Isovanillic Acid Research Articles

Isolation of a Morphinan Alkaloid and a Methoxybenzoic Acid with The Investigation on The Antibacterial Effect of Alphonsea cylindrica King Leaves

Alphonsea cylindrica King belongs to the family Annonaceae, which is traditionally used to treat rheumatism, bruises, and edema. Investigation of its antibacterial properties was carried out on hexane and dichloromethane crude extracts using agar diffusion method and minimum inhibitory concentration against ESKAPE pathogens. Both extracts showed positive results in inhibiting E. faecium, S. aureus, and K. pneumoniae, while the dichloromethane extract showed further inhibition against P. aeruginosa. A morphinan alkaloid, O-methylpallidinine (1), along with a methoxybenzoic acid, isovanillic acid (2), were isolated from the dichloromethane leaf extract of the plant and elucidated via NMR spectroscopy, FTIR spectroscopy, UV-vis spectroscopy, and GC-MS, and compared with the reported data. Both compounds are reported for the first time from A. cylindrica, while O-methylpallidinine was isolated as natural product for the first time from the family Annonaceae. Both 1 and 2 showed low activity against S. aureus with an IC50 value of 371.82 μg/mL and 385.37 μg/mL, respectively. This is the first report on the antibacterial activity of compound 1. The results can be used as future references for the discovery of morphinans and the potential of A. cylindrica as an antibacterial source.

Microbiome Catabolites as Novel Modulators of Cellular Glucose and Energy Metabolism

The gut microbiome supplies bioactive metabolites such as butyrate from dietary fiber to enhance the function of skeletal muscle mitochondria, and influences metabolism during exercise. Trained athletes have a distinctly different microbiome compared to sedentary individuals, since the composition and activity of the microbiota is in turn affected by muscle fitness. The gut microbiota regulate mitochondrial biogenesis through modulation of PGC-1α, SIRT1 and AMPK, and the mitochondria regulate the gut microbiota by modulating mucosal immune responses and intestinal barrier function. Skeletal muscle is the main site of postprandial glucose disposal; the glucose transporter GLUT4 is activated by insulin by translocation to the plasma membrane from internal vesicles. In diabetic and pre-diabetic insulin-resistant tissues, this GLUT4 translocation is compromised. Therapeutic strategies against insulin resistance, including exercise and diet-related interventions, aim to lower postprandial glycemia at least partly by restoring skeletal muscle glucose uptake and enhancing metabolism. Dietary phenolics can be considered as prebiotic-type molecules, including precursors present in the unbound form as well as covalently-attached to dietary fiber such as in cereal brans. After microbial action, many potentially bioactive phenolics are released and absorbed in the colon. These microbial products, once absorbed, interact with other tissues, including muscle and adipose cells, and stimulate the uptake of glucose by several mechanisms. For example, the microbial metabolite isovanillic acid sulfate (IVAS) stimulated a dose-dependent increase in glucose transport in human LHCN-M2 muscle cells through a GLUT4- and PI3K-dependent mechanism. IVAS also upregulated GLUT1, GLUT4 and PI3K p85α protein, and increased phosphorylation of Akt. The stimulation of glucose uptake and metabolism provides a novel link between the diet, gut microbiota and skeletal muscle energy utilization.

Simultaneous Determination of the Acid Dissociation Constants of Phenolics by Multivariate Analysis of pH and Ultraviolet-Visible Spectrophotometric Measurements

In the development of new commercial products in the pharmaceutical and food industries, acid dissociation constant (Ka) values of active and inactive ingredients are important factors for the estimation of the biological activity. In this regard, new spectrophotometric approaches based on parallel factor analysis (PARAFAC) and multivariate curve resolution-alternating least squares (MCR-ALS) to pH-absorbance dataset are described for the simultaneous determination of the acid dissociation constants of the phenolics ferulic acid, 4-hydroxybenzoic acid, syringic acid, protocatechuic acid, vanillic acid, and isovanillic acid that have more than one dissociation equilibrium without using classical titration procedures. The acid dissociation constants were determined by the pH profiles obtained by bilinear MCR-ALS and trilinear PARAFAC decomposition of pH-ultraviolet and pH-ultraviolet-visible spectroscopic datasets of the phenolics. For the quantification of the acid dissociation constants with the MCR-ALS and PARAFAC approaches, the estimated spectral profiles provided an opportunity for the direct observation of the individual spectral bands of each phenolic without the use of additional software. The results showed that MCR-ALS and PARAFAC applications to spectrophotometric measurements at various pH values were alternatives for solving acid dissociation constant problems that cannot be determined by classical methods.

