Pyridoxal Research Articles

Quantitative Determination of Ascorbic Acid in Herbal Medicinal Products by HPLC

Ascorbic acid (vitamin C) is involved in many vital biochemical processes in the human body. Rose hips are a natural source of ascorbic acid. Rose hips are used in decoctions and many vitamin herbal teas. Russian compendial methods for the quantitative determination of ascorbic acid have certain limitations precluding its objective measurement in herbal drugs, herbal drug preparations, and herbal medicinal products.The aim of the study was to develop an analytical procedure for the quantitative determination of ascorbic acid in herbal drugs, herbal medicinal preparations, and herbal medicinal products using high performance liquid chromatography (HPLC).Materials and methods. The study involved two herbal medicinal products, Rose Hips (rose hips) and Vitamin Herbal Tea 2 (rose hips and rowan fruits), and reference standards for ascorbic acid, rutoside, quercetin, gallic acid, caffeic acid, chlorogenic acid, luteolin-7-glucoside, citric acid, DL-malic acid, thiamine, and pyridoxine hydrochloride. The authors used a 1260 Infinity II chromatograph with a diode array detector by Agilent and an Inertsil ODS-3 chromatographic column (250 mm × 4.6 mm, 5 µm) by GL Sciences. The HPLC system was operated in gradient elution mode, and the detector was set at 244 nm.Results. Ascorbic acid content in herbal drugs, herbal medicinal preparations, and herbal medicinal products can be determined by HPLC. Adequate sample preparation and chromatography conditions allow for inhibiting ascorbic acid oxidation in aqueous solutions for a period sufficient to complete testing (not less than 8 h).Conclusions. The authors developed a highly sensitive and selective HPLC procedure for the quantitative determination of ascorbic acid intended for the standardisation of herbal drugs, herbal medicinal preparations, and herbal medicinal products. The procedure is worthy of inclusion in the Rose Hips and Vitamin Herbal Tea 2 monographs of the State Pharmacopoeia of the Russian Federation. Switching to HPLC should not require lowering the limit for ascorbic acid (not less than 0.2%) established in the Rose Hips and Vitamin Herbal Tea 2 monographs for the titration method. The ascorbic acid content was below this limit in the vast majority of study samples. However, this discrepancy may be explained by the presence of dog rose (Rosa canina) species low in vitamin C, which should normally be used only as choleretics.

Biochemical and cellular effects of a novel missense mutation of the AGXT gene associated with Primary Hyperoxaluria Type 1

Primary Hyperoxaluria Type 1 (PH1) is a rare autosomal disease caused by mutations in AGXT that lead to the deficiency of alanine:glyoxylate aminotransferase (AGT). AGT is a liver pyridoxal 5′-phosphate (PLP)-dependent enzyme that detoxifies glyoxylate inside peroxisomes. The lack of AGT activity results in a build-up of glyoxylate that is oxidized to oxalate, then culminating in hyperoxaluria often leading to kidney failure. Most pathogenic mutations reduce AGT specific activity because of catalytic defects, improper folding, mistargeting to mitochondria, reduced intracellular stability, dimerization, and/or aggregation. Administration of pyridoxine (PN), a precursor of PLP, is a therapeutic option available for PH1 patients carrying responsive genotypes through the ability of the coenzyme to behave as a chaperone.Here, we report the clinical and biochemical characterization of the novel mutation c.1093G > T (p.Gly365Cys) identified in a Japanese patient. In silico studies predict that the p.Gly365Cys mutation causes a steric clash resulting in a local rearrangement of the region surrounding the active site, thus possibly affecting PLP binding and catalysis. Indeed, the purified p.Gly365Cys mutant displays proper folding but shows an extensive decrease of catalytic efficiency due to an altered PLP-binding. When expressed in AGXT1-KO HepG2 cells the variant shows reduced specific activity and protein levels in comparison with wild type AGT that cannot be rescued by PN treatment.Overall, our data indicate that the mutation of Gly365 induces a conformational change at the AGT active site translating into a functional and structural defect and allow to predict that the patients will not be responsive to vitamin B6, thus supporting the usefulness of preclinical studies to guide therapeutic decisions in the era of precision medicine.

