Suberic Acids Research Articles

P324 Urine metabolite profile characterizes clinical activity and disease extent in patients with inflammatory bowel disease

Abstract Background Inflammatory Bowel Disease (IBD), which comprises Crohn's Disease (CD) and Ulcerative Colitis (UC), is a disorder in which complex interactions between genetic, environmental, and microbial factors trigger alterations in the immune intestinal response. On the other hand, nutrient catabolism from the diet carried out by the microbiota results in the formation of metabolites that also impact immune responses on the intestinal mucosa. Considering that IBD patients have altered microbiota compared to healthy controls (HC) and that the urinary metabolic profile of an individual is the result of a combination of genetic, dietary, and microbial components, we propose the hypothesis that the urinary metabolic profile distinguishes IBD patients from HC. The aim of the study was to compare metabolomic analysis of urine samples from HC and IBD patients. Methods 27 patients were included [HC (n=10), UC (n=10), and CD (n=7)]. Clinical IBD activity was evaluated with partial Mayo score (UC) and Harvey-Bradshaw index (CD). Metabolites in urine were measured using gas chromatography-mass spectrometry (GC-MS). Metabolomic analysis and machine learning were performed using the MetaboAnalyst software. PLS-DA was used for multivariate analysis, and clustering separation was performed using hierarchical clustering. To identify and interpret patterns of metabolite concentration changes in a biologically meaningful way we perform Over Representation Analysis. Results In total, 62 organic acids were detected. Comparing UC and HC revealed 11 significantly altered metabolites (9 increased and 2 decreased). Main increased metabolites comprised lactic acid (p=0.0015), pyroglutamic acid (p=0.0147), isocitric acid (p=0.0325), and phosphoric acid (p=0.0091). Interestingly, the value of adipic and suberic acids were higher in remission vs. active patients. Furthermore, adipic acid was higher in UC patients with proctitis compared to left-side colitis/extensive colitis. Comparing CD and HC revealed only 2 significantly altered metabolites, glycolic acid (p=0.0214), and lactic acid (p=0.0111). Oxalic acid was more concentrated in CD patient with perianal disease. Finally, propionic and phosphoric acid were able to discriminate UC from CD patients. The most affected metabolic pathways were related to energy metabolism and oxidative stress, including the Warburg effect (p=0.0016), gluconeogenesis (p=0.0106), pyruvate metabolism (p=0.0197) and glutathione metabolism (p=0.0039) (Fig.1). Conclusion We found that the urinary metabolic profile of IBD patients differs from the HC, particularly for UC patients. These metabolites profile could be used to improve diagnosis and monitoring in patients with IBD.

Medium-chain dicarboxylic acids: chemistry, pharmacological properties, and applications in modern pharmaceutical and cosmetics industries.

Succinic (SUA), glutaric (GLA), pimelic (PA), suberic (SUBA), adipic (ADA), azelaic (AZA), and sebacic acids (SA) make up the majority of medium-chain dicarboxylic acids (MCDAs) with chain lengths of C4-C10, and are widely utilised in the chemical, food, textile, pesticide, pharmaceutical, and liquid crystal sectors. The MCDAs' two carboxyl groups provide them with an incredibly broad variety of applications. The focus of significant scientific research now is on the increasingly varied pharmacological effects of MCDAs. However, only a few studies have compared the biological characteristics of MCDAs in the contemporary pharmaceutical and cosmetic sectors and thoroughly examined the most recent research and marketing initiatives for MCDAs. This review's objective is to offer a thorough analysis of academic works on MCDAs, to assess the usefulness of these substances' chemical-pharmacological properties for use in the contemporary pharmaceutical and cosmetic industries, and to investigate the direction of their possible applications in these two disciplines. In addition, this review investigates how these compounds are metabolised in the human body.

Anthropogenic and biogenic tracers in fine aerosol based on seasonal distributions of dicarboxylic acids, sugars and related compounds at a rural background site in Central Europe

