Free Cinnamic Acid Research Articles

Investigations into the Ability to Reduce Cinnamic Acid as Undesired Precursor of Toxicologically Relevant Styrene in Wort by Different Barley to Wheat Ratios (Grain Bill) during Mashing.

Styrene is a food-borne toxicant in wheat beer and due to its classification as possibly carcinogenic to humans by the International Agency for Research on Cancer in 2002, mitigation strategies had to be developed. Aiming at understanding the impact of the barley to wheat malt ratio (grain bill) during mashing on the contents of soluble and free (i) cinnamic, (ii) p-coumaric, and (iii) ferulic acid, precursors of (i) styrene and the desired vinyl aromatics (ii) 4-vinylphenol and (iii) 2-methoxy-4-vinylphenol in wheat beer, wort was prepared at four different barley to wheat malt ratios of 100:0, 25:75, 50:50, and 0:100 (w/w). Additionally, the malts were produced at different germination temperatures and aeration rates (12/32, 18/35, 18/25, 24/18, and 26/25 (°C; L/min)) to consider these two further parameters as well. Thereby, soluble and free phenolic acid contents in wort showed linear correlations to the percentage of wheat in the grain bill, highlighting the absence of synergistic effects when mixing barley and wheat malts. In contrast, the results described the phenolic acid contents as a function of the concentrations in the respective barley and wheat wort, multiplied by their percentage in the grain bill. However, a clear recommendation for favorable barley to wheat malt ratios leading to a decrease of soluble and free cinnamic acid in wort could not be made, as the contents in the present study proved to be highly dependent on the barley and wheat varieties used during mashing and the parameters applied during malting. This was not the case for p-coumaric acid for which a clear decrease of the soluble and free forms was found with increasing wheat malt contents. Differently, the soluble form of ferulic acid increased with an increasing percentage of wheat malt, while the free form decreased. The malting parameters clearly recommended high germination temperatures and low aeration rates when aiming at a reduction of undesired cinnamic acid in wort. Fortunately, soluble and free p-coumaric and ferulic acid contents were only slightly affected, indicating that the formation of the characteristic wheat beer aroma might not suffer when applying these favorable conditions for styrene reduction.

Avenanthramides as lipoxygenase inhibitors

Avenanthramides (AVAs) present in oats are amides of anthranilic and cinnamic acids. AVAs are potent antioxidants and have anti-inflammatory properties. There are various potential mechanisms for their anti-inflammatory effects, including inhibition of lipoxygenases (LOX), which catalyse oxygenation of polyunsaturated fatty acids into potent signal molecules involved in inflammatory processes. In this study, AVAs were screened for LOX inhibition in vitro and structure-activity relationships were examined. Twelve different AVAs at 0.6 mM were tested as LOX inhibitors. The corresponding free cinnamic acids, the AVA analogue Tranilast® and the known LOX inhibitor trans-resveratrol were included for comparison. It was found that AVAs comprising caffeic or sinapic acid exhibited significant lipoxygenase inhibition (60–90%) (P < 0.05), whereas low or no inhibition was observed with AVAs containing p-coumaric or ferulic acid. No difference in inhibition was seen on comparing AVAs with their free corresponding cinnamic acids, which implies that the anthranilic acid part of the avenanthramide molecule does not affect inhibition. Trans-resveratrol showed inhibition, whereas no inhibition was seen for Tranilast® at the concentrations used in this study. This study suggests that aventahtramides comprising caffeic acid or sinapic acid partly exert their antioxidant and anti-inflammatory effects via lipoxygenase inhibition.

Cinnamic acid decreases periodontal inflammation and alveolar bone loss in experimental periodontitis.