The results of the use of a combined probiotic (Lactobacillus rhamnosus GG and Bifidobacterium animalis spp. lactis ВB-12) in children with gastrointestinal and skin manifestations of food allergy

At present, there are sufficient data on the influence of the gut microbiome on the development of food allergy and its progression. Changes in gut microbiome composition could positive impact on the course of allergic diseases by means of regulating the ratio of pro- and anti-inflammatory cytokines, as well as immunoglobulin E level. The purpose of the research was to study the effectiveness of combined probiotic in treatment of food allergies in children. Material and methods. The prospective randomized controlled study included 92 children aged from 4 to 5 years with symptoms of food allergy, involving the skin and gastrointestinal tract. The main group (n=46) took two chewable tablet Bifiform Kids (Lactobacillus rhamnosus GG >1x109 CFU, Bifidobacterium animalis spp. lactis BB-12 >1x109 CFU, thiamine mononitrate 0.40 mg, pyridoxine hydrochloride 0.50 mg per tablet) 2 times per day during 21 days. The control group (n=46) did not take the complex. The dynamics of the severity of food allergy skin symptoms was assessed using the SCORAD index, of gastrointestinal manifestations - on a point scale after 21 days and after 4 and 6 months (visits 2, 3 and 4). The concentration of immunoglobulin E, interleukins IL-17 and IL-10 was determined by enzyme immunoassay in blood serum at the baseline, as well as after 21 days and after 6 months (visits 1, 2 and 4) after the study initiation. Results. The SCORAD index among children from the main group decreased from 12.4±2.3 до 7.6±1.8 (р=<0.05) while taking a combined probiotic. It was significantly lower (р=<0.05) compared to the control group (SCORAD index changed from 12.1±2.4 to 12.2±1.9). On the 21st day, a statistically significant decrease in level of pro-inflammatory IL-17 (by 27%) and a statistically significant increase in the concentration of anti-inflammatory IL-10 (by 38.9%) were recorded. In children from the main group, the severity of such gastrointestinal symptoms as pain, rumbling in the abdomen, belching with air, bloating, gas discharge, increased stool and its unformularity, decreased compare to the control group of patients (р=<0.05), in which the intensity of complaints related to gastrointestinal manifestations did not change. In the main group of patients, the most clinical efficacy was noted immediately after the end of the probiotic intake. In the following five months, the intensity of symptoms increased in individual subjects from the main group, but in general, the intensity of complaints remained significantly lower than before probiotic intake (р=<0.05). Children from the main group showed a significant decrease in IgE level from 184±121 kU/l by 43.5% at visit 2 and by 38.0% at visit 4 (p=<0.05), while in children from the control group its level didn't change, amounting to 176±141, 165±121 and 178±132 kU/l, respectively. Conclusion. The results of the study show the effectiveness of the use of a combined probiotic (Lactobacillus rhamnosus GG, Bifidobacterium animalis spp. lactis ВB-12) with vitamins B1 and B6 in children with mild forms of gastrointestinal and skin manifestations of food allergy, both in relation to the severity reduction of the clinical symptoms of the disease (skin manifestations, pain, rumbling in the abdomen, belching with air, bloating, gas discharge, increased stool and its unformularity), and in relation to the dynamics of biochemical parameters - a decrease in the level of IgE.

EFFECTIVENESS OF THE MAGNESIUM APPLICATION IN OBSTETRICAL PRACTICE.

The aim: Conducting an evaluation of the effectiveness and safety of the use of magnesium in pregnant women. Materials and methods: A comprehensive examination of 60 pregnant women was conducted, of which 30 were taking a magnesium preparation in a daily dose of 2473.72 mg of magnesium citrate and 40 mg of pyridoxine hydrochloride (the main group) and 30 pregnant women who were not taking a magnesium preparation (сomparison group). The analysis of the clinical course of the first half of the pregnancy with the determination the frequency and structure of complications, blood pressure levels, indicators of ultrasound, general and biochemical blood tests, urinalysis, lipid status and carbohydrarate metabolism. Results: The main complications of the first half of pregnancy were: threatening miscarriage, abortion in progress, early gestosis, anemia, respiratory viral infection, exacerbation of extragenital pathology, hypertension. During the analysis of carbohydrate and lipid metabolism increased atherogenic potential. Analyzing the results of ultrasound studies reliably earlier comes down the local hypertonus. Сonclusions: The correction of chronic magnesium deficiency, performed by the drug magnesium has allowed to reduce cases of threat of abortion, the abortion that was started, the symptoms of early preeclampsia, anemia of pregnant women, symptoms of respiratory viral infection, reduces the number of bed-days in the case of hospitalization. The use of magnesium helped to normalize blood pressure, carbohydrate and lipid metabolism, reduces hypertonus of the myometrium.

