Isoprene like compounds are widely distributed in nature. The lower terpenoids are mainly found in higher plants, algae, mosses and lichens, and also in insects and microorganisms. However, steroids (Fig. 1) mainly exist in animal kingdom, plant kingdom and microorganism. At present, there are more than 23000 isoprene like compounds, and they are increasing at the rate of dozens every week.
Isoprenoids (ISOs) compounds, also known as terpenoids (Terpenoids) compounds, as organic compounds are more or less present in various types of animals and plants on the earth, in the form of huge and diverse natural lipids, It has become the world’s largest natural product extracted from animals and plants, widely used in cosmetics, flavoring, coloring, food additives, antibacterial, anti-tumor and other pharmaceutical applications. Among them, aromatic lipids extracted from plants are the most popular, and the world market size in 2013 reached US$1 billion. However, in general, the ISOs compounds have slower growth and lower yields. The more difficult the collection, the richer the content of animals and plants, which seriously restricts the sustainable development of related industries.
Isoprenoid derivatives of plants have different functions. In addition to some common physiological, metabolic and structural functions, many special terpenoid complexes have communication and defense functions.
Isoprene like is a kind of natural compound widely existing in nature, which has important economic value. At present, great progress has been made in the research of isoprene like synthesis at the level of molecular biology. More and more scientists have successfully cloned enzyme genes and transferred these genes into other organisms.
Wallach put forward the isopentene rule as early as 1887, and speculated that the carbon framework of terpenes was formed by polymerization of isoprene. This hypothesis was verified until lynen experiment proved the existence of isopentene pyrophosphate (IPP). In 1956, folkers also proved that the key precursor of iPP synthesis was mevalonate (MVA).
In isoprene like biosynthesis pathway , IPP is an important precursor in this pathway. It is synthesized by MVA pathway in cytoplasm and glyceraldehyde-3-phosphate pathway in plastid. A series of C10 (GPP), C15 (FPP), C20 (GGPP) and more high molecular weight c5n (PPP) compounds were formed by increasing IPP one by one, starting from dmapp, a carbon 5 (C5) molecule isomerized with IPP. With GPP, FPP and GGPP as the parent materials, various isoprene like compounds with different functions were formed under the catalysis of various enzymes.
The study of isoprene like compounds is gradually showing the details of the biosynthesis pathway and regulation of this complex compound. In this paper, the main enzymes and their regulation in isoprene like biosynthesis pathway are mainly introduced.
The transgenic work of isoprene like biosynthesis can improve the color and taste of food, enhance the commercial value of industrial products, and also enable biological defense against diseases and pests. The benefits of this work, like the form and function of isoprene like biosynthesis, seem unlimited. Therefore, The study of enzymes and regulation in isoprene – like biosynthesis is of great significance to make full use of nature.