Anthocyanin is a kind of flavonoid which mainly exists in plants. It has strong biological activities such as anti-cancer and anti-oxidation, and is widely used in the field of nutrition and health care. Most anthocyanins are extracted directly from plants by physical or chemical means, but the yield is low, and the extracted anthocyanins are mostly mixtures due to the restrictions of time, region and season. Biosynthesis of anthocyanins have attracted much attention by researchers worldwide in recent years. As the biosynthesis of anthocyanins can be controlled artificially and the purity of the obtained products is high, it has been widely studied. Anthocyanins cannot exist stably in the environment, and need to be modified by glycosylation, acylation and methylation to increase their stability. The modified anthocyanins can be synthesized by microorganisms and significant color changes can be seen in the medium. The biosynthesis and modification of anthocyanins were reviewed in this paper, and the preparation technology of anthocyanin synthesis from plants and microorganisms was briefly introduced, the factors affecting anthocyanin synthesis were analyzed, and finally the future research direction of anthocyanin was predicted.
5-Hydroxymethylfurfural (HMF) is one of the most important biomass-based platform molecules and widely used in the preparation of multifunctional compounds such as fine chemicals, key pharmaceutical intermediates, functional polyesters, solvents and liquid fuels. At present, the preparation of HMF is a hot spot in the field of biomass research, and the raw materials and methods for preparing HMF have been continuously expanded. This paper reviews the main preparation methods and research progress of HMF. Catalysis systems for HMF preparation is systematically described, including the types of the catalysts (mineral acids, ionic liquids, metal chlorides, solid acids and others) used in the catalytic process and the solvent systems. Then, the preparation paths and applications of important derivatives from HMF are summarized. Finally, suggestions for future research on HMF are provided based on the understanding of problems existing in the current research.