Pantothenate, Calcium

Valentinite, see Antimony(III) oxide Verdigris, see Copper acetate hydrate Vermillion, see Mercury(II) sulflde Villiaumite, see Sodium fluoride Vitamin B3, see Calcium (+)pantothenate Washing soda, see Sodium carbonate 10-water Whitlockite, see Calcium phosphate Willemite, see Zinc silicate(4—)... 

R)-Pantothenic acid (1) contains two subunits, (R)-pantoic acid and P-alanine. The chemical abstract name is A/-(2,4-dihydroxy-3,3-dimethyl-l-oxobutyl)-P-alanine (11). Only (R)-pantothenic acid is biologically active. Pantothenic acid is unstable under alkaline or acidic conditions, but is stable under neutral conditions. Pantothenic acid is extremely hygroscopic, and there are stabiUty problems associated with the sodium salt of pantothenic acid. The major commercial source of this vitamin is thus the stable calcium salt (3) (calcium pantothenate). 

R)-Calcium pantothenate (3) is prepared by condensing (R)-pantolactone (9) with P-alanine (10) in the presence of base, followed by treatment of the sodium salt (11) with calcium hydroxide. 

An alternative procedure for the preparation of (R)-calcium pantothenate (3) is to condense (R)-pantolactone (9) with the preformed calcium salt (12) of p-alaniue (15). 

For most assays, the incorporated pantothenic acid has to be Hberated en2ymatically. Usually, a combination of pantotheinase and alkaline phosphatase is used to hberate the bound pantothenic acid. The official method for pantothenic acid of the Association of Official Analytical Chemists (AOAC) is the microbiological assay that uses U. Plantarium (A.TCC 8014) as the test organism (71). Samples are extracted at 121°C at pH 5.6—5.7, proteins are precipitated at pH 4.5, and the resulting clear extracts are adjusted to pH 6.8 prior to assay. This procedure is only suitable to determine calcium pantothenate or other free forms of pantothenic acid. 

Pantothenic acid toxicity has not been reported in humans. Massive doses (10 g/d) in humans have produced mild intestinal distress and diarrhea. Acute toxicity was observed in case of mice and rats by using calcium pantothenate at fairly large doses (92). 

The major producers of the calcium salt of pantothenic acid and panthenol are Hoffmann-La Roche, Daiichi, BASF, and Alps. Racemic panthenol is used mainly in hair care products, whereas (R)-panthenol is exclusively used in top-of-the-line, more expensive skin and hair care products. The current (ca 1997) price of (R,3)-panthenol varies between 12 and 18 per kg, that of D-panthenol varies between 30 and 45 per kg, and that of D-calcium pantothenate (Calpan) varies between 22 and 30 per kg. 

C3H3N 107-13-1) see Calcium pantothenate Cibenzoline Cinolazepam Dihydroxydibutyl ether Indecainide lodoxamic acid Maprotiline Nipradilol Ramatroban Sulfaphenazole Tiquizium bromide... 

C3H7NO2 107-95-9) see Balsalazide sodium Calcium pantothenate Pamidronic acid L-alanine benzyl ester... 

C(,H,2CaN204 J6i27-40-Q see Calcium pantothenate DL-alanine ethyl ester hydrochloride (C5H12CINO2 677-27-6) see Pyridoxine (5)-alaninol... 

CNNa 143-33-9) see Alclofenac Alpidem Amphetaminil Atorvastatin calcium Azatadine Calcium pantothenate Carnitine Clopidogrel hydrogensulfate Clortermine Dexrazoxane Diclofenac Diloxanide Edetic acid Epinastine hydrochloride Ethosuximide Ethotoin Fenoprofen Ibuprofen Irbesartan Ketoprofen Lonazolac Mephenytoin Mepindolol Montelukast sodium Nabilone Oxymetazoline Paramethadione Pentorex Saquinavir Suprofen Thiamphenicol Tolmetin Trimazosin Zolpidem sodium cyanoborohydride... 

Pantothenic acid (Figure 19.19) is known also as vitamin Bj. It is A-(2,4-dihydroxy-3,3-dimethyl-l-oxobutyl)- 3-alanine. It occurs in nature only in the o-form. Free pantothenic acid and its sodium salt are chemically unstable, and therefore the usual pharmacological preparation is the calcium salt (calcium pantothenate). The latter is stable in neutral solutions but it is destroyed by heat and acid solution. 

---