Acetic Acid Group Research Articles

Suppression of Eimeria tenella sporulation by disinfectants.

The disinfectant effects (DEs) of 10 types of chemicals, defined by their ability to destroy or inhibit oocysts and consequently prevent sporulation of Eimeria tenella field isolate, were evaluated in vitro. Correct species assignments and sample purities were confirmed by the singular internal transcribed spacer (ITS)-PCR analysis. A total of 18 treatments were performed, and the disinfection suppression levels were 75.9% for 39% benzene + 22% xylene (1:10 dilution), 85.5% for 30% cresol soup (1:1 dilution), and 91.7% for 99.9% acetic acid (1:2 dilution) group. The results indicate that acetic acid, cresol soup, and benzene+xylene are good candidates for suppression of E. tenella oocyst sporulation.

Conformational equilibria and large-amplitude motions in dimers of carboxylic acids: rotational spectrum of acetic acid-difluoroacetic acid.

We report the rotational spectra of two conformers of the acetic acid-difluoroacetic acid adduct (CH3COOH-CHF2COOH) and supply information on its internal dynamics. The two conformers differ from each other, depending on the trans or gauche orientation of the terminal -CHF2 group. Both conformers display splittings of the rotational transitions, due to the internal rotation of the methyl group of acetic acid. The corresponding barriers are determined to be V3(trans)=99.8(3) and V3(gauche)=90.5(9) cm(-1) (where V3 is the methyl rotation barrier height). The gauche form displays a further doubling of the rotational transitions, due to the tunneling motion of the -CHF2 group between its two equivalent conformations. The corresponding B2 barrier is estimated to be 108(2) cm(-1). The increase in the distance between the two monomers upon OH→OD deuteration (the Ubbelohde effect) is determined.

Performance of new single rhodanine indoline dyes in zinc oxide dye-sensitized solar cell

A new single rhodanine indoline dye GU112 having both cyanoacrylic and rhodanine acetic acid groups in an anchor moiety showed the best stability among GU110, GU111, and GU112 in zinc oxide dye-sensitized solar cell.

2 month of 1% Rubus coreanus vinegar drink reduces body weight and adipocyte size in dietary induced obesity rats (LB361)

The study aimed to investigate the effects of Rubus coreanus (RC) vinegar supplementation on anti‐obesity in high‐fat‐diet‐induced obesity rat. The RC vinegar was processed starting with 25°Brix of sugar concentration and was alcohol fermented at temperature of 30℃ for 10 days. The conditions for the acetic acid fermentation were 14 days of stationary fermentation at 30℃, with 6% alcohol. A total 52 4‐wk old male Sprague‐Dawley rats were fed a normal chow diet or a high‐fat diet (HFD) for 12 weeks to induce obesity and then were randomized into normal control group (NC), HFD + distilled water group (OB‐DW), HFD + 1% Acetic acid group (OB‐AA) for control, HFD + 1% RC vinegar group (OB‐RC), HFD + 15mg/d caffeine group (OB‐CAF). After 2 months, body weights, organ and fat weights, adipocyte size were analyzed. OB‐CAF rats showed most decreased body weight about 15% and OB‐AA and OB‐RC also showed decreased body weight about 6% compared to the obese rats. The adipocyte size were decreased in OB rats treated with vinegar, AA and CAF than those of OB‐DW rats. Further studies are needed to assess the health benefit of drinking vinegar. This work was carried out with the support of “Cooperative Research Program for Agriculture Science & Technology Development (Project No. PJ009826)” Rural Development Administration, Republic of Korea.