Water-soluble organic compounds in aerosols are considered as relevant indicators of atmospheric processes. Fine particulate matter (PM1) samples were collected at National Atmospheric Observatory Košetice (NAOK), a rural background site representative of Central Europe, from September 27, 2013 to August 9, 2014. The samples (n = 146) were analyzed for water-soluble dicarboxylic acids (hereafter referred to as diacids) and related compounds to identify their seasonal variations and origins. Based on the Positive Matrix Factorization (PMF) analysis, we identified 5 factors – 2 anthropogenic, 2 biogenic and 1 background factors.In winter, anthropogenic contributions dominated in total organic matter (OM). Typical tracers for the main winter anthropogenic factor 1, connected with biomass burning (BB), were anhydrosugars together with maleic (M), methylmaleic (mM) and methylsuccinic (iC5) acids. This BB factor accounted for 64.1 ± 14.3% of OM in winter (annual avg. 36.7 ± 27.4%). A secondary anthropogenic factor 2 was characterized by phthalic (Ph), terephthalic (tPh) and ketomalonic (kC3) acids, which we assigned to secondary combustion products. The contribution of anthropogenic factor 2 was at a similar level throughout the year (12.5 ± 10.1% in OM). Mainly in winter, although also in spring and autumn, was the characteristic formation of diacids by secondary aqueous phase reactions, typically accompanied by lower temperatures, global radiation and ozone (O3) concentrations, yet higher relative humidity (RH) and aerosol liquid water content (ALWC).In summer, contributions of biogenic origin dominated. Secondary organic aerosols (SOA) of biogenic origin were typically represented by malonic (C3), methylmalonic (iC4), 3-oxopropanoic (ωC3), 4-ketopimelic (kC7), 7-oxoheptanoic (ωC7), pimelic (C7) and suberic (C8) acids. The factor, named as Biogenic 1, was dominant in summer with a contribution of 40.3 ± 19.6% in OM, while in other seasons, its contribution was below 10%. This factor was mainly characterized by a relative summer increase in the concentrations of kC7 and ωC7 acids. The second biogenic factor 2, also significant in summer (36.8 ± 20.5%) and dominant in spring (34.9 ± 19.9%), was represented by primary sugars (fructose, galactose and sucrose), normal chain diacids (oxalic (C2) to azelaic (C9)) and their oxidative precursors (ωC3, 4-oxobutanoic (ωC4) and 5-oxopentanoic (ωC5) acids). The photochemical formation of SOA in the gas phase was characteristic mostly for the summer season, accompanied by higher temperatures, global radiation and O3 concentrations, and lower RH.Additionally, background factor was resolved, which represents compounds with no distinctive seasonal variation and can therefore be of both anthropogenic and biogenic origin and contained mainly less oxidized compounds (methylglyoxal (MeGly), glyoxal (Gly), glyoxylic acid (ωC2) and pyruvic acid (Pyr)).

ODP221 Late-Onset Hypoglycemia in a Patient with Fatty Acid Oxidation Disorder

Abstract Background Multiple acyl-CoA dehydrogenase deficiency (MADD) is a disorder of fatty acid and protein metabolism due to a defect in electron transfer flavoprotein or in electron transfer flavoprotein dehydrogenase, and can present with hypoglycemia as a component of its clinical phenotype. We describe a rare case of hypoglycemia due to MADD with unusually late onset at age of 63 years. Clinical case: 63-year-old female with history of hypertension and depression, admitted to the hospital with a several month history of progressive weakness resulting in inability to walk, lightheadedness, unintentional 40-pound weight loss and oropharyngeal dysphagia to solids. On exam, she was noted to have predominant cranial neuropathies and proximal muscle weakness. Patient was found to be hypoglycemic to 47 mg/dL [75-200], with a lactic acidosis of 2.1 mmol/L [0.5-1.9], elevated CK of 630 U/L [22-269], elevated aldolase of 12.7 U/L [1.5-8.1], and increased beta-hydroxybutyrate of 2.9 mmol/L [<0.3] along with transaminitis without cholestatic pattern. Fasting insulin level was 6 uIU/mL [3-19], C-peptide was low normal 1.1 ng/dl [0.8-3.5] with corresponding glucose of 57 mg/dl. Proinsulin level and sulfonylurea panel were unremarkable, and insulin antibodies were negative. Adrenal insufficiency was ruled out with normal cosyntropin stimulation test. IGF-1 and IGF-2 levels were also within normal limits. CT scan of the head, abdomen and pelvis did not evidence any issues. Furthermore, prior to this admission, patient had extensive work-up done for generalized weakness including evaluation for myasthenia gravis, myositis, HIV, thyroid disease, and other autoimmune conditions which was unrevealing. A muscle biopsy was performed with patology suggestive of a lipid storage disorder. Genetic testing only demonstrated variants of uncertain significance in LARGE1, PLEC and TTN genes. Additional testing revealed elevated serum concentrations of short, medium and long chain acylcarnitine species. Urinary organic acids were also increased with predominant elevation of 2-hydroxy-glutaric, ethylmalonic, adipic and suberic acids. This pattern, along with increased plasma acylcarnitine is typically associated with multiple acyl-CoA dehydrogenase deficiency. Serum free fatty acids were also high, supportive of MADD as previously reported in some cases. She was started on high-dose riboflavin replacement and advised to ingest a low-fat, low-protein diet, with frequent feeding and blood glucose monitoring. Conclusion MADD is a rare cause of hypoglycemia in adults. It is important to consider this condition as a differential diagnosis of hypoglycemia associated with generalized weakness even in older individuals. Presentation: No date and time listed

