About: Phenylpropene is a research topic. Over the lifetime, 54 publications have been published within this topic receiving 2193 citations. The topic is also known as: prop-2-enylbenzene.
TL;DR: Petal tissue was responsible for the bulk of the phenylpropanoid emission and data show that the floral emission of (iso)methyleugenol is controlled at the site of emission, that a positive correlation exists between volatile emission and IEMT activity, and that control of the level of I EMT activity is exerted at a pretranslational step.
Abstract: We have previously shown (R.A. Raguso, E. Pichersky [1995] Plant Syst Evol 194: 55-67) that the strong, sweet fragrance of Clarkia breweri (Onagraceae), an annual plant native to California, consists of 8 to 12 volatile compounds, including 4 phenylpropanoids. Although some C. breweri plants emit all 4 phenylpropanoids (eugenol, isoeugenol, methyleugenol, and isomethyleugenol), other C. breweri plants do not emit the latter 2 compounds. Here we report that petal tissue was responsible for the bulk of the phenylpropanoid emission. The activity of S-adenosyl-L-methionine: (iso)eugenol O-methyltransferase (IEMT), a novel enzyme that catalyzes the methylation of the para-4'-hydroxyl of both eugenol and (iso)eugenol to methyleugenol and isomethyleugenol, respectively, was also highest in petal tissue. IEMT activity was absent from floral tissues of plants not emitting (iso)methyleugenol. A C. breweri cDNA clone encoding IEMT was isolated, and its sequence was shown to have 70% identity to S-adenosyl-L-methionine:caffeic acid O-methyltransferase. The protein encoded by this cDNA can use eugenol and isoeugenol as substrates, but not caffeic acid. Steady-state IEMT mRNA levels were positively correlated with levels of IEMT activity in the tissues, and no IEMT mRNA was observed in flowers that do not emit (iso)methyleugenol. Overall, the data show that the floral emission of (iso)methyleugenol is controlled at the site of emission, that a positive correlation exists between volatile emission and IEMT activity, and that control of the level of IEMT activity is exerted at a pretranslational step.
TL;DR: Results indicate metabolite channeling of intermediates towards eugenol by a specific 4CL and is the first report demonstrating the involvement of 4CL in creation of virtual compartments through substrate utilization and committing metabolites for e Eugenol biosynthesis at an early stage of the pathway.
Abstract: Biosynthesis of eugenol shares its initial steps with that of lignin, involving conversion of hydroxycinnamic acids to their corresponding coenzyme A (CoA) esters by 4-coumarate:CoA ligases (4CLs). In this investigation, a 4CL (OS4CL) was identified from glandular trichome-rich tissue of Ocimum sanctum with high sequence similarity to an isoform (OB4CL_ctg4) from Ocimum basilicum. The levels of OS4CL and OB4CL_ctg4-like transcripts were highest in O. sanctum trichome, followed by leaf, stem and root. The eugenol content in leaf essential oil was positively correlated with the expression of OS4CL in the leaf at different developmental stages. Recombinant OS4CL showed the highest activity with p-coumaric acid, followed by ferulic, caffeic and trans-cinnamic acids. Transient RNA interference (RNAi) suppression of OS4CL in O. sanctum leaves caused a reduction in leaf eugenol content and trichome transcript level, with a considerable increase in endogenous p-coumaric, ferulic, trans-cinnamic and caffeic acids. A significant reduction in the expression levels was observed for OB4CL_ctg4-related transcripts in suppressed trichome compared with transcripts similar to the other four isoforms (OB4CL_ctg1, 2, 3 and 5). Sinapic acid and lignin content were also unaffected in RNAi suppressed leaf samples. Transient expression of OS4CL-green fluorescent protein fusion protein in Arabidopsis protoplasts was associated with the cytosol. These results indicate metabolite channeling of intermediates towards eugenol by a specific 4CL and is the first report demonstrating the involvement of 4CL in creation of virtual compartments through substrate utilization and committing metabolites for eugenol biosynthesis at an early stage of the pathway.
TL;DR: Genes involved in the biosynthesis of phenylpropenes have been characterized and manipulated in strawberry and apple, which has validated the importance of these compounds to fruit aroma and may help elucidate other functions for phenyl Propenes in fruit.
Abstract: Phenylpropenes such as eugenol, chavicol, estragole, and anethole contribute to the flavor and aroma of a number of important herbs and spices. They have been shown to function as floral attractants for pollinators and to have antifungal and antimicrobial activities. Phenylpropenes are also detected as free volatiles and sequestered glycosides in a range of economically important fresh fruit species including apple, strawberry, tomato, and grape. Although they contribute a relatively small percentage of total volatiles compared with esters, aldehydes, and alcohols, phenylpropenes have been shown to contribute spicy anise- and clove-like notes to fruit. Phenylpropenes are typically found in fruit throughout development and to reach maximum concentrations in ripe fruit. Genes involved in the biosynthesis of phenylpropenes have been characterized and manipulated in strawberry and apple, which has validated the importance of these compounds to fruit aroma and may help elucidate other functions for phenylprope...
TL;DR: The most relevant results obtained during the last 15 years with regard to the synthetic uses of eugenol are discussed in this paper, including its use as starting material or building block for the total synthesis of natural products, their analogs and derivatives, as well as other structurally interesting or bioactive compounds.
Abstract: Phenylpropenes are produced by plants as part of their defense strategy against microorganisms and animals, and also as floral attractants of pollinators. Eugenol, the main component of clove’s essential oil, is an inexpensive and easily available phenylpropene that has been known by humankind since antiquity, and used as a medicinal agent, but also for food flavoring and preservation. The review includes the most relevant results obtained during the last 15 years with regard to the synthetic uses of eugenol. Discussed here are the multiple applications of eugenol in organic synthesis, including its use as starting material or building block for the total synthesis of natural products, their analogs and derivatives, as well as other structurally interesting or bioactive compounds. The preparation technologically relevant macrocycles and polymeric derivatives of eugenol, is included, and the impact of biotechnology on the use of eugenol as feedstock for biotransformations, leading to other valuable small molecules is also addressed.
TL;DR: Although the chemotypes greatly differ in their phenylpropenoids composition, both are efficient in in vitro forming t-anethole and estragole, which are the major constituents of the essential oils of bitter fennel chemotypes.