Ferulic acid: an antioxidant found naturally in plant cell walls and feruloyl esterases involved in its release and their applications

Biotechnological and molecular approaches for vanillin production: a review

Vanillin is one of the most widely used flavoring agents in the world. As the annual world market demand of vanillin could not be met by natural extraction, chemical synthesis, or tissue culture technology, thus biotechnological approaches may be replacement routes to make production of bio-vanillin economically viable. This review's main focus is to highlight significant aspects of biotechnology with emphasis on the production of vanillin from eugenol, isoeugenol, lignin, ferulic acid, sugars, phenolic stilbenes, vanillic acid, aromatic amino acids, and waste residues by applying fungi, bacteria, and plant cells. Production of biovanillin using GRAS lactic acid bacteria and metabolically engineered microorganisms, genetic organization of vanillin biosynthesis operons/gene cassettes and finally the stability of biovanillin generated through various biotechnological procedures are also critically reviewed in the later sections of the review.

UPLC-QTOF-MS with chemical profiling approach for rapidly evaluating chemical consistency between traditional and dispensing granule decoctions of Tao-Hong-Si-Wu decoction

Background

In the present study, chemical consistency between traditional and dispensing granule decoctions of Tao-Hong-Si-Wu decoction was rapidly evaluated by UPLC-QTOF-MS coupled with the MarkerLynx software. Two different kinds of decoctions, namely traditional decoction: water extract of mixed six constituent herbs of Tao-Hong-Si-Wu decoction, and dispensing granules decoction: mixed water extract of each individual herbs of Tao-Hong-Si-Wu decoction, were prepared.

Results

Chemical difference was found between traditional and dispensing granule decoctions, and albiflorin, paeoniflorin, gallic acid, amygdalin, and hydroxysafflor yellow A were identified as the significantly changed components during decocting Tao-Hong-Si-Wu decoction. All the peaks of mass spectrum from Tao-Hong-Si-Wu decoction and each herb were extracted and integration by using QuanLynx™. And the optimized data was used for linear regression analysis. The contribution of each herb in Tao-Hong-Si-Wu decoction, and the optimal compatibility proportion of dispensing granule decoction were derived from the linear regression equation.

Conclusions

The optimal dosage proportionality of Tao-Hong-Si-Wu dispensing granule decoction was obtained as 2.5:0.2:1:0.5:0.6:0.1 (DG : CX : BS : SD : TR : HH), which guided better clinic application of Tao-Hong-Si-Wu decoction as dispensing granule decoctions usage, and it also provided some experimental data to reveal the compatibility rule of the relative TCM formulae.

Consecutive fragmentation mechanisms of protonated ferulic acid probed by infrared multiple photon dissociation spectroscopy and electronic structure calculations

Protonated ferulic acid and its principle fragment ion have been characterized using infrared multiple photon dissociation spectroscopy and electronic structure calculations at the B3LYP/6-311 + G(d,p) level of theory. Due to its extensively conjugated structure, protonated ferulic acid is observed to yield three stable fragment ions in IRMPD experiments. It is proposed that two parallel fragmentation pathways of protonated ferulic acid are being observed. The first pathway involves proton transfer, resulting in the loss of water and subsequently carbon monoxide, producing fragment ions m/z 177 and 149, respectively. Optimization of m/z 177 yields a species containing an acylium group, which is supported by a diagnostic peak in the IRMPD spectrum at 2168 cm(-1). The second pathway involves an alternate proton transfer leading to loss of methanol and rearrangement to a five-membered ring.

