Enzymic Synthesis of Caffeoylglucaric Acid from Chlorogenic Acid and Glucaric Acid by a Protein Preparation from Tomato Cotyledons

Abstract

The phenylpropane metabolism of tomato (Lycopersicon escukntm Mill) cotyledons was investigated. The (10,18) and glucaric acid (3). To date two mechanisms for the formation of such esters have been described (1); one involving the hydroxycinnamoyl-CoA thioester and the other one the l-O-(hydroxycinnamic acid)-acyl glucoside. The former mechanism was first shown to operate in the formation of chlorogenic acid (12), the 5-0-caffeoylquinic acid (6), in Nicotiana cell-suspension cultures and the latter one in the formation ofthe sinapic acid (4-hydroxy-3,5-dimethoxycinnamic acid) ester of malate (17) in Raphanus cotyledons. Both pathways can even lead to the same product, depending on the source of enzyme used, since recently it was shown that Ipomoea root tissue catalyzes the formation of chlorogenic acid from 1-0-caffeoylglucose ( 19,20).We studied the metabolism of hydroxycinnamic acid conjugates in tomato expecting one of the two described biosynthetic mechanisms to be operative in the formation of caffeoylglucaric acid. Earlier work ( 11) had shown that chlorogenic acid in tomato was formed via the caffeoyl-CoA thioester. However, all attempts to find an analogous reaction for the formation of caffeoylglucaric-acid, as well as experiments using 1 -O-caffeoylglucose as possible acyl donor, failed. The latter mechanism was considered possible for the formation of caffeoylglucaric acid in Cestrum 'Supported by the Deutsche Forschungsgemeinschaft. leaves which contain metabolically active l-O-caffeoylglucose (9).Since the accumulation patterns of chlorogenic and caffeoylglucaric acids indicated a precursor-product relationship, we considered chlorogenic acid as the possible acyl donor as was found in the biosynthesis of isochlorogenic acid (3,5-di-O-caffeoylquinic acid) in Ipomoea root tissue (8). Our results show that the enzymic formation of caffeoylglucaric acid in tomato cotyledons proceeds exclusively with chlorogenic acid as the acyl donor.MATERIALS AND METHODS Plant Material. Tomato seeds (Lycopersicon esculentum Mill cv Moneymaker Spezialzucht) were obtained from Waltz, Stuttgart, FRG; seedlings were grown for 3 weeks in a growth chamber with a 14-h day at 24°C and 70% RH in a defined soil as described (15). Adult plants were grown in a greenhouse.Substrates. CoA (free acid), caffeic and chlorogenic acids (5-O-caffeoylquinic acid; IUPAC nomenclature [6]) were purchased from Fluka (Neu-Ulm, FRG), and quinic, glucaric, galactaric and gluconic acids from Merck (Darmstadt, FRG). CaffeoylCoA was synthesized chemically and identified according to Zenk and coworkers (4, 13) and purified by a modification (D Strack, H Keller, G Weissenbock, unpublished data) of a described method (7) involving the hydroxycinnamoyl-N-hydroxysuccinimide ester and subsequent transesterification of the hydroxycinnamoyl moiety onto CoA. Purification was achieved on a polyamide column (details not documented) by stepwise elution with water, methanol and increasing concentrations of aqueous NH40H in methanol (0.01%, 0.05%, 0.1%...

Identification of Flavonoids in Leaves of a Labile Bicolor Flowering Dahlia (<i>Dahlia variabilis</i>) ‘Yuino’

“…1B). The structures of known compounds were determined by comparing their spectroscopic and/or chromatographic data with values in the literature and were identified as 3-O-[(trans)-caffeoyl]-glucaric acid (A) (Maas et al, 2009;Nagels et al, 1982), 2-O-[(trans)-caffeoyl]-glucaric acid (B-1) (Strack et al, 1987), 5-O-[(trans)-caffeoyl]-quinic acid (neo-chlorogenic acid)…”

Green and roasted arabica coffees differentiated by ripeness, process and cup quality via electrospray ionization mass spectrometry fingerprinting

“…26,27 The concentration of chlorogenic acid oligomers are known to decrease along ripeness, which reflects in the better quality of the beverage obtained with ripe cherry beans. The variability of lipids concentration was studied by Jham et al, 28 who showed a pronounced decrease of diacylglycerols in coffees beans from unripe to ripe, the same happening with fatty acids.…”

Metabolomics reveals organ-specific metabolic rearrangements during early tomato seedling development

“…For any organ where a metabolite was absent or excluded in more than 15 out of the total of 45 Strack et al (1987) b Moco et al (2006) c Iijima et al (2008) d Vallverdu-Queralt et al (2010) e Tikunov et al (2010) f Gómez-Romero et al (2010) g Ferreres et al (2010) h Butelli et al (2008) i Bovy et al (2002) j Schmidt et al (2011) samples, this metabolite was removed from the mixed model analysis. The number of metabolites analysed for each organ is indicated in Supplementary Table S4.…”

“…In addition, compounds described in the literature to be present in WT tomato fruits (Gómez-Romero et al 2010;Tikunov et al 2010;Vallverdu-Queralt et al 2010), transgenic tomato fruits (Butelli et al 2008), transgenic tomato seedlings (Bovy et al 2002), tomato seeds (Ferreres et al 2010) and tomato leaves (Strack et al 1987;Lawson et al 1997;Schmidt et al 2011) were incorporated into the list of known tomato compounds. New metabolites were putatively annotated based on their elemental formulae calculated from the observed accurate mass and using additional information such as UV absorption spectra and high-mass resolution fragmentation data.…”