Periodontitis is the chronic destructive disease of the periodontium, which causes severe inflammation in the tissues. Cinnamic acid as an unsaturated carboxylic acid might prevent inflammation and periodontal destruction. The present study aimed to evaluate the effects of cinnamic acid in two different forms as free cinnamic acid and cinnamic acid liposome on experimental periodontitis in Wistar rats. Thirty-two female rats were used in the present study. Four main groups were created as follows: C: control group; P: periodontitis group; C-P: free cinnamic acid-administered periodontitis group; and CL-P: cinnamic acid liposome applied group. Periodontitis was induced via ligating 4-0 silk sutures around lower first molar teeth on both right and left mandibles. The study duration was 30days, and the ligatures were removed from half of the rats in the periodontitis-induced groups. The other half carried the ligatures throughout 30days, and all rats were euthanized at 30th day. Mandibles were removed and evaluated via stereomicroscope and underwent histological procedures. Inflammatory cell counts, osteoblast, and osteoclast cell counts were determined in hematoxylin-eosin-stained slides, and peroxisome proliferator-activated receptor (PPAR)-γ, cyclooxygenase (COX)-2, receptor activator of nuclear factor κ-B (RANKL), and osteoprotegerin (OPG) expressions were evaluated by immunohistochemistry. Control group had the lowest bone loss, and periodontitis group which kept ligatures had the highest bone loss compared to the other groups. Ligature removal provided significant improvement in bone measurements. Cinnamic acid groups also showed lower bone loss compared to the periodontitis group. The inflammatory cell and osteoclast counts were also higher in the periodontitis group, and both applications of cinnamic acid decreased these values. Osteoblast cells were the lowest in the periodontitis group, and cinnamic acid increased these counts. PPAR-γ and COX-2 levels were higher in the periodontitis group, and cinnamic acid decreased these levels but not to a significant level except for the cinnamic acid liposome ligature removal group, which had significantly lower values in the PPAR-γ and COX-2. OPG levels were lower in the periodontitis group compared to the other groups. Cinnamic acid significantly decreased RANKL and increased OPG levels. Periodontitis caused increased inflammation and bone destruction accompanied by increased PPAR-γ, COX-2, and RANKL levels and osteoclast counts. Cinnamic acid decreased osteoclast counts and inflammation and increased osteoblast counts and OPG expression in the present animal model of periodontitis.

Constituents of Melittis melissophyllum subsp. albida

In this paper, for the first time, we have reported the analysis of the polar fraction of Melittis melissophyllum subsp. albida, a species with ecological relevance which is also used in traditional medicine of Central-Southern Italy. Iridoid glucosides were mainly identified, together with verbascoside, an ubiquitous phenyl-ethanoid glycoside, with chemotaxonomic implications in Lamiales order. The majority of the isolated compounds is endowed with interesting bio- activities and may justify the traditional uses of this plant also from a chemical point of view. Several peculiarities were also recorded in the metabolic pattern of this subspecies, i.e. the presence of virginioside and geniposidic acid, two rare compounds in the Lamiaceae family. The presence of free cinnamic acid was an additional characteristic of this subspecies which showed a specific secondary metabolites content. These phytochemical peculiarities, together with the morphological differences showed by the subsp. albida in respect to the nominal species, may be a base for a reconsideration of the systematic of Melittis melissophyllum subsp. albida.

Characterization of Cinnamic Acid-Attached Nonionic Amphiphiles in UV Extinction, Emulsification, and In Vitro Toxicity

Cinnamic acid (CA) was covalently attached to nonionic surfactants by condensation reaction. The mass and the molar extinction coefficient of CA residue of each conjugate did not markedly deviate from those of free CA, indicating CA could absorb the UV light after being conjugated to the surfactants. When the concentration of the conjugates in aqueous phase was 0.1% and 1.0%, mineral oil could readily be emulsified by polyoxyehtylene(20) cetyl ether–CA conjugate (CE20–CA), polyoxyethylene(20) oleyl ether–CA conjugate (OE20–CA), and polyoxyehtylene(20) sorbitan monolaurate–CA conjugate (Tween 20–CA). The extinction coefficients of the surfactant–CA conjugates contained in O/W emulsion did not markedly deviate from those of the conjugates dissolved in water, suggesting that the conjugate could maintain their extinction coefficients when they coexisted with oil droplets. According to the result of 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, the viability of cell (BALB/c 3T3 clone A31) was greater than 80% for all the surfactant–CA conjugates tested when the conjugate concentration was 0.2%. It is believed that CE20–CA, OE20–CA, and Tween 20–CA could be used as an emulsifier which absorbs UV light effectively.

