Inhibitory Effect Of Phenolic Compounds Research Articles

Effects of structural characteristics of phenolic compounds on oxidation of glycerol trioleate: Action rule and mechanism

Effects of structural characteristics of phenolic compounds on the oxidation of glycerol trioleate were investigated, and the action rule and mechanism were further explored. By using thermal and multispectral analyses, all tested phenolic compounds significantly inhibited the oxidation of glycerol trioleate, and reduced the decomposition of CC and ester bonds of glycerol trioleate, which were attributed to their capability to inhibit the production of free radicals. Quercetin and gallic acid were the most effective among the condensed and hydrolyzable phenolic compounds in present study, respectively. For condensed phenolic compounds, the hydroxyl groups in B ring, substitution in C ring, and the structure of C ring played a crucial role in their inhibitory action. For hydrolyzable phenolic compounds, the amount of hydroxyl groups and their molecular weight had obvious effects on their inhibitory action. According to the measurement of molecular electrostatic potential and frontier molecular orbitals by density functional theory, the large maximum electrostatic potential and the small energy gap value were beneficial to enhance the inhibitory capability of phenolic compounds on the oxidation of glycerol trioleate. All present results suggested the potential action rule and molecular mechanism about the inhibitory effects of phenolic compounds on the oxidation of glycerol trioleate.

Specific degradation of phenolic compounds from palm oil mill effluent using ozonation and its impact on methane fermentation

In this study, the inhibition to anaerobic digestion of phenolic compounds present in palm oil mill effluent (POME) was quantified in batch and continuous operations to assess their effects on methane fermentation. Caffeic acid (CAF), at its concentration in POME, was found to be the most effective inhibitor of the microbial community in hydrolysis, acidogenesis, and methanogenesis phases. To mitigate the toxicity of anaerobic digestion (AD), the pretreatment of POME with various ozone dosages (0.1 to 0.4 gO3/Lwastewater) was performed to determine the effectiveness of specific phenolic compounds destruction. The ozone pretreatment was able to significantly degrade these phenolic molecules and alter their profile in POME over the wide ranges of ozone dosage. Ozone dosage of 0.2 gO3/Lwastewater was optimal to cause the individual concentration to drop below the strong inhibitory levels. When POME was ozonized, the overall total phenolic compounds in the effluent were reduced by 75 % from 613 to 155 mg/L. The overall volumetric biogas yields correspondingly increased by 67 % from 0.3 to 0.5 L/Lreactor.d with the improved specific methane yield from 6.3 ± 0.2 to 9.3 ± 0.1 LCH4/m3. The results demonstrated that the inhibitory effects of phenolic compounds could significantly be detoxified by pretreatment with ozone to enhance anaerobic digestion performance.

Study of the antibacterial capacity of extracts of Solanum incanum L., (Solanaceae) traditionally used for the management of avian cholera in rural areas of Burkina Faso

Nowadays, thanks to the rise of microbial resistance, the lack of health care personnel and especially the high cost of synthetic molecules, phytotherapy could be a panacea in many developing countries. For this reason, the present work which aims to evaluate the phenolic compounds and to study the antibacterial capacity of extracts of roots, stems, leaves and fruits of Solanum incanum L., (Solanaceae) traditionally used for the treatment of pasteurellosis or avian cholera in Burkina Faso, was undertaken. For this purpose, we collected plant material in the commune of Dedougou. After extraction with acetone and water, colorimetric tests were carried out on the different extracts and revealed mostly the presence of tannins and coumarins. The Hydroacetone macerated extract was found to be very interesting for biological activities compared to the macerated extracts and the aqueous decoctions. Inhibition of bacterial growth on different bacterial strains was also shown for all the extracts, especially with Hydroacetone extract. These results could be mainly explained by the inhibitory effect of phenolic compounds. The Hydroacetone extract was also found to be especially very relevant for the prevention and treatment of microbial diseases from poultry.

Inhibitory effect of phenolic compounds and plant extracts on the formation of advance glycation end products: A comprehensive review.

