L-ascorbate-2-sulfate

L-Ascorbic acid Sodium-L-ascorbate 2,3-Di-O-methylascorbic acid 3-Benzoyl ascorbate 5,6-Isopropylidene-L-ascorbic acid 3-0-[ (Dimorpholino)phosphinate]-5,6-0-isopropyli-dene-L-ascorbate Potassium-L-ascorbate 2-sulfate Cysteine HCl Cysteine free base D-Isoascorbic acid Dehydro-L-ascorbic acid... 

L-Ascorbate-2-sulfate - L-Ascorbate-2-sulfate (AAS) (14) prevented the Increase in serum lipid levels and the accumulation of cholesterol in the aorta of cholesterol-fed rabbits to a greater degree than did ascorbic acid (AA). AAS had similar effects on serum lipid levels in guinea pigs, a species which, like man, does not biosynthesize AA. It was... 

Aq. 10 M NaOH-soln. added to aq. soln. of L-ascorbic acid to pH 10.0, heated to 70 , commercial SOg-trimethylamine added with periodic addition of more NaOH-soln. to maintain the pH at 9.5-10.5, and the product isolated as the Ba-salt after 0.5 hr. stirring Ba-L-ascorbate 2-sulfate dihydrate. Y 80%. F. method s. P. A. Seib et al., Soc. Perkin I 1974, 1220. 

Patients of varying skin types (1-V) having striae distensae alba on the abdomen or thighs can apply topical 20% glycolic acid daily to the entire treatment area. In addition, these patients apply 10% L-ascorbic acid, 2% zinc sulfate, and 0.5% tyrosine to half of the treatment area and 0.05% tretinoin emollient cream to the other half of the treatment area. The creams are applied on a daily basis for 12 weeks. Improvement is evaluated at 4 and 12 weeks with increased elastin content within the reticular and papillary dermis [14]. 

DMSO (Wako Pure Chemicals Inc.) was distilled twice from 4A molecular sieves(Wako) under reduced pressure. Dicyanobis(l,10-phenanthroline)iron(II) [Fe(CN)2(phen)2] was synthesized by mixing 0.03 mol of phen and 0.01 mol of ammonium iron(II) sulfate hexahydrate in 400 cm3 of water, followed by the addition of KCN (0.15 mol). The resulting crude crystals were then dissolved in 30 cm3 of concentrated sulfuric acid followed by the addition of ldm3 of water. Dicyanobis(l,10-phenanthroline)iron(III) nitrate was obtained by the oxidation of corresponding iron(II) complex with concentrated nitric acid. The perchlorate salt was obtained by the addition of sodium perchlorate to the nitrate solution. Analytical grade hydroquinone, catechol, and L-ascorbic acid (Wako) were used without further purification. 

Among the salts in the ascorbate series is also Ba 2-O-sulfonato-L-ascorbate dihydrate that is derived from the ascorbic acid 2-sulfate ester. This biologically important compound (17) was much debated because it was diflScult to decide whether the sulfate group was attached to C2 or C3. The structural analysis by McClelland (18) proved the site to be at C2 as shown in Figure 7. The bond lengths, angles, and resonance forms are clearly similar to those of the simple ascorbate anions irrespective of the effect of the sulfate group attached to C2. 

The observation of L-ascorbic acid 2-0-sulfate, 18, in a number of animal species, including humans, has provoked extensive research into the chemistry and biochemistry of this inorganic ester of ascorbic acid (J, 19,20). Ascorbic acid 2-0-sulfate has been implicated as a biological sulfating agent and proposed as an anticholesteremic agent (21-24). 

Researchers have used C NMR spectroscopy to assign structure to several ester and ether derivatives of I. That method is particularly useful to diflFerentiate 2-0- and 3-0-substituted derivatives of I because ionization of the OH3 induces the large downfield shift of C3, as previously discussed. Thus, 2-0-methyl-L-ascorbic acid, but not 3-0-methyl-L-ascorbic acid, showed a 16-ppm change in the chemical shift of C3 when the pH values of their solutions were changed from 2 to 7 (Table II). At pH 7, the chemical shifts of the C3 carbons in L-ascorbate (II) and in its 2-sulfate and 2-phosphate esters were similar in magnitude (Table II). 

Workers have used NMR spectroscopy to assign structures to the 5- and 6-sulfate esters of L-ascorbic acid and to the 4Z and 4E isomers of 2-sulfo-2,3,4,6-tetrahydroxyhexa-2,4-dienoate-8-lactone (Table V). Sulfonation at C6 (C5) of L-ascorbic acid shifted the signal of C6 (C5) downfield by 7-8 ppm the signal(s) of the adjacent carbon(s) moved slightly upheld (18). Those shifts were noted previously by others (19) in sugar sulfates. When I was dissolved in concentrated sulfuric acid-d2, NMR shows approximately 90% monosulfonation at C6 (18). 