Hydrogen peroxide induced phenylpropanoids pathway eliciting a defensive response in plants micropropagated in Temporary Immersion Bioreactors (TIBs)

The relation between the oxidative burst and phenylpropanoid pathways has been studied using the sugarcane cultivar C86-56, which does not release phenolics in agar-base micropropagation systems. In stationary liquid culture, a significant production of phenolic compounds and plant survival were determined in sugarcane plants treated with 5mM H(2)O(2). The spectrophotometer determinations and the gene expression analysis corroborated that releasing of phenolics and soluble θ-quinones was induced during the first 24h of treatment. In comparison with the control treatments, sugarcane plants treated with H(2)O(2) demonstrated differences in the micropropagation-related variables when multiplied in Temporary Immersion Bioreactors (TIBs) supplemented with polyethyleneglycol (PEG 20%). Expression of selected genes related to photosynthesis, ethylene, auxins, oxidative burst, and defense pathways were confirmed during the entire PEG 20% stress in the plants coming from the 5mM H(2)O(2) treatment; whereas, much more heterogeneous expression patterns were evidenced in plants stressed with PEG but not previously treated with H(2)O(2). RT-PCR expression analysis supports the hypothesis that while H(2)O(2) induces the oxidative burst, the phenylpropanoids pathways elicit and maintain the defensive response mechanism in micropropagated sugarcane plants.

Advances in the chemical analysis and biological activities of chuanxiong

Chuanxiong Rhizoma (Chuan-Xiong, CX), the dried rhizome of Ligusticum chuanxiong Hort. (Umbelliferae), is one of the most popular plant medicines in the World. Modern research indicates that organic acids, phthalides, alkaloids, polysaccharides, ceramides and cerebrosides are main components responsible for the bioactivities and properties of CX. Because of its complex constituents, multidisciplinary techniques are needed to validate the analytical methods that support CX's use worldwide. In the past two decades, rapid development of technology has advanced many aspects of CX research. The aim of this review is to illustrate the recent advances in the chemical analysis and biological activities of CX, and to highlight new applications and challenges. Emphasis is placed on recent trends and emerging techniques.

Crystallization and preliminary X-ray analysis of a novel halotolerant feruloyl esterase identified from a soil metagenomic library

Feruloyl esterase cleaves the ester linkage formed between ferulic acid and polysaccharides in plant cell walls and thus has wide potential industrial applications. A novel feruloyl esterase (EstF27) identified from a soil metagenomic library was crystallized and a complete data set was collected from a single cooled crystal using an in-house X-ray source. The crystal diffracted to 2.9 Å resolution and belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 94.35, b = 106.19, c = 188.51 Å, α = β = γ = 90.00°. A Matthews coefficient of 2.55 Å(3) Da(-1), with a corresponding solvent content of 51.84%, suggested the presence of ten protein subunits in the asymmetric unit.

Attenuation of age-related changes in FOXO3a activity and the PI3K/Akt pathway by short-term feeding of ferulate

Ferulate (4-hydroxy-3-methoxycinnamic acid) is a well-known phenolic compound that scavenges free radicals and exerts anti-inflammatory effects. Forkhead box O3a (FOXO3a), a transcription factor that plays important roles in aging processes, decreases with age and is negatively regulated through phosphorylation by phosphatidylinositol 3-kinase (PI3K)/Akt signaling. The present study investigated the efficacy of short-term ferulate feeding on age-related changes in PI3K/Akt/FOXO3a and upstream insulin signaling pathways in aged rats. In addition, changes in manganese superoxide dismutase (MnSOD) and catalase expression were examined because of their dependence on PI3K/Akt/FOXO3a activity. Short-term feeding experiments were done with a diet containing ferulate that was given to aged rats at doses of 3 or 6 mg kg(-1) day(-1) for 10 days. Results showed that FOXO3a activity was increased in the ferulate-fed old group compared with the control old group. Also, ferulate suppressed the PI3K/Akt signaling pathway that is responsible for FOXO3a inhibition in aged rats. Plasma insulin levels and the upstream insulin signaling pathway were also modulated by ferulate correspondingly with PI3K/Akt/FOXO3a activity. The age-related decrease in two major antioxidant enzymes, MnSOD and catalase, was blunted by ferulate, which was accompanied by FOXO3a transcriptional activity. The significance of the present study is the finding that short-term feeding of ferulate effectively modulates age-related renal FOXO3a, PI3K/Akt and insulin signaling pathways, and MnSOD and catalase expression, all of which may be beneficial for attenuating the aging process.

