Proposed biosynthetic pathway for rosmarinic acid in cell cultures of Coleus blumei Benth

Petersen, Maike; Häusler, Elisabeth; Karwatzki, B.; Meinhard, Juliane

doi:10.1007/bf00201337

Cited by 111 publications

(72 citation statements)

References 22 publications

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“…3B), as was found for the related enzyme from Coleus blumei (Petersen et al, 1993). This was especially true for the activity that transferred hydroxycinnamoyl groups to shikimate (CST).…”

Section: Partial Purification and Properties Of Basil Hydroxycinnamoymentioning

confidence: 60%

“…This suggests that these hydroxylases in sweet basil peltate glands and leaves are not likely to be nonspecific phenolases (Patil and Zucker, 1965), nor are they likely to be the potential hydroxylases that have been reported to require FAD (Kamsteeg et al, 1981) or Zn 2ϩ and ascorbate (Kneusel et al, 1989) for activity. It seems likely that the enzyme(s) responsible for the 3Ј-hydroxylation of p-coumaroyl 4-hydroxyphenyllactate in sweet basil will be related to the analogous enzyme in C. blumei (Petersen et al, 1993;Petersen, 1997). This enzyme, not purified to date, is also very specific for its substrate, and p-coumaric acid cannot be utilized as a substrate (Petersen, 1997).…”

Section: Discussionmentioning

confidence: 99%

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Differential Production of meta Hydroxylated Phenylpropanoids in Sweet Basil Peltate Glandular Trichomes and Leaves Is Controlled by the Activities of Specific Acyltransferases and Hydroxylases

et al. 2002

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Sweet basil (Ocimum basilicum) peltate glandular trichomes produce a variety of small molecular weight phenylpropanoids, such as eugenol, caffeic acid, and rosmarinic acid, that result from meta hydroxylation reactions. Some basil lines do not synthesize eugenol but instead synthesize chavicol, a phenylpropanoid that does not contain a meta hydroxyl group. Two distinct acyltransferases, p-coumaroyl-coenzyme A:shikimic acid p-coumaroyl transferase and p-coumaroyl-coenzyme A:4-hydroxyphenyllactic acid p-coumaroyl transferase, responsible for the production of p-coumaroyl shikimate and of p-coumaroyl 4-hydroxyphenyllactate, respectively, were partially purified and shown to be specific for their substrates. p-Coumaroyl-coenzyme A:shikimic acid p-coumaroyl transferase is expressed in basil peltate glands that are actively producing eugenol and is not active in glands of noneugenol-producing basil plants, suggesting that the levels of this activity determine the levels of synthesis of some meta-hydroxylated phenylpropanoids in these glands such as eugenol. Two basil cDNAs encoding isozymes of cytochrome P450 CYP98A13, which meta hydroxylates p-coumaroyl shikimate, were isolated and found to be highly similar (90% identity) to the Arabidopsis homolog, CYP98A3. Like the Arabidopsis enzyme, the basil enzymes were found to be very specific for p-coumaroyl shikimate. Finally, additional hydroxylase activities were identified in basil peltate glands that convert p-coumaroyl 4-hydroxyphenyllactic acid to its caffeoyl derivative and p-coumaric acid to caffeic acid.Basil (Ocimum basilicum) plants synthesize significant quantities of phenylpropanoid derivatives that contain an hydroxyl group at the meta position on the aromatic ring. Several of these compounds, such as eugenol, rosmarinic acid, and caffeic acid (Fig. 1), are found in high concentrations in specialized structures that are located on the surface of the aerial parts of the plant and are known as peltate glandular trichomes (glands; Gang et al., 2001). These specialized metabolites have been found in other plant species as well, but the nature of the enzymes that catalyze the meta hydroxylation has so far remained poorly understood.One of the difficulties in identifying the enzymes catalyzing the 3-hydroxylations in the phenylpropanoid pathways is that they appear to be found at very low abundance in the tissues examined (Petersen, 1997). We have recently shown (Gang et al., 2001) that, as in peppermint (Mentha ϫ piperita; Gershenzon et al., 1992;McCaskill and Croteau, 1995), the basil gland cells can be removed from the plant and studied in isolation from the rest of the plant, greatly facilitating biochemical and molecular investigations of a single, fully differentiated cell type (Gershenzon et al., 1992;McCaskill et al., 1992;McCaskill and Croteau, 1995;Lange et al., 2000;Gang et al., 2001). Furthermore, because these gland cells are so highly specialized for production of plantspecialized metabolites, the enzymes in these metabolic pathways are highly express...

