts of the plant. Most glycosides have a wide range of biological activities. For example, gastroside is the main active ingredient of gastrodia sedation; Notoginseng saponin is the active ingredient of notoginseng to promote blood circulation and remove blood stasis: cardioside has cardioside effect; flavonoid side has antibacterial, cough, asthma and coronary artery dilation effect.

2 Alkaloids

A nitrogenous organic compound of plant origin. Most of them have a complex ring structure in which nitrogen atoms are bound. Most of them are alkaline and can be combined with acid to form salt; Most of them have significant physiological activity. In general, in addition to nitrogen-containing organic compounds essential to organisms, such as amino acids, peptides, proteins, nucleic acids and nitrogen-containing vitamins, other nitrogen-containing organic compounds can be regarded as alkaloids. Alkaloids account for a large proportion in the chemical components of traditional Chinese medicine. Alkaloids are mainly distributed in the plant kingdom, and most of them exist in dicotyledonous plants of higher plants, such as Coptis, aconite and aconite of ranunculaceae, and rhizome and corydalis of linoleaceae. Hanphandrix and rhizome of Phandridae; Nightshade, belladonna, scopolia; Three needles of Berberaceae, etc. Alkaloids have significant and special biological activities. For example, morphine and fumarine have analgesic effects, ephedrine has antitussive and asthmatic effects, berberine, matrine and batarine have anti-inflammatory effects; Camptothecin, colchicine, vincristine and paclitaxel have different degrees of anticancer effects.

3 Flavonoids

It is a large class of compounds widely existing in nature. Because most of these compounds are yellow or light yellow, and the molecules also contain more ketone genes this is called flavonoids. Flavonoids are widely distributed in higher plants and most concentrated in angiosperms. For example, there are many flavonoids in labiaceae, Scrophulariaceae, Acanthaceae and Compositae. It is also found in gymnosperms, especially in coniferae, Ginkgo, and Aeolophora. Flavonoids are also an important active component in traditional Chinese medicine, with various biological activities, such as total pueraria flavones, pueraria flavones and total flavonoids of ginkgo biloba, which have the effect of dilating coronary vessels and can be clinically used to treat coronary heart disease. Rutin, hesperidin and D-catechin have the effect of reducing capillary fragility and abnormal compatibility, and can be used as hemostatic agents for capillary bleeding and adjuvant drugs for treating hypertension and arteriosclerosis. Silymarin, isosilymarin and so on have liver protection.

4 Quinones

Quinoid compounds are a kind of chemical constituents with quinoid structure in traditional Chinese medicine. They are widely distributed in plants. Such as polygonaceae rhubarb, Polygonum polygonum, Polygonum polygonum; Salvia miltiorrhiza of labiaceae; Rubia rubiaceae, cassia seed of leguminous family, muscata leaf, comfrey of comfrey family, aloe vera of Liliaceae, etc., all contain quinones. The biological activities of quinones are multifaceted. For example, the strysidine compounds in the leaves of Strysidine have strong cathartic effect, the free hydroxy-anthraquinone compounds in rhubarb have antibacterial effect, especially on the golden grape balls have strong inhibitory effect, the rubitin components in madder have hemostatic effect, and the salviquinone in salviorrhiza have the effect of expanding coronary artery, which is used to treat coronary heart disease and myocardial infarction. There are also some quinones with pain relief, exorcism tapeworm, diuretic, gallbladder, cough, asthma and other effects.

5 Terpenoids

Terpenoids are a class of compounds that are derivatives of meglutaric acid and have the structure characteristics of 2 or more isoprene units (C5 units) in the basic carbon frame. Terpenoids are widely distributed in algae, fungi, lichens, mosses, ferns, gymnosperms and angiosperms, especially in gymnosperms and angiosperms. The biological activities of terpenoids have various aspects:

①circulatory effects, many terpenoids have better anti-platelet aggregation, expansion of cardiovascular and cerebrovascular, increase blood flow, adjust heart rate, reduce blood pressure, reduce blood lipids and other effects, such as paeoniflorin, ginkgolide, etc.

② Digestive system effects, many terpenes have liver protection and enzyme, gallbladder and stomach, anti-gastric ulcer and other effects, such as zidonic acid, glycyrrhetinic acid and iridoid. ③Respiratory system effects, andrographolia andrographolis enzymes and other certain anti-upper respiratory tract infection. Peppermint one has the effect of relieving asthma, expectorating phlegm and antitussive.

④Disease-resistant microbial action, such as myrmecolactone has inhibitory activity.

⑤ Anti-tumor effect, such as paclitaxel has a good effect on breast cancer and ovarian cancer.

6 Steroid compounds

Steroidal saponins are a kind of steroidal glycosides formed by the combination of spirosteroid compounds and sugars. After shaking, the aqueous solution of steroidal saponins can produce a large number of soapy aqueous foams, hence the name of steroidal saponins. Steroidal saponins are widely distributed in plants, most of which exist in Liliaceae, Dioscoreaceae, Solanaceae, Scrophulariaceae, legumes, and ginger, etc., such as Ophiopogon, Allium Macrostemon, Chongou, Lilium, Yuzhu, and Zhimother, etc., are rich in steroidal saponins. With the development of steroid chemistry, many new biological activities have been gradually discovered, especially the biological active ingredients for prevention and control of cerebrovascular diseases, anti-tumor, lowering blood sugar, lowering cholesterol, lowering blood lipids, antithrombotic and antibacterial effects.

In addition, the chemical components of traditional Chinese medicine include sugar, phenylpropyl, volatile oil, tannin, etc. Mastering the chemical components of each drug has important guiding significance for the extraction, separation, identification, processing, storage and clinical application of traditional Chinese medicine.