Pseudo vitamin

Analogues of vitamin Bi2 are known in which the dimethylbenzimidazole is replaced by other bases it is 5-hydroxybenzimidazole in Factor III, adenine in pseudo-vitamin Bj2, 2-methyladenine in Factor A and 2-methylhypoxanthine in Factor H. Where adenine units occur, they are linked to ribose through position 7, rather than position 9 as in other adenine nucleosides. 

In both bacteria and liver, the 5 -deoxyadenosyl coenzyme is the most abundant form of vitamin B12, while lesser amounts of methylcobalamin are present. Other naturally occurring analogs of the coenzymes include pseudo vitamin B12 which contains adenine in place of the dimethylbenzimidazole. 

Usual dietary sources of vitamin B12 are animal food products (meat, milk, eggs, and shellfish), but not plant food products. To evaluate whether foods contain true vitamin B12 or inactive corrinoids, vitamin B12 compounds were purified and characterized using TLC on silica gel. The Rf values of the unknown vitamin B12 compound, purified from an algal health food (Spmilina tablets) were identical to those of pseudo vitamin B12 (Rf values 0.14 and 0.42), but not to those of vitamin Bi2 (or 5,6-dimethylbenzimidazolyl cyanocobamide) (Rf values 0.23 and 0.56), benzimidazolyl cyanocobamide (Rf values 0.18 and 0.52), 5-dydroxybenzunida-zolyl cyanocobamide (Rf values 0.20 and 0.47), and p-cresolyl cyanocobamide (Rf values 0.38 and 0.62) by TLC on silica gel 60 with l-butanol-2-propanol-water (10 7 10 vol/vol) and 2-propanol-NH40H (28%)-water (7 1 2 vol/vol) as solvents, respectively. The results indicate that an inactive vitamin B12 compound (pseudovitamin B12) is predominant in Spirulina tablets. 

Fig. 1 Structural formulae of B12 compounds. The partial structures of B12 compounds show only those portions of the molecule that differ from B12. (1) AdoBi2 (2) MeBi2 (3) OH-B12 (4) SO Bi2 (5) CN-B12 or B12 (6) benzimidazolyl cyanocobamide (7) pseudo vitamin B12 (8) 5-hydroxy benzimidazolyl cyanocobamide (9) p-cresolyl cyanocobamide.

Deficient la-hydroxylase activity, characterized by the infantile onset of severe hypocalcemia, moderate hypophosphatemia, and responsiveness to pltysiologic doses of calcitriol, has been called hereditary pseudo-vitamin D deficiency rickets (PDDR), vitamin D dependency because of its responsiveness to active vitamin D, or vitamin D-dependent rickets type 1. This disease is now more simply and appropriately termed vitamin D la-hydroxylase deficiency. Affected persons are normal at birth but have growth retardation, poor motor development, arrd generalized muscle weakness by 2 years of age. Affected children develop hypocalcerrria, hypophosphatemia, increased seram alkaline phosphatase activity, and increased seram PTH some develop hypocalcerrric seizures. Serum concentratiorrs of 1,25(0H)2D are low despite normal concerrtra-tions of 250HD responses to administration of 1,25(0H)2D are excellent. 

Edouard T, Alos N, Chabot G, Roughley P, Glorieux FH, Rauch F (2011) Short- and long-term outcome of patients with pseudo-vitamin D defieieney rickets treated with calcitriol. J Clin Endocrinol Metab 96 82-89... 

P. arabinosum and the bacteria that live in the gut of humans and animals synthesize mostly the purine-containing cobamides. If DMB is added to the feed, then the synthesis of cobalamins in the stomach of animals increases (Rickard et al., 1975). The finding of incomplete corrinoids in various bacteria and algae (Neujahr and Frires, 1966) shows that their biosynthesis may proceed with difficulty. Cobinamide, pseudo-vitamin B, factor A and factor III can act as growth factors for microorganisms if they contain a nucleotide, they are also active in enzymatic reactions in animals. 

Most of the corrinoids in propionic acid bacteria are represented by AdoCbl MeCbl is usually present in low amounts. The principal form is pseudo-vitamin B12, containing adenine nucleotide as the lower ligand. MeCbl is formed by the reaction of S-adenosylmethionine with the cobalamin that contains reduced Co(I). 

HA Barker, H Weissbach, RD Smyth. A coenzyme containing pseudo-vitamin B,2. Proc Natl Acad Sci USA 44 1093-1097, 1958. 

Antivitamins (Vitamin Antagonists, or Pseudo-vitamins). Antivitamins, which are present in some natural foods, are compounds that do not function as vitamins even though they are chemically related to them. As a result, they may cause vitamin deficiencies if the E)ody (1) is unable to distinguish between them and true vitamins, and (2) incorporates them into essential body compounds. 

A new series of vitamin Bj2 model compounds has been prepared by treating the cobalt(ii) clielate (100) with BH in the presence of RX (R = Me, Et, Pr", Bu", n-pentyl, n-hexyl, n-heptyl, n-octyl, or n-decyl). All the complexes RCoL have pseudo-octahedral structures in the solid state and, in poorly... 