Dietary supplementation with tributyrin alleviates intestinal injury in piglets challenged with intrarectal administration of acetic acid

Tributyrin (TBU) is a good dietary source of butyrate and has beneficial effects on the maintenance of normal intestinal morphology. The present study tested the hypothesis that dietary TBU supplementation could alleviate intestinal injury in the acetic acid (ACA)-induced porcine model of colitis. A total of eighteen piglets (25d old) were randomly allocated to one of three treatment groups (control, ACA and TBU). The control and ACA groups were fed a basal diet and the TBU group was fed the basal diet supplemented with 0·1% TBU. On day 15 of the trial, under anaesthesia, a soft catheter was inserted into the rectum of piglets (20-25cm from the anus), followed by administration of either saline (control group) or ACA (10ml of 10% ACA solution for ACA and TBU groups). On day 22 of the trial, after venous blood samples were collected, piglets were killed to obtain mid-ileum and mid-colon mucosae. Compared with the control group, the ACA group exhibited an increase (P<0·05) in lymphocyte counts, creatinine, PGE2, and malondialdehyde concentrations and diamine oxidase and inducible NO synthase activities in the plasma and lymphocyte density in the colon and a decrease in insulin concentrations and glutathione peroxidase activity, ileal villus height:crypt depth ratios and goblet cell numbers in the colon. These adverse effects of ACA were attenuated by TBU supplementation. Moreover, TBU prevented the ACA-induced increase in caspase-3 levels while enhancing claudin-1 protein and epidermal growth factor receptor (EGFR) mRNA expression in the colonic mucosa. Collectively, these results indicate that dietary supplementation with 0·1% TBU alleviates ACA-induced intestinal injury possibly by inhibiting apoptosis, promoting tight-junction formation and activating EGFR signalling.

Investigation of Sesamol on Myeloperoxidase and Colon Morphology in Acetic Acid-Induced Inflammatory Bowel Disorder in Albino Rats

Background. Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of gastrointestinal tract of immune, genetic, and environmental origin. In the present study, we examined the effects of sesamol (SES), which is the active constituent of sesame oil in the acetic acid (AA) induced model for IBD in rats. Methods. The groups were divided into normal control, AA control, SES, and sulfasalazine (SS). On day 7, the rats were killed, colon was removed, and the macroscopic, biochemical, and histopathological evaluations were performed. Results. The levels of MPO, TBARS, and tissue nitrite increased significantly (P < 0.05) in the AA group whereas they reduced significantly in the SES and SS treated groups. Serum nitrite levels were found to be insignificant between the different groups. Conclusions. The mucosal protective effects of sesamol in IBD are due to its potential to reduce the myeloperoxidase and nitrite content.

Radiofrequency (thermal) ablation versus no intervention or other interventions for hepatocellular carcinoma