Pharmacokinetic comparison of ferulic acid in normal and blood deficiency rats after oral administration of Angelica sinensis, Ligusticum chuanxiong and their combination

Radix Angelica Sinensis (RAS) and Rhizome Ligusticum (RLC) combination is a popular herb pair commonly used in clinics for treatment of blood deficiency syndrome in China. The aim of this study is to compare the pharmacokinetic properties of ferulic acid (FA), a main bioactive constituent in both RAS and RLC, between normal and blood deficiency syndrome animals, and to investigate the influence of compatibility of RAS and RLC on the pharmacokinetic of FA. The blood deficiency rats were induced by injecting 2% Acetyl phenylhydrazine (APH) on the first day, every other day, to a total of five times, at the dosage of 100, 50, 50, 30, 30 mg/kg body mass, respectively. Quantification of FA in rat plasma was achieved by using a simple and rapid HPLC method. Plasma samples were collected at different time points to construct pharmacokinetic profiles by plotting drug concentration versus time, and estimate pharmacokinetic parameters. Between normal and blood deficiency model groups, both AUC((0-) (t) ()) and C(max) of FA in blood deficiency rats after RAS-RLC extract administration increased significantly (P < 0.05), while clearance (CL) decreased significantly. Among three blood deficiency model groups, t(1/2α), V(d), AUC((0-) (t) ()) and AUC((0-∞)) all increased significantly in the RAS-RLC extract group compared with the RAS group. The results indicated that FA was absorbed better and eliminated slower in blood deficiency rats; RLC could significantly prolong the half-life of distribution, increase the volume of distribution and the absorption amount of FA of RAS in blood deficiency rats, which may be due to the synergic action when RAS and RLC were used together to treat blood deficiency syndrome.

Plant cell walls to ethanol

Conversion of plant cell walls to ethanol constitutes second generation bioethanol production. The process consists of several steps: biomass selection/genetic modification, physiochemical pretreatment, enzymatic saccharification, fermentation and separation. Ultimately, it is desirable to combine as many of the biochemical steps as possible in a single organism to achieve CBP (consolidated bioprocessing). A commercially ready CBP organism is currently unreported. Production of second generation bioethanol is hindered by economics, particularly in the cost of pretreatment (including waste management and solvent recovery), the cost of saccharification enzymes (particularly exocellulases and endocellulases displaying kcat ~1 s−1 on crystalline cellulose), and the inefficiency of co-fermentation of 5- and 6-carbon monosaccharides (owing in part to redox cofactor imbalances in Saccharomyces cerevisiae).

Modifications of glycans: biological significance and therapeutic opportunities

Carbohydrates play a central role in a wide range of biological processes. As with nucleic acids and proteins, modifications of specific sites within the glycan chain can modulate a carbohydrate's overall biological function. For example, acylation, methylation, sulfation, epimerization, and phosphorylation can occur at various positions within a carbohydrate to modulate bioactivity. Therefore, there is significant interest in identifying discrete carbohydrate modifications and understanding their biological effects. Additionally, enzymes that catalyze those modifications and proteins that bind modified glycans provide numerous targets for therapeutic intervention. This review will focus on modifications of glycans that occur after the oligomer/polymer has been assembled, generally referred to as post-glycosylational modifications.

Fungal protein production: design and production of chimeric proteins

For more than a century, filamentous fungi have been used for the production of a wide variety of endogenous enzymes of industrial interest. More recently, with the use of genetic engineering tools developed for these organisms, this use has expanded for the production of nonnative heterologous proteins. In this review, an overview is given of examples describing the production of a special class of these proteins, namely chimeric proteins. The production of two types of chimeric proteins have been explored: (a) proteins grafted for a specific substrate-binding domain and (b) fusion proteins containing two separate enzymatic activities. Various application areas for the use of these chimeric proteins are described.

