Acid Succinate Research Articles

Simultaneous derivative spectrophotometric analysis of doxylamine succinate, pyridoxine hydrochloride and folic acid in combined dosage forms

Two UV spectrophotometric methods have been developed, based on first derivative spectrophotometry for simultaneous estimation of doxylamine succinate, pyridoxine hydrochloride, and folic acid in tablet formulations. In method I, the concentrations of these drugs were determined by using linear regression equation. Method II is also based on first derivative spectrophotometry however simultaneous equations (Vierdot's method) were derived on derivative spectra. The first derivative amplitudes at 270.0, 332.8 and 309.2 nm were utilized for simultaneous estimation of these drugs respectively by both methods. In both the methods, linearity was obtained in the concentration range 2.5-50 μg/ml, 1-40 μg/ml and 1-30 μg/ml for doxylamine succinate, pyridoxine hydrochloride, and folic acid respectively. The developed methods show best results in terms of linearity, accuracy, precision, LOD, LOQ and ruggedness for standard laboratory mixtures of pure drugs and marketed formulations. The common excipients and additives did not interfere in their determinations.

Organic Acid Enhancement of Pelargonic Acid

Selected fatty acids, such as pelargonic acid and caprylic acid, are effective nonselective herbicides for a wide spectrum of annual weed species. Greenhouse and field studies evaluated the potential of certain food-grade organic acids to enhance herbicide activity of pelargonic acid-based formulations. The addition of diammonium succinate and succinic acid improved the efficacy of a pelargonic acid formulation from 117 to 200% in the greenhouse. l-Lactic acid and glycolic acid enhanced the efficacy of pelargonic acid formulations on velvetleaf and common lambsquarters in the greenhouse by 126 to 168% and in the field by 117 to 138%. Thus, combinations of fatty and organic acids with selected emulsifiers can be highly effective as safe, nonselective herbicides.Nomenclature: Caprylic acid, pelargonic acid, common lambsquarters, Chenopodium album L., CHEAL, velvetleaf, Abutilon theophrasti Medic. ABUTH

Isolation and characterization of arbuscules from roots of an increased-arbuscule-forming mutant of Lotus japonicus.

Previous methods for isolation of arbuscules from mycorrhizal roots are time-consuming, complex and expensive. Therefore, a simple, rapid and inexpensive method for the isolation of metabolically active arbuscules from plant root of an increased-arbuscule-forming mutant of Lotus japonicus (Ljsym78-2) is described. Roots of the L. japonicus mutant plants Ljsym78-2 colonized by Glomus sp. were separated from soil, washed with water, immersed in CaSO(4) before being cut into 5-mm pieces and homogenized with a Waring blender at 6000 rpm for 30 s. The arbuscules were purified by separation from plant tissues with a 50-mum nylon mesh, finally collecting on a 30-mum nylon mesh. Enzyme histochemical staining showed that the collected arbuscules had succinate dehydrogenase, alkaline phosphatase and acid phosphatase activities. The enzymic activity of the arbuscules was not affected after the isolation process. The establishment of this simple, rapid and inexpensive method for the isolation of metabolically active arbuscules will be useful to clarify the biochemical processes occurring in nutrient exchange at the arbuscular interface.

ATRA promotes alpha tocopherol succinate-induced apoptosis in freshly isolated leukemic cells from chronic myeloid leukemic patients

