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Biosynthesis of food constituents: Vitamins. 2. Water-soluble vitamins: Part 2 − a review النص الكامل
2008
This review article gives a survey of the biosynthetic pathways that lead to water-soluble vitamins in microorganisms, plants and some animals. The biosynthetic pathways leading to some the B-group vitamins (biotin, folacin, cobalamins) and to vitamin C are described in detail using reaction schemes and mechanisms with enzymes involved and detailed explanations based on chemical principles and mechanisms.
اظهر المزيد [+] اقل [-]Biosynthesis of food constituents: Vitamins. 2. Water-soluble vitamins: Part 2 - a review النص الكامل
2007
Jan Velíšek | Karel Cejpek
This review article gives a survey of the biosynthetic pathways that lead to water-soluble vitamins in microorganisms, plants and some animals. The biosynthetic pathways leading to some the B-group vitamins (biotin, folacin, cobalamins) and to vitamin C are described in detail using reaction schemes and mechanisms with enzymes involved and detailed explanations based on chemical principles and mechanisms.
اظهر المزيد [+] اقل [-]Biosynthesis of food constituents: Vitamins. 2. Water-soluble vitamins: Part 1 - a review النص الكامل
2007
Jan Velíšek | Karel Cejpek
This review article gives a survey of the generally accepted biosynthetic pathways that lead to water-soluble vitamins in microorganisms, plants and some animals. The biosynthetic pathways leading to the B-group vitamins (thiamin, riboflavin, nicotinic acid and nicotinamide, pantothenic acid, vitamin B6) are described in detail using the reaction schemes, sequences, and mechanisms with the enzymes involved and detailed explanations based on chemical principles and mechanisms. Keywords:
اظهر المزيد [+] اقل [-]Biosynthesis of food constituents: Vitamins. 2. Water-soluble vitamins: Part 2 - a review النص الكامل
2007
Velisek, J.,Vysoka Skola Chemicko-technologicka, Prague (Czech Republic). Ustav Chemie a Analyzy Potravin | Cejpek, K.,Vysoka Skola Chemicko-technologicka, Prague (Czech Republic). Ustav Chemie a Analyzy Potravin
This review article gives a survey of the biosynthetic pathways that lead to water-soluble vitamins in microorganisms, plants and some animals. The biosynthetic pathways leading to some of the B-group vitamins (biotin, folacin, cobalamins) and to vitamin C are described in detail using reaction schemes and mechanisms with enzymes involved and detailed explanations based on chemical principles and mechanisms.
اظهر المزيد [+] اقل [-]Micellar Electrokinetic Chromatography Method for Determination of the Ten Water-Soluble Vitamins in Food Supplements النص الكامل
2013
da Silva, Danielle C. | Visentainer, Jesuí V. | de Souza, Nilson E. | Oliveira, Cláudio C.
The separation and determination of the ten water-soluble vitamins by using capillary electrophoresis in the micellar electrokinetic chromatography in a single run are proposed. The method uses low toxicity and cost solvent (ethanol) as modifier of background electrolyte (BGE) attending to the Green Chemistry principles. The electrophoretic method uses 10.0 % (v/v) ethanol, 2.0 % (w/v) SDS, 0.02 mol L⁻¹borate at pH 8.70 as BGE. The standard and real sample solutions were injected in the eletrophoretic system by hydrodynamic injection under pressure of 0.80 psi for 8 s, and the separation was carried out in a fused silica capillary under a potential of 28 kV at 25 °C; the analytical signals were monitored at 214 nm. The analytical method is precise (r.s.d. < 6 %), accurate (better than 9 %), selective, sensitive, robust, simple, and presents high analytical frequency as ten water-soluble vitamins were separated in only 18 min, with migration times of 5.75 ± 0.02, 6.81 ± 0.02, 8.13 ± 0.04, 8.80 ± 0.07, 8.98 ± 0.06, 11.10 ± 0.08, 11.34 ± 0.05, 13.85 ± 0.15, 14.82 ± 0.04, and 17.85 ± 0.30 min. Detection and quantification limits of 0.34, 0.32, 0.27, 0.20, 2.50, 4.98, 4.92, 0.30, 0.86 and 0.28 mg L⁻¹and 1.02, 0.97, 0.83, 0.62, 7.56, 15.09, 14.91, 0.90, 2.59 and 0.83 mg L⁻¹, for vitamins PP (nicotinamide), B₁₂(cyanocobalamin), B₂(riboflavin), B₆(pyridoxine), B₈(biotin), C (ascorbic acid), B₅(pantothenic acid), B₃(nicotinic acid), B₁(thiamine), and B₉(folic acid), respectively. Excellent recoveries (intra and inter-day) were obtained and, when the method was applied to food supplement analyses the results were in agreement with the conventional HPLC methods.
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