An endogenous factor enhances ferulic acid decarboxylation catalyzed by phenolic acid decarboxylase from Candida guilliermondii

The gene for a eukaryotic phenolic acid decarboxylase of Candida guilliermondii was cloned, sequenced, and expressed in Escherichia coli for the first time. The structural gene contained an open reading frame of 504 bp, corresponding to 168 amino acids with a calculated molecular mass of 19,828 Da. The deduced amino sequence exhibited low similarity to those of functional phenolic acid decarboxylases previously reported from bacteria with 25-39% identity and to those of PAD1 and FDC1 proteins from Saccharomyces cerevisiae with less than 14% identity. The C. guilliermondii phenolic acid decarboxylase converted the main substrates ferulic acid and p-coumaric acid to the respective corresponding products. Surprisingly, the ultrafiltrate (Mr 10,000-cut-off) of the cell-free extract of C. guilliermondii remarkably activated the ferulic acid decarboxylation by the purified enzyme, whereas it was almost without effect on the p-coumaric acid decarboxylation. Gel-filtration chromatography of the ultrafiltrate suggested that an endogenous amino thiol-like compound with a molecular weight greater than Mr 1,400 was responsible for the activation.

Transcriptional analysis of Lactobacillus brevis to N-butanol and ferulic acid stress responses

Background

The presence of anti-microbial phenolic compounds, such as the model compound ferulic acid, in biomass hydrolysates pose significant challenges to the widespread use of biomass in conjunction with whole cell biocatalysis or fermentation. Currently, these inhibitory compounds must be removed through additional downstream processing or sufficiently diluted to create environments suitable for most industrially important microbial strains. Simultaneously, product toxicity must also be overcome to allow for efficient production of next generation biofuels such as n-butanol, isopropanol, and others from these low cost feedstocks.

Methodology and Principal Findings

This study explores the high ferulic acid and n-butanol tolerance in Lactobacillus brevis, a lactic acid bacterium often found in fermentation processes, by global transcriptional response analysis. The transcriptional profile of L. brevis reveals that the presence of ferulic acid triggers the expression of currently uncharacterized membrane proteins, possibly in an effort to counteract ferulic acid induced changes in membrane fluidity and ion leakage. In contrast to the ferulic acid stress response, n-butanol challenges to growing cultures primarily induce genes within the fatty acid synthesis pathway and reduced the proportion of 19∶1 cyclopropane fatty acid within the L. brevis membrane. Both inhibitors also triggered generalized stress responses. Separate attempts to alter flux through the Escherichia coli fatty acid synthesis by overexpressing acetyl-CoA carboxylase subunits and deleting cyclopropane fatty acid synthase (cfa) both failed to improve n-butanol tolerance in E. coli, indicating that additional components of the stress response are required to confer n-butanol resistance.

Conclusions

Several promising routes for understanding both ferulic acid and n-butanol tolerance have been identified from L. brevis gene expression data. These insights may be used to guide further engineering of model industrial organisms to better tolerate both classes of inhibitors to enable facile production of biofuels from lignocellulosic biomass.

Purification and properties of phenolic acid decarboxylase from Candida guilliermondii

A heat-labile phenolic acid decarboxylase from Candida guilliermondii (an anamorph of Pichia guilliermondii) was purified to homogeneity by simple successive column chromatography within 3 days. The molecular mass was 20 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 36 kDa by gel-filtration chromatography, suggesting that the purified enzyme is a homodimer. The optimal pH and temperature were approximately 6.0 and 25°C. Characteristically, more than 50% of the optimal activity was observed at 0°C, suggesting that this enzyme is cold-adapted. The enzyme converted p-coumaric acid, ferulic acid, and caffeic acid to corresponding products with high specific activities of approximately 600, 530, and 46 U/mg, respectively. The activity was stimulated by Mg(2+) ions, whereas it was completely inhibited by Fe(2+), Ni(2+), Cu(2+), Hg(2+), 4-chloromericuribenzoate, N-bromosuccinimide, and diethyl pyrocarbonate. The enzyme was inducible and expressed inside the cells moderately by ferulic acid and p-coumaric acid and significantly by non-metabolizable 6-hydroxy-2-naphthoic acid.

Aiming for the complete utilization of sugar-beet pulp: Examination of the effects of mild acid and hydrothermal pretreatment followed by enzymatic digestion

BACKGROUND

Biomass use for the production of bioethanol or platform chemicals requires efficient breakdown of biomass to fermentable monosaccharides. Lignocellulosic feedstocks often require physicochemical pretreatment before enzymatic hydrolysis can begin. The optimal pretreatment can be different for different feedstocks, and should not lead to biomass destruction or formation of toxic products.