A Vanadium(V) complexes derived from pyridoxal/salicylaldehyde. Interaction with CT-DNA/HSA, and molecular docking assessments

With the increasing development of metallopharmaceuticals, coordination compounds become viable alternatives for therapeutic uses. Despite the importance of platinum derivatives in this area, first-row transition metals complexes are welcome due to their characteristics. Vanadium is a promising metal in this context, as it has a range of compounds with different biological applications, including anticancer therapeutic effects. In this effort, the study of interactions between coordination compounds with deoxyribonucleic acid and with human serum albumin is fundamental. In this way, ten iminic ligands were synthesized by condensing p-substituted aromatic benzohydrazides (OH, CH3, H, NO2, and NH2) with salicylaldehyde (L1As-L5As) or pyridoxal hydrochloride (L1P-L5P). These ligands have characteristics that allow the tridentate coordination of vanadium cations, leading to the formation of ten vanadium(V) complexes (C1As-C5As and C1P-C5P) with different structural features, all characterized by single-crystal X-ray diffraction, UV–Vis and infrared spectroscopies, and cyclic voltammetry. In addition, the complexes were tested for their interactions with calf thymus deoxyribonucleic acid and human serum albumin by spectroscopic assays and molecular docking calculations. These new results can contribute to further research and provide different ways to design new vanadium complexes with biological applications.

Abstract 13187: Inhibition of Advanced Glycation End Products Formation and Serum Protein Infiltration in Bioprosthetic Heart Valves: Investigations of Anti-Glycation Agents

Introduction: Bioprosthetic heart valves (BHV) fabricated from glutaraldehyde pretreated bovine pericardium (BP), are the most commonly used heart valve replacements. However, BHV durability is limited by structural valve degeneration (SVD) resulting from both calcification and advanced glycation end product (AGE) deposition together with serum protein infiltration. This study investigated, for the first time, the application of anti-glycation agents as a way to mitigate AGE-related structural degeneration of BHV. Hypothesis: We investigated the hypothesis that anti-AGE agents (Aminoguanidine (AG), Pyridoxamine (PYR), and N-Acetylcysteine (NAC)) could mitigate BP glycation in model studies, both in vitro and in vivo. Methods: To model AGE accumulation in BHV, we used well-established accelerated in vitro glycation models using BP incubation with or without inhibitors. Incorporation of AGE in BP was monitored using radiolabeled glycation precursors. Changes in collagen structure were examined by two photon confocal microscopy and differential scanning calorimetry. In vivo studies used a juvenile rat subdermal BP implantation model with drug administration via drinking water. Endpoints were AGE formation, collagen structure, thermal denaturation temperature, serum albumin uptake, calcification, and serum glycation marker levels. Results: In vitro studies demonstrated that each of these agents significantly inhibited AGE formation in BP. However, after 28-day rat subdermal BP implantation in vivo, only PYR demonstrated significant inhibition of both AGE and serum albumin accumulation per immunostaining. BHV calcification was not mitigated by PYR, AG or NAC. Conclusions: This study is the first to demonstrate the use of AGE inhibitors in mitigating BHV glycation. PYR demonstrated significant efficacy both in vitro and in vivo, mitigating AGE formation and albumin infiltration in BP. Thus, this study provides a rationale for investigating PYR as a possible candidate for improving the durability and biocompatibility of clinically used BHV, providing the solution for this unmet clinical need.

Metabolomics analysis of antiquitin deficiency in cultured human cells and plasma: Relevance to pyridoxine-dependent epilepsy.

