scholarly journals The changes in the total vitamin B6 and the pyridoxal phosphate content of cells of Bacillus sphaericus during growth and sporulation: their possible relationships with α∈-diaminopimelic acid metabolism

1958 ◽  
Vol 70 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Joan F. Powell
Keyword(s):  
Vitamin B6 ◽  
Pyridoxal Phosphate ◽  
Acid Metabolism ◽  
Bacillus Sphaericus ◽  
Diaminopimelic Acid ◽  
Phosphate Content ◽  
Total Vitamin

Nutritionally Relevant Supplementation of Vitamin B6 in Lactating Women: Effect on Plasma Prolactin

PEDIATRICS ◽  
1985 ◽  
Vol 76 (5) ◽  
pp. 769-773
Author(s):  
Mark B. Andon ◽  
Mary P. Howard ◽  
Phylis B. Moser ◽  
Robert D. Reynolds
Keyword(s):  
Breast Milk ◽  
Vitamin B6 ◽  
Pyridoxal Phosphate ◽  
Postpartum Women ◽  
Plasma Prolactin ◽  
Elevated Plasma ◽  
Total Vitamin ◽  
Lactating Women

Pharmacologic doses of vitamin B6 administered to lactating women have been reported to suppress plasma prolactin. As a result, some physicians have recommended restriction of vitamin B6 intake for lactating women. In the present investigation, 20 lactating women were given supplemental doses of vitamin B6, 0.5 to 4.0 mg/d, beginning 24 hours after delivery. Plasma prolactin, plasma pyridoxal phosphate, and breast milk total vitamin B6 concentrations were determined during the first 9 months postpartum. Women receiving the supplement of 4.0 mg compared with 0.5 mg of vitamin B6 per day had significantly higher plasma pyridoxal phosphate (P < .01) and breast milk total vitamin B6 concentrations (P < .05) beginning at 1 month postpartum and continuing through the duration of the study. Plasma prolactin concentrations were not significantly different between the two groups. The percentage of all women, regardless of treatment, in whom lactation persisted at 1 and 2 weeks and 1, 3, 6, and 9 months were 100%, 100%, 100%, 90%, 80%, and 65%, respectively. All women who ceased to lactate during the study reported doing so by choice. Nutritionally relevant doses of vitamin B6 elevated plasma pyridoxal phosphate and breast milk total vitamin B6 concentrations of lactating women without reducing plasma prolactin concentration or halting lactation.

scholarly journals α∈-Diaminopimelic acid metabolism and sporulation in Bacillus sphaericus

1957 ◽  
Vol 65 (4) ◽  
pp. 700-708 ◽  
Author(s):  
Joan F. Powell ◽  
R. E. Strange
Keyword(s):  
Acid Metabolism ◽  
Bacillus Sphaericus ◽  
Diaminopimelic Acid

scholarly journals Assay and properties of diaminopimelate epimerase from Bacillus megaterium

1969 ◽  
Vol 113 (4) ◽  
pp. 589-601 ◽  
Author(s):  
P. J. White ◽  
B. Lejeune ◽  
Elizabeth Work
Keyword(s):  
Bacillus Megaterium ◽  
Vitamin B6 ◽  
Pyridoxal Phosphate ◽  
Initial Rate ◽  
Equilibrium Mixture ◽  
Enzymic Activity ◽  
Diaminopimelic Acid ◽  
Michaelis Constants ◽  
Assay Methods ◽  
Derivatives Of

