Barium hydroxide, hydrolysis

Barium hydroxide hydrolysis followed by amino acid analysis revealed a sulfated Tyr residue. Subsequently, the myotropic nature of PSK was demonstrated on the isolated hindgut preparation of P. americana where the threshold of activity concentration was determined to be 0.25 nM, virtually the same as the threshold concentration (0.22 nM) of LSK on the isolated L. maderae hindgut (13). In addition to PSK, the non-sulfated form of LSK-II was isolated and structurally characterized from the P. americana cc extracts, but the biologically active sulfated form was not found (19). 

Approximate value. tND, not detectable. tAfter barium hydroxide hydrolysis. 

Cellobiose was prepared first by Skraup and Konig by the saponification of the octaacetate with alcoholic potassium hydroxide, and the method was improved by Pringsheim and Merkatz.3 Aqueous barium hydroxide also has been employed for the purpose, and methyl alcoholic ammonia has been used extensively for the hydrolysis of carbohydrate acetates. The method of catalytic hydrolysis with a small quantity of sodium methylate was introduced by Zemplen,i who considered the action to be due to the addition of the reagent to the ester-carbonyl groups of the sugar acetate and the decomposition of the addition compound by reaction with alcohol. The present procedure, reported by Zemplen, Gerecs, and Hadacsy, is a considerable improvement over the original method (see Note 2). 

Othosenine otosenine), CjgH270jN, m.p. 221-2°, forms a picrate m.p. 233-5°. On hydrolysis with barium hydroxide solution it furnishes... 

On hydrolysis by boiling aqueous solution of barium hydroxide, isatidine (p. 603) yields two acid products. Isatinedc acid, CioHigOg, m.p. 148-5°, [a]ff° + 86° (HjO), which appears to contain one ethylenic linkage, one carboxyl group and one per-carboxyl group (R. CO. O. O), the evidence for the latter being the liberation of iodine from neutral or alkaline potassium iodide solution. The second product is isatinedc monolactonic add, CiqH 405, m.p. 197-8°, + 108-8°, which contains... 

An interesting observation was reported concerning the hydrolysis of nitrile 253 with barium hydroxide (Scheme 166). It was stated that 3-hydroxyfurazancarbox-ylic acid was formed, although an adequate proof of the structure was not given (12LA196, 30LA43). 

Kasuganobiosamine (4) by Hot Alkaline Hydrolysis. An aqueous solution (150 ml.) saturated with barium hydroxide was added to a solution of kasugamycin hydrochloride (5.3 grams, 12.22 mmoles) dissolved in 50 ml. of water free from carbon dioxide. The solution was refluxed on a steam bath for 10 hours. By the similar treatment of the reaction mixture as described in the case of cold alkaline hydrolysis, ammonia (11.10 mmoles), barium oxalate (3.037 grams, 12.48 mmoles) and kasuganobiosamine (3.638 grams, 11.80 mmoles) were obtained. 

Kasuganobiosamine (4) and Kasugamycinic Acid (9a) by cold Alkaline Hydrolysis. Kasugamycin hydrochloride (622 mg., 1.43 mmoles) was dissolved in 5 ml. of water free from carbon dioxide and 50 ml. of water saturated with barium hydroxide was added. The solution was allowed to stand at room temperature for 36 hours. Ammonia (0.30 mmole) was produced and barium oxalate (199 mg., 0.80 mmole) was obtained. After removal of barium oxalate by filtering, the filtrate was neutralized with dry ice. After removal of barium carbonate by filtering, the filtrate was adjusted to pH 7.0 and placed on a column of Amberlite CG-50 (ammonium form, 1.5 x 22 cm.), allowed to pass with a rate of... 

Alkaline Hydrolysis of Kasugamycinic Acid (9a) with Barium Hydroxide. Kasugamycinic acid (250 mg., 0.63 mmole) was hydrolyzed with barium hydroxide-saturated-water at 100°C. for 10 hours, and the reaction mixture was treated in the similar manner as described in the case of alkaline hydrolysis of kasugamycin, affording kasuganobiosamine (4) (179 mg., 0.68 mmole) and barium oxalate (151 mg., 0.62 mmole). 

Proteins have been hydrolyzed by treatment with sulfuric acid, hydrochloric acid, barium hydroxide, proteolytic enzymes, and other hydrolytic reagents, but no condition has been found which avoids some destruction or incomplete liberation of tryptophan, cystine, and some other amino acids. The early work on this problem has been reviewed by Mitchell and Hamilton (194). The literature and their own excellent experiments on the hydrolysis problem in relation to the liberation and destruction of tryptophan have been presented recently by Spies and Chambers (269). 

Methyliminodiacetic acid has been prepared by the action of methylamine on formaldehyde cyanohydrin, subsequent hydrolysis of the dinitrile with barium hydroxide, and regeneration from the barium salt with sulfuric acid.1 This method was found by the submitter to be much less satisfactory than the procedure given above. 

Resacetophenome, 21, 103 Resorcinol, 21, 23, 103 opResorcylic acid, 21, 27 Ring opening by hydrolysis with barium hydroxide, 22, 91 Rosenmund synthesis, aldehyde, 21, 84, 110... 

Urea is but slowly hydrolysed. A solution is boiled with barium hydroxide solution. How can hydrolysis be detected ... 

Methylenedinitramine (l,3-dinitro-l,3-diazapropane) (168) can be prepared from the nitration of the bis-acetamide (166), followed by hydrolysis of the product (167) with barium hydroxide and subsequent acidification.Methylenedinitramine has no practical value as an explosive due to its facile decomposition in solution. 

Elemental composition Ba 81.08%, S 18.92%. The metal may be analyzed by various instrumental techniques (see Barium). In the powder form, the compound may be identified by x-ray methods. In solution, it undergoes hydrolysis forming barium hydroxide and hydrosulfide. The former is neutralized by acid titration to a pH of 8.4 while the hydrosulfide is titrated with acid to pH 4.2 for neutralization. 

---