We investigated the in vitro efficacy of all-trans retinoic acid (ATRA) and alpha-tocopherol succinate (alpha-TS) alone and in combination on the induction of cell death in freshly isolated leukemic cells obtained from chronic myeloid leukemia (CML) patients. In vitro cytotoxicity and induction of lipid peroxidation by ATRA (10 microM) and alpha-TS (25 or 50 microM) were evaluated in primary leukemic cells by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and malondialdehyde formation respectively. Treatment of leukemic cells with alpha-TS alone or in combination with ATRA significantly (P < 0.05) decreased the cell viability in a concentration and time dependent manner as compared to peripheral blood mononuclear cells obtained from normal healthy controls. Lipid peroxidation was enhanced by 98% (P < 0.05) on combined treatment of cells with ATRA (10 microM) and alpha-TS (50 microM). ATRA alone did not enhance the externalization of phosphatidyl serine as studied by annexin-V binding using fluorescence activated cell sorter analysis, whereas in combination with alpha-TS it increased to 400% at 12 h. The treatment of leukemic cells to combination of ATRA with alpha-TS significantly decreased (P < 0.05) mitochondrial membrane potential and enhanced lysosomal destabilization. The combination of these drugs also increased mitochondrial and cytosolic reactive oxygen species (ROS) production, nitric oxide levels, and caspase-3 activity significantly and caused DNA fragmentation at 24 h in a concentration dependent manner in the leukemic cells. Our data suggest that ATRA in combination with alpha-TS efficiently induces apoptosis in leukemic cells, which may be a useful therapeutic modality in CML patients.

Aspartate-444 Is Essential for Productive Substrate Interactions in a Neuronal Glutamate Transporter

In the central nervous system, electrogenic sodium- and potassium-coupled glutamate transporters terminate the synaptic actions of this neurotransmitter. In contrast to acidic amino acids, dicarboxylic acids are not recognized by glutamate transporters, but the related bacterial DctA transporters are capable of transporting succinate and other dicarboxylic acids. Transmembrane domain 8 contains several residues that differ between these two types of transporters. One of these, aspartate-444 of the neuronal glutamate transporter EAAC1, is conserved in glutamate transporters, but a serine residue occupies this position in DctA transporters. When aspartate-444 is mutated to serine, cysteine, alanine, or even to glutamate, uptake of d-[3H]-aspartate as well as the inwardly rectifying steady-state currents induced by acidic amino acids is impaired. Even though succinate was not capable of inducing any steady-state transport currents, the dicarboxylic acid inhibited the sodium-dependent transient currents by the mutants with a neutral substitution at position 444. In the neutral substitution mutants inhibition of the transients was also observed with acidic amino acids. In the D444E mutant, acidic amino acids were potent inhibitors of the transient currents, whereas the apparent affinity for succinate was lower by at least three orders of magnitude. Even though L-aspartate could bind to D444E with a high apparent affinity, this binding resulted in inhibition rather than stimulation of the uncoupled anion conductance. Thus, a carboxylic acid–containing side chain at position 444 prevents the interaction of glutamate transporters with succinate, and the presence of aspartate itself at this position is crucial for productive substrate binding compatible with substrate translocation.

Stabilization of cranberry anthocyanins in nutraceutical capsules

Anthocyanins can be considered spy-substances, useful in obtaining information regarding the shelf-life of food supplements containing cranberry juice or cranberry-derived extracts. The level of total anthocyanins, as evaluated by high-performance liquid chromatography-diode-array detector and analytically expressed as cyanidin aglycone, represents a ‘quality index’ useful for routine estimation of shelf-life. The objective of this work was to study the stability of anthocyanins in a commercial cranberry (Vaccinium macrocarpon) dried extract compared with the stability of the same extract contained in a food supplement enriched with α-tocopheryl succinate and ascorbic acid. The values obtained after exposure of the samples to natural light and to alternating hot and cold temperatures show considerable sensitivity of the commercial cranberry dried extract to the agents used for the same evaluation (time, temperature and light) and emphasize a positive effect of the enrichment of the derived preparation with α-tocopheryl succinate and ascorbic acid.

