Studies of Folic Acid Compounds in Nature. III. Folic Acid Compounds in Cabbage

1973 ◽  
Vol 51 (12) ◽  
pp. 1617-1623 ◽  
Author(s):  
C. Chan ◽  
Y. S. Shin ◽  
E. L. R. Stokstad

The folate pattern in cabbage was studied by chromatography on Sephadex G-25 and DEAE-cellulose columns associated with markers of high specific radioactivity and with differential microbiological assay. More than 90% of cabbage folate is polyglutamates containing more than five glutamic acid residues, mainly as the 5-methyl derivatives. The distribution is as follows: 52% of total cabbage folate is 5-CH3-H4PteGlu7, 32% is 5-CH3-H4PteGluc6, 7% is 5-CH3-H4PteGlu8, 4% is 5-CHO-H4PteGlu7, and the rest is 5-CH3-H4PteGlu3–5.

1977 ◽  
Vol 55 (8) ◽  
pp. 865-868 ◽  
Author(s):  
K. K. Batra ◽  
J. R. Wagner ◽  
E. L. R. Stokstad

The composition of folate coenzymes in romaine lettuce was studied. Lettuce extract was purified on QAE-Sephadex A-25 and folate compounds were separated into a monoglutamate fraction and a polyglutamate fraction by chromatography on Sephadex G-15. Both the mono- and poly-glutamate fractions were resolved on DEAE-cellulose. Positive identification of DEAE peaks was made by further cochromatography with high specific activity radioactive marker folate compounds and with differential microbiological assay. The distribution of folate compounds in lettuce is as follows: 32% 5-CH3-H4PteGlu; 1% 5-CHO-H4PteGlu; 3% 5-CHO-H4PteGlu4; 9% 5-CH3-H4PteGlu4; 13% 5-CHO-H4PteGlu5; and 31% 5-CH3-H4PteGlu5.


1972 ◽  
Vol 43 (6) ◽  
pp. 799-813 ◽  
Author(s):  
R. Corrocher ◽  
B. K. Bhuyan ◽  
A. V. Hoffbrand

1. The composition of guinea-pig liver folates and the biochemical route of formation of liver folates from injected tritium-labelled pteroylglutamic acid (folic acid) have been studied. 2. Endogenous folate was measured by microbiological assay with Lactobacillus casei and Streptococcus faecalis, with and without deconjugation of whole liver pteroylpolyglutamates (conjugated folates). Individual folate compounds were identified by microbiological assay after fractionation of liver folates by DEAE cellulose ion-exchange column chromatography. 3. Liver folate in the guinea-pig consists of about 84–87% reduced pteroylpolyglutamates with more than three glutamate moieties/molecule, about 12–15% reduced pteroyltriglutamates, about 1% reduced pteroyldiglutamates and only traces of reduced pteroylmonoglutamates. 4. About 53% of the liver folate consists of methylated derivatives. 5. Injected pteroylglutamic acid was first rapidly reduced and formylated or methylated. Glutamate moieties were then added, probably singly, to form di-, tri- and poly-glutamates. This was a relatively slow process with a hold-up at the triglutamate stage. 6. The proportion of the labelled pteroylglutamic acid in the polyglutamate form approximated to the proportion of endogenous folates in this form after 3–4 days. 7. The amount of radioactive folate in the liver increased progressively from 1 to 84 h after injection of a standard amount of radioactive pteroylglutamic acid.


1949 ◽  
Vol 177 (1) ◽  
pp. 117-124
Author(s):  
A. Sreenivasan ◽  
A.E. Harper ◽  
C.A. Elvehjem

2017 ◽  
Vol 76 ◽  
pp. 743-751 ◽  
Author(s):  
Laura Jaimes-Aguirre ◽  
Enrique Morales-Avila ◽  
Blanca E. Ocampo-García ◽  
Luis Alberto Medina ◽  
Gustavo López-Téllez ◽  
...  

2018 ◽  
Vol 154 ◽  
pp. 01017 ◽  
Author(s):  
Agustine Susilowati ◽  
Puspa Dewi Lotulung ◽  
Yati Maryati ◽  
Aspiyanto

A modification on nixtamalization process of dent corn (Zea mays identata) was conducted in order to recover natural folic acid-rich corn. Nixtamalization process on varieties of white dent corn and yellow dent corn subsequently were performed by steeping solution of Ca(OH)2 at concentrations of 0, 10, 20 and 30 % (w/w corn dissolved protein) for 18 hours, and boiling at 90 °C for 15, 30, 45 and 60 minutes. Result of research showed that concentration of Ca(OH)2 solution becoming more and more high and long boiling time increased both folic acid and reducing sugar, dropped total solids and total sugar, and fluctuated dissolved protein for both types of corn. Nixtamalization optimalization of white dent corn and yellow dent corn were achieved at combination of Ca(OH)2 20 % (w/w corn dissolved protein) for 60 minutes of boiling and Ca(OH)2 30 % for 30 minutes of boiling and gave folic acid of 466.81 and 506.74 μg/mL, respectively. In this condition, it is occurred an increase of folic acid 192.3 % (1.9 folds) and 139.89 % (1.4 folds) when compared to initial material of corn. Identification on folic acid monomer and glutamic acid monomer of both nixtamalized dent corn and yellow dent corn at optimum operation condition displayed domination of folic acid monomer with molecular weight (MW) 442.56 Dalton (Da.) with relative intensity 25.51 %, and 441.73 Da. with relative intensity 100 %, while glutamic acid monomer of nixtamalized yellow dent corn and nixtamalized white dent corn were dominated by monomer with MWs of 148.27 Da. and 148.32 Da., and relative intensity 3.73 and 1.8 %.


