Ferulic and p-coumaric acid

The reported (14) mechanisms of action of allelochemlcals Include effects on root ultrastructure and subsequent Inhibition of Ion absorption and water uptake, effects on hormone-induced growth, alteration of membrane permeability, changes In lipid and organic acid metabolism, inhibition of protein synthesis and alteration of enzyme activity, and effects on stomatal opening and on photosynthesis. Reduced leaf water potential Is one result of treatment with ferulic and p-coumaric acids (15). Colton and Einhellig (16) found that aqueous extracts of velvetleaf (Abutllon theophrastl Medic.) Increased diffusive resistance In soybean fGlycine max. (L.) Merr.] leaves, probably as a result of stomatal closure. In addition, there was evidence of water stress and reduced quantities of chlorophyll In Inhibited plants. 

Einhellig and Rasmussen (17) reported that In addition to ferulic and p-coumaric acids, vanillic acid reduced chlorophyll content of soybean leaves but did not affect chlorophyll In grain sorghum fSorghum bicolor (L.) Moench.]. It Is not known whether these reported mechanisms are primary or secondary events In the Inhibition of plant growth by allelochemlcals. 

Price, W.P., Jr., and Deming, S.N. (1979), Optimized Separation of Scopoletin and Umbelliferone and cis-trans Isomers of Ferulic and p-Coumaric Acids by Reverse-Phase High-Performance Liquid Chromatography, Anal. Chim. Acta, 108, 227-231. 

Phenolic acids interfere with many major physiological processes of higher plants (35). These disruptions of function include an alteration of plant water balance. We found depression of leaf water potential to be an early indicator of allelochemical stress from ferulic and p-coumaric acids (42). Likewise one mechanism of allelopathic action by cultivated sunflower, velvetleaf Abutilon theophrasti Medic.), Koahia [Koahia saoparia (L.) Schrad.], and several other weeds was water stress (43-45). Since some allelochemicals interfere with plant-water relationships, it seemed logical that their action might be most critical at times when plants are under water stress from other causes. 

Some of the acidic and basic polymers of the cell wall bear phenolic side-chains. The acidic polysaccharides carry ferulic and p-coumaric acid and related cinnamate-derivatives, esterified to specific hydroxy groups... 

Dimeric forms of ferulic and p-coumaric acids also occur in bound form within plant cell walls. The most common of these is didehydroferulic acid 23, which has been isolated from some plants of the Gramineae (53,54) and spinach cell cultures (7). While no such p-coumaric acid 2 derived dimer (i.e., C5-C5 linked) has ever been reported, cell walls of Lolium multiflorum contain another intriguing structural variation, namely 4,4 -dihydroxytruxillic acid 24 (5,55). 

For white wines (85), a similar HPLC condition to that of Betes-Saura et al. (79) was employed with a Nucleosil C)8 column (250 X 4.0-mm ID, 5 /zm) with binary gradient using eluent (A) acidified water (pH 2.65) and eluent (B) 20% A with 80% acetonitrile applied for hydroxy-cinnamate derivatives esters (caffeoyl tartaric, p-coumaroyl tartaric, and feruloyl tartaric acid esters) and free hydroxycinnamic acids (caffeic, ferulic, and p-coumaric acids). 

Ferulic and p-coumaric acids altered the water balance of grain sorghum and soybean seedlings (55,74). Even at treatment levels that were below the threshold for short-term growth reduction, water stress was evident by the depression of seedling water potential. Sorghum treated with 0.25 mM ferulic or p-coumaric acids had midday leaf water potentials of approximately -10 bars, compared to -5 bars for the controls. Treatments with phenolic compounds that reduced growth also were correlated with partial stomatal closure (55,63,64). 

Seitz, L.M. 1989. Stand and sterol esters of ferulic and p-coumaric acids in wheat, eorn, rye, and tritieale. J. Agric. Food Chem. 37 662-667. 

Several strains of LAB isolated from wine were tested for their abilities to metabolize ferulic and p-coumaric acids. Cavin et al. (1993) showed that these acids were strongly decarboxylated by growing cultures of Lactobacillus brevis, Lactobacillus plantarum, and Pediococcus when decarboxylation was observed, volatile phenols (4-ethylguaiacol and 4-ethylphenol) were detected, indicating the possibility of reduction of the side chain before or after decarboxylation. Couto et al. (2006) reported L. collinoides as a producer of volatile phenols, although strain specificity concerning this capacity was observed. L. mali, L. sake, L. viridescens, and P. acidi-lactici were also found to be able to produce volatile compounds but they only perform the decarboxylation step. Volatile phenols cause animal taints such as horse sweat, wet animal and urine that are usually attributed to Brettanomyces spoilage. 

The procedure for ferulic acid determination was adapted from a chlorogenic acid quantification protocol [24]. A 100-pl sample was diluted with 100 pi dH20. 50 pi of MeOH containing 0.0041 mg of chrysin was added as an internal standard. Ferulic and p-coumaric acid concentrations were determined for 20 pi aliquots of the solution by reverse-phase HPLC (model 1050, Hewlett Packard) using an H20/MeOH linear gradient from 10% (v/v) to 100%... 