Prostate cancer effect. Saw palmetto, vitamin E, and selenium supplements were used by 26.5% of the questioned men diagnosed with prostate cancer . PC-SPES, an herbal mixture of chrysanthemum, isatis, licorice, Ganoderrm lucidum, Panax pseudo-ginseng, Rabdosia rubescens, saw palmetto. 

Leonurus heterophyllus Sweet L. japonicus Houttuyn. L. macranthus Maxim. L. mongolicus V. Kreczet. et Kupr. L. pseudo-macranthus Kitag. Yi Mu Cao (Motherwort) (aerial part) Leonurine, stachydrine, vitamin A, leonaridine, leonurinine, fatty oils.33 Stimulates uterine contractions, respiratory system, proliferation of T cells, skeletal muscles. 

The protein complex of T. elongatus consists of 12 subunits that contain 96 Chi a and 22 carotenoid molecules, 3 [4Fe4S] centres and 2 phylloquinone (vitamin K,) molecules (for molecular structures see Fig. 2). The cofactors of the ET chain are arranged in two branches as pairs of molecules related by a pseudo-C2 axis. After light excitation an electron is donated from the primary donor P700, a pair of chlorophylls, to monomeric chlorophyll a (acceptor A0), phylloquinone (A() and the 3 iron-sulfur centres (F , Oa and B). It has been controversially discussed in the literature whether both highly symmetric pigment branches are... 

Figure 17 Pseudo-first-order plot of thermal degradation of ascorbic acid (vitamin C) in a solid dosage form.

Vitamin B12 (1) was discovered some 55 years ago as the (extrinsic) antipemicious anemia factor, important for human and animal metabolism The cobalt complex (1) was structurally characterized by X-ray analysis in the laboratory of D.C. Hodgkin. In these studies, the unique buildup of the tetrapyrrolic corrin ligand and the intramolecularly coordinating pseudo-nucleotide function of the vitamin were discovered. ... 

If the destruction of a component is presumed to be zero-order, a plot of C vs. t should give a straight line. Certain losses of vitamin C, particularly in frozen foods, are presumed to follow first-order kinetics (89). Labuza (76) observed that zero-order reaction rates for quahty losses may be assumed in some fluctuating temperature studies, but this may lead to a miscalculation of predicted changes. Therefore, from a theoretical standpoint, it is important that the proper order be used for predictions. In general, ascorbic acid destruction is assumed to be first-order, or pseudo first-order (17,27) except under specific conditions of heat and moisture (79). 

Carotinoiden gezahlt werden, gleichgultig, ob sie partiell hydriert oder dehydriert sind. So z. B. das Vitamin A, die lonone (a-, Pseudo-), Cyclocitral und Citral. In der nachstehenden Formel des y-Carotins sind durch Striche einige typische Vertreter gekennzeichnet ... 

A recently proposed method (314) for the separation of fat-soluble vitamins by electrokinetic chromatography was further developed (315). The separation medium consisted of acetonitrile water (80 20 v/v) and contained tetradecylam-monium bromide as a pseudostationary phase. The high acetonitrile content was necessary to keep the hydrophobic vitamins in solution during electrophoresis. With the cathode placed at the capillary outlet, the fat-soluble vitamins were separated based on different hydrophobic interactions with the pseudo-stationary phase. The vitamins migrated in order of decreasing hydrophobicity prior to the electroosmotic flow. 

The contributions from these terms frequently cannot be separated with the result that only the composite term k is known. One example for which the separation of these terms was possible, concerns the complex-formation reaction of aqua-cobalamin (vitamin Bn). Here the usually inert Co(III) center is labilized by the corrin ring, which induces a dissociative substitution mode. From the non-linear dependence of the observed pseudo-first-order rate constant on the entering ligand concentration for the reaction shown in Eq. (1.5), the precursor formation constant and rate-determining interchange constant can be determined, as can their pressure dependences. 

The direction of radical reactions that involve competitive, mixed-order kinetics could be changed as dose rate is increased. Bimolecular reactions would be favored in competition with unimolecular (or pseudo-unimolecular) reactions, because of the higher instantaneous radical concentrations. This effect could be encountered in lipids and in polymers. It is responsible for the greater retention of vitamin B] (thiamin) in pork when irradiated with electron beams than when irradiated with gamma rays (Figure 1) [6]. 

Ionone is an important chemical in the synthesis of vitamin A. It is prepared by the reaction of pseudo-ionone with sulfuric acid, d, il-a-ionone... 

A. flos-aquae grows naturally in Upper Klamath Lake, OR, USA. This cyanobacterium contains various nutrients including polyunsaturated fatty acids, protein, carotenoids, vitamins, and minerals and have therapeutic effects [32]. Dried Aphanizomenon cells contained 616 pg of B12 per 100 g when assayed using microbiological method [33]. However, the corrinoid compound purified from these dried cells was identified as pseudo-Bi2 [33]. 

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