Phytochemical Screening of Peronema Canescens Jack

Peronema canescens Jack, locally known as sungkai, is used as medicinal plant because it contains chemical compounds such as peronemins, catechol, quinic acid, isovanillic acid and guaiacol. The study was conducted to determine the chromatographic profile of the P. canescens leaves extract via liquid chromatography. It was found that the optimised mobile phase for thin layer chromatography (TLC) of P. canescens leaves was hexane: ethyl acetate: isopropanol (7:3:0.3). In addition, high performance liquid chromatography (HPLC) chromatograms (λ = 210 and 254 nm) of the methanol extract, run in 0.1% formic acid and acetonitrile, provided eight acceptable peaks.

Microbiome Catabolites as Novel Modulators of Cellular Glucose and Energy Metabolism

The gut microbiome supplies bioactive metabolites such as butyrate from dietary fiber to enhance the function of skeletal muscle mitochondria, and influences metabolism during exercise. Trained athletes have a distinctly different microbiome compared to sedentary individuals, since the composition and activity of the microbiota is in turn affected by muscle fitness.The gut microbiota regulate mitochondrial biogenesis through modulation of PGC‐1α, SIRT1 and AMPK, and the mitochondria regulate the gut microbiota by modulating mucosal immune responses and intestinal barrier function. Skeletal muscle is the main site of postprandial glucose disposal; the glucose transporter GLUT4 is activated by insulin by translocation to the plasma membrane from internal vesicles. In diabetic and pre‐diabetic insulin‐resistant tissues, this GLUT4 translocation is compromised. Therapeutic strategies against insulin resistance, including exercise and diet‐related interventions, aim to lower postprandial glycemia at least partly by restoring skeletal muscle glucose uptake and enhancing metabolism.Dietary phenolics can be considered as prebiotic‐type molecules, including precursors present in the unbound form as well as covalently‐attached to dietary fiber such as in cereal brans. After microbial action, many potentially bioactive phenolics are released and absorbed in the colon. These microbial products, once absorbed, interact with other tissues, including muscle and adipose cells, and stimulate the uptake of glucose by several mechanisms. For example, the microbial metabolite isovanillic acid sulfate (IVAS) stimulated a dose‐dependent increase in glucose transport in human LHCN‐M2 muscle cells through a GLUT4‐ and PI3K‐dependent mechanism. IVAS also upregulated GLUT1, GLUT4 and PI3K p85α protein, and increased phosphorylation of Akt.The stimulation of glucose uptake and metabolism provides a novel link between the diet, gut microbiota and skeletal muscle energy utilization.

Synthesis, Characterization, and Low-Toxicity Study of a Magnesium(II) Complex Containing an Isovanillate Group.

The beneficial effect of polyphenols and magnesium(II) against oxidative stress motivated our research group to explore the antioxidant activity of phenMgIso, an aqueous soluble magnesium(II) complex containing 1,10-phenanthroline (phen) and isovanillic acid (Iso) as ligands. Combined electrospray ionization–mass spectrometry and DOSY-NMR techniques identified two complexes in methanolic solution: hexacoordinated [Mg(phen)2(Iso)]+ and tetracoordinated [Mg(phen)(Iso)]+. The cyclic voltammogram of phenMgIso in the anodic region showed a cyclic process that interrupts the isovanillic acid degradation, probably by stabilization of the corresponding phenoxyl radical via complexation with Mg(II), which is interesting for antioxidant applications. phenMgIso competes with 2,2,6,6-tetramethylpiperidine by 1O2 with IC50(1O2) = 15 μg m–1 and with nitrotetrazolium blue chloride by superoxide ions (IC50(O2•–) = 3.6 μg mL–1). Exposure of both zebrafish (2 mg L–1) and wistar male rats (3 mg kg–1 day–1 dose for 21 days) to phenMgIso does not cause mortality or visual changes compared with the respective control groups, thus phenMgIso could be considered safe under the conditions of this study. Moreover, no significant changes in comparison to both control groups were observed in the biochemical parameters on the brain-acetylcholinesterase activity, digestive tract enzyme catalase, and glutathione-S-transferase. Conversely, the performance of superoxide dismutase activity in wistar male rats increased in the presence of a complex, resulting in enhanced capacity of rats for superoxide radical enzymatic scavenging. The synergistic action of phenMgIso may be explained by the strong electrostatic interaction between Mg(II) and the O,O(phenolate) group, which makes the Iso ligand easier to oxidize and deprotonate, generating a cyclic stable species under oxidative conditions.