Hepatocellular carcinoma is the fifth most common cancer worldwide. Percutaneous interventional therapies, such as radiofrequency (thermal) ablation (RFA), have been developed for early hepatocellular carcinoma. RFA competes with other interventional techniques such as percutaneous ethanol injection, surgical resection, and liver transplantation. The potential benefits and harms of RFA compared with placebo, no intervention, chemotherapy, hepatic resection, liver transplantation, or other interventions are unclear. To assess the beneficial and harmful effects of RFA versus placebo, no intervention, or any other therapeutic approach in patients with hepatocellular carcinoma. We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and ISI Web of Science to September 2012. We handsearched meeting abstracts from ASCO, ESMO, AASLD, EASL, APASL, and references of articles. We also contacted researchers in the field (last search September 2012). We considered for inclusion randomised clinical trials investigating the effects of RFA versus placebo, no intervention, or any other therapeutic approach on hepatocellular carcinoma patients regardless of blinding, language, and publication status. Two review authors independently performed the selection of trials, assessment of risk of bias, and data extraction. We contacted principal investigators for missing information. We analysed hazard ratios (HR) as relevant effect measures for overall survival, two-year survival, event-free survival, and local recurrences with 95% confidence intervals (CI). In addition, we analysed dichotomous survival outcomes using risk ratios (RR). We used trial sequential analysis to control the risk of random errors ('play of chance'). We identified no trials comparing RFA versus placebo, no intervention, or liver transplantation. We identified and included 11 randomised clinical trials with 1819 participants that included four comparisons: RFA versus hepatic resection (three trials, 578 participants); RFA versus percutaneous ethanol injection (six trials, 1088 participants) including one three-armed trial that also investigated RFA versus acetic acid injection; RFA versus microwave ablation (one trial, 72 participants); and RFA versus laser ablation (one trial, 81 participants). Ten of the eleven included trials reported on the primary outcome of this review, overall survival. Rates of major complications or procedure-related deaths were reported in 10 trials. The overall risk of bias was considered low in five trials and high in six trials. For a subgroup analysis, we included only low risk of bias trials. Regarding the comparison RFA versus hepatic resection, there was moderate-quality evidence from two low risk of bias trials that hepatic resection seems more effective than RFA regarding overall survival (HR 0.56; 95% CI 0.40 to 0.78) and two-year survival (HR 0.38; 95% CI 0.17 to 0.84). However, if we included a third trial with high risk of bias, the difference became insignificant (overall survival: HR 0.71; 95% CI 0.44 to 1.15). With regards to the outcomes event-free survival and local progression, hepatic resection also yielded better results than RFA. However, the number of complications was higher in surgically treated participants (odds ratio (OR) 8.24; 95% CI 2.12 to 31.95). RFA seemed superior to percutaneous ethanol or acetic acid injection regarding overall survival (HR 1.64; 95% CI 1.31 to 2.07). The RR for mortality was also in favour of RFA, but did not reach statistical significance (150/490 (30.6%) people in the percutaneous ethanol or acetic acid group versus 119/496 (24.0%) people in the RFA group; RR 1.76; 95% CI 0.97 to 3.22). The proportion of adverse events did not differ significantly between RFA and percutaneous ethanol or acetic acid injection (HR 0.70; 95% CI 0.33 to 1.48). Trial sequential analyses revealed that the number of participants in the included trials was insufficient and that more trials are needed to assess the effects of RFA versus other interventions. The effects of RFA versus no intervention, chemotherapeutic treatment, or liver transplantation are unknown. We found moderate-quality evidence that hepatic resection is superior to RFA regarding survival. However, RFA might be associated with fewer complications and a shorter hospital stay than hepatic resection. We found moderate-quality evidence showing that RFA seems superior to percutaneous ethanol injection regarding survival. There were too sparse data to recommend or refute ablation achieved by techniques other than RFA. More randomised clinical trials with low risk of bias and low risks of random errors assessing the effect of RFA are needed.

Evaluation of the morphological changes of gastric mucosa induced by a low concentration of acetic acid using a rat model

Oral ingestion of concentrated acetic acid causes corrosive injury of the gastrointestinal tract. To assess the effects of a low concentration of acetic acid on gastric mucosa, we examined the gastric mucosal changes in rats at 1 and 3 days after the injection of 5% or 25% acetic acid into the gastric lumen. The area of the gastric ulcerative lesions in the 25% acetic acid group was significantly larger than that in the 5% acetic acid group. The lesion area was reduced significantly at 3 days after injection in the 5% acetic acid group, whereas no significant difference in lesion area was observed at 1 and 3 days in the 25% acetic acid group. Histologically, corrosive necrosis was limited to the mucosal layer in the 5% acetic acid group, whereas necrosis extended throughout the gastric wall in the 25% acetic acid group. At 3 days post-injection, the 25% acetic acid group showed widespread persistent inflammation, whereas the 5% acetic acid group showed widespread appearance of fibroblasts indicative of a healing process. These results indicate that a low concentration of acetic acid damages the gastric mucosa and that the degree of mucosal damage depends on the concentration of acetic acid.

Aggregation‐Induced Emission of 1,8‐NaphthalimideCasein Micelle: Investigation by Synchronous Spectrographic Method

A novel 1,8-naphthalimide probe 1, bearing two acetic-acid moieties was synthesized. The acetic-acid groups, docked into the sub-domains of casein micelle and bound with tryptophan residues, and the 1,8-naphthalimide chromophore adsorbed on the surface of casein micelle, forming a supermolecule, 1-casein micelle, which exhibited the aggregation-induced synchronous emission (AISE) characters. The effect of pH on the intensity of supermolecule was investigated, and the result indicated that the emission enhancement was mainly due to the 1,8-naphthalimide chromophore aggregated onto the casein micelle. Based on AISE, a novel casein quantification method was developed, which exhibited a good linear range of 0.05-10.0 μg ml(-1) and 0.07-9.5 μg ml(-1) with the detection limits of 2.8 and 3.0 ng ml(-1) . The effects of metal ions and pH on the system of 1-casein micelle were investigated. The proposed method was applied to determine casein in milk samples, and the results were in good agreement with the result of the Biuret method.