Advance glycation end products (AGEs) are a diverse group of compounds formed through the non-enzymatic maillard reaction of reducing sugars with the free amino groups in proteins, lipids or nucleic acids. Accumulation of AGEs has been suggested to be a pathogenic mechanism of oxidative stress, inflammation and structural tissue damage leading to chronic vascular problems in many ailments including diabetes, atherosclerosis, neuropathy, retinopathy, nephropathy, aging, and chronic renal disease. Treatment with AGEs inhibitors is believed to be a potential strategy for preventing lifestyle-related diseases. To inhibit the AGEs development is supposed to show part in the inhibition of diabetic problems. Study of dietary bioactive combinations with antiglycation properties delivers future views for inhibition or mediation associated to AGEs complications. Many study show the possibility of dietary constituents to stop AGE development. Therefore, search for natural compounds able to prevent glycation and have the potential therapeutic ability to inhibit diabetes and age associated diseases. The purpose of this review is to critically evaluate the existing literature on different phenolics on AGEs inhibition.

Phenolic Compounds in Fruit Beverages

In this current special issue, different aspects related to phenolic compounds in fruit beveragesare presented.[...]

Mathematical model to appraise the inhibitory effect of phenolic compounds derived from lignin for biobutanol production

This study aimed to establish a mathematical modeling to evaluate the inhibitory effect of phenolic derivatives on acetone-butanol-ethanol (ABE) fermentation by Clostridium saccharoperbutylacetonicum N1-4. Vanillin, 4-hydroxybenzoic acid, and syringaldehyde were selected to represent guaiacyl, hydroxyphenyl, and syringyl phenols, respectively, to be examined in a series of fed-batch experiments. Results show the presence of phenolic derivatives blocked the pathway of the assimilation of organic acids and reduced cell growth and glucose utilization. The inhibition model projected that the levels of 0.13, 0.14, and 0.04 g L−1 for vanillin, 4-hydroxybenzoic acid, and syringaldehyde, respectively, resulted in 25% inhibition of butanol production, whereas 100% inhibition was predicted at the levels of 4.94, 4.37, and 4.20 g L−1 for vanillin, 4-hydroxybenzoic acid, and syringaldehyde, respectively. Syringaldehyde was more toxic than the other two compounds. The established model described that the phenolic compounds derived from different phenyl propane monomers of lignin severely obstructed biobutanol production.

Synergistic positive effect of organic acids on the inhibitory effect of phenolic compounds on Acetone-Butanol-Ethanol (ABE) production

The synergistic effect of potential inhibitory compounds (organic acids and phenolic compounds) on ABE fermentation was studied with model media containing sucrose and real media prepared from beet and cane sugar refining molasses.The presence of phenolic compounds inhibited ABE fermentation at concentrations as low as 0.5g/L for gallic acid and 0.1g/L for catechin. The co-presence of organic acids (2.2g/L acetic, 1.8g/L lactic and 0.6g/L formic) showed a synergistic positive effect that can counteract the inhibitory character of phenolics. This effect was significantly higher at low phenolic concentrations. This means that the inhibitory effect of phenolic compounds on ABE production with Clostridium beijerinckii could be overcome by the presence of organic acids at low concentration in fermentation media.The results were confirmed by using a substrate of molasses. Better fermentation was achieved with beet molasses due to the lower concentration of phenolics, especially catechin. The fermentation using beet and cane sugar refining molasses as substrate (60g/L) provided an ABE yield of 0.40g ABE/g sugars and 0.31g ABE/g sugars, respectively and ABE concentrations of 12.3g/L (205g ABE/kg beet molasses) and 7g ABE/L (120g ABE/kg cane molasses).

Inhibitory effects of phenolic compounds of rice straw formed by saccharification during ethanol fermentation by Pichia stipitis

In this study, it was found that the type of phenolic acids derived from rice straw was the major factor affecting ethanol fermentation by Pichia stipitis. The aim of this study was to investigate the inhibitory effect of phenolic acids on ethanol fermentation with rice straw. Different cellulases produced different ratios of free phenolic acids to soluble conjugated phenolic acids, resulting in different fermentation efficiencies. Free phenolic acids exhibited much higher inhibitory effect than conjugated phenolic acids. The flow cytometry results indicated that the damage to cell membranes was the primary mechanism of inhibition of ethanol fermentation by phenolic acids. The removal of free phenolic acids from the hydrolysates increased ethanol productivity by 2.0-fold, indicating that the free phenolic acids would be the major inhibitors formed during saccharification. The integrated process for ethanol and phenolic acids may constitute a new strategy for the production of low-cost ethanol.