METHODS

We examined the influence of six mild sulfuric acid or water pretreatments at different temperatures on the enzymatic degradability of sugar-beet pulp (SBP).

RESULTS

We found that optimal pretreatment at 140°C of 15 minutes in water was able to solubilize 60% w/w of the total carbohydrates present, mainly pectins. More severe treatments led to the destruction of the solubilized sugars, and the subsequent production of the sugar-degradation products furfural, hydroxymethylfurfural, acetic acid and formic acid. The pretreated samples were successfully degraded enzymatically with an experimental cellulase preparation.

CONCLUSIONS

In this study, we found that pretreatment of SBP greatly facilitated the subsequent enzymatic degradation within economically feasible time ranges and enzyme levels. In addition, pretreatment of SBP can be useful to fractionate functional ingredients such as arabinans and pectins from cellulose. We found that the optimal combined severity factor to enhance the enzymatic degradation of SBP was between log R'0 = -2.0 and log R'0 = -1.5. The optimal pretreatment and enzyme treatment solubilized up to 80% of all sugars present in the SBP, including ≥90% of the cellulose.

Cloning, sequencing, and overexpression in Escherichia coli of the Enterobacter sp. Px6-4 gene for ferulic acid decarboxylase

Ferulic acid decarboxylase (FADase) can catalyze the transformation of ferulic acid into 4-vinyl guaiacol via decarboxylation in microorganisms. In this study, a gene encoding FADase was first isolated from the bacterium Enterobacter sp. Px6-4 using degenerate primers and a genome walking technique. The putative encoding gene (fad) of FADase consists of 507-bp nucleotides, coding a polypeptide of 168 amino acid residues. In addition, a putative gene encoding the transcriptional regulator was identified from the upstream of the fad gene. The deduced peptide sequence of the FADase from Enterobacter sp. Px6-4 showed a 51.2-53.3% sequence identity to decarboxylases from other bacteria. The gene fad was successfully expressed in Escherichia coli BL21, and the recombinant FADase was purified as a protein of ca. 23 kDa with an optimal activity at pH 4.0 and 28 °C. The purified FADase could convert ferulic acid to 4-vinyl guaiacol effectively, and its hydrolytic activity could be inhibited by Cu(2+) (99%) and Hg(2+) (99.5%). A phylogenetic analysis of the FADase protein from bacteria revealed several different clades. Our result provided a basis for further studies of the ferulic acid transformation pathway and for enhanced production of vanillin in the future.

(E)-1-(3,4-dihydroxyphenethyl)-3-styrylurea inhibits proliferation of MCF-7 cells through G1 cell cycle arrest and mitochondria-mediated apoptosis

Growing interest in the beneficial effects of antioxidants has inspired the synthesis of new phenolic acid phenethyl ureas (PAPUs) with enhanced antioxidant potential. We have previously shown the capacity of one PAPU compound, (E)-1-(3,4-dihydroxyphenethyl)-3-styrylurea (PAPU1), to induce caspase-dependent apoptosis in melanoma cells. In the present study, we examined the anti-proliferative effects of PAPU compounds on MCF-7 human breast cancer cells and determined the molecular mechanisms involved. Treatment with PAPU compounds inhibited predominantly proliferation in these cells, where the PAPU1 was the most efficient form. Flow cytometric analysis showed that PAPU1 blocked cell cycle progression in the G(0)/G(1) phase, and reduced the proportion of cells in G(2)/M phase. This was related to the inhibition of cell cycle regulatory factors, including cyclin D/E and cyclin-dependent kinase (CDK) 2/4, through induction of p21(Cip1). PAPU1 also induced the mitochondrial-mediated and caspase-dependent apoptosis in MCF-7 cells. This was evidenced by cellular changes in the levels of Bcl-2 and Bax, loss of the mitochondrial membrane potential, release of cytochrome c into the cytosol, and caspase-9 activation. Collectively, our results suggest that G(1) cell cycle regulatory proteins and mitochondrial pathways are the crucial targets of PAPU1 in the chemoprevention of breast cancer cells.

