Containing sodium ascorbate

The further fate of the excited molecule depends on the concrete conditions of the experiment. As an example we can take the processes occurring in liposome membranes101 containing sodium ascorbate on the inside and Cu2+ on the outside. After an excited CHL molecule appears at the interface between the membrane and the water containing an oxidizer, the following reaction takes place ... 

N-Nitrosamine inhibitors Ascorbic acid and its derivatives, andDC-tocopherol have been widely studied as inhibitors of the N-nitrosation reactions in bacon (33,48-51). The effect of sodium ascorbate on NPYR formation is variable, complete inhibition is not achieved, and although results indicate lower levels of NPYR in ascorbate-containing bacon, there are examples of increases (52). Recently, it has been concluded (29) that the essential but probably not the only requirement for a potential anti-N-nitrosamine agent in bacon are its (a) ability to trap NO radicals, (b) lipophilicity, (c) non-steam volatility and (d) heat stability up to 174 C (maximum frying temperature). These appear important requirements since the precursors of NPYR have been associated with bacon adipose tissue (15). Consequently, ascorbyl paImitate has been found to be more effective than sodium ascorbate in reducing N-nitrosamine formation (33), while long chain acetals of ascorbic acid, when used at the 500 and lOOO mg/kg levels have been reported to be capable of reducing the formation of N-nitrosamines in the cooked-out fat by 92 and 97%, respectively (49). 

One to 5 g material was mixed by a glass rod with 1 mL/g material of "stopping solution", that contained 25 mg/mL of ammonium sul-famate, 25 mg/mL of sodium ascorbate, and 2.0-2.5 mg/mL of cis-2,6-dimethylmorpholine (cis-DMM), and was adjusted to pH 1 with H2S0. The pH of the slurry was readjusted to 1 with concentrated H2S0. The mixture was stirred with 10 g Celite 560 (from Johns Manville Corp. previously sifted to remove< 60 mesh particles), and packed dry in a "Monoject" plastic 50 mL syringe barrel (Shermwood Industries) prepacked with 8 g Celite. The column was eluted (without flow-rate control) with 100 mL... 

A buffer comprises (1) a weak acid and a salt of that acid, (2) a weak base and a salt of that base, or (3) it may contain an acid salt. We define an acid-base buffer as a solution whose pH does not change after adding (small amounts of) a strong acid or base . Sodium ascorbate is a favourite buffer in the food industry. 

Incompatibilities Do not mix IV minocycline before or during administration with any solutions containing the following Adrenocorticotropic hormone (ACTH), aminophylline, amobarbital sodium, amphotericin B, bicarbonate infusion mixtures, calcium gluconate or chloride, carbenicillin, cephalothin sodium, cefazolin sodium, chloramphenicol succinate, colistin sulfate, heparin sodium, hydrocortisone sodium succinate, iodine sodium, methicillin sodium, novobiocin, penicillin, pentobarbital, phenytoin sodium, polymyxin, prochlorperazine, sodium ascorbate, sulfadiazine, sulfisoxazole, thiopental sodium, vitamin K (sodium bisulfate or sodium salt), whole blood. 

Ascorbate, cysteine, hydroquinone, and NADH are capable of acting as re-ductants for NOMb formation in model systems containing sodium nitrite and Mb (Fox and Ackerman, 1968). Ascorbate, cysteine, and hydroquinone all form nitroso-reductant intermediates which released NO, forming a NO-MMb complex which was then reduced to NOMb. Release of NO from the reductant-NO complex was rate limiting in production of NOMb. For NADH as reductant, reduction of NOMMb to NOMb was the rate limiting step. In summary, two reduction steps were required, the reduction of nitrite (as nitrous acid or its anhydride, N2O3) to NO, and reduction of NOMMb to NOMb. 

The applicability of the theoretical expressions discussed above has been tested with different systems such as the oxidation of protein myoglobin in the presence of sodium ascorbate [96] or the oxidation of ferrocene in the presence of potassium ferrocyanide [95]. The case corresponding to ferrocene-containing monolayers on a gold electrode in the presence of potassium ferrocyanide will be addressed here. 

Ascorbates. The fact that ascorbic acid and sodium ascorbate inhibit light-induced yellowing of lignin-containing papers was first reported 25 years ago (15). For a limited time ascorbic acid stops yellowing, but eventually yellowing proceeds at the same rate as the untreated paper (6,17), as seen in Figure 2. 

Fig. 4. H2 photoevolution from ascorbate via P. laminosum PSI particles under different conditions of immobilization. The complete assay system contained 100 mM Mes-NaOH buffer, pH 7.0 75 mM sodium ascorbate 15 mM DTT 2 mM TMPD 1% (w/v) BSA PSI particles (30 pg Chi) 50 pi (saturating amount) of Clostridium pasteurianum hydrogenase and 12.5 pM Spirulina maxima Fd as electron mediator, (a) Conditions all components free (b) hydrogenase immobilized in Ca alginate according to Gisby and Hall (1980) (c) PSI particles immobilized in Ca alginate (d) hydrogenase and PSI coimmobilized in Ca alginate.