Synthesis of Aliphatic Polyanhydrides with Controllable and Reproducible Molecular Weight.

Polyanhydrides have been synthesized for decades by melt-polycondensation of diacid monomers and 5 to >10 times mole excess acetic anhydride to diacid monomers to form polymers with a polydispersity ranging from 2.5 to 6 and low reproducibility. Hydrophobic segments in polyanhydrides are beneficial to hinder the characteristic hydrolytic cleavage of an anhydride bond that provides stable polyanhydrides at room temperature. The objective of this work is to synthesize aliphatic polyanhydrides with various hydrophobic segments, controllable and reproducible molecular weight, and low polydispersity that are essential for potential use as drug carriers. A series of polyanhydrides of suberic, azelaic, sebacic, and dodecanedioic acids with controlled molecular weight, reduced polydispersity, and standard deviation of molecular weights, have been synthesized. All synthesized polyanhydrides were thoroughly characterized by NMR, Fourier transform infrared spectroscopy, and gel permeation chromatography. Molecular weights of the synthesized polyanhydrides are highly controllable, depending on the degree of activation of the dicarboxylic acid monomers, i.e., the amount of acetic anhydride used during synthesis. Polyanhydrides have been synthesized in triplicate by melt-polycondensation, using various mole ratios of acetic anhydride to diacids. The standard deviation of the molecular weights of the polyanhydrides is minute when using 1 equivalent of acetic anhydride during the activation of dicarboxylic acids, whereas if excess acetic anhydride is used, the standard deviation is very high. The effect of safe and natural inorganic catalysts, Calcium oxide, Zinc oxide, and Calcium carbonate on polymerization is also studied. As-synthesized poly(sebacic acid) can offer convenience to use in controlled drug delivery applications. In vitro drug release study using Temozolamide (TMZ), a medication used to treat brain tumors such as glioblastoma and anaplastic astrocytoma, shows 14% TMZ release after the first hour and 70% release over one day from the poly(sebacic acid) wafers.

Кинетические закономерности процесса водно-щелочного гидролиза березовой коры в СВЧ-поле

Birch bark consists of silver bark and bast. Silver bark contains up to 50 % of extractives and serves as a raw material for obtaining valuable biologically active substances (BAS), including betulin. A distinctive feature of the birch bark structure is a cross-linked polymer, suberin. Its monomers are suberic acids. They have found use in the production of lubricants, oils, insecticides, fungicides, polymers, polyesters, coatings, etc. A common method for extracting suberic acid salts from silver bark is exhaustive hydrolysis with an aqueous or water-alcohol solution of alkali (NaOH or KOH). We have proposed the activation of raw materials during hydrolysis by using an ultrahigh-frequency electromagnetic field (microwave hydrolysis). Isolation of suberin from silver bark is both a chemical and mass transfer process. Salts that are formed during hydrolysis of suberic acids diffuse to the surface of silver bark particles and pass into the hydrolysate. The limiting stage of mass transfer during birch bark hydrolysis is internal diffusion in the pores (mass conductivity). The anisotropy of the silver bark structure complicates the mathematical description of the mass transfer kinetics in the diffusion process. The process of internal diffusion during microwave hydrolysis is characterized by a steady regime starting from the 4th minute. The kinetics of this process and the effectiveness of diffusion in the tangential and longitudinal directions were determined. As the size of birch bark particles increases in both length (tangential direction) and width (longitudinal direction), the rate of the hydrolysis process and the degree of suberin isolation increase. Internal diffusion coefficients during microwave bark hydrolysis were determined. The highest value was obtained for fractions with a particle size of 3–4.5 mm (silver bark); the lowest – for fractions less than 1 mm (bast). The article shows that the small fraction (bast) should be separated and silver bark should be cut along the fiber in order to increase the yield of suberin after birch bark grinding.