Deficiency of antiquitin (α-aminoadipic semialdehyde dehydrogenase), an enzyme involved in lysine degradation and encoded by ALDH7A1, is the major cause of vitamin B6 -dependent epilepsy (PDE-ALDH7A1). Despite seizure control with high dose pyridoxine (PN), developmental delay still occurs in approximately 70% of patients. We aimed to investigate metabolic perturbations due to possible previously unidentified roles of antiquitin, which may contribute to developmental delay, as well as metabolic effects of high dose pyridoxine supplementation reflecting the high doses used for seizure control in patients with PDE-ALDH7A1. Untargeted metabolomics by high resolution mass spectrometry (HRMS) was used to analyze plasma of patients with PDE-ALDH7A1 and two independently generated lines of cultured ReNcell CX human neuronal progenitor cells (NPCs) with CRISPR/Cas mediated antiquitin deficiency. Accumulation of lysine pathway metabolites in antiquitin-deficient NPCs and western-blot analysis confirmed knockdown of ALDH7A1. Metabolomics analysis of antiquitin-deficient NPCs in conditions of lysine restriction and PN supplementation identified changes in metabolites related to the transmethylation and transsulfuration pathways and osmolytes, indicating a possible unrecognized role of antiquitin outside the lysine degradation pathway. Analysis of plasma samples of PN treated patients with PDE-ALDH7A1 and antiquitin-deficient NPCs cultured in conditions comparable to the patient plasma samples demonstrated perturbation of metabolites of the gamma-glutamyl cycle, suggesting potential oxidative stress-related effects in PN-treated patients with PDE-ALDH7A1. We postulate that a model of human NPCs with CRISPR/Cas mediated antiquitin deficiency is well suited to characterize previously unreported roles of antiquitin, relevant to this most prevalent form of pyridoxine-dependent epilepsy.

Tuning Zn(Ⅱ) selectivity by conjugating vitamin B6 cofactors over bovine serum albumin stabilized red-emitting silver nanoclusters

The red-emitting bovine serum albumin stabilized silver nanoclusters (BSA-AgNCs) were conjugated with the vitamin B6 cofactors pyridoxal 5′-phosphate (PLP) and pyridoxal (PL). The deconvoluted bands in XPS revealed that the conjugation occurred due to the formation of imine-linkage between the vitamin B6 cofactors and the BSA functionalized over BSA-AgNCs. The TEM images supported the formation of pseudo-spherical shaped nano-aggregates upon conjugating vitamin B6 cofactor PLP over BSA-AgNCs. An emission band appeared at 532 nm after the conjugation of PLP or PL over the surface of BSA-AgNCs. The in situ formed nano-assembly PLP_BSA-AgNCs and PL_BSA-AgNCs showed a significant fluorescent enhancement, respectively, at 490 nm and 481 nm in the presence of Zn2+. The complexation-induced fluorescence enhancement from PLP_BSA-AgNCs and PL_BSA-AgNCs was reversed by adding a strong chelating agent EDTA. In addition, the fluorescence of PL_BSA-AgNCs was irreversibly quenched with the appearance of an emission band at 423 nm in the presence of Hg2+. The analytical performance and sensing mechanism of the developed nanoprobes PLP_BSA-AgNCs and PL_BSA-AgNCs were discussed, and the highly selective and sensitive nanoprobe PLP_BSA-AgNCs was applied for the quantification of Zn2+ in real samples.

Validated UPLC-MS/MS method for the analysis of vitamin B6 pyridoxal 5́-phosphate, pyridoxal, pyridoxine, pyridoxamine, and pyridoxic acid in human cerebrospinal fluid

Vitamin B6 and its metabolites play a crucial role in the development and interaction of brain metabolism. Following diagnostic improvements additional inherited disorders in vitamin B6 metabolism have been identified, most of them leading to a severe epileptic disorder accompanied by progressive neurological deficits including intellectual disability and microcephaly. Since early treatment can improve the outcome, fast and reliable detection of metabolic biomarkers is important. Therefore, the analysis of vitamin B6 metabolites has become increasingly important, but is, however, still challenging and limited to a few specialized laboratories.Until today, vitamin B6 metabolites are measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) using trichloroacetic acid for protein precipitation. In this work, we present the development and validation of a new, accurate and reliable method for analysis and quantification of the vitamin B6 vitamers pyridoxal 5́-phosphate (PLP), pyridoxal (PL), pyridoxine (PN), pyridoxamine (PM) and pyridoxic acid (PA) in human CSF samples using acetonitrile for protein precipitation. The method is based on ultra-performance liquid chromatography-tandem mass spectrometry using electrospray ionization (UPLC-ESI-MS/MS). The calibration was performed in surrogate matrix Ringer solution and metabolites were quantified by their corresponding isotopically labelled internal standards. A protein precipitation by acetonitrile was applied greatly improving chromatographic separation of the metabolites in a 4.7 min chromatographic run. The method was validated following the European Medical Agency (EMA) and Food and Drug Administration (FDA) guidelines for bioanalytical method validation. The metabolites were quantified from 5 to 200 nmol/L with a seven-point calibration curve and minimum coefficient of regression of 0.99. The validation was performed with quality control samples at four concentration levels with surrogate matrix ringer solution and pooled CSF material. Within- and inter-day accuracy and precision in Ringer solution were within 85.4 % (PLP) and 114.5 % (PM) and from 2.6 % (PA) to 16.5 % (PLP). Within- and inter-day accuracy and precision in pooled CSF material were within 90.5 % (PN) and 120.1 % (PL) and from 1.7 % (PA) to 19.0 % (PM). The method was tested by measuring of 158 CSF samples to determine reference ranges. The B6 vitamers PLP and PL were determined in all CSF samples above 5 nmol/L while PN, PM and PA showed concentrations below or near LOQ. Probable supplementation of PLP was detected in eight CSF samples, which revealed high concentrations of PM, PN, PL, or PA, whereas PLP was in the reference range or slightly elevated. The method is suitable for the application within a routine diagnostic laboratory.

