Alkyl Ferulates Research Articles

Suppressive effect of alkyl ferulate on the oxidation of microencapsulated linoleic acid

AbstractThe oxidation processes of linoleic acid mixed with ferulic acid or the 1‐pentyl, 1‐hexyl and 1‐heptyl ferulates, encapsulated with gum arabic or maltodextrin, were studied. The alkyl ferulates had a higher antioxidative effect than ferulic acid, but there was no significant difference among the three alkyl ferulates. Suppression of the oxidation by 1‐hexyl ferulate or ferulic acid was more effective at the higher molar ratios of the additive to linoleic acid. The processes were analyzed using the Weibull equation to evaluate the rate constant, k, and the shape constant, n. Although the k values for linoleic acid encapsulated with gum arabic were lower than that with maltodextrin, the suppressive effect of the alkyl ferulates was more remarkable for linoleic acid encapsulated with maltodextrin than with gum arabic because of the non‐antioxidative ability of maltodextrin. Because the partition coefficient of the alkyl ferulates was much greater than that of ferulic acid, most of the alkyl ferulates would be located in the linoleic acid phase of the microcapsules and effectively suppress the oxidation of linoleic acid.

Suppressive Effect of Alkyl Ferulate on the Oxidation of Linoleic Acid

The oxidation processes of linoleic acid in the presence of ferulic acid, and 1-pentyl, 1-hexyl and 1-heptyl ferulates were observed at various temperatures and different molar ratios of each additive to linoleic acid. The processes were analyzed based on a kinetic equation of the autocatalytic type to evaluate the oxidative rate constant, k, and the kinetic parameter, Y(0), by which the initiation period for the oxidation of linoleic acid was mainly governed. The k values for linoleic acid mixed with each of the alkyl ferulates were smaller than that for linoleic acid mixed with ferulic acid. The greater suppressive effect of the alkyl ferulates would be ascribable to their higher solubility in linoleic acid. Both the activation energy, E, and the frequency factor, k(0), for the oxidation of linoleic acid mixed with ferulic acid or pentyl ferulate decreased with increasing molar ratio of the additive to linoleic acid.

Analytical characterization of a ferulic acid/γ-cyclodextrin inclusion complex

Ferulic acid (FA) is a well-known antioxidant of natural source with promising properties as photoprotective agent (approved in Japan as sunscreen) and its derivatives (alkyl ferulates) are under screening for the prevention of photoinduced skin tumours. In the present work we describe the preparation of a solid inclusion complex between ferulic acid and γ-cyclodextrin (γ-CD) and its characterization by different analytical techniques: differential scanning calorimetry (DSC), X-ray diffractometry (XRD), nuclear magnetic resonance spectroscopy ( 1H NMR) and by supporting information of molecular modelling. All these approaches indicate that ferulic acid is able to form an association complex with γ-CD but only 1H NMR and molecular modelling studies give an unequivocal evidence that the antioxidant molecule is embedded into the γ-CD cavity to form an inclusion complex. In detail it is entrapped inside the hydrophobic core of γ-CD with the lipophilic aromatic ring and the ethylenic moieties, leaving the more polar functional groups close to wider rim or outside the cavity.

Mapping the hydrolytic and synthetic selectivity of a type C feruloyl esterase (StFaeC) from Sporotrichum thermophile using alkyl ferulates

The active site of Sporotrichum thermophile type C feruloyl esterase (StFaeC) was probed using a series of C 1–C 4 alkyl ferulates. The affinities for straight and branched alkyl ferulates were demonstrated by the K m values of 1.64–0.51 and 0.19–0.1, respectively. Comparison of k cat and k cat/ K m values shows that the enzyme hydrolyzed n-propyl ferulate faster and iso-propyl ferulate more efficiently. Alkyl ferulates were applied also for substrate selectivity mapping of feruloyl esterase to catalyze feruloyl group transfer to l-arabinose, using as a reaction system a ternary water–organic mixture consisting of n-hexane, t-butanol and water. Lengthening the aliphatic side chain was the most significant factor causing lower synthetic activity of the enzyme. The reaction parameters affecting the feruloylation rate and the conversion of the enzymatic process, such as the temperature and substrate concentration have been investigated. Under identical reaction conditions, the enzyme feruloylated other monosaccharides such as d-arabinose, d-glucose, d-xylose, d-mannose, d-fructose, d-galactose, d-ribose and model substrates such as 4-nitrophenyl α- l-arabinofuranoside and 4-nitrophenyl α- l-arabinopyranoside.