Synthesis and biological evaluation of aminobenzimidazole derivatives with a phenylcyclohexyl acetic acid group as anti-obesity and anti-diabetic agents

A series of benzimidazole derivatives with a phenylcyclohexyl acetic acid group as DGAT-1 inhibitors was developed. Among the benzimidazole series, compound 5k showed submicromolar in vitro activity toward human and mouse DGAT-1, good selectivity toward DGAT-2, human liver metabolic stability, and pharmacokinetic (PK) and safety profiles such as hERG, CYP and acute toxicity. Additionally, 5k showed good in vivo efficacy in 4weeks study with DIO mouse model.

Synthesis and pharmacological properties of a new hydrophilic and orally bioavailable 5-HT4 antagonist

5-HT4 receptor antagonists have been suggested to have clinical potential in treatment of atrial fibrillation, diarrhea-prone irritable bowel syndrome and urinary incontinence. Recently, the use of 5-HT4 antagonists has been suggested to have a therapeutic benefit in heart failure. Affinity for the hERG potassium ion channel and increased risk for prolonged QT intervals and arrhythmias has been observed for several 5-HT4 ligands. Serotonin may also have beneficial effects in the central nervous system (CNS) through stimulation of the 5-HT4 receptor, and reduced distribution of 5-HT4 antagonists to the CNS may therefore be an advantage. Replacing the amide and N-butyl side chain of the 5-HT4 receptor antagonist SB207266 with an ester and a benzyl dimethyl acetic acid group led to compound 9; a hydrophilic 5-HT4 antagonist with excellent receptor binding and low affinity for the hERG potassium ion channel. To increase oral bioavailability of carboxylic acid 9, two different prodrug approaches were applied. The tert-butyl prodrug 11 did not improve bioavailability, and LC-MS analysis revealed unmetabolized prodrug in the systemic circulation. The medoxomil ester prodrug 10 showed complete conversion and sufficient bioavailability of 9 to advance into further preclinical testing for treatment of heart failure.

Adsorptions of Formic and Acetic Acids on Ice Surface: Surface Binding Configurations and a Possibility of Interfacial Proton Transfer

Adsorptions of formic (FA) and acetic acids (AA) on Ih ice surface were studied using quantum mechanical/effective fragment potential (QM/EFP) scheme. Contrasting to the earlier studies in which trans-conformers were found as major surface configurations, our QM/EFP models found various cis-and trans-conformers on ice surfaces with the cis-conformers being more stable. The surface binding energies and configurations were largely dependent on surface heterogeneity yielding the various surface conformers. In addition, the overall binding energies of acetic acid are slightly higher as compared to formic acid, implying the stabilization effect of methyl group. Our study also found a feasible deprotonation route of adsorbed trans-formic acid. In contrast, acetic acid prefers molecular form due to the unfavorable hydrophobic methyl group. Therefore it is interesting to note that the additional methyl group of acetic acid enhances surface binding energies. But at the same time it reduces the chance of its deprotonation. Our ice model clearly demonstrated the significant effects of intrinsic surface heterogeneity on the distributions of surface binding energies and configurations, which cannot be represented by small water clusters.