INSECTICIDAL AND FUNGICIDAL ACTIVITY OF A MAGNESIUM COMPOUND CONTAINING ISOVANILLIC ACID AGAINST LEAF-CUTTING ANT AND ITS SYMBIOTIC FUNGUS

Pesticides offer a simple, cost-effective solution to ensure food supplies for a growing world population. However, their environmental performance needs improvement if pesticides are to continue contributing importantly. This study explores the insecticidal potential of a magnesium (II) metal complex containing 1,10-phenanthroline and isovanillic acid (MgPhenIso) against leaf-cutting ant (Atta sexdens rubropilosa) and its symbiotic fungus (Leucoagaricus gongylophorus). The MgPhenIso complex is easy-to-prepare, stable in solid state and in aqueous solution, and resistant to sunlight irradiation. The insecticidal activity of MgPhenIso-containing bait against A. sexdens rubropilosa and L. gongylophorus showed a delayed action mode at 2 mg g-1 (100% kill, 6th day, S50=2b) and suppressed fungus development and growth. These results, together with earlier investigations on MgPhenIso regarding its absence of toxicity to Zebrafish and Wistar male rats, emphasize the potential of this complex as an environmentally friendly insecticide candidate.

Whitening Activity of Constituents Isolated from the Trichosanthes Pulp.

Whitening cosmetics market has a bright future, and pure natural whitening products of traditional Chinese medicine have always been a research hotspot. In this research, the whitening active ingredient of Chinese medicine Trichosanthes pulp was isolated and purified for the first time, and its whitening mechanism was clarified. Chromatographic methods such as silica gel, ODS, and HPLC were used to isolate and purify them. B16 cells were used to measure the antioxidant activity, tyrosinase activity, and melanin removal activity. A total of 20 compounds were isolated, including p-hydroxybenzaldehyde (1), salicylic acid (2), vanillic acid (3), isovanillic acid (4), protocatechuate (5), trans-cinnamic acid (6), 4-coumaric acid (7), trans-ferulic acid (8), drechslerol-B (9), cyclotucanol 3-palmitate (10), 5-acetoxymethyl-2-furaldehyde (11), 5-hydroxymethylfurfural (12), diosmetin (13), apigenin (14), chrysoeriol (15), luteolin (16), 4′-hydroxyscutellarin (17), quercetin (18), 3′,5-dihydroxy-7-(β-D-glucopyranosyloxy)-4′-methoxyflavone (19), and cofloxacin-7-O-β-D-glucoside (20). Among them, compounds 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20 have good antioxidant repairing effects; compounds 3, 4, 5, 6, and 7 have high black inhibition; compounds 1, 2, 3, 4, 5, 6, 7, 8, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20 have obvious tyrosine acidase inhibitory activity. The results laid foundation for the further development and utilization of Trichosanthes pulp resources and also provide a basis for the development of natural whitening cosmetics.

Depolymerization of lignin by wet air oxidation

In the present study, effect of temperature (150–250 °C) and pressure (500–1500 psi) was investigated for depolymerization of lignin by wet air oxidation (WAO). Commercial alkali lignin was used as representative lignin material. The degradation/oxidation products of WAO treatments were identified to understand the potential value of the depolymerization products. Depolymerization efficiency of alkali lignin was also compared to lignin extracted from corn stover and eastern redcedar (cedar) under the same WAO condition. Isovanillic acid was found to be the main product of WAO at 150 °C and 1000 psi oxygen conditions. The higher temperature (200 and 250 °C) and higher oxygen pressure (1000 and 1500 psi) conditions led to formation of more oxidized products, mostly carboxylic acid-derived compounds. The results showed that alkali lignin was more vulnerable to depolymerization compared to the lignins extracted from corn stover and cedar.