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“…3B), as was found for the related enzyme from Coleus blumei (Petersen et al, 1993). This was especially true for the activity that transferred hydroxycinnamoyl groups to shikimate (CST).…”

Section: Partial Purification and Properties Of Basil Hydroxycinnamoymentioning

confidence: 60%

Section: Discussionmentioning

confidence: 99%

Differential Production of meta Hydroxylated Phenylpropanoids in Sweet Basil Peltate Glandular Trichomes and Leaves Is Controlled by the Activities of Specific Acyltransferases and Hydroxylases

et al. 2002

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“…The structural similarity to phenyl lactic acid and 4-hydroxyphenyl lactic acid suggests that syringyl lactic acid could be formed from these compounds: starting from 4-hydroxyphenyl lactic acid, subsequent hydroxylations and methylations would introduce the necessary methoxyl substituents on the benzene ring to produce syringyl lactic acid. The biosynthetic route from Tyr to 4-hydroxyphenyl lactic acid has been described for plants and holds a transamination followed by a reduction (Petersen et al, 1993).…”

Section: Discussionmentioning

confidence: 99%

Different Routes for Conifer- and Sinapaldehyde and Higher Saccharification upon Deficiency in the Dehydrogenase CAD1

Déjardin²,

et al. 2017

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In the search for renewable energy sources, genetic engineering is a promising strategy to improve plant cell wall composition for biofuel and bioproducts generation. Lignin is a major factor determining saccharification efficiency and, therefore, is a prime target to engineer. Here, lignin content and composition were modified in poplar (Populus tremula 3 Populus alba) by specifically down-regulating CINNAMYL ALCOHOL DEHYDROGENASE1 (CAD1) by a hairpin-RNA-mediated silencing approach, which resulted in only 5% residual CAD1 transcript abundance. These transgenic lines showed no biomass penalty despite a 10% reduction in Klason lignin content and severe shifts in lignin composition. Nuclear magnetic resonance spectroscopy and thioacidolysis revealed a strong increase (up to 20-fold) in sinapaldehyde incorporation into lignin, whereas coniferaldehyde was not increased markedly. Accordingly, ultra-high-performance liquid chromatography-mass spectrometry-based phenolic profiling revealed a more than 24,000-fold accumulation of a newly identified compound made from 8-8 coupling of two sinapaldehyde radicals. However, no additional cinnamaldehyde coupling products could be detected in the CAD1-deficient poplars. Instead, the transgenic lines accumulated a range of hydroxycinnamate-derived metabolites, of which the most prominent accumulation (over 8,500-fold) was observed for a compound that was identified by purification and nuclear magnetic resonance as syringyl lactic acid hexoside. Our data suggest that, upon down-regulation of CAD1, coniferaldehyde is converted into ferulic acid and derivatives, whereas sinapaldehyde is either oxidatively coupled into S9(8-8)S9 and lignin or converted to sinapic acid and derivatives. The most prominent sink of the increased flux to hydroxycinnamates is syringyl lactic acid hexoside. Furthermore, low-extent saccharification assays, under different pretreatment conditions, showed strongly increased glucose (up to +81%) and xylose (up to +153%) release, suggesting that down-regulating CAD1 is a promising strategy for improving lignocellulosic biomass for the sugar platform industry.

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“…This corresponds to highest C4H activities on days 6 to 7 observed shortly before the maximum of RA accumulation. After having established the biosynthetic pathway for RA in cell cultures of C. blumei (Lamiaceae; Petersen et al 1993) we were interested in whether or not the same enzymes are also involved in RA biosynthesis in the hornwort A. agrestis. The enzymatic activities of all three enzymes of the general phenylpropanoid pathway, namely PAL, C4H and hydroxycinnamic acid:coenzyme A ligase, were detected in enzyme preparations of Anthoceros as well as the activities of tyrosine aminotransferase and hydroxyphenylpyruvate reductase (data not shown).…”

Section: Discussionmentioning

confidence: 99%

Cinnamic acid 4-hydroxylase from cell cultures of the hornwort Anthoceros agrestis

Petersen

2003

Planta

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Proposed biosynthetic pathway for rosmarinic acid in cell cultures of Coleus blumei Benth

Cited by 111 publications

References 22 publications

Differential Production of meta Hydroxylated Phenylpropanoids in Sweet Basil Peltate Glandular Trichomes and Leaves Is Controlled by the Activities of Specific Acyltransferases and Hydroxylases

Differential Production of meta Hydroxylated Phenylpropanoids in Sweet Basil Peltate Glandular Trichomes and Leaves Is Controlled by the Activities of Specific Acyltransferases and Hydroxylases

Different Routes for Conifer- and Sinapaldehyde and Higher Saccharification upon Deficiency in the Dehydrogenase CAD1

Cinnamic acid 4-hydroxylase from cell cultures of the hornwort Anthoceros agrestis

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