Multifunctional terpolymeric MRI contrast agent with superior signal enhancement in blood and tumor

A new multifunctional terpolymeric system for simultaneous imaging and drug delivery has been recently developed in our laboratory. Herein we report the investigation of terpolymeric contrast agent for magnetic resonance imaging and doxorubicin (Dox) delivery. The polymer was synthesized by graft polymerization of methacrylic acid (MAA) and polysorbate 80 (PS 80) onto starch with multiple, chemically bound diethylenetriaminepenta acetic acid (DTPA) groups for gadolinium chelating. The terpolymer self-assembled to form nanoparticles upon addition of doxorubicin which binds with the PMAA chain. The physicochemical, biological and pharmacokinetic properties of the polymeric system were characterized and their contrast enhancement capability was evaluated in vitro and in vivo. The polymer was able to load gadolinium with high thermodynamic stability and exhibited low cytotoxicity. The Gd-loaded polymer (PolyGd), and Gd-Dox co-loaded nanoparticles (PolyGd-Dox) significantly enhanced MR signals, with ionic T1 relaxivities 3–5 times higher than those from Omniscan®, a small molecule contrast agent. In vivo studies showed superior and prolonged contrast enhancement compared to Omniscan® at one fourth the equivalent dose, without adverse effects. The PolyGd and PolyGd-Dox accumulated in the tumor and painted the tumor boundaries clearly for at least 48h. The PolyGd also enhanced angiogram contrast with contrast to noise ratio values of up to 55-fold and a blood half-life time of 200min. Seven days after intravenous administration, only relatively small amounts of gadolinium could be detected in the major organs of the mice (supplementary materials). These results suggest that the new terpolymeric system is useful as a theranostic platform for contrast enhanced MR imaging of vasculature and tumor as well as Dox delivery.

Protective effect of naringenin on acetic acid-induced ulcerative colitis in rats

To evaluate the ameliorative effect of naringenin (NG) during ulcerative colitis (UC) in rats. Rats were treated with three different doses (25, 50 and 100 mg/kg per day) of NG and a single dose of mesalazine (MES, 300 mg/kg per day) for seven days prior to ulcerative colitis induction by 4% acetic acid (AA). Twenty four hours after AA rectal administration, animals were scarified and the colonic tissues were dissected. Colonic mucus content was estimated using Alcian blue dye binding technique. In colon tissues, levels of total glutathione sulphadryls (T-GSH), non-protein sulphadryls (NP-SH) and thiobarbituric acid reactive substances (TBARS) were evaluated. The activities of the antioxidant enzymes, catalase (CAT) and superoxide dismutase (SOD) were measured. Concentrations of nucleic acids (DNA and RNA) and total protein were also estimated in colon tissues. Colonic levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), prostaglandin E2 (PGE2) and nitric oxide (NO) were estimated. In cross section of colitis tissue the histopathological changes were observed. Colonic mucus content was decreased in AA compared to controls (587.09 ± 65.59 mg/kg vs 941.78 ± 68.41 mg/kg, P < 0.001). AA administration markedly reduced T-GSH (5.25 ± 0.37 nmol/L vs 3.04 ± 0.24 nmol/L, P < 0.01), NP-SH (3.16 ± 0.04 nmol/L vs 2.16 ± 0.30 nmol/L, P < 0.01), CAT (6.77 ± 0.40 U/mg vs 3.04 ± 0.2 U/mg, P < 0.01) and SOD (3.10 ± 0.11 U/mg vs 1.77 ± 0.18 U/mg, P < 0.01) while TBARS, TNF-α, IL-1β, IL-6, PGE2 and NO levels (15.09 ± 3.84 nmol/L vs 59.90 ± 16.34 nmol/L, P < 0.01; 113.56 ± 1.91 pg/mg vs 134.24 ± 4.77 pg/mg, P < 0.01; 209.20 ± 36.38 pg/mg vs 422.19 ± 31.47 pg/mg, P < 0.01; 250.83 ± 25.09 pg/mg vs 638.58 ± 115.9 pg/mg, P < 0.01; 248.19 ± 36.98 pg/mg vs 541.74 ± 58.34 pg/mg, P < 0.01 and 81.26 ± 2.98 mmol/g vs 101.90 ± 10.73 mmol/g, P < 0.001) were increased in colon of rats with UC compared controls respectively.Naringenin supplementation, significantly and dose dependently increased the colonic mucus content. The elevated TBARS levels were significantly decreased (39.35 ± 5.86 nmol/L, P < 0.05; 26.74 ± 3.17 nmol/L, P < 0.01 nmol/L and 17.74 ± 2.69 nmol/L, P < 0.01) compared to AA (59.90 ± 16.34 nmol/L) group while the decreased levels of T-GSH and NP-SH and activities of CAT and SOD found increased by NG treatments in dose dependent manner. The decreased values of nucleic acids and total protein in AA group were also significantly (P < 0.01) increased in all three NG supplemented groups respectively. NG pretreatment inhibited the TNF-α levels (123.76 ± 3.76 pg/mg, 122.62 ± 3.41 pg/mg and 121.51 ± 2.61 pg/mg vs 134.24 ± 4.78 pg/mg, P < 0.05) compared to AA group, respectively. Interleukins, IL-1β and IL-6 levels were also decreased in NG50 + AA (314.37 ± 16.31 pg/mg and 292.58 ± 23.68 pg/mg, P < 0.05) and NG100 + AA (416.72 ± 49.62 pg/mg and 407.96 ± 43.87 pg/mg, P < 0.05) when compared to AA (352.46 ± 8.58 pg/mg and 638.58 ± 115.98 pg/mg) group. Similar decrease (P < 0.05) was seen in PGE2 and NO values when compared to AA group. The group pretreated with MES, as a reference drug, showed significant (P < 0.01) protection against the changes induced in colon tissue by AA administration respectively. In present study, NG produced antioxidant and anti-inflammatory effects demonstrating protective effect in inflammatory bowel disease.