Effects of Maclura tricuspidata (Carr.) Bur fruits and its phytophenolics on obesity-related enzymes.

The purpose of the present study was to investigate whether several phytophenolic ingredients isolated from Maclura tricuspidata (Carr.) Bur fruits inhibit the activity of obesity-related enzymes including pancreatic lipase, α-amylase, β-glucosidase, phosphodiesterase IV, alkaline phosphatase, and citrate synthase, and the compounds play as an inhibitor against the target enzymes in kinetic studies. The enzyme assays indicated that the fruit extract and its phytophenolic compounds inhibited significantly the enzymatic activity of the five target enzymes. The kinetic studies demonstrated that the inhibitory properties of p-hydroxybenzoic acid (4-HA), protocatechuic acid (PA), and isovanillic acid (IA) against pancreatic lipase, β-glucosidase, citrate synthase, or alkaline phosphatase. Our results suggested that the compounds detected from Maclura tricuspidata (Carr.) Bur fruit extract may regulate carbohydrate/lipid/energy metabolism by obesity-related enzymes' inhibition. PRACTICAL APPLICATIONS: The obesity-related metabolizing enzymes affect (in)directly the metabolites absorption on carbohydrate/lipid/energy metabolism. Accordingly, it is an important strategy to treat obesity through target pathways and enzymes which include the reduction in energy intake and consumption. In our results, Maclura tricuspidata (Carr.) Bur fruit extract and its phytophenolic compounds inhibited significantly the enzymatic activity of the five target enzymes, in particular, 4-HA, PA, and IA have each specific inhibition type on pancreatic lipase, β-glucosidase, citrate synthase, and alkaline phosphatase. Therefore, M. tricuspidata (Carr.) Bur fruit may be a strong candidate as a food material or therapeutic agent for obesity improvement.

Phenolic Content and Antioxidant Activity of Extracts of 12 Melon (Cucumis melo) Peel Powders Prepared from Commercial Melons.

Melons are a diverse group of fresh, dessert fruits that includes orange flesh cantaloupe, green flesh honeydew, and mixed hybrid melons. As part of an effort to discover potential health benefits of fruit and vegetable peels that are considered to be byproducts of food processing, we determined the total phenolic content and antioxidative activities of methanolic extracts of the powdered peels of the following commercial melon (Cucumis melo) varieties sold at retail markets in California that were imported from Mexico and Honduras: nonorganic Canary, Charentias, Hani Gold, Vine ripened, and Santa Claus; and organic Ambrosia, Cantaloupe, Galia, Goddess, Ham, Honeydew, and Tuscan. The total phenolic content (in mg gallic acid equivalents/g extract) ranged from 0.69 (Tuscan) to 2.96 (Galia) or 4.3-fold variation from lowest to highest value. The antioxidative activity (in mg ascorbic acid equivalents/mL extract) ranged from 0.13 (organic Tuscan) to 0.26 (organic Galia). Similar results were observed using the ABTS antioxidative assay. The content of the phenolic and flavonoid compounds 3-hydroxybenzoic acid, chlorogenic acid, neochlorogenic acid, isovanillic acid, apigenin-7-α-glucoside, luteolin-7-o-glucoside, and quercetin-3-galactoside in three melon flesh samples (nonorganic and organic Galia from Honduras and organic Galia from Mexico and two peel samples (Mexican organic peel and flesh) were analyzed using HPLC. The results suggest that the peel from the Honduran Galia melon with the highest antioxidative activity merits further study to investigate potential health properties. Potential nutritional and health benefits of melon peels, Seeds, and their bioactive compounds are discussed. PRACTICAL APPLICATION: The peel from the Honduran Galia melon variety merits further study for potential health benefits, including antioxidative, anticholesterol, and antidiabetic activities, and stimulation of thyroid function, as reported for peels from other melon varieties, as well as antibiotic activities against pathogenic bacteria, protozoa, and viruses.