A novel Aspergillus oryzae esterase that hydrolyzes 4-hydroxybenzoic acid esters

In this study we report the biochemical characterization of a hypothetical protein from Aspergillus oryzae exhibiting sequence identity with feruloyl esterase and tannase from the genus Aspergillus. The purified recombinant protein showed a hydrolytic activity toward the ethyl, propyl, or butyl esters of 4-hydroxybenzoic acid, but did not show feruloyl esterase or tannase activity. Finally, the enzyme decreased the antimicrobial activity of parabens against A. oryzae via hydrolysis of the ester bond present in butyl 4-hydroxybenzoic acid.

The decarboxylation of the weak-acid preservative, sorbic acid, is encoded by linked genes in Aspergillus spp

The ability to resist anti-microbial compounds is of key evolutionary benefit to microorganisms. Aspergillus niger has previously been shown to require the activity of a phenylacrylic acid decarboxylase (encoded by padA1) for the decarboxylation of the weak-acid preservative sorbic acid (2,4-hexadienoic acid) to 1,3-pentadiene. It is now shown that this decarboxylation process also requires the activity of a putative 4-hydroxybenzoic acid (3-octaprenyl-4-hydroxybenzoic acid) decarboxylase, encoded by a gene termed ohbA1, and a putative transcription factor, sorbic acid decarboxylase regulator, encoded by sdrA. The padA1,ohbA1 and sdrA genes are in close proximity to each other on chromosome 6 in the A. niger genome and further bioinformatic analysis revealed conserved synteny at this locus in several Aspergillus species and other ascomycete fungi indicating clustering of metabolic function. This cluster is absent from the genomes of A. fumigatus and A. clavatus and, as a consequence, neither species is capable of decarboxylating sorbic acid.

Free water-soluble phenolics profiling in barley ( Hordeum vulgare L.)

The phenolic profile of barley ( Hordeum vulgare L.) leaves, seeds, awns, and stems, collected in two different locations from Portugal, was determined by a high-performance liquid chromatography/diode array detector (HPLC/DAD). A total of 28 compounds were identified and quantified, which included 4 phenolic acids, 6 C-glycosylflavones, and 18 O-glycosyl-C-glycosyl flavones, with some of them acylated. Distinct profiles were noticed among the analyzed materials. The greatest diversity of compounds was found in barley leaves (26 flavonoids and 2 phenolic acid derivatives), which also exhibited the highest concentration of phenolics. Isoorientin-7-O-glucoside (lutonarin) was the major compound in leaves, while, in general, the pair isovitexin-7-O-rutinoside plus isoscoparin-7-O-glucoside were the main phenolics in the other materials. Thus, barley leaves may constitute an important dietary source of protective compounds, which could be used, for example, to take profit from the wastes resulting from alcoholic drink obtainment.

Characterization of two distinct feruloyl esterases, AoFaeB and AoFaeC, from Aspergillus oryzae

Two hypothetical proteins XP_001818628 and XP_001819091 (designated AoFaeB and AoFaeC, respectively), showing sequence identity with known type-C feruloyl esterases, have been found in the genomic sequence of Aspergillus oryzae. We cloned the putative A. oryzae feruloyl esterase-encoding genes and expressed them in Pichia pastoris. Both purified recombinant AoFaeB (rAoFaeB) and AoFaeC (rAoFaeC) had apparent relative molecular masses of 61,000 and 75,000, respectively, on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. After N-deglycosylation, both proteins had a relative molecular mass of 55,000. The optimum pH for rAoFaeB was 6.0, although it was stable at pH values ranging from 3.0 to 9.0; rAoFaeC had an optimum pH of 6.0 and was stable in the pH range of 7.0-10.0. Thermostability of rAoFaeC was greater than that of rAoFaeB. Whereas rAoFaeC displayed hydrolytic activity toward methyl caffeate, methyl p-coumarate, methyl ferulate, and methyl sinapate, rAoFaeB displayed hydrolytic activity toward methyl caffeate, methyl p-coumarate, and methyl ferulate but not toward methyl sinapate. Substrate specificity profiling of rAoFaeB and rAoFaeC revealed type-B and type-C feruloyl esterases, respectively. Ferulic acid was efficiently released from wheat arabinoxylan when both esterases were applied with xylanase from Thermomyces lanuginosus. Both recombinant proteins also exhibited hydrolytic activity toward chlorogenic acid.