Aqueous OH kinetics of saturated C6–C10 dicarboxylic acids under acidic and basic conditions between 283 and 318 K; new structure-activity relationship parameters

Bimolecular reaction rate coefficients (kOH) for reaction of hydroxyl radicals (OH) with adipic, pimelic, suberic, azelaic, sebacic and cis-pinonic acids were measured in aqueous phase for the neutral (pH = 2) and completely deprotonated (pH = 9) forms of the acids listed. Reactions were carried out in bulk solution between 283 and 318 K. Camphoric acid was used as a reference compound for measuring kOH values using a relative rate method, and with hydrogen peroxide (H2O2) as a photochemical source of OH. Concentrations of the reactants were monitored with liquid chromatography coupled with electrospray tandem mass spectrometry (LC-ESI/MS2).The kOH values measured were between 1 and 8 × 10−9 M−1s−1; only adipic and pimelic acids showed a significant pH-dependence to their OH reactivity. The kinetic data acquired and the data reported in the literature for camphoric, glutaric and succinic acids were used to optimize new structure-activity relationship (SAR) parameters. The SAR developed here allowed accurate prediction of kOH values for aliphatic carboxylic acids in the temperature range between 283 and 318 K. The accuracy of the developed SAR was evaluated against the experimental kOH values measured in this work and obtained from the literature data. Moreover, this work is the first to accurately predict the temperature-dependent kOH values for carboxylic acids.

Preparation and Characterization of Biobased Lignin-Co-Polyester/Amide Thermoplastics.

More than 23 million tonnes of lignin are produced annually in the US from wood pulping and 98% of this lignin is burnt. Therefore, creating products from lignin, such as plastics, offers an approach for obtaining sustainable materials in a circular economy. Lignin-based copolymers were synthesized using a single pot, solvent free, melt condensation reaction. The synthesis occurred in two stages. In the first stage, a biobased prepolymer consisting of butanediol (BD, 0.8–1 molar content) and a diacid (succinic (SA), adipic (AA) and suberic acids (SuA), with varying amounts of diaminobutane (DAB, 0–0.2 molar content) was heated under vacuum and monitored by Fourier transform infra-red (FTIR) spectroscopy and electrospray ionization-mass spectrometry (ESI-MS). In the second stage, prepolymer was mixed with a softwood kraft lignin (0–50 wt.%) and further reacted under vacuum at elevated temperature. Progression of the polymerization reaction was monitored using FTIR spectroscopy. The lignin-copolyester/amide properties were characterized using tensile testing, X-ray diffraction (XRD), dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) techniques. Lignin co-polymer tensile (strength 0.1–2.1 MPa and modulus 2 to 338 MPa) properties were found to be influenced by the diacid chain length, lignin, and DAB contents. The lignin-copolymers were shown to be semi-crystalline polymer and have thermoplastic behavior. The SA based copolyesters/amides were relatively stiff and brittle materials while the AA based copolyesters/amides were flexible and the SuA based copolyesters/amides fell in-between. Additionally, > 30 wt.% lignin the lignin- copolyesters/amides did not exhibit melt behavior. Lignin-co-polyester/amides can be generated using green synthesis methods from biobased building blocks. The lignin- copolyesters/amides properties could be tuned based on the lignin content, DAB content and diacid chain length. This approach shows that undervalued lignin can be used in as a macromonomer in producing thermoplastic materials.

Secondary organic aerosol markers and related polar organic compounds in summer aerosols from a sub-urban site in Athens: Size distributions, diurnal trends and source apportionment

Size-segregated aerosols (six stages with a diameter from <0.49 to >7.2 μm) were collected during daytime and nighttime in the summer of 2020 and were analyzed for dicarboxylic acids, isoprene, α/β-pinene and β-caryophyllene secondary organic aerosol (SOA) tracers, aromatic acids, hydroxy-polyacids, monocarboxylic acids and levoglucosan. The vast majority of the detected compounds presented significantly higher (p < 0.05) concentrations in fine than in coarse modes, excluding benzoic and oleic acids for which the higher fine mode than coarse mode concentrations were not significant and pinonic acid which was found at higher coarse mode concentrations. The dominant compound in the fine mode was 2-methylerythritol (mean of 213 ± 79.4 ng m−3), whereas in coarse particles palmitic acid was the most abundant (mean of 22.8 ± 9.7 ng m−3). All of the detected compounds, except for terephthalic acid, presented higher daytime concentrations, a difference that in the cases of glutaric, suberic, azelaic and pinic acids was significant (p < 0.05). The six-stage size distribution showed various patterns, with most species peaking at particles with a diameter of <1.1 μm suggesting photoxidation sources, while significant peaks at the size of 3–7.2 μm have been observed for suberic, azelaic, pinonic, benzoic, trimellitic and monocarboxylic acids. The hydroscopic growth of particles during nighttime may explain the observed decrease of the fine to coarse concentration ratio. From the employed source apportionment tools four factors where derived explaining 83.0% of total the variance including oxidation of anthropogenic volatile organic compounds (35.6%), oxidation of monoterpenes and sesquiterpenes (21.5%), isoprene's oxidation (14.1%) and photoxidation of unsaturated fatty acids (11.8%).