Bioguided Fractionation and Isolation of Free Radical Scavenging Components from in Vitro Propagated Chinese Medicinal Plants Dendrobium tosaense Makino and Dendrobium moniliforme SW

This study was performed to investigate the free radical scavenging active components from in vitro propagated medicinal herbs of the genus Dendrobium, namely, Dendrobium tosaense Makino and Dendrobium moniliforme SW, using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical antioxidative assay. Seeds of the capsules derived after 12 weeks of hand-pollination germinated asymbiotically (50-74%) on half-strength Murashige and Skoog's (MS) basal medium with 3% sucrose and solidified with 0.9% Difco agar. Active growth in the germinated seedlings was achieved by reculturing on full-strength MS basal medium supplemented with 8% banana homogenate, 8% potato homogenate, 8% coconut water, 1.5% sucrose, and 0.9% Difco agar. Healthy plantlets transferred to plastic trays containing moss or moss and tree fern successfully acclimatized (84-100%) in the greenhouse. Extracts were prepared from plants grown in the greenhouse for a period of 6 months. Methanolic extracts of D. tosaense and D. moniliforme scavenged DPPH at 95.9 and 83.4%, respectively, at a concentration of 0.4 mg/mL. Therefore, methanolic solubles of D. tosaense and D. moniliforme were subjected to bioguided fractionation and separation by column chromatographic methods individually. After chromatographic separation of these crude extracts, the obtained fractions (Dm 1, Dm 2, Dm 3, Dt 1, Dt 2, and Dt 3) were tested for their activity. Among them, fractions Dm 2 and Dt 1 showed significant antioxidant activity by DPPH radical antioxidative assay. Active fractions were purified further by column chromatography and resulted in identification of the antioxidant components alkyl ferulates from D. moniliforme and quercetin from D. tosaense.

Antioxidant activity of ferulic acid alkyl esters in a heterophasic system: a mechanistic insight.

The antioxidant activity of some esters of ferulic acid with the linear fatty alcohols C7, C8 (branched and linear), C9, C11, C12, C13, C15, C16, and C18 has been studied in homogeneous and heterogeneous phases. Whereas in homogeneous phase all of the alkyl ferulates possessed similar radical-scavenging abilities, in rat liver microsomes they showed striking differences, the more effective being C12 (7) (IC50 = 11.03 M), linear C8 (3) (IC50 = 12.40 microM), C13 (8) (IC50 = 18.60 microM), and C9 (5) (IC50 = 19.74 microM), followed by C7 (2), C15 (9), C11 (6), branched C8 (4), C16 (10), and C18 (11) (ferulic acid was the less active, IC50 = 243.84 microM). All of the molecules showed similar partition coefficients in an octanol-buffer system. Three-dimensional studies (NMR in solution, modeling in vacuo) indicate that this behavior might be due to a different anchorage of the molecules with the ester side chain to the microsomal phospholipid bilayer and to a consequent different orientation/positioning of the scavenging phenoxy group outside the membrane surface against the flux of oxy radicals.

Wax and suberin development of native and wound periderm of potato (Solanum tuberosum L.) and its relation to peridermal transpiration.