1. Diaminopimelate epimerase from a soluble extract of Bacillus megaterium N.C.I.B. 7581 was purified about 25-fold by fractionation with ammonium sulphate and chromatography on calcium phosphate gel–cellulose. The product was impure but was unstable on further purification. 2. Quantitative assay methods for the enzyme were devised in which meso- or ll-diaminopimelic acid may be the substrate. 3. Between 25° and 45° at pH7·0 enzyme action leads to an equilibrium mixture containing 65% meso-isomer and 35% ll-isomer. 4. The initial rate of epimerization was 2–3 times as fast with ll-diaminopimelic acid as substrate as with the meso-isomer; a number of other amino acids were not racemized by the enzyme. The Michaelis constants at 37° were 6·7mm (ll-isomer) and 100mm (meso-isomer); with both substrates enzyme activity was maximal at pH7–8. The relative rates of epimerization of ll-diaminopimelic acid at 25°, 37° and 45° were 0·77:1·00:1·15. 5. A thiol compound (of which 2,3-dimercaptopropan-1-ol was the most effective) was needed as an activator of the purified enzyme. 6. Carbonylbinding reagents and several other compounds did not inhibit diaminopimelate epimerase. 7. Pyridoxal phosphate did not stimulate enzymic activity even in preparations that had been almost completely freed of derivatives of vitamin B6 (as shown by microbiological assay).

Iminiumsalz-Strukturen bei der durch Pyridoxalphosphat (Vitamin B6) katalysierten Bildung von Aromastoffen und Fehlaromen im Wein

2018 ◽  
Vol 73 (7) ◽  
pp. 521-533 ◽  
Author(s):  
Nikolaus Müller
Keyword(s):  
Vitamin B6 ◽  
Pyridoxal Phosphate ◽  
Acid Metabolism ◽  
Aroma Compounds ◽  
Vitamin B ◽  
Reaction Intermediates ◽  
Wine Production ◽  
Iminium Salt ◽  
Different Types ◽  
Sulfur Containing

Abstract Enzymes that use pyridoxal phosphate (PLP, Vitamin B6) as cofactor constitute a ubiquitous class of biocatalysts. A variety of PLP-dependant enzymes mainly involved in biochemical pathways concerning amino acid metabolism are found in all forms of life. These enzymes also play an important role in wine production, as well in grape growing as in enological processes. The formation of pleasant aroma compounds often runs with participation of pyridoxal-dependant enzymes. But these are also brought into context with the formation of off-odors, especially from sulfur compounds (i.e. sulfur containing amino acids cysteine, methionine). The versatility of PLP-dependant bioreactions arises from its ability to covalently bind the substrate and then to function as an electrophilic catalyst, thereby stabilizing different types of carbanionic reaction intermediates, containing iminium salt structures. This article summarizes the influence of PLP on sensorically important aroma compounds in wine growing and wine processing.

scholarly journals The Affinity of Carboplatin to B-Vitamins and Nucleobases

2021 ◽  
Vol 22 (7) ◽  
pp. 3634
Author(s):  
Beata Szefler ◽  
Przemysław Czeleń ◽  
Przemysław Krawczyk
Keyword(s):  
Vitamin B6 ◽  
Pyridoxal Phosphate ◽  
Antitumor Agents ◽  
Lone Pair ◽  
Chemical Compounds ◽  
Free Energies ◽  
Aromatic Rings ◽  
Anti Cancer ◽  
Potential Impact ◽  
Reactive Molecule

Platinum compounds have found wide application in the treatment of various types of cancer and carboplatin is one of the main platinum-based drugs used as antitumor agents. The anticancer activity of carboplatin arises from interacting with DNA and inducing programmed cell death. However, such interactions may occur with other chemical compounds, such as vitamins containing aromatic rings with lone-pair orbitals, which reduces the anti-cancer effect of carboplatin. The most important aspect of the conducted research was related to the evaluation of carboplatin affinity to vitamins from the B group and the potential impact of such interactions on the reduction of therapeutic capabilities of carboplatin in anticancer therapy. Realized computations, including estimation of Gibbs Free Energies, allowed for the identification of the most reactive molecule, namely vitamin B6 (pyridoxal phosphate). In this case, the computational estimations indicating carboplatin reactivity were confirmed by spectrophotometric measurements.

