Reinecke acid

The undissolved residue from the second extraction consists chiefly of Morland salt (the guanidine salt of the Reinecke acid) and amounts to 130-135 g. (33-34 per cent of the theoretical amount) (Note 8). 

The following acids are commonly used HCl, HBr, HCIO4, HNO3, H2SO4, and also phosphotungstic acid (47), silicotungstic acid (48), Reinecke acids (49), and, sometimes, chloroplatinic and chloroauric acids (50-53). 

In 1935, Dakin and West reported a different method of fractionating Cohn s fraction G (22). A preliminary purification was obtained by treating the extract with calcium acetate or chloride in 75-80 per cent alcoholic solution, the active material appearing in the filtrate. The active material was precipitable by Reinecke salt in acid solution. In the regeneration of such a precipitate, the bulk of the Reinecke acid was separated from a weak alcoholic solution of the active material as the sparingly soluble salt of a tertiary base—e.g., dimethyl aniline. The small amoimt of additional unprecipitable Reinecke acid was removed with solvents such as amyl alcohol w hich did not remove the active material. These procedures were carried out at virtually neutral reaction. The steps involved in the preparation described are diagrammed in Table III. 

Dissolved in HjO, removed Ca, precipitated with Reinecke acid and -regenerated (clinically inactive)... 

Removed salts and precipitated with Reinecke acid (clinically inactive both before and after Reinecke separation)... 

Contained no glucosamine.) Peptide recovered by acidifying with H3SO4 filtered off the PbS04 prodin-tated with Reinecke acid 0 g.) regenerated the Rei-neckate concentrated the decomposed R neckate and precipitated with absolute alcohol. 

Fraction B, equivalent to 1 ton of liver, was taken up in 16 liters of water and was precipitated at pH 1.5 with 1100 g. of Reinecke salt. This mixture was kept at 0° C. for 12 to 18 hours after which time the precipitate was filtered and washed with ice cold water. It was then taken up in 50% acetone. The Reinecke acid was removed by addition of AgNO and excess silver then removed with NaCl. After removal of acetone in vacuo, the pH... 

Removed Reinecke acid with AgNOi and excess Ag with NaCl.—Removed acetone in vacuo and adjusted to pH 5.0... 

In 1936, Wilkinson (126) applied Reinecke acid precipitation as employed by Dakin and West to the preparation of active liver extracts, (124, 125, 127). He compared the clinical activity of his liver product with those prepared according to the 1935 method of Dakin and West and that of Laland, Klem, Strandell, ci al. Dakin and West s material showed maximal reticulocyte response with a dose of 58 to 120 mg. administered intramuscularly. With preparations similar to those used by the Scandinavian workers, Wilkinson obtained maximal response with a total dose of 40 to 80 mg. (68). With his own product, Wilkinson was able to elicit maximal response with total doses of 18 to 36 mg., representing an original amount of 661 to 1332 g. of fresh liver. 

The remaining aqueous layer was then acidified with acetic acid a saturated aqueous solution of ammonium reineckate was added to a portion, but no precipitation occurred. No precipitate was noted with Valser s or Mayer s reagent. 

The method of protein hydrolysis was important acid hydrolysis caused destruction of tryptophan but alkaline treatment gave even greater losses of other amino acids especially cystine. The amino acids were usually separated by then standard chemical procedures based on differences in solubility, selective precipitation by agents such as Reinecke salt (proline and hydroxyproline), or flavianic acid (arginine). 

If potassium dichromate is used instead of the ammonium salt, approximately an equal weight of a mixture of the potassium and ammonium salts of the reineckate anion ia obtained. The free solid acid may be readily made by decomposing the barium salt with sulfuric add followed by ether extraction. 

King, P., Ma, G., Miao, W., Jia, Q., McDougall, B., Reinecke, M., Cornell, C., Kuan, J., Kim, T., and Robinson, W. 1999. Structure-activity relationships analogues of the dicaffeoylquinic and dicaffeoyltartaric acids as potent inhibitors of human immunodeficiency virus type 1 integrase and replication. J. Med. Chem. 42, 497-509. 

Robinson, W., Cordeiro, M., Abdel-Malek, S., Jia, Q., Chow, S., Reinecke, M., and Mitchell, W. 1996b. Dicaffeoylquinic acid inhibitors of human immunodeficiency virus integrase inhibition of the core catalytic domain of human immunodeficiency virus integrase. Mol. Pharmacol. 50, 846-855. 

Reinecke salt is of value as a precipitant for primary and secondary amines, proline and hydroxyproline, and certain amino acids.1... 

Fried and Wintersteiner first prepared a crystalline salt of streptomycin. Crude streptomycin phosphotungstate was converted to a crude picrate which was fractionated by flowing chromatography. One or more of the fractions, after removal of the picric acid, yielded a highly active amorphous product from which a crystalline streptomycin reineck-ate was obtained. 

The nickel complex, Ni ( 5115)2, has been made by the action of the Grignard reagent on nickel (II) acetylacetonate (217) or from potassium cyclopentadienyl and the ammine [Ni(NHs)el (S N)2 in liquid ammonia (58). It forms dark emerald-green crystals which sublime at 80-90° and which, when heated in nitrogen, melt, with decomposition and the formation of a nickel mirror, at 173-174°. It is only slowly oxidized in air, and cold water neither attacks nor dissolves it it is, however, readily soluble in organic liquids. Oxidation of the compound yields an orange-yellow solution containing the ion [Ni( 5H5)2]+, which is stable for a short period in weakly acidic media, and which may be precipitated as the reineckate or tetraphenylborate. 

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