Disrupted Mitochondrial and Metabolic Plasticity Underlie Comorbidity between Age-Related and Degenerative Disorders as Parkinson Disease and Type 2 Diabetes Mellitus.

Idiopathic Parkinson’s disease (iPD) and type 2 diabetes mellitus (T2DM) are chronic, multisystemic, and degenerative diseases associated with aging, with eventual epidemiological co-morbidity and overlap in molecular basis. This study aims to explore if metabolic and mitochondrial alterations underlie the previously reported epidemiologic and clinical co-morbidity from a molecular level. To evaluate the adaptation of iPD to a simulated pre-diabetogenic state, we exposed primary cultured fibroblasts from iPD patients and controls to standard (5 mM) and high (25 mM) glucose concentrations to further characterize metabolic and mitochondrial resilience. iPD fibroblasts showed increased organic and amino acid levels related to mitochondrial metabolism with respect to controls, and these differences were enhanced in high glucose conditions (citric, suberic, and sebacic acids levels increased, as well as alanine, glutamate, aspartate, arginine, and ornithine amino acids; p-values between 0.001 and 0.05). The accumulation of metabolites in iPD fibroblasts was associated with (and probably due to) the concomitant mitochondrial dysfunction observed at enzymatic, oxidative, respiratory, and morphologic level. Metabolic and mitochondrial plasticity of controls was not observed in iPD fibroblasts, which were unable to adapt to different glucose conditions. Impaired metabolism and mitochondrial activity in iPD may limit energy supply for cell survival. Moreover, reduced capacity to adapt to disrupted glucose balance characteristic of T2DM may underlay the co-morbidity between both diseases. Conclusions: Fibroblasts from iPD patients showed mitochondrial impairment, resulting in the accumulation of organic and amino acids related to mitochondrial metabolism, especially when exposed to high glucose. Mitochondrial and metabolic defects down warding cell plasticity to adapt to changing glucose bioavailability may explain the comorbidity between iPD and T2DM.

New crystalline betulin-based materials: improving betulin solubility via cocrystal formation

The cocrystal formation potential of betulin with aliphatic dicarboxylic acids was investigated. Carboxylic acids of varying carbon chain length, namely: adipic, succinic and suberic acids, were selected to explore the effect of the coformer structure on cocrystal formation when liquid-assisted grinding was used. Cocrystal formation was characterized by powder XRD and IR studies. Betulin cocrystals with adipic acid were successfully synthesized and HPLC analysis showed that solubility of the betulin cocrystal was significantly improved compared to the initial betulin and its mechanocomposite with polymer