Natural product inhibitors of carbonic anhydrase I and II isoenzymes: osajin and pomiferin

The aim of this study is to purify carbonic anhydrase I and II isoenzymes from human erythrocyte, isolate two natural products osajin (OSJ) and pomiferin (PMF) from Maclura pomifera fruits, and evaluate the in vitro effect of these natural metabolites on these isoenzymes. These natural products may be used as starting points for drug discovery (like drugs used in several therapeutic applications, including antiglaucoma activity). For the purification procedure, the Sepharose-4B-l-tyrosine-sulphonamide affinity chromatography was used. Column chromatography and thin layer chromatography methods were used for isolation of OSJ and PMF from M. pomifera fruits and their chemical structures were elucidated by IR, 1D, and 2D NMR methods. We compared inhibitory effects of these natural products with inhibitory effects of phenolic compounds and found that these products demonstrated average inhibition effects. We thought that this study will give inspiration to scientists interested in this issue.

Removal of phenolic compounds from palm oil mill effluent by thermophilic Bacillus thermoleovorans strain A2 and their effect on anaerobic digestion

Anaerobic digestion is commonly used for the treatment of palm oil mill effluent (POME) due to its efficiency in removing high organic content with the production of renewable energy in the form of methane. The presence of phenolic compounds in the POME has inhibitory effects on anaerobic bacterial growth. The major POME phenolic compounds were identified as gallic acid, protocatechuic acid, p-hydroxybenzoic acid, caffeic acid, syringic acid, vanillic acid, p-coumaric acid, ferulic acid and phenol. In this study, to reduce their toxicity, pretreatment of POME with the thermophilic phenol-degrading bacteria, Bacillus thermoleovorans strain A2, was performed. The A2 strain was able to aerobically degrade the phenolic compounds over a wide range of temperatures and pH values but the optimum conditions were found at 60 °C and pH 7. The maximum efficiency of the removal of phenolic compounds was 61.1% with a degradation rate of 4.03 mg L−1 h−1. This aerobic pretreatment was able to partially degrade all the individual phenolic compounds but to different extents. Some of the remaining phenolic compounds were further reduced by the anaerobic process. The anaerobic digestion of the aerobically pretreated POME was able to produce a methane yield 1.7–10.8 times higher than that of untreated POME. The results show that the inhibitory effects of phenolic compounds can be detoxified by pretreatment with thermophilic bacteria.

Structure dependent toxicity of lignin phenolics and PEG detoxification in VHG ethanol fermentation

The inhibitory effects of phenolic compounds on ethanol fermentation were alleviated by intermolecular hydrogen bond of phenolic compounds with PEGs.

Harmaline and hispidin from Peganum harmala and Inonotus hispidus with binding affinity to Candida rugosa lipase: In silico and in vitro studies

The inhibitory effect of phenolic compounds and alkaloids of Inonotus hispidus and Peganum harmala on Candida rugosa lipase was investigated, also, their antioxidant activities using DPPH, ABTS and phosphomolybdenum were studied in this paper. The phenolic extracts have shown a stronger antiradical activity than the alkaloids extracts. The enzymatic inhibition produced by these extracts is described here for the first time. The results have shown that the phenolic and the alkaloid extracts are good inhibitors of C. rugosa lipase. Thus, the inhibitor molecules (harmaline and hispidin) have been isolated from P. harmala and I. hispidus. Their structures were elucidated by 1H NMR analysis. Molecular docking has been achieved using AutoDock Vina program to discuss the nature of interactions and the mechanism of inhibition. Therefore, these isolated molecules could be used in the treatment of candidiasis.

Bioabatement with hemicellulase supplementation to reduce enzymatic hydrolysis inhibitors

A stepwise removal of inhibitory compounds by bioabatement combined with hemicellulase supplementation was conducted to enhance cellulose hydrolysis of liquid hot water-pretreated corn stover. Results showed that the fungus Coniochaeta ligniaria NRRL30616 eliminated most of the enzyme and fermentation inhibitors from liquid hot water-pretreated corn stover hydrolysates. Moreover, addition of hemicellulases after bioabatement and before enzymatic hydrolysis of cellulose achieved 20% higher glucose yields compared to non-treated samples. This work presents the mechanisms by which supplementation of the fungus with hemicellulase enzymes enables maximal conversion, and confirms the inhibitory effect of xylo-oligosaccharides in corn stover hydrolysates once the dominant inhibitory effect of phenolic compounds is removed.