Augmented suppression of androgen receptor signaling by a combination of α‐tocopheryl succinate and methylseleninic acid

Previous reports showed that alpha-tocopheryl succinate (alphaTS) and methylseleninic acid (MSA) independently reduce the abundance of androgen receptor (AR) in prostate cancer cells. The response to MSA happens quickly, whereas the response to alphaTS takes much longer. The present study was designed to investigate whether a combination of alphaTS and MSA would produce an additive or a greater than additive effect in suppressing AR level, AR transactivation, and prostate-specific antigen (PSA). LNCaP cells were treated with alphaTS alone for 31 hours, MSA alone for 3 hours, or alphaTS first for 28 hours and alphaTS/MSA together for the last 3 hours. AR and PSA mRNA levels were quantitated by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). AR transactivation was determined by the ARE-luciferase reporter assay. Both cellular and secretory PSA was also measured by the enzyme-linked immunosorbent assay (ELISA) method. Different doses of alphaTS were evaluated in combination with MSA. Some striking results are highlighted below for alphaTS alone, MSA alone, or alphaTS/MSA (presented in that order). AR mRNA level was depressed by 0%, 20%, or 60%, respectively; AR transactivation was inhibited by 35%, 10%, or 60%, respectively; whereas the PSA mRNA level was decreased by 40%, 60%, or 90%, respectively. Interestingly, secretory PSA was consistently reduced to a greater extent than cellular PSA. A combination of alphaTS/MSA produced a greater than additive effect in suppressing AR signaling compared with the single agent. Decreased AR abundance is a major factor, but not necessarily the sole factor, in diminishing the transcriptional activity of AR by alphaTS or MSA.

Investigation on the acute biochemical effects of light rare earths on rat serum by NMR-based metabonomic approaches

1H-NMR spectroscopy and pattern recognition (PR) method were used to assess the acute biochemical effects of light rare earths. Male Wistar rats were treated with both La(NO3)3 and Ce(NO3)3 at doses of 2, 10, and 50 mg/kg body weight. Serum samples from the rats with the two kinds of doses of light rare earths were obtained after 48 h and analyzed by a 600 MHz 1H-NMR spectrometer. Each NMR spectra was data-processed to provide 238 intensity-related descriptors as input coordinates in a multidimensional space and analyzed by PR method. Many low-molecular weight metabolites were identified by 1H-NMR spectra of the rat serum. An increase in ketone bodies, creatinine, lactate, succinate, and various amino acids (valine, leucine, and glutamine) were found from the higher doses (10 and 50 mg/kg body weight) of rare earths-treated groups, together with a decrease of glucose in the serum from Ce(NO3)3-dosed groups. These findings may mean that high-dosage of La and Ce impair a specific region of liver. The similar toxicities with various mechanisms for La and Ce are implicated by NMR-based metabonomic approach. Ce(NO3)3 exhibited a higher toxicity than La(NO3)3 at the same doses.

Oxidative Stress Causes Heart Failure with Impaired Mitochondrial Respiration

Elderly people insidiously manifest the symptoms of heart failure, such as dyspnea and/or physical disabilities in an age-dependent manner. Although previous studies suggested that oxidative stress plays a pathological role in the development of heart failure, no direct evidence has been documented so far. In order to investigate the pathological significance of oxidative stress in the heart, we generated heart/muscle-specific manganese superoxide dismutase-deficient mice. The mutant mice developed progressive congestive heart failure with specific molecular defects in mitochondrial respiration. In this paper, we showed for the first time that the oxidative stress caused specific morphological changes of mitochondria, excess formation of superoxide (O(2)(*)(-)), reduction of ATP, and transcriptional alterations of genes associated with heart failure in respect to cardiac contractility. Accordingly, administration of a superoxide dismutase mimetic significantly ameliorated the symptoms. These results implied that O(2)(*)(-) generated in mitochondria played a pivotal role in the development and progression of heart failure. We here present a bona fide model for human cardiac failure with oxidative stress valuable for therapeutic interventions.