CLINICAL NUTRITION PROGRAM IMPROVES CHRONIC FATIGUE AND INTESTINAL PAIN IN 50 YEAR OLD MAN WITH HASHIMOTO’S

Event Abstract Back to Event CLINICAL NUTRITION PROGRAM IMPROVES CHRONIC FATIGUE AND INTESTINAL PAIN IN 50 YEAR OLD MAN WITH HASHIMOTO’S David J. Clark1* 1 Carrick Institute, United States Background: A 50 year old man presented with a history of chronic fatigue, gastrointestinal pain, cramping and gas. Within one hour after eating he experienced pain and gas, and then 3 to 4 hours later, he suffered severe lower intestinal cramping. He also suffered constipation (only one to two bowel movements per week). Frequently, a few hours after waking , he would be so fatigue that he needed to nap. This also occurred after doing any kind of exercising such as cycling. Eight years prior to presentation he was diagnosed with hypothyroidism and prescribed levothyroxine. Three years later he demonstrated elevated thyroid autoantibodies (Hashimoto’s) and was switched to bioidentical thyroid replacement. He followed various interventions including acupuncture, low FODMAPS diet and Small Intestine Bacterial Overgrowth protocol— but with no positive effects on his symptoms. He followed a gluten-free diet at time of presentation. He was taking Armour daily as well as vitamin D. Methods: Blood chemistry revealed high homocysteine (13.9), potassium (5.4), TSH (13.26), TPO antibodies (144) and thyroglobulin antibodies (2), low HDL (39), T4 (4.2), Reverse T3 (6), free T4 (0.7), normal T3 and Free T3, clinically significantly high BUN (25), clinically significantly low B12 (375), vitamin D (35). Urea Breath Test for H. pylori was negative. Urinary Organic Acids testing revealed high Arabinose (36), 4-Hydroxybenzoic (0.90), oxalic (135), 3-Hydroxyglutaric (6.8), Suberic (4.0), and 2-Hydroxyhippuric (1.2) acids. Dried urine testing for hormones revealed low levels of epitestosterone, clinically significantly low levels of beta-pregnanediol, alpha-pregnanediol, DHEA sulfate, androsterone, testosterone, 5-alpha DHT, He was placed on an anti-inflammatory diet and a supplement protocol utilizing turmeric, resveratrol, sublingual vitamin D, high EPA fish oil, broad-spectrum digestive enzyme formula, pregnenolone, a multi-nutrient formula for lowering homocysteine and a multi-multi-nutrient formula for support of normal tissue glucose levels. Results: At 60 day follow up, the patient reported a 60% increase in his energy. He no longer needed to nap in the mornings, nor after exercise. He reported a 50% improvement in the frequency of gastrointestinal pain and cramping. Frequency of bowel movements had increased to four to five times per week. In addition, blood chemistry showed improved B12 (580), vitamin D (68.4), homocysteine (11.1). Conclusion: The author suggests further investigation into clinical nutrition, diet and supplementation in the treatment of chronic fatigue and gastrointestinal complaints in patients with Hashimoto’s. Keywords: Hashimoto's autoimmune thyroiditis, HPA axis (hypothalamus-pituitary-adrenal), supplementation, Anti-inflammatory diet, Clinical Nutrition Conference: International Symposium on Clinical Neuroscience, Orlando, United States, 24 May - 26 May, 2019. Presentation Type: Poster Presentation Topic: Clinical Neuroscience Citation: Clark DJ (2019). CLINICAL NUTRITION PROGRAM IMPROVES CHRONIC FATIGUE AND INTESTINAL PAIN IN 50 YEAR OLD MAN WITH HASHIMOTO’S. Front. Neurol. Conference Abstract: International Symposium on Clinical Neuroscience. doi: 10.3389/conf.fneur.2019.62.00025 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 02 Apr 2019; Published Online: 27 Sep 2019. * Correspondence: Mx. David J Clark, Carrick Institute, Cape Canaveral, Florida, 32920, United States, mail@doctordavidclark.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers David J Clark Google David J Clark Google Scholar David J Clark PubMed David J Clark Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Investigation on solubility of hydroxy dibasic acids in alkanolamine solutions

Solubilities of three hydroxy dibasic (adipic, suberic, and sebacic) acids in alkanolamine solutions were measured within the 30-90℃ temperature range. It is found that solubility of these acids sharply grows with temperature and concentration of alkanolamine solvent. In addition, the study substantiates the adjustment of pH to optimize the CO2 absorption and desorption processes. The precipitation of added acids from alkanolamine solvents by cooling is found to be quite problematic, which makes the recovery of residual acids from lean alkanolamine solvents non-feasible and requires the application of alternative methods.

Effect of carbon chain length of dicarboxylic acids as cross-linking agents on morphology, encapsulation, and release features of protein-loaded chitosan microparticles

Chitosan microparticles were obtained by emulsion cross-linking technique. Impact of the carbon chain length of dicarboxylic acids (malonic, succinic, glutaric, adipic, pimelic, suberic, and azelaic) as cross-linking agents on morphology, encapsulation, and release of bovine serum albumin (BSA) was studied. Role of the polyglycerol polyricinoleate as surfactant to stabilize the pre-emulsions and its influence on the structure of the particles obtained was considered. The increase in the carbon chain length of dicarboxylic acids gives rise of the mass-average diameter of the microparticles. The greatest encapsulation ability of the cross-linked samples is observed for pimelic and suberic acids. The BSA encapsulation for azelaic acid decreases with the increase in the carbon chain length. The ratios of the initial and total cumulative releases of BSA for 24 h increase with the increase of the number of carbon atoms in dicarboxylic acid from 3 to 7. Beginning with the sample of cross-linked suberic acid, the dramatic decrease in the percentage of the initial release of BSA is occurred. The same dependence is observed for the swelling ratio due to the increase in the hydrophobic interactions within chitosan matrix and the growth of the thickness of dicarboxylic acid-polyelectrolyte layers on the surface of the microparticles. The carbon chain length of the above dicarboxylic acids was concluded to be available mode to control the properties of chitosan microparticles as vehicles for drug delivery and drug release.