Oxygen-limited aeration for relieving the impact of phenolic compounds in anaerobic treatment of coal gasification wastewater

Anaerobic digestion is an efficient tool for improving aerobic biodegradability of coal gasification wastewater, but the shock loading usually results in a failed performance of the anaerobic process. The oxygen-limited aeration was conducted to handle the impact of coal gasification wastewater in an anaerobic expanded-bed GAC reactor. Results indicated that the oxygen-limited aeration of 0–0.5 mgO2/L could shorten the recovery time from 23 to 11 days under natural condition, and the addition of 1 g/L PAC could reduce the recovery time to 14 days. The corresponding removal efficiencies of COD and phenolic compounds could increase to above 60 and 50%, respectively. The phenol utilization rates of sludge reached 83.9 ± 5.7 mg phenol/(g VSS d) after recovery of reactor performance by using oxygen-limited aeration, and only 70.4 ± 3.8 mg phenol/(g VSS d) by using natural recovery and 65.2 ± 5.9 mg phenol/(g VSS d) by using PAC addition. The recovery strategy of oxygen-limited aeration might be helpful to relieve the inhibitory effect of phenolic compounds and restore metabolic activity of anaerobic bacteria.

Inhibitory effects of phenolic compounds from Artocarpus styracifolius on respiratory burst of rat neutrophils

Context: Searching for polymorphonuclear neutrophils (PMNs) respiratory burst inhibitors is an important topic in the treatment of human diseases associated with inflammation.Objective: To investigate the inhibitory effects of phenolics isolated from Artocarpus styracifolius Pierre (Moraceae) on respiratory burst induced by phorbol myristate acetate (PMA).Materials and methods: The anti-respiratory burst activities of eight phenolics (20 µM) were assessed by determining luminol-dependent chemiluminiscence in rat PMNs. Cytotoxicity of active compounds (1–1000 µM) was assayed by Trypan blue dye exclusion method. Cell-free models were employed to evaluate scavenging capacity of active compounds (20 µM) against reactive oxygen species.Results: The PMA-induced respiratory burst was significantly inhibited (p < 0.05) by six isoprenylated phenolics (AS1–6) at the concentration of 20 µM (below the toxic concentration) with the inhibition rate ranging from 25.0 to 99.6%. The inhibitory potency estimated by IC50 was in the order of AS1 (3.1 µM) >AS6 (5.9 µM) >AS2 (9.1 µM) >AS3 (10.0 µM) >AS5 (29.7 µM) >AS4 (57.7 µM). AS1–4, four isoprenylated flavones, potently quenched superoxide anion, hydroxyl radical, and hydrogen peroxide at the concentration of 20 µM with their scavenging rates in the range of 30.1–78.1%, 35.4–69.7%, and 65.5–86.3%, respectively. In contrast, AS5–6, two isoprenylated 2-arylbenzofurans, showed less effect than that exhibited by AS1–4.Conclusion and discussion: The isoprenylated phenolics from A. styracifolius can potently inhibit PMA-induced respiratory burst in rat neutrophils without showing cytotoxicity. The inhibitory effects of these isoprenylated phenolics on the respiratory burst might depend on their different types of structure.

Inhibition of crystallization caused by Proteus mirabilis during the development of infectious urolithiasis by various phenolic substances

Infectious urolithiasis is a consequence of persistent urinary tract infections caused by urease producing bacteria e.g. Proteus mirabilis. These stones are composed of struvite and carbonate apatite. Their rapid growth and high recurrence indicate that so far appropriate methods of treatment have not been found. In the present study, the inhibitory effect of phenolic compounds was investigated in vitro against formation of struvite/apatite crystals. The impact of these substances with different chemical structures on crystallization caused by clinical isolates of P. mirabilis was tested spectrophotometrically using a microdilution method. Among the 11 tested compounds resveratrol, epigallocatechin gallate, peralgonidin, vanillic and coffee acids at the concentrations 250–1000μg/ml inhibited P. mirabilis urease activity and crystallization. However, only vanillic acid had such an effect on all tested strains of P. mirabilis. Therefore, using an in vitro model, bacterial growth, crystallization, urease activity and pH were examined for 24h in synthetic urine with vanillic acid. Effect of vanillic acid was compared with that of other known struvite/apatite crystallization inhibitors (acetohydroxamic acid, pyrophosphate) and it was shown that vanillic acid strongly inhibited bacterial growth and the formation of crystals. It can be assumed that this compound, after further studies, can be used in the treatment or prophylaxis of infectious urolithiasis.