Tween 20-cinnamic acid conjugate as a UV-absorbing emulsifier

Cinnamic acid (CA) was covalently attached to the head of Tween 20 in order to prepare a UV absorbing emulsifier. The molar ratio of Tween20 to CA of the Tween 20-CA conjugate was calculated to be 1:1.3 on 1H NMR spectrum. The interfacial tensions of Tween 20-CA conjugate solution were lower than those of Tween 20 solutions in the full range of concentration tested (0.0005–0.01% (w/v)), indicating that the interfacial activity of Tween 20-CA conjugate is higher than that of Tween 20. The dimerization degree of Tween 20-CA conjugate in 180min was about 77% and it was higher than that of free CA. The molar extinction coefficient of Tween20-CA conjugate at 280nm was 14,391.8M−1cm−1, not markedly different from that of CA. Emulsion prepared using Tween20-CA conjugate was much more stable for 70h in terms of oil droplet size change than emulsion prepared using Tween 20, possibly because the interfacial activity of Tween 20-CA conjugate was higher than that of Tween 20. The oil droplet size of emulsions prepared using Tween 20-CA conjugate increased during UV irradiation period (100min), however, the increment was not so great that the droplet size was kept below 7μm. It is believed that Tween 20-CA conjugate can be used as a UV-absorber.

Identification and quantification of bioactive compounds in coffee brews by HPLC–DAD–MSn

Coffee is a beverage widely consumed worldwide because of its organoleptic characteristics and stimulating and beneficial health effects. This paper presents the identification and quantification of chlorogenic acids and derivatives, trigonelline, nicotinic acid, 5-hydroxymethylfurfural, theobromine, theophylline, and caffeine in brews of 10 roasted ground coffee and 4 soluble coffee determined by HPLC–DAD–MSn. Among the chlorogenic acids and derivatives, 17 chlorogenic acids, 5 chlorogenic acid lactones, 2 cinnamoyl-amino acid conjugates, and 2 free cinnamic acids were identified. This is the first study that reports the presence of caffeoylferuloylquinic acid isomers, and cinnamoyl-amino acid conjugates in soluble coffee brews. Regular roasted ground coffee brews showed higher contents of chlorogenic acids (4162mg/100g), chlorogenic acid lactones (779mg/100g), p-coumaric acid (2.4mg/100g), trigonelline (2044mg/100g), nicotinic acid (100.4mg/100g), caffeine (4565mg/100g), and theobromine (12.5mg/100g) than regular soluble coffee brews. Decaffeinated coffee brews presented higher levels of chlorogenic acids, chlorogenic acid lactones, caffeic acid, and trigonelline when compared to the regular ones. Despite the differences in the levels of these compounds, brews of roasted ground coffee and soluble coffee, both regular and decaffeinated, represent an important source of bioactive compounds for habitual coffee consumers.

Anti-inflammatory activity of hydroxycinnamic acid derivatives isolated from corn bran in lipopolysaccharide-stimulated Raw 264.7 macrophages