A New Amide From Piper maingayi Hk.F. (Piperaceae)

Phytochemical investigation from the leaves and stem extracts of Piper maingayi Hk.F. resulted in the isolation of a new amide, N-isobutyl-15-(3″,4″-methylenedioxyphenyl)-2 E,4 E,12 Z-pentadecatrienamide (1), together with sesamin (2), piperumbellactam A (3), cepharadione A (4), cepharadione B (5), piperolactam A (6), oleic acid (7), methyl linolenate (8), β-sitosterol (9), butyl dodecanoate (10), and isovanillic acid (11). Their structures were established by the analysis of their spectroscopic (1D and 2D NMR) and spectrometric (MS) data, as well as by comparison with those reported in the literature. Compound (1) exhibited strong inhibition against lipoxygenase (15-LOX) at IC50 42.5 μM and antibacterial activity toward Bacillus subtillis and Pseudomas aeruginosa with minimum inhibitory concentration (MIC) value of 250 μg/mL each.

Chemical constituents from green walnut husks and their antitumor activity in vitro

Fourteen chemical constituents, including 5-hydroxy-4-methoxy-1-tetralone(1), 4,8-dihydroxy-1-tetralone(2), 4,5-dihydroxy-α-tetralone(3), blumenol B(4), dehydrovomifoliol(5), megastigm-5-ene-3,9-diol(6), juglanin B(7), blumenol C(8), loliolide(9), oleracone B(10), syringarsinol(11), pinoresinol(12), methyl 4-hydroxy-3-methoxybenzoate(13), and isovanillic acid(14), were isolated from the dichloromethane fraction of 95% methanol extract of green walnut husks by silica gel and MCI column chromatography, and Pre-HPLC. Their structures were determined by spectroscopic methods, such as NMR, MS and so on. Among them, compounds 1, 4-6, 8-13 were isolated from the green walnut husks for the first time, and compounds 4-6, 8, 10, 12, 13 were isolated from the Juglans genus for the first time. All of isolates were detected their inhibitory activities against HeLa, HGC-27 and Ht-29 cell lines by the MTT assay. The result showed that compounds 2, 3, 7, 9 and 11 exhibited inhibitory activity against the tested cell line. The IC_(50) of 7 were 26.5, 9.0, 25.4 μmol·L~(-1), respectively.

Evaluation of Paeonia emodi for its cardioprotective potentials: An investigative study towards possible mechanism

Ethnopharmacological relevancePaeonia emodi Wall. ex Royle (peony) is an important member of family Paeoniaceae. Different parts of the plant have been folklorically used for treatment of different diseases. Infusion of dried flowers is used to treat diarrhea, the seeds are emetic and cathartic while the rhizome has been indicated for the treatment of hysteria, abdominal spasm, nervine tonic and headache. Besides these, peony has also been used in different respiratory and cardiovascular diseases (CVDs) like hypertension, palpitations, congestive heart failure and atherosclerosis. Being a folkloric remedy for the treatment of CVDs, Paeonia emodi (P. emodi) requires to be explored scientifically for MI management. AimThe current research work was designed to explore the possible cardioprotective mechanism of P. emodi in Isoproterenol hydrochloride (ISO) induced MI in mice. Materials and methodsExperimental animals randomly divided in different groups, received methanolic extract of P. emodi (Pe.ME) and its subsequent fractions for 15 days followed by ISO (100 mg/kg s.c) at 24 h interval for two days. The cardioprotective potential of the test samples were investigated by determining the serum levels of Alanine Amino Transferase (ALT), Aspartate Amino Transferase (AST), Lactate Dehydrogenase (LDH) and Creatine Phosphokinase (CPK). The ethyl acetate fraction (Pe.EA) was found potent among all the tested samples of P. emodi. Based on its high potency, Pe.EA was subjected to GC-MS analysis and further relevant experiments including anti-hyperlipidemic, antioxidant, lipid peroxidation, membrane stabilization, thrombolytic, DNA ladder assay and histopathological study. ResultsPe.EA exhibited significant cardioprotective activity through reduction in levels of serum biomarkers responsible for MI. It significantly reduced serum levels of ALT (p < 0.001), AST (p < 0.001), CPK (p < 0.05) and LDH (p < 0.001) at a dose of 300 mg/kg as compared to ISO treated group. The GC-MS analysis confirmed the presence of potential compounds (esculetin, methyl eugenol, isovanillic acid) which might play a role in cardioprotection. Further screening confirmed that the effect of Pe.EA is mediated through multiple targets/mechanisms, which include anti-hyperlipidemia, antioxidant, lipid peroxidation inhibition, membrane stabilization, thrombolytic and DNA protective effects. Histopathological studies revealed the palliative effect for the damage caused in myocardial tissues. ConclusionFindings of current study provide evidence that P. emodi is a potential candidate for the treatment and management of MI.