The processing of milk into various dairy products may result in vitamin C losses. Ice cream contains no vitamin C, nor does cheese. The production of powdered milk involves a 20 to 30 percent loss, evaporated milk a 50 to 90 percent loss. Bullock et al. (1968) studied the stability of added vitamin C in evaporated milk and found that adding 266 mg of sodium ascorbate per kg was sufficient to ensure the presence of at least 140 mg/L of ascorbic acid during 12 months of storage at 21 °C. Data on the stability of vitamin C in fortified foods have been assembled by deRitter (1976) (Table 9-15). 

All meat samples contained 2Z NaCl and 1.5Z sucrose. The additives were sodium ascorbate SA, sodium tripolyphosphate STPP, butylated hydroxyanisole BHA, tert-butylhydroquinone TBHQ, and sodium nitrite, NaN02. 

The reaction of [Pt(cis-dach)(H20)2] with sodium ascorbate gives a white precipitate that contains two isomeric forms of the [Pt(cis-dach)-(ascorbato-C, 0 )] chelate (due to a lack of rotational symmetry in the cis-dach ligand). The two isomers have different HPLC retention times and solubility properties, and may be separated by using the following method. 

Stability beta-carotene is very susceptible to oxidation and antioxidants such as ascorbic acid, sodium ascorbate, or tocopherols should be added. Store protected from light at a low temperature (-20°C) in containers sealed under nitro-gen. 

Description, identification, specifications, and tests of L-ascorbic acid and sodium L-ascorbate are given in the U.S. Pharmacopoeia 15) and the Food Chemicals Codex 16). Similar information on palmitoyl L-ascorbic acid (ascorbyl palmitate) is contained in the Codex. Sodium ascorbate is twice as soluble in water as ascorbic acid. Ascorbyl palmitate is soluble in ethanol (25°C) at 12.5%, in hot (80°C) glycerin, propylene glycol, or decaglycerol octaoleate to 10%, in vegetable oils (25°C) at 0.01--0.1% and in water (70°C) at 0.2%. 

The food processing industry can obtain L-ascorbic acid and sodium ascorbate commercially in a variety of mesh sizes to meet the requirements of various kinds of food products. These crystalline compounds are stable for years when stored under cool, dry conditions in closed containers. Esters of ascorbic acid such as ascorbyl palmitate are also available. 

The rate of /V-nitrosation increases with the pKa of the amine and depends on the pH — it is highest at a pH range of 2-4. The reaction can be inhibited by compounds capable of binding the nitrosating agents — in meat curing, sodium ascorbate is very effective. Foods low in amines and nitrites generally contain about 1-10 ppb, while cured and heavy smoked meat and fish contain up to several hundred ppb of /V-nitroso compounds. 

HypervitaminosisC. The vitamin is considered very safe. At one time, many of the over-the-counter products contained significant amounts of sodium ascorbate, which would be contraindicated in people on low sodium diets. Today s products are virtually sodium free unless labeled otherwise. Nevertheless, there are intermittent reports of adverse reactions associated with high doses. Therefore, there are Tolerable Upper Intake Levels, but these are very high relative to the RDAs. The UL to RDA ratio averages about 20. 

Reaction vials contained in a total volume of 0,4 mL, 227 X 10 heterocysts isolated in the presence of sodium ascorbate, 5mM ATP, 8milf MgCk, 13mAf TES pH 72, 5mM sodium ascorbate, 50fiM dichlorophenol indophenol as reductant, and 5mM a-keto-glutarate. 

DOrner and Westermann [149] reported the preparation of the pseudodisaccharide 143 with a triazole tether (Scheme 37) as a prototype for the synthesis of carbohydrate-containing macrocycles, through a Huisgen-catalysed reaction and ring-closing methathesis as the key steps. Standard conditions were used, Cu(OAc)2 and sodium ascorbate as the Cu(I) source and a mixture of water and f-BuOH as solvent, for the conversion of protected glucopyra-nosyl azide 141 into pseudo-disaccharide 143 by using dialkyne 142 in a 77% yield. 

Table I shows the recovery of specific activity in cytosolic fraction of rat liver containing several additives after 1 and 2 weeks of storage. Recoveries are expressed as the percentage of the activity in the fresh cytosolic fraction homogenised in 50 mM sodium phosphate buffer, pH 7.4, containing 20mM KCl. y-BBH activity was best conserved at 4°C in the presence of lOmM DTT and 200g/1 glycerol. Addition of co-factors like sodium ascorbate, a-ketoglutarate and (NH4)2pe(S04)2 or combinations of the former did not appear to stabilise the enzyme. Addition of EDTA resulted in total loss of enzyme activity.

Multicomponent approaches toward the formation of more complex phthalazine-containing compounds were reported in 2014. A four-component one-pot condensation reaction was employed by Dabiri and coworkers to generate (1,2,3-triazol-4-yl)methyl-3-amino-5,10-dihydro-5,10-dioxo-lH-pyrazolo[l,2-f)]phthalazine-2-carboxylates 26 (Scheme 18) (14SC2037). Catalyzed by Cu(OAc)2 (10mol%) and sodium ascorbate (20mol%), the reaction of benzaldehyde derivatives (1 equivalent), azides (1 equivalent), prop-2-ynyl-2-cyanoacetate (27) (1 equivalent), and phthalhydrazide (28) (1... 

---