In this study, the effect of the 80% ethanolic extract of corn bran (EECB) on inhibition of nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression in lipopolysaccharide (LPS)-stimulated Raw 264.7 cells was investigated. The EECB inhibited LPS-induced NO production and iNOS expression in a dose-dependent manner. Four hydroxycinnamic acid derivatives (HADs), including two free cinnamic acids, p-coumaric acid (CA) and ferulic acid (FA), and their conjugate phenolic amides, p-dicoumaroyl-putrescine (DCP) and diferuloylputrescine (DFP), were found to be present in the EECB by LC–MS analysis, and DFP (378.66μg/g) was the predominant phenolic compound, followed by DCP (7.83μg/g)>CA (5.58μg/g)>FA (1.84μg/g). The four HADs significantly inhibited NO production and iNOS expression in a dose-dependent manner. Among the four HADs tested, DFP showed the most potent inhibition on NO production and iNOS mRNA and protein expression, followed by DCP>FA⩾CA. DFP also exhibited the strongest inhibition on LPS-induced iNOS and NF-κB luciferase activity, which was followed by DCP⩾FA (CA)>CA (FA). Thus, these results suggest that phenolic amides in the corn bran may be a potential source of natural anti-inflammatory agents.

옥수수의 품종별 및 가공별 Hydroxycinnamic Acid 유도체 및 Anthocyanin 색소의 함량 변화

Hydroxycinnamic acid derivatives (HADs) and anthocyanins in corn (Zea mays L.) have recently been reported to have anticarcinogenic, anti-hypertensive, antidiabetic, antifungal, antioxidant, and anti-melanogenic activities. Five HADs and anthocyanins in corn were quantified by HPLC according to cultivars and heat processes. In addition, major anthocyanin of a black waxy corn was isolated and identified by several instrumental analysis, and its content was also quantified by HPLC according to heat processes. Of the ten corn cultivars, five waxy corn cultivars had moderate five HADs contents except Baksa waxy corn with higher two free cinnamic acids (FCAs), p-coumaric and ferulic acids. In contrast, three dent corn cultivars contained higher levels of three polyamine conjugates (PCs), CFP, DCP and DFP, and especially P3394 had the highest amount of the three PCs. Two sweet corn cultivars had generally intermediate HADs levels between waxy and dent corn cultivars. Of the three colored-waxy corns, a black Mibaek waxy corn had the highest anthocyanin content. During heat processes, levels of two FCAs in the black waxy corn generally increased, whereas no significant change on three PCs contents was observed except the puffing process. Roasting, retort and puffing processes significantly increased two FCAs and especially, the puffed black waxy corn had the highest amount of FCAs. Meanwhile, most heat treatments except retort process, considerably decreased total anthocyanin contents, and especially the puffed black waxy corn had nearly no anthocyanin. Level of one major anthocyanin, pelargonidin 3-glucoside (P3G) isolated from a black waxy corn was appreciably decreased by heat treatments except retort process, which greatly increased P3G content. These results suggest that the retorted black waxy corn may be a promising high quality functional corn product.

Cinnamic acid based thiazolidinediones inhibit human P450c17 and 3beta-hydroxysteroid dehydrogenase and improve insulin sensitivity independent of PPARgamma agonist activity

Thiazolidinediones improve insulin sensitivity in type 2 diabetes mellitus by acting as peroxisome proliferator-associated receptor gamma (PPARgamma) agonists, and decrease circulating androgen concentrations in polycystic ovary syndrome by unknown mechanisms. Some thiazolidinediones directly inhibit the steroidogenic enzymes P450c17 and 3beta-hydroxysteroid dehydrogenase type II (3betaHSDII) by distinct mechanisms. We synthesized five novel thiazolidinediones, CLX-M1 to -M5 by linking a 2,4-thiazolidinedione moiety to a substituted alpha-phenyl cinnamic acid previously shown to have glucose-lowering effects. Using yeast microsomes expressing human P450c17 and 3betaHSDII we found that cinnamic acid methyl esters with a double bond in the thiazolidinedione core structure (M3, M5) were stronger inhibitors of P450c17 than methyl esters with the conventional core (M1, M4). These four compounds inhibited 3betaHSDII equally well, while the free cinnamic acid analog (M2) did not inhibit either enzyme. Thus, the inhibition of P450c17 and 3betaHSDII by these novel thiazolidinediones reveals structure-activity relationships independent of PPARgamma transactivation. PPARgamma transactivation was moderate (M1), weak (M2, M3) or even absent (M4, M5). While the PPARgamma agonist activity of M1 was only 3% of that of rosiglitazone, both increased glucose uptake by 3T3-L1 adipocytes and reduced serum glucose levels in ob/ob and db/db mice to a similar extent. The similar glucose-lowering effects of M1 and rosiglitazone, despite their vast differences in PPARgamma agonist activity, suggests these two actions may occur by separate mechanisms.