Inhibitory effect of phenolic compounds from grape seeds (Vitis vinifera L.) on the activity of angiotensin I converting enzyme

Inhibition of the angiotensin I converting enzyme (ACE) is an important therapeutic approach in the treatment of several cardiovascular disorders. In this study the inhibitory potential of procyanidin-rich fractions of grape seed (Vitis vinifera L.) was evaluated. The inhibitory capacity was assayed by fluorometric determination of the amount of histidyl-leucine released from the substrate utilized in the presence of ACE from rabbit lung. Four purified monomers [(+)-catechin, (−)-epicatechin, (+)-catechin-O-gallate, and (−)-epigallocatechin] were also tested for comparison. Results showed that the natural phenolic extracts exhibit higher inhibitory potential than the monomers, and that fractions with higher average degrees of polymerization (DPn = 8, IC50 = 0.1 mg/L) present lower IC50 than the intermediate ones (DPn = 5, IC50 = 3.5 mg/L). Such findings strengthen the idea that the inhibitor extension, and the number of heterocyclic oxygen and hydroxyl groups in their structures, could define their in vitro action.

Peatland geoengineering: an alternative approach to terrestrial carbon sequestration

Terrestrial and oceanic ecosystems contribute almost equally to the sequestration of ca 50 per cent of anthropogenic CO(2) emissions, and already play a role in minimizing our impact on Earth's climate. On land, the majority of the sequestered carbon enters soil carbon stores. Almost one-third of that soil carbon can be found in peatlands, an area covering just 2-3% of the Earth's landmass. Peatlands are thus well established as powerful agents of carbon capture and storage; the preservation of archaeological artefacts, such as ancient bog bodies, further attest to their exceptional preservative properties. Peatlands have higher carbon storage densities per unit ecosystem area than either the oceans or dry terrestrial systems. However, despite attempts over a number of years at enhancing carbon capture in the oceans or in land-based afforestation schemes, no attempt has yet been made to optimize peatland carbon storage capacity or even to harness peatlands to store externally captured carbon. Recent studies suggest that peatland carbon sequestration is due to the inhibitory effects of phenolic compounds that create an 'enzymic latch' on decomposition. Here, we propose to harness that mechanism in a series of peatland geoengineering strategies whereby molecular, biogeochemical, agronomical and afforestation approaches increase carbon capture and long-term sequestration in peat-forming terrestrial ecosystems.

Response of Lactobacillus casei BL23 to phenolic compounds

To determine the inhibitory effect of phenolic compounds on Lactobacillus casei BL23, the role of two component signal transduction systems (TCS) and the response of Lact. casei BL23 to p-coumaric acid. Growth of Lact. casei BL23 and 17 derivative strains defective in each TCS harboured by this strain in the presence of p-coumaric acid, ferulic acid, caffeic acid or methyl gallate was monitored. Furthermore, changes in the protein content of Lact. casei BL23 when exposed to p-coumaric acid were evaluated by 2D-SDS-PAGE. Eleven proteins differentially expressed in the presence of p-coumaric acid were detected. Six of them could be identified: ClpP and HtrA, involved in protein turnover and folding, acetyl-CoA carboxylase, involved in lipid metabolism, and an arginyl-tRNA synthetase were more abundant, whereas PurL and PurN, involved in purine biosynthesis, were less abundant. No significant differences were observed between the parental strain and the TCS-defective mutants. p-Coumaric acid elicited a response against membrane and cytoplasmic damages. The inhibitory effect of phenolic compounds on Lact. casei BL23 has been determined. For the first time, cytoplasmic proteins presumably involved in the response of Lact. casei BL23 against p-coumaric acid have been identified.

In vitro estimation of the antibacterial activity and antioxidant capacity of aqueous extracts from grape-seeds (Vitis vinifera L.)

The aim of this work was to investigate the effect of grape seeds aqueous extracts on Gram-positive and Gram-negative bacteria and their antioxidant activity. Grape seeds are considered a rich source of polyphenolic compounds that show antioxidant and antimicrobial effects. Grape seeds extracts were tested for antibacterial activity by minimum inhibitory concentration method, finding that the inhibitory effect of phenolic compounds from seeds extracts are more potent against Gram-positive bacteria than Gram-negative. The antioxidant capacity of the seeds extracts depends on the content of total polyphenol compounds, and this antioxidant activity and antibacterial capacity were observed to be lower when extracts were obtained from seeds after making of wine. Our results suggest that the use of grape seed extract is a feasible alternative as antibacterial and antioxidant agents to prevent the deterioration of stored foods by bacteria and oxidation.