Dietary vitamin B6 restriction aggravates neurodegeneration in mice fed a high-fat diet

AimsIt is well known that a low-status of B vitamins is associated with cognitive impairment. However, the impact of vitamin B6 (VB6) restriction on neurodegenerative diseases and its underlying mechanisms are rarely understood. This study investigated whether VB6 restriction aggravates neurodegeneration in mice fed either a low-fat (LF) control diet or a high-fat (HF) diet. Main methodsSix-week-old male C57BL/6J mice were divided into 4 groups (LF7, LF1, HF7 and HF1) and fed either an LF diet [7 mg pyridoxine (PN)/kg diet], an LF with 1 mg PN/kg diet, an HF diet or an HF with 1 mg PN/kg diet for 16 weeks. Brain cortex and hippocampus were collected and used for the determination of biochemical parameters including VB6, lipid peroxides, and neurodegeneration-related mRNA and protein levels. Key findingsVB6 restriction reduced levels of the biologically active form of VB6, pyridoxal phosphate (PLP) in the brain. Low consumption of VB6 inactivated brain-derived neurotrophic factor signaling and cell proliferation, and induced oxidative stress, endoplasmic reticulum stress and apoptotic cell death. Significant correlation between brain lipid peroxide levels and PLP levels were observed. VB6 restriction also induced characteristic features of neurodegeneration such as amyloid-β deposition and tau hyperphosphorylation. Similarly, high-fat diet increased parameters associated with neurodegeneration. Aggravating effects of VB6 restriction were observed in both LF control and HF groups. SignificanceDietary VB6 restriction plays a key role in neurodegeneration, and VB6 restriction worsens HF-induced neuronal damage in mice. Our study emphasizes the essential role of VB6 in maintaining brain health.

In vitro Rapid Regeneration of Bitter Melon (Momordica charantia L.) Using Direct Organogenesis in Kenya

Bitter melon is a traditional therapeutic vegetable in tropical and subtropical countries due to its carotenoid content, which provides health advantages. However, the production is significantly impacted by the poor seed germination rate and variability of progenies associated with the cultivation of this plant. Clonal propagation would increase the yield and usefulness of bitter melon. Momordica charantia was micropropagated using nodal explants in a modified MS medium containing vitamins (Glycine, myo-inositol, nicotinic acid pyridoxine HCl). Nodal explants were obtained from in vivo seedlings grown for 30 days in a greenhouse and then cultured on MS media with a range of BAP or KIN concentrations (0.50 - 2.5 mg/L), either alone or in combination. Shoots were induced within a minimum (6.33±0.58) day when 0.5 mg/L BAP was coupled with 0.50 mg/L KIN, resulting in the maximum shoot induction frequency (72.17±2.83%), 4.40±0.17 shoots/explant and 4.13±0.98 cm shoot length. Then, shoots were inoculated on 1/2 strength MS media either without growth regulator or with a supplement of IBA, NAA, and IAA in various concentrations (0.5 - 1.5 mg/L) to promote root induction. MS medium without growth regulator induced maximum rooting rates (93.33±2.66%) with 12.33 roots/shoot and 23.33 cm of root length. Rooted plantlets were successfully established in greenhouses after undergoing a hardening period in a regulated environment. The combination of BAP and KIN (0.50 mg/L and 0.50 mg/L) was most suitable for bitter melon shoot formation, whereas MS medium without growth regulator was optimal for rooting. This reproducible protocol for the regeneration of bitter melon plantlets would allow for rapid mass multiplication, conservation, and genetic manipulation for its agronomic improvement.