Native and wound periderm was isolated enzymatically from potato (Solanum tuberosum L. cv. Desirée) tubers at different time intervals between 0 days up to 4 weeks after harvesting. Wound periderm formation was induced by carefully removing native periderm from freshly harvested tubers before storage. The chemical composition of lipids (waxes) obtained by chloroform extraction, as well as the monomeric composition of native and wound suberin polymer after transesterification by boron trifluoride/methanol, was analyzed using gas chromatography and mass spectrometry. Both types of periderm contained up to 20% extractable lipids. Besides linear long-chain aliphatic wax compounds, alkyl ferulates were detected as significant constituents. In wound periderm they amounted to more than 60% of the total extracts. Within 1 month of storage, suberin amounts in the polymer increased 2-fold in native periderm (180 microg cm(-2)), whereas in wound periderm about 75.0 microg cm(-2) suberin polymer was newly synthesized. Native potato tuber periderm developed a very efficient transport barrier for water with permeances decreasing from 6.4 x 10(-10) m s(-1) to 5.5 x 10(-11) m s(-1) within 1 month of storage. However, the water permeability of wound periderm was on average 100 times higher with permeances decreasing from 4.7 x 10(-8) m s(-1) after 3 days to only 5.4 x 10(-9) m s(-1) after 1 month of storage, although suberin and wax amounts in wound periderm amounted to about 60% of native periderm. From this result it must be concluded that the occurrence of suberin with wax depositions in cell walls does not necessarily allow us to conclude that these cell walls must be nearly perfect barriers to water transport. In addition to the occurrence of the lipophilic biopolymer suberin and associated waxes, the still unknown molecular arrangement and precisely localized deposition of suberin within the cell wall must contribute to the efficiency of suberin as a barrier to water transport.

Conformational analysis: a tool for the elucidation of the antioxidant properties of ferulic acid derivatives in membrane models

With the aim to search and design more effective and safe antioxidant molecules to be used as functional ingredients in cosmetic formulations for UV protection, we evaluated the antioxidant/radical scavenging activities of ferulic acid and of some alkyl ferulates in both acellular and cellular systems. Ferulic acid esters, equipotent as antioxidant in homogeneous phase, showed when tested in membranous systems (rat liver microsomes, rat erythrocytes) marked differences in antioxidant potency. The n-C 12 derivative was the most potent, followed by n-C 8, n-C 16 and branched C 8, and then by ferulic acid. A conformational study carried out by NMR and modelling, indicates that the different antioxidant activity of ferulates in membrane models is due to the different spatial conformation and arrangement of the side chain of the molecule, which governs the access and binding to the phospholipid bilayer, the modality of orientation of the scavenging/quenching nucleus (phenol moiety), and hence the overall antioxidant potency of the derivative. These results emphasize the need of analytical studies (NMR and molecular modelling) addressed to the knowledge of the conformational parameters in combination with conventional antioxidant testings for understanding the antioxidant behaviour of a molecule in a biological membrane/system.

Presence of Higher Alcohols as Ferulates in Potato Pulp and Its Radical-Scavenging Activity

Higher alcohols with a carbon length ranging from 16 to 30 found in the lipophilic fraction from potato pulp were shown to be present as ferulate and in a free form, but not as wax. Thin-layer chromatography of the neutral lipids in potato pulp indicated a few spots with scavenging activity toward the 1,1-diphenyl-2-picrylhydrazyl (DPPH) stable radical, the major active component being characterized as alkyl ferulate which showed almost the same level of activity as gamma-oryzanol.

Useful Application of Ferulic Acid Produced from Rice Bran

AbstractFor Abstract see ChemInform Abstract in Full Text.

Constituintes das cascas de Tapirira guianensis (Anacardiaceae)

From the hexane extract of barks of Tapirira guianensis were isolated and identified b-sitosterol, 3b-O-b-D-glucopyranosyl-sitosterol, sitostenone and stigmast-4-en-6b-ol-3-one. Besides these compounds six alkyl ferulates were obtained including a new one with an unusual odd alkyl chain, nonadecyl coumarate. All structures were determined by spectral data.