2001 ◽  
Vol 9 (3) ◽  
pp. 677-694 ◽  
Author(s):  
Oliver Langer ◽  
Frédéric Dollé ◽  
Héric Valette ◽  
Christer Halldin ◽  
Françoise Vaufrey ◽  
...  

1965 ◽  
Vol 43 (8) ◽  
pp. 1367-1374 ◽  
Author(s):  
P. L. McGeer ◽  
N. P. Sen ◽  
D. A. Grant

The excretion of 4(5)-amino-5(4)-imidazolecarboxamide (AIC) in the urines of normal rats, rats raised on a folic acid deficient diet, and rats raised on a vitamin B12 deficient diet was measured. The AIC excretion was elevated 3-fold above normal in the B12 deficient group and 1.5-fold above normal in the folic acid deficient group.No evidence could be found that the raised AIC excretion was associated with a block in the conversion of AIC to purines. The recovery of radioactive AIC in the urine after an intraperitoneal dose of 2 μmoles AIC per kg was not increased over normal in any of the deficient groups, and was significantly less than normal in the B12-deficient group. Most of the urinary radioactivity in all groups was in allantoin, uric acid, and purines.When a load of 220 μmoles of AIC per kg was administered there was no difference between the vitamin B12 deficient and the normal groups in AIC recovery in the urine. When a load of 220 μmoles of urocanic acid per kg was administered, however, the B12-deficient group had an 18-fold increase over normal in Figlu excretion, and the folic acid deficient group a 17-fold increase. Thus, a substantial block in formimino-L-glutamic acid (Figlu) metabolism, but not in AIC metabolism, existed in the vitamin-deficient groups.Feeding a B12-deficient group a 2% methionine supplement reduced the Figlu excretion after a urocanic acid load to less than half that observed in B12-deficient groups without methionine supplementation, but had no influence on the AIC excretion.


Marine Drugs ◽  
2022 ◽  
Vol 20 (1) ◽  
pp. 49
Author(s):  
William Kem ◽  
Kristin Andrud ◽  
Galen Bruno ◽  
Hong Xing ◽  
Ferenc Soti ◽  
...  

Nereistoxin (NTX) is a marine toxin isolated from an annelid worm that lives along the coasts of Japan. Its insecticidal properties were discovered decades ago and this stimulated the development of a variety of insecticides such as Cartap that are readily transformed into NTX. One unusual feature of NTX is that it is a small cyclic molecule that contains a disulfide bond. In spite of its size, it acts as an antagonist at insect and mammalian nicotinic acetylcholine receptors (nAChRs). The functional importance of the disulfide bond was assessed by determining the effects of inserting a methylene group between the two sulfur atoms, creating dimethylaminodithiane (DMA-DT). We also assessed the effect of methylating the NTX and DMA-DT dimethylamino groups on binding to three vertebrate nAChRs. Radioligand receptor binding experiments were carried out using washed membranes from rat brain and fish (Torpedo) electric organ; [3H]-cytisine displacement was used to assess binding to the predominantly high affinity alpha4beta2 nAChRs and [125I]-alpha-bungarotoxin displacement was used to measure binding of NTX and analogs to the alpha7 and skeletal muscle type nAChRs. While the two quaternary nitrogen analogs, relative to their respective tertiary amines, displayed lower α4β2 nAChR binding affinities, both displayed much higher affinities for the Torpedo muscle nAChR and rat alpha7 brain receptors than their respective tertiary amine forms. The binding affinities of DMA-DT for the three nAChRs were lower than those of NTX and MeNTX. An AChBP mutant lacking the C loop disulfide bond that would potentially react with the NTX disulfide bond displayed an NTX affinity very similar to the parent AChBP. Inhibition of [3H]-epibatidine binding to the AChBPs was not affected by exposure to NTX or MeNTX for up to 24 hr prior to addition of the radioligand. Thus, the disulfide bond of NTX is not required to react with the vicinal disulfide in the AChBP C loop for inhibition of [3H]-epibatidine binding. However, a reversible disulfide interchange reaction of NTX with nAChRs might still occur, especially under reducing conditions. Labeled MeNTX, because it can be readily prepared with high specific radioactivity and possesses relatively high affinity for the nAChR-rich Torpedo nAChR, would be a useful probe to detect and identify any nereistoxin adducts.


Blood ◽  
1986 ◽  
Vol 67 (2) ◽  
pp. 429-435
Author(s):  
E Boven ◽  
T Lindmo ◽  
JB Mitchell ◽  
PA Jr Bunn

The radiolabeled anti-T cell antibody T101 can be used for specific tumor localization, but unlabeled T101 produces limited cytotoxicity in patients. We thus studied the in vitro cytotoxic effects of T101 labeled with 125I, a radionuclide known for its short-range, high- linear-energy electrons. We showed that 125I-T101 could be readily prepared at high specific activity with high immunoreactivity. Human malignant T cell lines HUT 102, MOLT-4, and HUT 78 were found to differ in the number of T65 determinants (the antigen recognized by T101) and the sensitivity to external x-ray radiation, which were of significance for the cytotoxicity of 125I-T101 in vitro. The cytotoxic effects of 125I-T101 were also found to be dose dependent and increased with exposure time under frozen conditions. As controls, unlabeled T101 had no cytotoxic effect, while free Na 125I or the 125I-labeled irrelevant antibody 9.2.27 exerted minor cytotoxicity. In HUT 102 and MOLT-4, more than 3 logs' cell killing was achieved within four weeks. Because considerable cytotoxicity was demonstrated in vitro by 125I-T101 on T65- positive malignant cells, and because low-dose 111In-T101 can be used successfully for tumor localization, future trials using 125I-T101 at high specific radioactivity may improve therapeutic results in patients with T65-positive malignancies.


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