Influences of adding media additives on synthesis of gamma‐aminobutyric acid in fermentation of defatted rice bran extract with lactic acid bacteria

SummaryGamma‐aminobutyric acid (GABA), a main inhibitory neurotransmitter in brain, is a nonproteinogenic amino acid. The production of GABA from rice bran by lactic acid bacteria (Lactobacillus brevis) is an approach for maximising the potential of agricultural byproduct and reducing production cost. The use of media additives enhances the efficiency of GABA production, but their effects on cells and biomass in fermentation must be assessed to determine the appropriate concentration and efficiency. The influences of CaCl2 (0–1.5% w/v), Tween 80 (0–0.9% w/v), MnSO4 (0–0.6% w/v) and Pyridoxine hydrochloride (0–90 ppm) at different concentrations on GABA production by defatted rice bran extract fermentation using Lb. brevis VTCC‐B397 were evaluated. The changes in cell density, GABA content, reducing sugar content and pH value were observed. Consequently, the impact of media additive compounds on growth, development and GABA synthesis of Lb. brevis was demonstrated. Results showed that CaCl2, MnSO4 and Tween 80 positively affected GABA production from defatted rice bran extract by fermentation method.

Simultaneous analysis of two drugs used as supportive treatment for COVID-19: comparative statistical studies and analytical ecological appraisal

Pharmaceutical quality control products (QC) demand quick, sensitive, and cost-effective methods to ensure high production at a low cost. Green analytical methods are also becoming more common in pharmaceutical research to cut down on the amount of waste that goes into the environment. Meclizine hydrochloride (MZH) and pyridoxine hydrochloride (PYH) are reported to be excellent for calming down COVID-19. As a result, the amount of MZH and PYH manufactured by multinational pharmaceutical organizations has increased considerably during the last several months. The present work proposes three environmentally friendly, straightforward, and sensitive spectrophotometric procedures for quantification of MZH in the presence of PYH in a pure and marketable formulations. The approaches under examination include ratio subtraction (RSM), induced dual wavelength (IDW), and Fourier self-deconvolution (FSD). PYH, on the other hand, was directly quantified at 290 nm. For both drugs, the procedures follow Beer’s law in the range of (5–50 µg/mL). The RSM, IDW, and FSD methods, as well as the zero-order approach for PYH, have all been verified in accordance with ICH standards. The ecological value of established methodologies was determined using four distinct ways: the national environmental methods index (NEMI), the analytical Eco-scale, the Analytical Greenness Metric (AGREE), and the green analytical process index (GAPI). Comparing the findings to those of the previously described spectrophotometric technique, no major changes were identified.

Multiple forms of vitamin B6 regulate salt tolerance by balancing ROS and abscisic acid levels in maize root

Salt stress causes osmotic stress, ion toxicity and oxidative stress, inducing the accumulation of abscisic acid (ABA) and excessive reactive oxygen species (ROS) production, which further damage cell structure and inhibit the development of roots in plants. Previous study showed that vitamin B6 (VB6) plays a role in plant responses to salt stress, however, the regulatory relationship between ROS, VB6 and ABA under salt stress remains unclear yet in plants. In our study, we found that salt stress-induced ABA accumulation requires ROS production, in addition, salt stress also promoted VB6 (including pyridoxamine (PM), pyridoxal (PL), pyridoxine (PN), and pyridoxal 5′-phosphate (PLP)) accumulation, which involved in ROS scavenging and ABA biosynthesis. Furthermore, VB6-deficient maize mutant small kernel2 (smk2) heterozygous is more susceptible to salt stress, and which failed to scavenge excessive ROS effectively or induce ABA accumulation in maize root under salt stress, interestingly, which can be restored by exogenous PN and PLP, respectively. According to these results, we proposed that PN and PLP play an essential role in balancing ROS and ABA levels under salt stress, respectively, it laid a foundation for VB6 to be better applied in crop salt resistance than ABA.

Analysis for variable manifestations and molecular characteristics of pyridox(am)ine-5'-phosphate oxidase (PNPO) deficiency.