Dicarboxylato ligands in osmium carbonyl sawhorse clusters: Chelating vs. bridging

Seven new complexes comprising of diosmium(I) tetracarbonyl sawhorse units bound to dicarboxylate anions (DCAs) have been synthesized using microwave heating. Succinic, adipic, pimelic, suberic, tetradecanedioic, and terephthalic acids react with Os3(CO)12 at temperatures ranging from 180 to 205 °C for 12–20 min to produce the osmium sawhorse complexes, which are subsequently reacted with phosphine ligands to replace the labile axial CO ligands. X-ray crystallographic analysis was used to determine the molecular structures of these complexes. Two complexes, those with suberato and tetradecanedioato ligands, are dinuclear species containing Os2 sawhorse molecules with chelating DCAs that form intramolecular loops. The succinato, adipato and pimelato complexes are tetranuclear species consisting of two Os2 sawhorse moieties linked together by two bridging DCAs. Thus the straight-chain hydrocarbon backbone of the DCAs must contain at least six carbon atoms in order for these ligands to prefer to chelate a single Os2 unit instead of forming bridges between multiple Os2 units. The terephthalato complex is a triangular hexanuclear species consisting of a trimer of dimers with three bridging dicarboxylato anions.

Recent advances in human sweat metabolomics for lung cancer screening

Lung cancer is the leading cause of cancer related mortality owing to the advanced stage it is usually detected because the available diagnostic tests are expensive and invasive; therefore, they cannot be used for general screening. To increase robustness of previous biomarker panels—based on metabolites in sweat samples—proposed by the authors, new samples were collected within different intervals (4 months and 2 years), analyzed at different times (2012 and 2014, respectively) by different analysts to discriminate between LC patients and smokers at risk factor. Sweat analysis was carried out by LC–MS/MS with minimum sample preparation and the generated analytical data were then integrated to minimize variability in statistical analysis. Panels with capability to discriminate LC patients from smokers at risk factor were obtained taken into account the variability between both cohorts as a consequence of the different intervals for samples collection, the times at which the analyses were carried out and the influence of the analyst. Two panels of metabolites using the PanelomiX tool allow reducing false negatives (95 % specificity) and false positives (95 % sensitivity). The first panel (96.9 % specificity and 83.8 % sensitivity) is composed by monoglyceride MG(22:2), muconic, suberic and urocanic acids, and a tetrahexose; the second panel (81.2 % specificity and 97.3 % sensitivity) is composed by the monoglyceride MG(22:2), muconic, nonanedioic and urocanic acids, and a tetrahexose. The study has allowed obtaining a prediction model more robust than that obtained in the previous study from the authors.

Relationship between adipic acid concentration and the core symptoms of autism spectrum disorders

Dicarboxylic acids are an important source of information about metabolism and potential physiopathological alterations in children with autism spectrum disorders (ASDs). We measured the concentration between dicarboxylic adipic and suberic acids in children with an ASD and typically-developing (TD) children and analyzed any relationships between the severity of the core symptoms of ASDs and other clinical features (drugs, supplements, drugs, or diet). The core symptoms of autism were evaluated using the DSM-IV criteria, and adipic acid and suberic acid were measured in urine samples. Overall, no increase in the concentration of adipic acid in children with ASDs compared to TD children, however when considering vitamin B supplementation in ASD there were significantly increased level of urinary adipic acid in children with an ASD not taking vitamin B supplementation compared to supplemented children or to TD children. No significant difference were observed in suberic acid. Interestingly, the increase in adipic acid concentration was significantly and indirectly correlated with the severity of the deficit in socialization and communication skills in children with an ASD. Therefore, therapeutic treatments aimed at decreasing adipic acid concentration might not be beneficial for treating the core symptoms of ASDs.

Dicarboxylic Acid Excretion in Normal Formula-Fed and Breastfed Infants.