Gut microbiome catabolites as novel modulators of muscle cell glucose metabolism.

The gut microbiome supplies essential metabolites such as short-chain fatty acids to skeletal muscle mitochondria, and the composition and activity of the microbiota is in turn affected by muscle fitness. To further our understanding of the complex interactions between the gut microbiome and muscle, we examined the effect of microbiota-derived phenolic metabolites on the ability of human muscle cells to take up and metabolize glucose. As a model, we used the differentiated human skeletal muscle myoblast line, LHCN-M2, which expresses typical muscle phenotypic markers. We initially tested a selected panel of parent phenolic compounds and microbial metabolites, and their respective phenolic conjugates, as found in blood. Several of the tested compounds increased glucose uptake and metabolism, notably in high glucose- and insulin-treated myotubes. One of the most effective was isovanillic acid 3 -O-sulfate (IVAS), a metabolite from the microbiome found in the blood, primarily derived from consumed cyanidin 3 -O-glucoside, a major compound in berry fruits. IVAS stimulated a dose-dependent increase in glucose transport through glucose transporter GLUT4- and PI3K-dependent mechanisms. IVAS also up-regulated GLUT1, GLUT4, and PI3K p85α protein, and increased phosphorylation of Akt. The stimulation of glucose uptake and metabolism by a unique microbiome metabolite provides a novel link among diet, gut microbiota, and skeletal muscle energy source utilization.-Houghton, M. J., Kerimi, A., Mouly, V., Tumova, S., Williamson, G. Gut microbiome catabolites as novel modulators of muscle cell glucose metabolism.

Chemical constituents from the calyxes of Physalis alkekengi L. var. franchetii (Mast.) Makino

Phytochemical investigations of the ethanolic extract from the calyxes of Physalis alkekengi L. var. franchetii (Mast.) Makino led to the isolation of n-heptadecanoic acid (1), n-pentadecanoic acid (2), n-hexadecoic acid (3), n-undecanoic acid (4), hendecane (5), β-sitosterol (6), n-octadecanoic acid (7), isovanillic acid (8), 4-methylgentisic acid (9), 2,3,4-trihydroxybenzoic acid (10), 5,7-di-O-methylquercetin (11), 8-hydroxy-7-methoxycoumarin (12), 4,7-didehydroneophysalin B (13), and (Z)-9,10,11-trihydroxy-12-octadecenoic acid (14). Their structures were established by extensive analysis of their NMR spectroscopic data and comparison with literature data. In the present research, compounds 8 and 11 are reported for the first time in the genus Physalis. Compounds 10 and 12 were firstly isolated from Solanaceae family. Compound 9 was isolated from plants for first time. The chemotaxonomic significance of the isolated compounds has been discussed.

Identification and Quantification of antivenom compounds from aqueous extract of Cyclea peltata root

Snakebite is a severe medical, social and economic failure in many parts of the world, chiefly in the tropical and subtropical nations due to occurrence of majority of the World’s dangerous snakes. In India, a range of medicinal plants are used as antidotes for snakebites, either single or in combination with other. Cyclea peltata is locally called as “Rajpatha” belongs to the family Menispermaceae.Roots are tuberous and are traditionally used in the treatment of snake poisoning and various other diseases. In our present study a variety of secondary metabolites like alkaloids, flavonoids, saponins, phenols, protein, coumarin, reducing sugars, tannins were present in Cyclea peltata root.Various compounds were identified by LCMS analysis which includes copane, deoxyelephantopin, coumaric acid, isovanillic acid, ferulic acid and a-bisabolol.The phenolic compounds mainly Coumaric acid, Ferulic acid and Isovanillic acid were found to possess antivenom activity and were quantified using HPLC analysis.The present study concluded that phenolic compounds present in the root extractof Cyclea peltata root may be responsible for the antivenom activity.