Lipids and antioxidants in groats and hulls of Swedish oats (Avena sativa L)

AbstractConcentrations and compositions of total lipids (TL), fatty acids, tocopherols and tocotrienols, avenanthramides and free hydroxycinnamic acids were determined in groats and hulls from single samples of seven Swedish oat cultivars. Total antioxidant capacity (TAC) was measured using the radical 1,1‐diphenyl‐2‐picrylhydrazyl as substrate. Results were evaluated by principal component analysis. Consistent differences in value of the variables analysed in groats and hulls were found, groats having higher concentrations of all compounds analysed except free cinnamic acids. Concentrations of E‐vitamers (especially tocotrienols) were high in both groat and hull samples with high TL. Avenanthramides were high in hull samples with high TL, but this was not found in groats. Free cinnamic acids did not follow TL in either groats or hulls. TAC was generally higher in groats than in hulls. The within‐group variation in TAC was less pronounced than that in chemical composition, especially in groats. The results did not suggest any strong relationship between TAC and individual antioxidants.© 2002 Society of Chemical Industry

Ethyl p-Methoxycinnamate from Kaempferia galanga L. in Vietnam

The title compound, ethyl (E)-3-(4-methoxyphenyl)propenoate, C12H14O3, was isolated from the rhizomes of the Vietnamese plant Kaempferia galanga L. Its chemical identity was confirmed by an X-ray investigation, which established clearly a molecular trans configuration. As expected, the molecule is completely planar with a bonding geometry similar to that found in free cinnamic acid and related derivatives.

Determination of cinnamic acid and 4‐coumaric acid in alfalfa (Medicago sativa L.) cell suspension cultures by gas chromatography

AbstractA capillary gas chromatographic (GC) method for the assay of cinnamic acid and 4‐coumaric acid in alfalfa (Medicago sativa L.) cell extracts is described. These compounds were assayed as their trimethylsilyl derivatives; hydrocinnamic acid was used as the internal standard for quantifications. This method was qualitatively validated by GC/mass spectral analysis and quantitatively validated by measuring the extraction recovery from alfalfa cells, the recovery from derivatization, the stability of silylated derivatives, the limits of detection, the linearity of the detector response to increasing amounts of analytes, and the intra‐ and inter‐assay precisions. Cinnamic acid and 4‐coumaric acid were present in alfalfa cell extracts and were resolved from all other components by this method. As little as 4 pmol of each acid could be quantified, and the detector response was linear over a range covering five orders of magnitude. The cellular concentrations of free cinnamic acid and 4‐coumaric acid ranged from ca. 5–100 μmol/kg fresh weight tissue.

Toxicokinetics of cinnamaldehyde in F344 rats

The toxicokinetic profile of cinnamaldehyde (CNMA) was investigated in Fischer 344 rats. CNMA was found to be unstable in blood. After iv administration, a large fraction of CNMA was immediately oxidized to cinnamic acid. The biological half-life of CNMA after iv administration was found to be 1.7 hr. After administration by gavage of CNMA at 250 or 500 mg/kg body weight using corn oil as vehicle, the maximum blood concentrations of CNMA were in the order of 1 μg/ml. These low blood concentrations were maintained over a 24-hr period after a dose of 500 mg/kg, which is relatively long considering the short (1.7 hr) biological half-life of CNMA. The estimated oral bioavailability of CNMA was less than 20% for both the 250 and 500 mg/kg doses. No CNMA was present in blood at any time in rats dosed with 50 mg CNMA/kg body weight. Only a small amount of the administered CNMA was excreted in rat urine as free cinnamic acid or β-glucuronide-conjugated cinnamic acid. The majority of CNMA administered orallywas excreted in urine as hippuric acid within 24 hr. The maximum excretion rate occurred at 8 hr after gavage. Hippuric acid recovered in 50-hr urine samples was found to be directly proportional to the oral dose of CNMA.