米糠から生産されるフェルラ酸の有用物質への展開

The authors prepared ferulic acid from rice bran pitch which was discharged in a process of the production of edible oil from rice bran and synthesized ethyl 3- (4-geranyloxy-3-methoxyphenyl) -2-propenoate (EGMP) using ferulic acid. EGMP was found to be a chemopreventive agent toward colon cancer in the rats. The condensation products consisting of ferulic and gallic acids showed strong antioxidative effects. Alkyl ferulates showed antimicrobial activity. Amide derivatives of ferulic acid were recognized as compounds accelerating secretion of insulin. The authors also synthesized nine bisferuloyl-myo-inositols, consisting of ferulic acid and myo-inositol moieties, using four key intermediates. These compounds showed the inhibitory effects on generation of tumor promoter 12-O-tetradecanoylphorbor-13-acetate (TPA) -induced superoxide in differentiated HL-60 cells, the suppressive effects on TPA-induced Esptein-Barr virus activation and the suppressive effects on cyclooxgenase-2 promoter activity. The authors prepared the derivative 42 which has i) a polyoxyethylene chain and methoxy groups on the phenyl rings for metal coordination, ii) aromatic rings for a π-π or CH-π interaction, and iii) carboxylic acids as a hydrogen-bonding moiety.

Antioxidant properties of ferulic acid and its related compounds.

Antioxidant activity of 24 ferulic acid related compounds together with 6 gallic acid related compounds was evaluated using several different physical systems as well as their radical scavenging activity. The radical scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) decreased in the order caffeic acid > sinapic acid > ferulic acid > ferulic acid esters > p-coumaric acid. In bulk methyl linoleate, test hydroxycinnamic acids and ferulic acid esters showed antioxidant activity in parallel with their radical scavenging activity. In an ethanol-buffer solution of linoleic acid, the activity of test compounds was not always associated with their radical scavenging activity. Ferulic acid was most effective among the tested phenolic acids. Esterification of ferulic acid resulted in increasing activity. The activity of alkyl ferulates was somewhat influenced by the chain length of alcohol moiety. When the inhibitory effects of alkyl ferulates against oxidation of liposome induced by AAPH were tested, hexyl, octyl, and 2-ethyl-1-hexyl ferulates were more active than the other alkyl ferulates. Furthermore, lauryl gallate is most effective among the tested alkyl gallates. These results indicated that not only the radical scavenging activity of antioxidants, but also their affinity with lipid substrates, might be important factors in their activity.

Extractive substances of the bark of Picea obovata

The chemical composition of a petroleum ether extract of the bark of the Siberian spruce has been studied. Extracts included saturated aliphatic alcohols and C16-C24 acids — abietic, dehydroabietic, isopimaric, oleic, lineolic, and linolenic — alkyl ferulates, ketones, and alcohols of the serratene type, and also Δ4-stigmasten-3-one. Onoceradienedione and onoceradienediol — precursors of the serratene triterpenoids — and also a saturated vicinal diol — triacontane-10,11-diol — have been isolated from the extractive substances of conifer in the native form for the first time.

Alkyl ferulates in wound healing potato tubers

Seven ferulic acid esters of 1-alkanols ranging in carbon length from C 16 to C 21 were synthesized and an HPLC protocol for their separation developed. Extracts prepared from wound healing potato ( Solanum tuberosum) tubers and analysed by HPLC indicated that alkyl ferulate esters begin to accumulate 3–7 days after wound treatment. Of the nine esters identified by EIMS, (including two esters of odd chain length alkanols) hexadecyl and octadecyl ferulates were predominant. Alkyl ferulate esters were restricted to the wound periderm.

Long-chain alkyl ferulates in three varieties of Ipomoea batatas (L.) Lam

Chemical components from the roots of Ipomoea batatas with white skin and two other varieties with violet color have been examined to obtain a mixture of long-chain alkyl ferulates, assigned by chemical and spectral methods. The alkyl alcohol parts of the esters were shown to consist of hexadecyl, heptadecyl, and octadecyl components on the basis of MS and GC/MS analysis

Alkyl ferulates from the bark and wood of plants of the Pinaceae family

Alkyl ferulates from the bark and wood of plants of the Pinaceae family

Waxes and sterols of erythrina suberosa bark

The petroleum ether extract of the bark of Erythrina suberosa was fractionated into wax esters, wax alcohols and acids, alkyl ferulates, stigmasterol, sitosterol, campesterol and cholesterol.