The principal phenolic acids in these vegetables are ferulic and p-coumaric acid derivatives, the green parts of chives and leeks containing more than in the white part. In leek, the white tissue contains 6-7 mg ferulic acid per kg f.w., while this compound reaches concentrations of 23-39 mg/kg in the green parts [64]. In the case of chive, p-coumaric acid derivatives reach 21-51 mg/kg and ferulic acid derivatives 32-76 mg/kg. In garlic a different pattern of phenolic metabolite accumulation is observed in skins and internal tissues. The external tissues contain 49-58 mg/kg p-coumaric acid, 27-31 mg/kg ferulic acid and 27-25 mg/kg sinapic acid, whereas the internal tissues only contain 2mg, 6-8 mg and 2 mg/kg, respectively. In addition, the internal tissues contain 12-13 mg/kg p-hydroxybenzoic acid [64]. 

The cinnamate decarboxylase (CD) of Saccharomyces cerevisiae is highly specific. These yeasts are incapable of converting benzoic acids into volatile phenols. Only certain acids in the cinnamic series (phenyl-propenoic acids) may be decarboxylated by this microorganism. Among the cinnamic acids in grapes, only ferulic and p-coumaric acids are affected by the CD activity. Caffeic (4,5-dihydroxycinnamic) and sinapic (4-hydroxy-3,5-dimethoxycinnamic) acids are not decarboxylated by S. cerevisiae. Cinnamic acid and... 

Recently, the presence of hydroxydnnamate esters consisting of ferulic and p-coumaric acids esterified to long-chain fatty alcohols (C20 to C28) and co-hydroxyfatty adds (C22 to 23) in abaca fiber has been reported by del Rio et al. [72]. del Rio et al. [73] also report that native lignin in kenaf, jute, sisal, and abaca is at least partially acetylated. 

At the phenylpropane level derivatives of ferulic and p-coumaric acid are accumulated. 

It is interesting to highlight the fact that the majority of the compounds were found in the totality of the samples. However, linolenic acid was only present in CJem and Marvel varieties at the second ripening degree. Some flavonoids (laricitrin, naringenin, chrysin, and kaempferide) were detected in ripe fruits from Colin V 33, Pinkerton, and Sir Prize. Ferulic and p-coumaric acids were determined in all of the samples ready for consumption and in just one unripe, Colin V 33. A similar situation is appreciated for syringic acid, which has been identified in Colin V 33 and Sir... 

Lam TBT, Kadoya K, Liyama K (2001) Bonding of hydroxycinnamic acids to lignin ferulic and p-coumaric acids are predominantly linked at the benzyl position of lignin, not the a-position, in grass cell walls. Phytochemistry 57 987... 

Kenyhercz TM, Kissinger PT (1977) A new approach to the phenolic components in beer. Application to the determination of sinapic, ferulic, and p-coumaric acids. J Agric Food Chem 25 959-961... 

Lehman ME, Blum U (1999) Evaluation of ferulic acid uptake as a measurement of aUelochemical dose effective concentration. J Chem Ecol 25 2585-2600 Lehman ME, Blum U, Gerig TM (1994) Simultaneous effects of ferulic and p-coumaric acids on cucumber leaf expansion in split-root experiments. J Chem Ecol 20 1773-1782 Liebl RA, Worsham AD (1983) Inhibition of morning-glory Ipomoea lacimosa L.) and certain other weed spedes by phytotoxic components of wheat (Triticum aestivum L.) straw. J Chem Ecol 9 1027-1043... 

There are probably more papers claiming that common phenohc acids derived from the shiki-mate pathway (e.g. cinnamic acid and some of its derivatives such as ferulic and p-coumaric acids, see Fig. 5) than for any other class of compound. These compounds are ubiquitous to higher plants and are generally very weakly phytotoxic, making it difficult to view them as allelochemicals. One reason for the abundance of papers on the allelopathic properties of simple phenolic acids is that these compounds are easily extracted and identified. In case after case, papers trying to correlate the activity of crude extracts with phenolic acid content were... 

Examples of conjugates ofbiogenic amines (10-193) with pheno-Kc acids, which exhibit fungicidal activity, are hordatines (10-195), dimers of p-coumaroylagmatine, occurring in germinating barley. Wheat, for example, contains amides of 2-hydroxyputrescine along with ferulic and p-coumaric acids, which arise as phytoalexins. 

Determination of Phenolic Compounds (Gallic, Caffeic, Ferulic, and p-Coumaric Acids)... 

Pan, G. X., J. L. Bolton, and G. J. Learly. 1998. Determination of ferulic and p-coumaric acids in wheat straw and the amounts released by mild acid and alkaline proxide treatment. J. Agr. Food Chem. 46 5283-5288. 

Grain Protein, fat, ash, moisture, fiber, carbohydrate by calc., amino acid profile, fatty acid profile, minerals, vitamin E, trypsin inhibitor, ferulic and p-coumaric acids, raffinose, 2-fiiraldeyde... 

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