To summarize the clinical and genetic characteristics of patients with pyridox(am)ine-5'-phosphate oxidase (PNPO) deficiency. Clinical and genetic data of the patients were collected and analyzed. Eighteen patients from 17 families with variants in PNPO were collected, and 15 cases survived to date. The age of onset ranged from 1day to 5months (median age 6.5days) and seven of them presented with seizures <24h. About 7/18 (39%) of patients showed seizure-free with pyridoxine (PN) or pyridoxal-5'-phosphate treatment. Two patients showed surprised therapeutic responses to antiseizure medications therapy: one could be controlled for up to 1year and 5months, and the other showed seizure-free for >8years. The neurodevelopment was normal in one patient, mild delay in four, in whom responded well to PN. Severe delay could be seen in the remaining 10 surviving patients. Genetic analysis revealed 14 variants of PNPO, seven of which were novel. Five pairs of unrelated patients were observed to carry the same variants, respectively, and had similar developmental status and onset age of seizures in some degree in each pair, whereas also had differences. The clinical characteristics, including age of onset, treatment response and prognosis, were variable and difficult to classify into different types clearly. Patients with PNPO deficiency who used PN as their main treatment and being able to control seizures seemed to be associated with better outcomes. Patients with the same genotype tended to show the correlation of phenotype-genotype.

Shared Hydrogen Atom Location and Chemical Composition in Picolinic Acid and Pyridoxal Hydrochloride Derivatives Determined by X-ray Crystallography.

Three new single-crystal structures were isolated for picolinic acid (2), the trifluoroacetate salt of picolinic acid (1), and pyridoxal hydrochloride (3). These compounds displayed unconventional crystallographic features that must be considered when structural refinements are carried out. Thus, the generated Fourier differences map obtained with the diffraction data collected at 100 K was crucial to visualize electron densities, which were balanced by either one hydrogen atom or a hydrogen atom with an occupancy factor of 1/2 located between either two carboxylate moieties, two phenolic oxygen atoms, or two pyridinic nitrogen atoms. Moreover, NMR studies were conducted to analyze the bulk chemical composition of single crystals of 2-pyridinecarboxylic acid obtained from the gem-diol/hemiacetal forms and the polymerization products after the treatment of 2-pyridinecarboxaldehyde with TFA:H2O (1) or a diluted Cu(NO3)2 solution (2). The quantitative yield of the pyridoxal hydrochloride crystalline material (3) obtained from a diluted CuCl2 solution was exhaustively characterized by solid-state NMR methods. These methods allowed the resolution of the signals corresponding to the protons of the hydroxyl moiety of the intramolecular hemiacetal group and the phenolic hydrogen. Theoretical calculations using DFT methods were done to complement the atomic location of the hydrogen atoms obtained from the X-ray analysis.

Lipase-catalyzed production of pyridoxine monolaurate in solvent-free bioreactor system

This study demonstrated that solvent-free gas bubbling system enhanced production efficiency of pyridoxine monolaurate in the esterification catalyzed by immobilized Candida antarctica lipase B (Lipozyme 435). Volumetric productivity in solvent-free gas bubbling system (41.24 mmol/L/h) was 3.7 and 2.1-fold higher than those in conventional organic solvent system (11.10 mmol/L/h) and solvent-free system (19.86 mmol/L/h) using magnetic stirring, respectively. Among the three bioreactor systems, solvent-free gas bubbling system provided the best reusability of the lipase retaining 94.45 % of initial activity for six batch reactions. In the bioreactor system, 5-O-lauroyl-pyridoxine was regioselectively produced with maximum production of 371.17 mmol/L at 70 °C and 0.10 of substrate molar ratio ([pyridoxine]/[lauric acid]) for 9 h. Pyridoxine monolaurate exhibited interfacial activity at oil-water interfaces, suggesting it had emulsifying properties. Pyridoxine monolaurate is expected to be applied as a multi-functional emulsifier with nutritional values to replace both small molecule emulsifiers and pyridoxine hydrochloride in fortified beverages.

