Besides Artemisia annua, artemisinin can also be extracted from tobacco, but the method of extracting artemisinin from Artemisia annua is relatively simple. There are three extraction methods of artemisinin: chemical synthesis, biosynthesis and extraction and purification, among which the chemical synthesis is the most difficult and the biosynthesis process is the most complicated.

Biosynthesis is a complex synthetic route, in which enzymes are needed, and the efficiency of enzymes should be controlled. Extraction and purification is to extract artemisinin from Artemisia annua by chemical means, and then process and purify it. Artemisinin content in Artemisia annua produced in southern China is usually higher and purer.

Artemisia annua is an annual plant of Compositae. Its plants are fragrant, mostly growing on wet river banks or valleys, and are also planted in coastal areas of China. Artemisia annua is a short-day plant, which has low requirements for light. Usually, if the light is too strong, the plants will wither and turn yellow, and if the light is insufficient, the fruit yield will be affected.

Morphological characteristics of Artemisia annua;

Panicum miliaceum; This plant has a strong volatile aroma. Roots solitary, vertical, narrowly spindle-shaped; The stem is solitary, with a height of 100-200cm, a base diameter of 1cm, longitudinal edges, green when young, brown or reddish brown in late stage, and many branches; Stems, branches and leaves on both sides and abaxial surface of involucral bracts are initially hairless or slightly sparsely pubescent, and then shed hairless.

Leaves: paper, green; The leaves at the lower part of the stem are ovoid or triangular in width, 3-7 cm long and 2-6 cm wide, green, with two small white glandular spots and tiny concave spots, three (to four) comb teeth deeply divided, with 5-8(- 10) lobes on each side, which are ovoid and ovoid, and divide again.

There are many comb-shaped triangular or Yangtze River Delta-shaped incisors at the edge of the lobule, the length of which is 1-2mm and the width is 0.5-1mm.. Midrib is obvious and slightly convex on the leaf surface. There are narrow wings on both sides of the central axis without small comb teeth, and there are several small comb teeth on the sparse upper part. Petiole length 1-2cm, with semi-braced leaves at the base. The middle leaf is feathered into two (to three) comb-shaped gyrus, and the leaflets are comb-shaped triangles.