Inhibitory activities of extracts of Rumex dentatus, Commelina benghalensis, Ajuga bracteosa, Ziziphus mauritiana as well as their compounds of gallic acid and emodin against dengue virus

Objective: To investigate the inhibitory effects against dengue virus serotype 2 (DENV-2) by five different fractions (extracted by methanol, ethanol, benzene, chloroform and n-hexane) of Rumex dentatus, Commelina benghalensis, Ajuga bracteosa and Ziziphus mauritiana, as well as their constituents (gallic acid, emodin, and isovanillic acid). Methods: All the samples were tested for cytotoxicity on baby hamster kidney cells by MTT assay and for anti-DENV-2 activity by plaque reduction neutralization assay using two DENV-2 doses (45 and 90 plaque- forming units or PFU). Results: All the samples except isovanillic acid exhibited significant prophylactic effects against DENV-2 infectivity (without cytotoxicity) when administered to cells before infection, but were not effective when given 6 h post-infection. The methanol extract of Rumex dentatus demonstrated the highest antiviral efficacy by inhibiting DENV-2 replication, with IC50 of 0.154 μg/mL and 0.234 μg/mL, when added before infection with 45 and 90 PFU of virus, respectively. Gallic acid also exhibited significant antiviral effects by prophylactic treatment prior to virus adsorption on cells, with IC50 of 0.191 μg/mL and 0.522μg/ mL at 45 and 90 PFU of DENV-2 infection, respectively. Conclusions: The highly potent activities of the extracts and constituent compounds of these plants against DENV-2 infectivity highlight their potential as targets for further research to identify novel antiviral agents against dengue.

Acid-catalyzed hydrolysis of conifer lignosulfonate in black liquor for the production of value-added chemicals

Commercial sodium lignosulfonate from conifer black liquor (RSL) was used in our study to investigate acid-catalyzed hydrolysis of lignosulfonate (LS) by inorganic acids in aqueous solution. Before the hydrolysis process, RSL was purified by alcohol-water solution. Combustion method and gel permeation chromatography (GPC) of the high performance liquid chromatography system (HPLC) were used to detect the purification efficiency. The results showed that methanol-water solution had better purification effect. In addition, for the purified RSL (PSL-M), 0.5mol/L NaOH solution was chosen as the best dissolving medium through the comparison of aggregation behaviors of PSL-M in deionized water and various concentrations of NaOH solutions. In the following acid-catalyzed hydrolysis process, the experimental results proved that the three kinds of inorganic acids (HCl, H2SO4 and H3PO4) could catalytically hydrolyze PSL-M to lower molecular weight fractions and other organic chemicals, but HCl had the best efficiency. Moreover, in 0.5mol/L NaOH solution, PSL-M (solid-liquid ratio, 50g/L) catalytically hydrolyzed by 0.68mol/L HCl at 50°C for 10min could produce 1.729g/kg isovanillic acid, 0.088g/kg vanillin, 0.007g/kg syringaldehyde, 0.056g/kg acetosyringone and 0.024g/kg acetovanillone respectively.

The Effect of Buckwheat Hull Extract on Lipid Oxidation in Frozen-Stored Meat Products.

This study investigated the effect of antioxidants on lipid stability of frozen-stored meat products. Buckwheat hull extract was used to enrich fried meatballs made from ground pork. During 180-d storage of meat products, lipid oxidation (peroxide and 2-thiobarbituric acid reactive substances [TBARS] value) was periodically monitored. The results were compared with butylated hydroxytoluene (BHT). The addition of antioxidants decreased lipid oxidation in stored meatballs. The highest ability to control peroxide and TBARS values was demonstrated for buckwheat hull extract. Moreover, buckwheat hull extract showed a higher 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity as well as higher Fe(II) ion chelating ability, as compared with BHT. The total content of phenolic compounds are highly correlated to the individual polyphenols in extract of buckwheat hull, among which the following were assayed: 3,4-dihydroxybenzoic acid, 4-hydroxybenzoic acid, gallic acid, isovanillic acid and p-coumaric acid, and flavonoids: isoorientin, quercetin, quercetin 3-d-glucoside, rutin, and vitexin. These results indicate that plant extracts can be used to prolong shelf life of products by protecting them against lipid oxidation and deterioration of their nutritional quality.