Classification of Plant Extracts

Plant extracts can be categorized based on various dimensions. Below are the primary classification methods:

By Extraction Purpose:

1. Ratio Extracts:
   These extracts are made by concentrating the raw materials into pastes, liquid extracts, or powders, maintaining a fixed ratio between the raw material and the final product. For example, if 10 kilograms of Scutellaria are used to produce 1 kilogram of powdered extract, it is called a 10:1 Scutellaria ratio extract. The components and concentrations in these extracts are often not precisely identified and require qualitative testing methods such as thin-layer scanning.
2. Standardized Extracts:
   These extracts adhere to uniform standards and are suitable for herbs, plants, animals, and other sources. Specifically, standardized Chinese herbal extracts are processed from traditional Chinese medicinal materials using modern scientific techniques, featuring clear quantitative and quality indicators.

By Extracted Components:

1. Alkaloids:
   These are nitrogen-containing basic organic compounds mainly found in dicotyledonous plants. They exhibit specific physiological activities and medical effects. For instance, ephedrine in Ephedra and berberine in Berberis.
2. Glycosides:
   These are compounds formed by the combination of sugars and non-sugar substances, offering a wide range of functions. Examples include cardiac glycosides in Digitalis leaves and ginsenosides in Ginseng.
3. Volatile Oils (Essential Oils):
   Also known as essential oils, these are aromatic, volatile oily liquids composed of various compounds. They exhibit multiple physiological activities. Examples include rich volatile oil content in plants like Platycladus, Magnolia, and Magnolia flower.
4. Tannins:
   These are mixtures of polyphenolic compounds found in many plants. They have astringent, antidiarrheal, and antiperspirant properties. For example, tannins in Chinese gall.

These classification methods help deepen the understanding and application of plant extracts while fostering the development of the plant extract industry.