Effect of [Bmim][Br] and [Emim][HSO4] on the solution properties of pyridoxine HCl at various temperatures: A physicochemical, thermodynamic and spectroscopic approach

The current paper is concerned with deliberation of physicochemical and thermodynamic parameters of pyridoxine HCl in water and binary aqueous (0.05, 0.10 and 0.15) mol kg−1 [Bmim][Br]/[Emim][HSO4] media by means of empirically acquired density, velocity of sound and viscosity data. These parameters have been evaluated for the examination of interactions prevailing between pyridoxine HCl and [Bmim][Br]/[Emim][HSO4] in aqueous medium over a temperature range (293.15 to 313.15) K and at 0.1 MPa pressure. The deliberated parameters include partial molar volumes (Vϕo), partial molar isentropic compressibilities (Kϕ,so), Jones-Dole coefficients (A and B) and thermodynamic parameters of viscous flow (Δμ10,Δμ20, ΔH20andTΔS20) etc. Further, apparent specific volume (ASV) has been studied for pyridoxine HCl in water and in aqueous IL systems, showing that the studied systems have sweet-bitter taste at all temperatures and compostions. Moreover, the trends corresponding to deviation in computed parameters have been analysed in light of the solute−solvent and solute−solute interactions prevailing in the systems. Additionally, UV spectral analysis has been carried out for the interpretation of interactions prevailing between pyridoxine HCl and [Bmim][Br]/[Emim][HSO4]. By the obtained results, we have inferred that there is dominance of ion-hydrophillic and hydrophilic-hydrophillic interactions in the investigational systems.

Chemometric Quality Assessment of Doxylamine Succinate With Its Degradation Product: Implementation of Two Predictive Models on UV-Spectrophotometric Data of Anti-Emetic Binary Mixture.

The combination of pyridoxine hydrochloride (PYR) and doxylamine succinate (DOX) as an antiemetic binary mixture is used to treat nausea and vomiting during pregnancy. Two validated, accurate, and selective chemometric models were developed to assay binary mixture in the presence of DOX oxidative degradation product (DOX DEG) that could be characterized using LC-MS. Partial least squares (PLS) regression and principal component regression (PCR) were selected for the determination of our binary mixture in presence of degradation. To exhibit a training set of 25 mixtures that had various percentages of tested substances in five level 3 variables, an experimental design was chosen. A set of 18 synthetic mixtures in the concentration range 10.0-50.0 μg/mL, 12.00-20.0 μg/mL, and 6.0-30.0 μg/mL for PYR, DOX, and DOX DEG, respectively, were used in the construction of the calibration models.Then set of seven synthetic mixtures with different concentrations were used in the construction of the validation models. In validation samples with low root mean square error of prediction (RMSEP), the suggested models successfully predicted the concentrations of our drugs. The models developed were evaluated by RMSEP calculation, and the values obtained were 0.341, 0.196, and 0.388 for PYR, DOX, and DOX DEG, respectively, using PLS. While using PCR, RMSEP calculation and the values obtained were 0.400, 0.256, and 0.375 for PYR, DOX, and DOX DEG, respectively. The developed models were validated according to ICH strategies. The corresponding methods are suitable to determine PYR and DOX in pure form, pharmaceutical dosage form, and in the presence of DOX DEG product. The study of drug breakdown pathways is very important nowadays, so even in the presence of degradation and extreme spectral overlapping, the suggested PLS and PCR spectrophotometric approaches were able to identify PYR and DOX.

A sensitive UPLC-MS/MS method for simultaneous quantification of one-carbon metabolites & co-factors in human plasma

One-carbon metabolism is an important metabolic pathway involved in many diseases, such as congenital malformations, tumours, cardiovascular diseases, anaemia, depression, cognitive diseases and liver disease. However, the current methods have specific defects in detecting and qualifying the related compounds of one-carbon metabolism. In this study, a validated method was established to simultaneously quantify 22 one-carbon metabolites & co-factors in human plasma and applied to the study of correlation between one-carbon metabolism and colorectal cancer in human plasma samples, which were from 44 healthy subjects and 55 colorectal cancer patients. The method used ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-MS/MS), and the analytes included betaine, L-carnitine, L-cystathionine, L-cysteine, dimethylglycine, DL-homocysteic acid, homocysteine, methionine, pyridoxal hydrochloride, pyridoxamine dihydrochloride, pyridoxine dihydrochloride, S-(5′-Adenosyl)-L-homocysteine, serine, choline chloride, folic acid, glycine, pyridoxal phosphate monohydrate, riboflavin, taurine, 5-methyltetrahydrofolate, S-(5′-adenosyl)-L-methionine disulfate salt, trimethylamine oxide. The developed method was successfully applied to the quantification of 22 one-carbon metabolites & co-factors in human plasma from colorectal cancer patients and healthy individuals. The plasma concentrations of dimethylglycine was significantly decreased in the patients compared with the healthy individuals, while L-cystathionine was increased.