The 2-sulfate ester of 4Z-2,3,4,6-tetrahydroxyhexa-2,4-dienoate-8-lac-tone (4,5-dehydroascorbate 2-sulfate) was characterized largely by NMR and H NMR. The data in Table V show that the signals of C4 and C5 were shifted downfield 70 and 38 ppm, respectively, compared to their positions in the spectrum of L-ascorbate at pH 7. In addition, the resonances of Cl and C3 moved upheld approximately 5 ppm upon introduction of the 4,5-double bond. 

As mentioned previously, ionization of OHS in L-ascorbic acid is accompanied by a shift in Amax to longer wavelengths. However, the opposite is true in the case of the 4,5-dehydro-2-sulfate derivatives (Table V). At pH 0.5-1.0 those derivatives gave Amax of 260-262 nm, but at pH 7 Amax was 244-247 nm. Apparently most of the charge in the anion is on 01 (Scheme 2), whereas most of the charge on the ascorbate monoanion (II) is on 03 (3). 

One of the least active compounds in the insect bioassay was the 2-sulfate ester of L-ascorbic acid. To develop normally the hornworm... 

Fluharty, A. L., Stevens, R. L., Miller, R. T., Shapiro, S. S., and Kihara, H., Ascorbic acid 2-sulfate sulfohydrolase activity of human arylsulphatase A. Biochim. Biophys. Acta 429, 508-516 (1976). 

Similar extensive work has been conducted with vitamin A (see T6, and references therein also B29). Experimental deficiency in animals reduces the incorporation of 2-amino-2-deoxy-n-[l- C] glucose and [ S]sulfate into the glycosaminoglycan chains (D16, W16). In this instance the stage of action has been identified, and the effect is due to a block at the first stage of the sulfate activation step (W17, R3, S50). Thus vitamin A is an agent that can activate ATP-sulfurylase and, like L-ascorbic acid, can be an important factor influencing the biosynthetic pathway of the glycosaminoglycans. However, other work... 

D-o-Tocopherol 3,4,4 -Trichlorocarbanilide preservative, photographic developers L-Ascorbic acid Hydroxylamine hydrochloride Hydroxylamine sulfate Sodium sulfite preservative, pigment dispersions 2,6-Bis (dimethylaminomethyl) cyclohexanone... 

Tin- -copper sulfate- -HCl [78,79], Sn(II)chloride [80], Sn(II)chloride and hydrazine sulfate [81], l-amino-2-naphthol-4-sulfonic acid [82], ascorbic acid, and potassium anti-monyl tartrate [83]. 

Sodium ascorbate and ascorbic acid esters, such as ascorbyl 6-palmitate (5-111) and ascorbyl 2-phosphate (5-113), are fully bioavailable, while ascorbyl 2-sulfate (5-114) is a completely inactive vitamin form. Phosphate and sulfate are about 20 times more stable to oxidation than the free acid. D-lsoascorbic acid (5-107) shows only 5-20% activity, 6-deoxy-L-ascorbic acid (5-115), found in fungi, has about 30% activity and the bound ascorbic acid form ascorbigen has 15-20% of the activity of ascorbic acid. Ascorbic acid 2-0-P-D-glucoside, systematic name 2-0-(P-D-glucopyranosyl)-L-ascorbic acid (5-116), has the same biological activity as ascorbic acid and is also stable against oxidation. 

Chlorosulfonic acid has been extensively used in the sulfation of many natural products. Vitamin C (L-ascorbic acid)-2-sulfate is prepared by treatment of 5,6-0-isopropylidene-L-ascorbic acid with chlorosulfonic acid the product was converted into the sodium salt which is added to poultry feeds to increase the thickness of the egg shells. Vitamin C may also be directly sulfated by treatment with excess chlorosulfonic acid (eight equivalents) in pyridine at room temperature (48 hours), followed by neutralization (sodium hydroxide) to give the sodium salt of ascorbic acid-2,5,6-trisulfate. ... 

Synthesis of the 1,2-dihydrodiol of BcP by conventional methods was blocked by the failure of attempts to synthesize its potential synthetic precursors 1-keto-l,2,3,4-tetrahydro-BcP and 1,2-dihydro-BcP (66). However, BcP 1,2-dihydrodiol was obtained in low yield ( 1%) by oxidation of BcP with ascorbic acid-ferrous sulfate (66). 

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