Depression of cellulose digestion by esterified cinnamic acids

AbstractCinnamic acids commonly found in forages were esterified to cellulose and tested for their inhibition of cellulose degradation by mixed cultures of rumen microorganisms in vitro. Concentrations of cinnamic acids used in the cellulose esterification procedure were 20–100 g kg−1, but measurement of actual ester concentrations by alkaline extraction were not possible for solka floc cellulose and ranged from 0–9.1 g kg−1 for Whatman No. 54 filter paper. Cinnamic acid esters significantly depressed cellulose digestion. For both cellulose sources, caffeic acid was the most inhibitory compound. Solka floc cellulose digestion was also inhibited by sinapic acid, whereas p‐coumaric and ferulic acids also depressed digestion of filter paper cellulose. The proportions of volatile fatty acids produced by fermentation of filter paper were not altered by cinnamic acid esters. Esterified cinnamic acids depressed cellulose digestion to a significantly greater extent than did free cinnamic acids. The data suggest that the natural form of cinnamic acids (ester‐linked to cell wall fibre) are inhibitors of microbial digestion at concentrations reported to occur in forages.

The phenolic cinnamates of white grapes and wine

AbstractAn isolation procedure was developed for the recovery of the cinnamate derivatives from Müller‐Thurgau white wine by means of adsorption on charcoal, elution with acidic methanol and repeated chromatography on Sephadex LH‐20 with dilute acetic acid as the eluent. The crystalline products recovered were cis‐ and trans‐p‐coumaroyl‐(+)‐tartaric (coutaric) acid and trans‐caffeoyl‐(+)‐tartaric (caftaric) acid, as shown by spectral data, hydrolysis, chromatography, etc. The corresponding quinates were not detected and neither were ferulic acid derivatives nor the free cinnamic acids in this young white wine. The data are briefly discussed in relation to previous reports on these compounds in grapes or wines and their significance as wine constituents.

Incorporation de phenylalanine, de glucose et d'acide cinnamique dans les flavonols de l'oignon

In Allium cepa bulb scales, incorporation of 14C-phenylalanine, cinnamic acid and glucose were studied in relation to flavonol synthesis. The best incorporation into flavonols is obtained with either cinnamic acid or phenylalanine. 14C-glucose gives a slow incorporation into flavonol aglycone; this is because there is a big pool of free glucose in the scales in which the precursor is diluted. Under certain conditions, free cinnamic acid is quickly incorporated in a complex which may be a glycoside. After short labelling experiments with phenylalanine or cinnamic acid, some free precursor can be found in the scales a few days later but it is not available for flavonol synthesis. In these conditions, flavonol analysis shows in some cases, no turnover and in others, a turnover of 10% per day due to catabolism.

Biosynthesis of the coumarins: Scopoletin formation in tobacco tissue cultures

Feeding experiments of tobacco tissue cultures with (U)- 14C-phenylalanine, 2- 14C-cinnamic acid, 2- 14C-glucosidoferulic acid and methyl- 14C-methionine were carried out over periods from 3 min to 10 hr. The use of short feedings enabled us to study the kinetic aspect of the biosynthesis and to demonstrate the following main pathway: phenylalanine → free cinnamic acid → free p-coumaric acid → free caffeic acid → free ferulic acid → scopoletin → scopolin. Turn-over rates of free forms were shown to be much higher than those of the corresponding bound forms.