Dietary Administration of the Proapoptotic Vitamin E Analogue α-Tocopheryloxyacetic Acid Inhibits Metastatic Murine Breast Cancer

The ability of the vitamin E (RRR-alpha-tocopherol) derivatives alpha-tocopheryl succinate (alpha-TOS) and alpha-tocopheryloxyacetic acid (alpha-TEA) to suppress tumor growth in preclinical animal models has recently led to increased interest in their potential use for treating human cancer. To make the use of these vitamin E analogues more clinically relevant, we compared the antitumor efficacy of orally and i.p. delivered forms of alpha-TEA and alpha-TOS against a murine mammary cancer (4T1) that bears resemblance to human breast cancer because of its poor immunogenicity and high metastatic potential. In cell culture studies, we showed that both compounds inhibited tumor colony formation and induced apoptotic death of tumor cells. To avoid solubility concerns associated with the hydrophobicity of alpha-TEA and alpha-TOS, we used the vesiculated forms of alpha-TEA (V alpha-TEA) and alpha-TOS (V alpha-TOS) for the in vivo tumor studies. Both compounds inhibited the growth of preestablished 4T1 tumors when given i.p. However, when given by oral gavage, only the esterase-resistant V alpha-TEA was able to suppress primary tumor growth and reduce lung metastasis. To make this approach more translatable to the clinic, alpha-TEA was incorporated into the diet and fed to tumor-bearing mice. We report here for the first time that dietary alpha-TEA delivery significantly inhibited primary tumor growth and dramatically reduced spontaneous metastatic spread to the lung in prophylactic and therapeutic settings. This study suggests that dietary alpha-TEA could prove useful as a relatively easy and effective modality for treating metastatic breast cancer.

Comparison of antioxidant activity in enzyme-independent system of six Stachys species

The antioxidant activity of six Stachys species native to Hungary in an enzyme-independent lipid-peroxidation system was examined. The methanolic extracts were found to be more effective than the controls α-tocopherol succinate and ascorbic acid. The following components were determined by spectrophotometric analysis: hydroxycinnamic acid derivatives, phenols content and flavonoids.

Synthesis of N-glycoconjugates of glycyrrhetic acid

New N-glycoconjugates that are analogs of glycyrrhizic acid were synthesized by condensation of α-L-rhamnopyranosylamine and β-D-lactosylamine with acid succinate and phthalate of glycyrrhetic acid methyl ester using N,N′-dicyclohexylcarbodiimide (DCC) or DCC-N-hydroxybenzotriazole.

Fecal D- and L- Lactate, Succinate, and Volatile Fatty Acid Levels in Young Dairy Calves

For evaluation of physiologically significant organic anions in the colonic environment, 87 samples of normal feces were collected from the rectum of 15 calves less than 60 days old. The calves were fed milk replacer with free access to starter diet and hay. After fecal extraction with water, pH, D- and L-lactate, succinate, and volatile fatty acid (VFA) concentrations were determined. There was wide variation in fecal pH (4.3 to 7.7). Higher lactate concentrations were observed in feces samples with lower pH, and most of these samples were collected during the first 4 weeks of life. Elevated lactate concentrations included both the D- and L-isomers, and the D-isomer comprised approximately 30-50% of total lactate. Elevated succinate concentrations were observed in only 8 fecal samples, while other samples had lower or trace amounts of succinate. Elevated fecal succinate showed no relationship with fecal pH or VFA concentrations. Fecal VFA concentrations were lower in samples collected in the early postnatal stage, but fecal VFA concentrations were not necessarily related to age. We confirmed that fecal D- and L-lactate concentrations increased with a concomitant decrease of VFA in the acidic lumen of the colon, although acidic feces were not necessarily accompanied by elevated concentrations of lactate. In contrast, succinate production was not related to fecal pH or VFA concentrations.

Cytotoxicity of liposomal α-tocopheryl succinate towards hamster cheek pouch carcinoma (HCPC-1) cells in culture

There is compelling evidence for the cancer chemopreventive effects of vitamin E and related compounds. Of all the vitamin E derivatives that have been investigated to date, vitamin E acid succinate is the most effective anti-cancer agent. This report describes the preparation and testing of liposomal formulation of mono α-tocopheryl ester of succinic acid (α-TOS) for cytotoxicity against hamster cheek pouch carcinoma cell line (HCPC-1). Small unilamellar vesicles (SUV) of phosphatidylcholine incorporating 70 μM α-TOS were superior to α-TOS alone or SUV without incorporated α-TOS, as inducers of apoptosis in HCPC-1 cells. Liposomal α-TOS perturbed the lipid structure in cells, promoted apoptosis, and decreased cell viability. The mechanism of action of α-TOS appears to involve membrane damage and induction of ceramide mediated apoptosis.

