D-pantothenate

Figure 1 shows the structure of pantothenic acid ((R)-(+)-N-(2,4-dihydroxy-3,3 -dimethyl-1 -oxobuty 1-13-alanine). Only D(+)-pantothenic acid occurs naturally and is biologically active. The alcohol (R)-pantothenol (= (D)-panthenol) shows biological activity as well. 

A concentrated Ca-D-pantothenate solution (1 mg/ml) is prepared in distilled water and dilutions made as needed. Refrigerated solutions are stable for 6 months. Pantothenate is added at 5, 10, 20, 40, 60, 80, and 100 mpg/ml final concentrations the control flask consists of basal medium alone for estimation of carry-over error—i.e., the pantothenate activity of the inoculum. The details of aseptic technique have been discussed elsewhere (H18, H19). Growth is measured in optical density units with a Welch Densichron, equipped with a red-sensitive probe to minimize blank readings due to the color of the medium. 

D-(+)-Pantothenic acid calcium salt (A-[2,4-dihydroxy-3,3-dimethylbutyryl] P-alanine... 

D-(+)-Pantothenic acid calcium salt (A-[2,4-dihydroxy-3,3-dimethylbutyryI] p-alanine calcium salt) [137-08-6] M 476.5, m 195-196°, 200-201°, [a]20 +28.2° (c 5, H20). It forms needles on recrystn from MeOH, EtOH or isoPrOH (with 0.5mol of isoPrOH). Moderately hygroscopic. The... 

Antagonists of niacin include pyridine-3-sulfonie acid (in bacteria), 3-acetylpyridine, 6-aminonicctinamide, and 5-thiazole carboxamide. Synergists include vitamins Bj, B, B. B]). and D, pantothenic acid, folic acid, and soiualotrupliin (growth hormone). 

Fig. 8. Possible routes for the synthesis of D-pantothenic acid through the enzymatic transformation. PL, pantolactone KPL, ketopantolactone KPA, ketopantoic acid d-PA, D-pantoic acid KPaOEt, ethyl 2 -ketopantothenate KPaCN, 2 -ketopantothenonitrile D-PaOEt, ethyl D-pan-tothenate D-PaCN, D-pantothenonitrile...

Application of Carbonyl Reductases to the Production of Chiral Intermediates for D-Pantothenate Synthesis... 

At present, commercial production of D-pantothenate depends exclusively on chemical synthesis. The conventional chemical process involves optical... 

Reduction of ethyl 2 -ketopantothenate to ethyl 2 -d-pantothenate ((g) in Fig. 8). The rate of condensation of ketopantolactone or D-pantolactone with ethyl (3-alanine, yielding ethyl 2 -ketopantothenate (0 in Fig. 8) or ethyl D-panto-thenate, respectively, is quite fast compared to the condensation of ketopantolactone or D-pantolactone with (3-alanine, and the reaction with ethyl (3-alanine proceeds more stoichiometrically [117]. Since the enzymatic hydrolysis of ethyl D-pantothenate has been established [118], if the stereoselective reduction of ethyl 2 -ketopantothenate to ethyl D-pantothenate is possible, both the troublesome resolution and the incomplete condensation might be avoided at the same time. Carbonyl reductase of C. macedoniensis is used for this purpose. Washed cells of the yeast converted ethyl 2 -ketopantothenate (80 g/1) almost specifically to ethyl D-pantothenate (> 98% e.e.), with a molar yield of 97.2% [103]. In a similar manner, 2 -ketopantothenonitrile (50 g/1) was converted to D-pan-tothenonitrile (93.6% e.e.), with a molar yield of 95.6%, on incubation with Sporidiobolus salmonicolor cells as a catalyst [104],... 

During the course of studies on the microbial production of chiral intermediates for D-pantothenic acid [2,134,135], Shimizu and co-workers found that several micro-organisms, such as Fusarium, Brevibacterium and so on, produce a novel enzyme that catalyzes the hydrolysis of aldonate lactones or aromatic lactones [136, 137],... 

Calcium D-Pantothenate Arocor Holdings Inc. Calcium pantothenate Mallinckrodt Baker,... 

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