Synthesis and Characterization of Telechelic Oligoethers with Terminal Cinnamylidene Acetic Acid Moieties

The formation of photoresponsive hydrogels were reported by irradiation of star-shaped poly(ethylene glycol)s with terminal cinnamylidene acetic acid (CAA) groups, which are capable of a photoinduced [2+2] cycloaddition. In this study we explored whether oligo(ethylene glycol)s and oligo(propylene glycol)s of varying molecular architecture (linear or star-shaped) or molecular weights could be functionalized with CAA as terminal groups by esterification or by amide formation. Oligo(ethylene glycol) (OEG) and oligo(propylene glycol) (OPG) with varying molecular architecture (linear, star-shaped) and weight average molecular weights between 1000 and 5000 g.mol-1 were functionalized by means of esterification of hydroxyl or amine endgroups with cinnamylidene acetic acid (CAA) or cinnamylidene acetyl chloride (CAC) as telechelic endgroups. The chemical structure, thermal properties, and molecular weights of the oligoethers obtained were determined by NMR spectroscopy, UV spectroscopy, DSC, and MALDI-TOF. CAA-functionalized linear and star-shaped OEGs or OPGs could be obtained with a degree of functionalization higher than 90%. In MALDI-TOF measurements an increase in Mw of about 150 g∙mol(-1) (for each terminal end) after the functionalization reaction was observed. OEGCAA and OPGCAA showed an increase in glass transition temperature (Tg) from about -70°C to -50°C, compared to the unfunctionalized oligoethers. In addition, the melting temperature (Tm ) of OEGCAA decreased from about 55°C to 30°C, which can be accounted for by the hampered crystallization of the precursors because of the bulky CAA end groups as well as by the loss of the hydroxyl telechelic end groups. The synthesis of photoresponsive oligoethers containing cinnamylidene acetic acid as telechelic endgroup was reported and high degrees of functionalization could be achieved. Such photosensitive oligomers are promising candidates as reactive precursors, for the preparation of biocompatible high molecular weight polymers and polymer networks.