Air pressure pulsation solid state fermentation of feruloyl esterase by Aspergillus niger

Air pressure pulsation solid state fermentation (APP-SSF) was applied to produce feruloyl esterase (FAE) by Aspergillus niger. With the optimization of some variables by orthogonal design, the optimal condition obtained was 0.2 MPa (gauge pressure) of high pressure intensity, 30 min of low pressure duration and 20s of high pressure duration. Based on the optimized condition, the APP-SSF achieved the reasonable enzyme yield of 881 mU/g at 48 h, which was 58% more than that by static solid state fermentation (static SSF) at 72 h. By comparison of two fermentation methods in temperature, O(2) and CO(2) concentration, and respiration intensity, it was concluded that APP-SSF enhanced heat and mass transfer of fermentation system and strengthened the metabolism of microorganisms. The APP-SSF had a greatly positive effect on FAE production by A. niger, by enhancing mass and heat transfer and activating growth and metabolism.

Chemiluminescence determination of ferulic acid by flow-injection analysis using cerium(IV) sensitized by rhodamine 6G

A simple, sensitive and rapid flow-injection chemiluminescence method has been developed for the determination of ferulic acid based on the chemiluminescence reaction of ferulic acid with rhodamine 6G and ceric sulfate in sulphuric acid medium. Strong chemiluminescence signal was observed when ferulic acid was injected into the acidic ceric sulfate solution in a flow-cell. The present method allowed the determination of ferulic acid in the concentration range of 8.0 x 10(-6) to 1.0 x 10(-4) mol l(-1) and the detection limit for ferulic acid was 8.7 x 10(-9) mol l(-1). The relative standard deviation was 2.4% for 10 replicate analyses of 1.0 x 10(-5) mol l(-1) ferulic acid. The proposed method was applied to the determination of ferulic acid in Taita Beauty Essence samples with satisfactory results.

Antioxidant potential of hydroxycinnamic acid glycoside esters

Hydroxycinnamic acids are natural antioxidants found in fruits, vegetables, and cereals. In this study, the antioxidant activity of various types of hydroxycinnamoyl glycoside esters that mimic the structure of polymeric carbohydrates was studied in different model systems prone to oxidation, namely, liposomes and emulsions. In addition, radical scavenging activity against the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was tested. It was found that the esterification in the primary hydroxyl group of the glycoside resulted in the improved radical scavenging activity of both sinapoyl and feruloyl glycosides compared to conjugation to the secondary hydroxyl group. Increased activity was also observed, particularly in the case of feruloyl glucosides in inhibiting the oxidation of liposomes emulsions. The results showed that sinapic and ferulic acid glycoside esters were as effective or more efficient antioxidants than their free forms. In conclusion, the strength of their antioxidant effect depends on the nature of conjugation.

Novel effects of a single administration of ferulic acid on the regulation of blood pressure and the hepatic lipid metabolic profile in stroke-prone spontaneously hypertensive rats

We studied the effects of a single oral administration of ferulic acid (FA) on the blood pressure (BP) and lipid profile in stroke-prone spontaneously hypertensive rats (SHRSP). Male 12-week-old SHRSP were administered FA (9.5 mg/kg of body weight) and distilled water as the control (C) (1 mL) via a gastric tube. The hypotensive effect of FA was observed at the lowest value after 2 h administration. A decrease in the angiotensin-1-converting enzyme (ACE) activity in the plasma corresponded well with the reduction of BP. Plasma total cholesterol and triglyceride levels were lower after 2 h administration. The mRNA expression of genes involved in lipid and drug metabolism was downregulated in the FA group. These results suggest that oral administration of FA appears beneficial in improving hypertension and hyperlipidemia.