COMMITTEE ON NUTRITION

PEDIATRICS ◽  
1966 ◽  
Vol 38 (6) ◽  
pp. 1068-1076
Author(s):  
Keyword(s):  
Vitamin B6 ◽  
Pyridoxal Phosphate ◽  
Normal Population ◽  
Clinical Signs ◽  
Normal Activity ◽  
Limited Information ◽  
Adequate Intake ◽  
Time Data ◽  
Binding Properties ◽  
Adequate Diet

Because of the limited information available it is not possible to derive precise figures for daily requirements of vitamin B6 in infants and children at this time. Data currently available suggest that the daily need in childhood is 0.5 to 1.5 mg and in adolescence is 1.5 to 2 mg. The requirement in infancy is clearly related to protein intake and is 20µg/gm of dietary protein. Requirements of a few individuals will undoubtedly be higher than the estimates for the normal population. Some of these patients will manifest frank biochemical and clinical signs of deficiency which will usually be promptly reversed by administration of small additional amounts of pyridoxine. Another group of patients will require large amounts of the vitamin to balance the heritable alteration in binding properties of a specific apoenzyme requiring pyridoxal phosphate for normal activity. It would appear that most infants, children and adults will have little difficulty in achieving an adequate intake of vitamin B6 if they receive what is considered to be in other respects an adequate diet.

Components of Vitamin B6 in Grains and Cereal Products

1964 ◽  
Vol 47 (4) ◽  
pp. 750-753 ◽  
Author(s):  
Marilyn Macarthur Polansky ◽  
Elizabeth W Murphy ◽  
Edward W Toepfer
Keyword(s):  
Ion Exchange ◽  
Proximate Composition ◽  
Vitamin B6 ◽  
Total Vitamin ◽  
Cereal Products

Abstract Extracts of 56 grains and cereal products were chromatographically separated on Dowex-50 ion exchange columns into pyridoxine, pyridoxal, and pyridoxamine fractions. These fractions were assayed microbiologically by using S. carlsbergensis. Procedures used and values obtained by the assays are presented, along with values for total vitamin B6 in unchromatographed extracts and proximate composition values for each sample.

scholarly journals The Alkaline Phosphatase (ALPL) Locus Is Associated with B6 Vitamer Levels in CSF and Plasma

Genes ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 8 ◽  
Author(s):  
Loes Loohuis ◽  
Monique Albersen ◽  
Simone de Jong ◽  
Timothy Wu ◽  
Jurjen Luykx ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Vitamin B6 ◽  
Pyridoxal Phosphate ◽  
Genome Wide Association Study ◽  
Active Form ◽  
Minor Allele ◽  
Chromosome 1 ◽  
Joint Analysis ◽  
Genome Wide ◽  
A Genome

The active form of vitamin B6, pyridoxal phosphate (PLP), is essential for human metabolism. The brain is dependent on vitamin B6 for its neurotransmitter balance. To obtain insight into the genetic determinants of vitamin B6 homeostasis, we conducted a genome-wide association study (GWAS) of the B6 vitamers pyridoxal (PL), PLP and the degradation product of vitamin B6, pyridoxic acid (PA). We collected a unique sample set of cerebrospinal fluid (CSF) and plasma from the same healthy human subjects of Dutch ancestry (n = 493) and included concentrations and ratios in and between these body fluids in our analysis. Based on a multivariate joint analysis of all B6 vitamers and their ratios, we identified a genome-wide significant association at a locus on chromosome 1 containing the ALPL (alkaline phosphatase) gene (minimal p = 7.89 × 10−10, rs1106357, minor allele frequency (MAF) = 0.46), previously associated with vitamin B6 levels in blood. Subjects homozygous for the minor allele showed a 1.4-times-higher ratio between PLP and PL in plasma, and even a 1.6-times-higher ratio between PLP and PL in CSF than subjects homozygous for the major allele. In addition, we observed a suggestive association with the CSF:plasma ratio of PLP on chromosome 15 (minimal p = 7.93 × 10−7, and MAF = 0.06 for rs28789220). Even though this finding is not reaching genome-wide significance, it highlights the potential of our experimental setup for studying transport and metabolism across the blood–CSF barrier. This GWAS of B6 vitamers identifies alkaline phosphatase as a key regulator in human vitamin B6 metabolism in CSF as well as plasma. Furthermore, our results demonstrate the potential of genetic studies of metabolites in plasma and CSF to elucidate biological aspects underlying metabolite generation, transport and degradation.

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