COMPARATIVE EFFECT OF FLAXSEED OIL AND FISH OIL IN ACETIC ACID- INDUCED COLITIS IN RATS

Objectives: The aim of the present study was to evaluate the possible protective effect of flaxseed oil and to compare this effect with fish oil in experimental ulcerative colitis (UC).Methods: Rats were equally divided into five groups of six animals each. Sham control group (corn oil, 1 ml), acetic acid group (normal saline, 1 ml), flaxseed oil group (FSO, 1 ml), fish oil group (FO, 1 ml) and mesalamine-treated group (3 ml ) as a positive control. All drugs were administered intrarectally (IR). One hour following treatment in the acetic acid group, FSO group, FO group and mesalamine group, 1 ml of 4% acetic acid was introduced as an enema. Rats were sacrificed after 24 hrs and histopathological scores of the all colonic specimens were assessed by microscope. Colonic weight/length ratio was also evaluated.Results: Microscopical improvement as manifested by the reduction in the inflammatory score and normalization of intestinal mucosal architecture was observed in fish oil pretreated rats compared to acetic acid group but there was no significant difference in flaxseed oil pretreated group. The decrease in weight/length ratio was statistically significant in fish oil-treated group compared with acetic acid group, but there was no significant difference between flaxseed oil-treated and acetic acid group.Conclusion: The results of this study suggest that fish oil but not flaxseed oil could ameliorate the mucosal damage in experimentally induced ulcerative colitis in rats when given in the form of an enema.

2,2′,2′′,2′′′-(1,4-Phenylenedinitrilo)tetraacetic acid dihydrate

In the title compound, C14H16N2O8·2H2O, the complete organic molecule is generated by crystallographic inversion symmetry. The dihedral angles between the aniline ring and the acetic acid groups are almost identical, viz. 82.61 (7) and 80.33 (7)°. In the crystal, O—H⋯O hydrogen bonds link the organic mol­ecules and water mol­ecules, forming zigzag chains the c axis. An intra­molecular O—H⋯O hydrogen bond is also observed.

2-[1,1-Dioxo-2-(2,4,5-trifluoro-benz-yl)-2H-1,2-benzothia-zin-4-yl]acetic acid.

In the title compound, C17H12F3NO4S, the heterocyclic thia­zine ring adopts a half-chair conformation with the S and the N atoms displaced by −0.608 (3) and 0.105 (3) Å, respectively, from the mean plane formed by the remaining ring atoms. The dihedral angle between the two benzene rings is 36.63 (8)° and the acetic acid group is inclined at right angles [89.78 (8) °] to the mean plane formed by the C atoms of the thia­zine ring. The crystal structure features O—H⋯O and C—H⋯O hydrogen bonds.

Protective effect of shikimic acid on acetic acid induced colitis in rats

The aim of the present study was to investigate the effect of shikimic acid (SA), an active component extracted from Chinese star anise, on acetic acid (AA)-induced colitis in rats. Male Sprague-Dawley rats were divided into five groups: control, AA, AA+sulfasalazine (SASP; 500 mg/kg), and AA + SA at doses of 200 and 400 mg/kg. Colitis was induced in all groups except the control group by AA. The AA group received saline; treatment groups received SA or SASP, respectively. The activities of myeloperoxidase (MPO), superoxide dismutase (SOD) and inducible nitric oxide synthase (iNOS), and the levels of malondialdehyde (MDA) and nitric oxide (NO) were measured from colonic samples. In AA-induced model, SA significantly ameliorated colon damage, inhibited the increase of MPO and iNOS activities, depressed MDA and NO levels, and enhanced SOD activity. The findings of this study demonstrate the protective effect of SA in AA-induced colitis, probably due to an antioxidant action. Key words: Shikimic acid, ulcerative colitis, acetic acid, antioxidation.

Synthesis and Characterization of Highly Crystalline MgO Nanopowders via a Modified Chemical-Precipitation Process

A modified chemical-precipitation method is proposed to synthesize MgO nanopowders with high crystallinity at a low temperature of 400 degrees C using acetic acid as a modifier. The as-obtained intermediates and final products were investigated by Fourier-transformed infrared spectroscopy, thermogravimetric analysis, X-ray diffraction and transmission electron microscopy, respectively. The influence of acetic acid in the MgO preparation process was also investigated by a comparison of the samples without acetic acid, and the mechanism of acetic acid modification is also proposed. The carboxyl group of acetic acid could coordinate with Mg atom in a monodentate mode to form a new organic ligand intermediate Mg(OH)(OCOCH3), which facilitates the thermal decomposition of the intermediate at low temperature and enhances the crystallization of MgO.