Infant formulas are often supplemented with medium-chain triglycerides (MCTs) to optimize calories for small for gestational age or preterm infants. High amounts of MCTs have been associated with an increase in dicarboxylic acid (DCA) in the urine. Elevated DCA in the urine is also a clinical indicator for fatty acid metabolism disorders. The purpose of this study was to identify if there is an amount of MCTs that can be provided without elevating urinary DCA excretion. A metabolic screening laboratory provided urinary DCA excretion data for 175 infants. It was verified that no infants were diagnosed with metabolic disorders and therefore were considered "metabolically normal." All infants were either formula fed or breastfed at the time of screening. The type and volume of formula provided at the time of urine screening was documented. The exact amount of MCTs provided to each infant was calculated. The mean age of the infants was 3.09 months. The mean total DCA was determined for both the breastfeeding and formula groups. Within the formula group, the means were 32.07, 13.36, and 5.77 mmol/mol creatinine for adipic, suberic, and sebacic acids, respectively. Spearman correlation coefficient indicated correlations of r = 0.0693, r = 0.0166, and r = -0.0128 between percent MCT and adipic, suberic, and sebacic acids, respectively. No value was statistically significant. DCA excretion amounts did not vary between breastfed and formula-fed infants. Our data suggest that clinicians should not expect elevated dicarboxylic aciduria in infants who are fed a standard formula without added MCT oil.

Historic records of organic compounds from a high Alpine glacier: influences of biomass burning, anthropogenic emissions, and dust transport

Abstract. Historic records of α-dicarbonyls (glyoxal, methylglyoxal), carboxylic acids (C6–C12 dicarboxylic acids, pinic acid, p-hydroxybenzoic acid, phthalic acid, 4-methylphthalic acid), and ions (oxalate, formate, calcium) were determined with annual resolution in an ice core from Grenzgletscher in the southern Swiss Alps, covering the time period from 1942 to 1993. Chemical analysis of the organic compounds was conducted using ultra-high-performance liquid chromatography (UHPLC) coupled to electrospray ionization high-resolution mass spectrometry (ESI-HRMS) for dicarbonyls and long-chain carboxylic acids and ion chromatography for short-chain carboxylates. Long-term records of the carboxylic acids and dicarbonyls, as well as their source apportionment, are reported for western Europe. This is the first study comprising long-term trends of dicarbonyls and long-chain dicarboxylic acids (C6–C12) in Alpine precipitation. Source assignment of the organic species present in the ice core was performed using principal component analysis. Our results suggest biomass burning, anthropogenic emissions, and transport of mineral dust to be the main parameters influencing the concentration of organic compounds. Ice core records of several highly correlated compounds (e.g., p-hydroxybenzoic acid, pinic acid, pimelic, and suberic acids) can be related to the forest fire history in southern Switzerland. P-hydroxybenzoic acid was found to be the best organic fire tracer in the study area, revealing the highest correlation with the burned area from fires. Historical records of methylglyoxal, phthalic acid, and dicarboxylic acids adipic acid, sebacic acid, and dodecanedioic acid are comparable with that of anthropogenic emissions of volatile organic compounds (VOCs). The small organic acids, oxalic acid and formic acid, are both highly correlated with calcium, suggesting their records to be affected by changing mineral dust transport to the drilling site.

Diversity in Supramolecular Solid-State Architecture Formed by Self-Assembly of 1-(Diaminomethylene)thiourea and Aliphatic Dicarboxylic Acids

A family of supramolecular complexes of 1-(diaminomethylene)thiourea with aliphatic dicarboxylic acids, HOOC(CH2)nCOOH, with odd and even numbers of methylene groups in the carbon chain of the acids has been characterized. Using solvent-assisted and evaporation-based techniques, crystallization of 1-(diaminomethylene)thiourea with aliphatic dicarboxylic acids from water solutions yielded ionic supramolecular complexes with base to acid ratio of 2:1 or 1:1. Malonic, succinic, adipic, and sebacic acids with 1-(diaminomethylene)thiourea form supramolecular complexes of 2:1 ratio (1, 2, 4, and 8), whereas glutaric, pimelic, azelaic, and suberic acids form supramolecular complexes of 1:1 ratio (3, 5, 6, and 7). Within all supramolecular complexes only one with adipic acid crystallizes as a hydrate containing water molecules of crystallization. In the hydrated crystal with adipic acid, the O–H···O chains of water molecules interact with adipiate(2-) anions forming anionic layers, and the charge is compensated b...