Current Trends in Acetins Production: Green versus Non-Green Synthesis

Abstract

To utilize excess glycerol produced from the biodiesel industry, researchers are developing innovative methods of transforming glycerol into value-added chemicals. One strategy adopted is the conversion of glycerol into acetins, which are esters of glycerol that have wide applications in cosmetics, pharmaceuticals, food and fuel additives, and plasticizers and serve as precursors for other chemical compounds. Acetins are synthesized either by traditional chemical methods or by biological processes. Although the chemical methods are efficient, productive, and commercialized, they are "non-green", meaning that they are unsafe for the environment and consumers. On the other hand, the biological process is "green" in the sense that it protects both the environment and consumers. It is, however, less productive and requires further effort to achieve commercialization. Thus, both methodologies have benefits and drawbacks, and this study aims to present and discuss these. In addition, we briefly discuss general strategies for optimizing biological processes that could apply to acetins production on an industrial scale.

Keywords: acetins; chemical synthesis; enzymes; glycerol; green; microbial synthesis; non-green.

Figure 1

Acetins synthesis by “green” and “non-green” methods. The non-green synthesis of acetins involves traditional chemical methods that use inorganic catalysts (upper panel). The green synthesis of acetins involves enzymatic and microbial methods (middle and lower panel). The abbreviations are as follows: OAc, acetate group; Maa, maltose O-acetyltransferase; Cat, Chloramphenicol O-acetyltransferase.

Figure 2

Common uses of acetins.

Figure 3

Advantages and disadvantages of different catalysts used in green and non-green synthesis methods of acetins.