DL-Hydroxyproline

C Tao, TB Huang. Resolution of DL-a-amino acids on a L-hydroxyproline chiral phase by ligand-exchange chromatography. Chin Chem Lett 6 383-384, 1995. 

Hydroxyproline has been used to assess the collagen content (and hence the commercial desirability) of various types of meat and hides as well as the effect of age, breeding, diet, anatomical location, and the processing or tanning methods used. Several of the methods in Table 1 are for this purpose (Bl, B18, Dl, G4, L19, W6, Zl) these studies would seem to be of value for the meat and leather industries. 

Dl. Dahl, O., and Persson, K-A., Hydroxyproline, methodolo cal studies of analysis. Acta Chem. Scand. 17, 2499-2503 (1963). 

L-Proline [147-85-3] M 115.1, m 215-220°(dec)(D-isomer), 220-222°(dec) (L-form), 205°(dec)(DL-isomer), [a] -53° (c 0.6, 0.5N HCl), -93° (c 2.4,6N KOH) for L-isomer), pi 6.3, pKf 1.95 pKJs 10.64. A likely impurity is hydroxyproline. Purify L-proline via its picrate which is crystallised twice from water, then decomposed with 40% H2SO4. The picric acid is extracted with diethyl ether, the H2SO4 in solution is precipitated with Ba(OH)2, and the filtrate is evaporated. The residue is crystallised from hot absolute EtOH [Mellan Hoover J Am Chem Soc 12 3879 1951] or EtOH/Et20. Its solubility in H2O is >100%. It sublimes... 

Hydroxylamine sulfate L-Hydroxyproline L-Isoleucine L-Leucine Linoleic acid Linolenic acid Lipoxidase D-Mannose Methyl linoleate D-Panthenol DL-Panthenol Pectinase Phenanthrene Pyrene Pyruvic acid... 

L-Alanine Bis (aminopropyl) piperazine Carotene Casein Cholecalciferol Choline bitartrate Chondroitin sulfate Copper Copper iodide (ous) Corn (Zea mays) oil Corn (Zea mays) starch L-Cysteine Ferric ammonium EDTA Ferric chloride Ferric chloride hexahydrate 3-Glucan Hesperidin Hydrogenated cottonseed oil L-Hydroxyproline Iodine DL-Leucine Magnesium aspartate Magnesium citrate dibasic Manganese chloride (ous), anhydrous MSG... 

A stopped-flow method has been used to study the reactions of the [Fe(H20) ] ion with the a-hydroxy-carboxylic acids glycolic, DL-lactic, DL-malic, and benzilic acids. The main pathway involves reactions of [Fe(H20)5(0H)] + ion with HL, and an 7d mechanism is proposed. A similar study involves reactions with acetohydroxamic acid, hydroxyproline hydroxamic acid, tryptophane hydroxamic acid, and histidine hydroxamic acid. The second-order rate constants at 25 °C fall in the range (1.14—5.90) x 10 s. ... 

Synthesis, Hydroxyproline is synthesized by the method of Mcllwain and Richardson (542). a-Acetyl-S-chloro-y-valerolactone, prepared from acetoacetic ester and epichlorohydrin by the method of Leuchs (497), is converted to a-oximino-8-chloro-y-valerolaetone (A) by the action of nitrosyl sulfuric acid. (A) is reduced to a-aniino-8-chIoro-r-valerolactone (B) by shaking it for 3 days with hydrogen and platinum oxide catalyst. (B) is converted to a mixture of the isomeric DL-hydroxy-prolines by treatment for 2 hours with a saturated aqueous solution of ammoma. The copper salts of the two pairs of optical isomers are pre- > see p. 360. 

The DL-hycbox]rproline8, synthesized and resolved by Leuchs and coworkers (496,498-500,502) were prepared by the reactions, malonic ester -f epichlorhydrin -> ethyl j-ehloro-y-valerolactone-a-oarboxylate - a-8-dichloro-y-valerolactone -> ,8-diamino-y-valerolactone - hydroxyproline -f- allo-hydroxyproline. Another synthesis through the intermediates, ethyl-y,8-dibromo-o-benzoylamino- -valerate and y-(benzoylhydroj ) proline, has been reported by Hammarsten (367). 

Ci7H2flN20fl, Benzoyl-DL-leucylglycine ethyl ester, 41B, 553 Ci7H2ftN205, t-Butyloxycarbonylsarcosylglycine benzyl ester, 42B, 368 Ci 7H2i N207S, Tosyl-L-prolyl-L-hydroxyproline monohydrate, 27, 1051 37B, 278... 

Ozaki A, Shibasaki T, Mori H (1995) Specific proline and hydroxyproline detection method by post-column deri tization for high-performance liquid chromatography. Biosci Biotechnol Biochem 59 1764—1765 Sano K, Mitsugi K (1978) En rmatic production of L-cysteine from DL-2-amino-A2-thiazoline-4-carboxyiic acid by Pseudomonas thiazolinohilum optimal conditions for the enzyme formation and enzymatic reaction. Agric Biol Chem 42 2315-2321... 

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