Anion-induced water flux as drug release mechanism through cationic Eudragit RS 30D film coatings

The objective of this study was to investigate the anion-controlled drug release mechanism through the cationic coating polymer Eudragit RS 30 D as a function of the anion attraction toward the polymer's quarternary ammonium group (QAG), anion valence, and film composition. The mechanism was investigated by dissolution testing, determination of chloride ion exchange using ion chromatography, plasticizer leaching by means of differential scanning calorimetry, and water uptake by Karl Fischer titration. All experiments were performed on coated theophylline micro tablets or isolated films of various compositions using 0.01 M sodium nitrate, sodium sulfate, disodium succinate, sodium acetate, and succinic acid as dissolution media. The mechanism of drug release involved an immediate penetration of dissolution medium into the polymer followed by an instant exchange of chloride against the medium's anion species at completely different rates compared with the drug release. Dependent on the attraction of the anion toward the QAGs, a water flux was induced by back and forth exchanging anions. Strong attraction (nitrate, sulfate) resulted in a low water flux while weak attraction resulted in a high flux (acetate, succinic acid). The water flux increased at increasing number of QAGs. Plasticizer acted as a diluent in respect of the number of QAGs, thus higher plasticizer concentrations led to lower drug release.

Opinion of the Scientific Panel on food additives, flavourings, processing aids and materials in contact with food (AFC) related to D-α-tocopheryl acid succinate as a source of vitamin E in foods intended for the general population, food supplements and f

Opinion of the Scientific Panel on food additives, flavourings, processing aids and materials in contact with food (AFC) related to D-α-tocopheryl acid succinate as a source of vitamin E in foods intended for the general population, food supplements and f

Direct high-performance liquid chromatographic analysis of d-tocopheryl acid succinate and derivatives

A method of analysis of a Vitamin E derivative d-tocopheryl acid succinate (TS) in biological fluids and commercially available products is necessary to study the kinetics of in vitro and in vivo metabolism, tissue distribution, and content uniformity. A simple and inexpensive high-performance liquid chromatographic method was developed for the direct determination of d-tocopheryl acid succinate in commercially available products, rat serum, and rat tissues. This method can also be applied to the determination of 15 Vitamin E derivatives. Rat serum (0.1 ml) was extracted with sodium dodecyl sulfate, ethanol, hexane, and then dried under nitrogen gas after addition of the internal standard, dl-α-tocopherol acetate. Separation was achieved on a C18 column with UV detection at 205 nm. The calibration curve for d-tocopheryl acid succinate was linear ranging from 0.025 to 100 μg/ml. The mean extraction efficiency was >92%. Precision of the assay was <5% (CV), and was within 5% at the limit of quantitation (0.025 μg/ml). Bias of the assay was lower than 5%, and was within 5% at the limit of quantitation. The assay was applied successfully to the serum and tissue distribution of d-tocopheryl acid succinate in rats, various Vitamin E derivatives, and content uniformity in commercially available products containing d-tocopheryl acid succinate.

In vivo modification of adriamycin-induced apoptosis in L-5178Y lymphoma cell-bearing mice by (+)-α-tocopherol and superoxide dismutase

Apoptosis was followed in L5178Y lymphoma cell-bearing mice at different times after intraperitoneal injections of adriamycin (ADM). Apoptosis was determined morphologically and confirmed by DNA laddering on electrophoresis. Apoptosis was observed 36 h after injection of 5 mg/kg ADM (apoptotic cell index 64.2±5.6 vs. 1.5±2.1 from the untreated group) and confirmed by DNA electrophoresis. However, when the animals were pretreated with (+)-α-tocopherol acid succinate or superoxide dismutase before ADM administration apoptotic index significantly diminished ( P<0.05) and the DNA electrophoresis did not show fragmentations. We conclude that in ADM-treated mice, tumour cell death occurs in two ways: first by necrosis, then later by apoptosis. These observations are likely to be associated with or caused by the generation of reactive oxygen species.

