The phenylpropene synthase pathway and its applications in the engineering of volatile phenylpropanoids in plants

Abstract

Phenylpropenes such as eugenol, isoeugenol, chavicol, and anethole are C 6 -C 3 volatile compounds derived from phenylalanine by modification of its benzene ring and reduction of its propyl side chain, with the final reduction step catalyzed by a product-specific phenylpropene synthase. Recent advances in the biochemical and molecular analysis of phenylpropene synthases have improved our understanding of their evolution, structural properties, and reaction mechanism, providing insights into how plants produce and regulate the many types of phenylpropene volatiles. Since phenylpropenes are important in determining the flavor of foods and the quality of essential oils in cosmetics, the identification of the genes and enzymes responsible for the biosynthesis of phenylpropene volatiles has also provided us with tools to meet the challenge of improving plant aromas through genetic engineering.

Alcohol acyl transferase 1 links two distinct volatile pathways that produce esters and phenylpropenes in apple fruit

“…Screening of apple expressed sequence tags in public databases identified five candidate PhRs ( MdoPhR1‐5 ) that were expressed in fruit. Phylogenetic analysis showed that MdoPhR1‐4 clustered with P. hybrida PhEGS1 (Class 2, Figure S3), whilst MdoPhR5 clustered with P. anisum isochavicol/IGS 1 ( PaAIS1 ) in a second clade (Class 1, Figure S3) of PhRs, previously described by Koeduka ().…”

Transcriptome analysis reveals a complex array of differentially expressed genes accompanying a source‐to‐sink change in phytoplasma‐infected sweet cherry leaves

“…Phenylpropanoids are a large group of secondary metabolites that exhibit diverse biological activities (Koeduka, ) and are believed to play crucial roles in plant defence, including resistance against phytoplasma infection (Fan, Xu, Deng, Zhao, & Niu, ). These secondary metabolites are synthesised through the general phenylpropanoid biosynthesis pathway and downstream branch pathways such as lignin and flavonoid biosynthesis pathways.…”

Synthesis of Alpha Olefins: Catalytic Decarbonylation of Carboxylic Acids and Vegetable Oil Deodorizer Distillate (VODD)

“…In addition to the saturated, long-chain fatty acids, 5-phenylvaleric acid and 5-(4-Fluorophenyl)valeric acid were also smoothly converted into corresponding alkenes (Figure 3, entries 7 and 8). Estragole (60%) (Figure 3, entry 5) and its derivatives (65%) (Figure 3, entry 6), which served as precursors for fungicide and fragrance [44], could be readily obtained via decarbonylation of 4-(4-methoxyphenyl)butyric acid and 4-(3,4-Dimethoxyphenyl)butyric acid, respectively. It is important to note that this study gives the first report of the synthesis of allylpyrene via decarbonylation of pyrenecarboxylic acid (60%) (Figure 3, entry 9).…”