Biodegradable and functionally superior starch–polyester nanocomposites from reactive extrusion

AbstractBiodegradable starch‐polyester polymer composites are useful in many applications ranging from numerous packaging end‐uses to tissue engineering. However the amount of starch that can form composites with polyesters without significant property deterioration is typically less than 25% because of thermodynamic immiscibility between the two polymers. We have developed a reactive extrusion process in which high amounts of starch (approx. 40 wt%) can be blended with a biodegradable polyester (polycaprolactone, PCL) resulting in tough nanocomposite blends with elongational properties approaching that of 100% PCL. We hypothesize that starch was oxidized and then crosslinked with PCL in the presence of an oxidizing/crosslinking agent and modified montmorillonite (MMT) organoclay, thus compatibilizing the two polymers. Starch, PCL, plasticizer, MMT organoclay, oxidizing/crosslinking agent and catalysts were extruded in a co‐rotating twin‐screw extruder and injection molded at 120° C. Elongational properties of reactively extruded starch‐PCL nanocomposite blends approached that of 100% PCL at 3 and 6 wt% organoclay. Strength and modulus remained the same as starch‐PCL composites prepared from simple physical mixing without any crosslinking. X‐ray diffraction results showed mainly intercalated flocculated behavior of clay at 1,3,6, and 9wt% organoclay. Scanning electron microscopy (SEM) showed that there was improved starch‐PCL interfacial adhesion in reactively extruded blends with crosslinking than in starch‐PCL composites without crosslinking. Dynamic mechanical analysis showed changes in primary α‐transition temperatures for both the starch and PCL fractions, reflecting crosslinking changes in the nanocomposite blends at different organoclay contents. Also starch‐polytetramethylene adipate‐co‐terephthalate (PAT) blends prepared by the above reactive extrusion process showed the same trend of elongational properties approaching that of 100% PAT. The reactive extrusion concept can be extended to other starch‐PCL like polymer blends with polymers like polyvinyl alcohol on one side and polybutylene succinate, polyhydroxy butyrate‐valerate and polylactic acid on the other to create cheap, novel and compatible biodegradable polymer blends with increased toughness. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1072–1082, 2005

The Antibacterial Activity and Biodegradable Properties of Biodegradable Polymers Containing a Silver-Based Antibacterial Agent

The purpose of this study is to investigate the spinnability, biodegradability and antibacterial properties of biodegradable polymers containing a silver-based antibacterial agent. The biodegradable polymers used were polybutyrene succinate (PBS) and polylactic acid (PLA). Two types of silver-based antibacterial agents, silver-based zeolite (AgZL) and silver-based zirconium phosphate (AgZR), were used. The experimental results show that the value of the weight-average molecular weight (Mw), which greatly affects the spinnability of the fiber sample, decreases with the increase in the contents of AgZL and AgZR for both PLA and PBS. The degree of the decrease in the Mw for AgZL was greater than that for AgZR because of the higher content of crystal water for AgZL. The value of antibacterial activity (R) for PLA was higher than that for PBS because of the lactic acid of PLA. AgZL was more effective in terms of antibacterial activity than AgZR in PLA and PBS fiber samples because the elution concentration of silver ions of AgZL is higher than that of AgZR from the initial stage of elution. The biodegradability of PLA and PBS increases with the increase in the content of the antibacterial agent. Especially, the hydrolysis of PLA is accelerated by the silver-based antibacterial agent. Finally, the value of R decreases as the number of washing cycles increases because the antibacterial agent falls of from the polymer surface.